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import "github.com/nats-io/go-nats"
A Go client for the NATS messaging system ().
A Go client for the NATS messaging system ().
context.go enc.go nats.go netchan.go parser.go timer.go
Indexe names into the Registered Encoders.
const ( Version = "1.7.2" DefaultURL = "nats://127.0.0.1:4222" DefaultPort = 4222 DefaultMaxReconnect = 60 DefaultReconnectWait = 2 * time.Second DefaultTimeout = 2 * time.Second DefaultPingInterval = 2 * time.Minute DefaultMaxPingOut = 2 DefaultMaxChanLen = 8192 // 8k DefaultReconnectBufSize = 8 * 1024 * 1024 // 8MB RequestChanLen = 8 DefaultDrainTimeout = 30 * time.Second LangString = "go" )
Default Constants
const ( // STALE_CONNECTION is for detection and proper handling of stale connections. STALE_CONNECTION = "stale connection" // PERMISSIONS_ERR is for when nats server subject authorization has failed. PERMISSIONS_ERR = "permissions violation" // AUTHORIZATION_ERR is for when nats server user authorization has failed. AUTHORIZATION_ERR = "authorization violation" )
const ( DISCONNECTED = Status(iota) CONNECTED CLOSED RECONNECTING CONNECTING DRAINING_SUBS DRAINING_PUBS )
const ( AsyncSubscription = SubscriptionType(iota) SyncSubscription ChanSubscription NilSubscription )
The different types of subscription types.
Pending Limits
const ( OP_START = iota OP_PLUS OP_PLUS_O OP_PLUS_OK OP_MINUS OP_MINUS_E OP_MINUS_ER OP_MINUS_ERR OP_MINUS_ERR_SPC MINUS_ERR_ARG OP_M OP_MS OP_MSG OP_MSG_SPC MSG_ARG MSG_PAYLOAD MSG_END OP_P OP_PI OP_PIN OP_PING OP_PO OP_PON OP_PONG OP_I OP_IN OP_INF OP_INFO OP_INFO_SPC INFO_ARG )
InboxPrefix is the prefix for all inbox subjects.
var ( ErrConnectionClosed = errors.New("nats: connection closed") ErrConnectionDraining = errors.New("nats: connection draining") ErrDrainTimeout = errors.New("nats: draining connection timed out") ErrConnectionReconnecting = errors.New("nats: connection reconnecting") ErrSecureConnRequired = errors.New("nats: secure connection required") ErrSecureConnWanted = errors.New("nats: secure connection not available") ErrBadSubscription = errors.New("nats: invalid subscription") ErrTypeSubscription = errors.New("nats: invalid subscription type") ErrBadSubject = errors.New("nats: invalid subject") ErrSlowConsumer = errors.New("nats: slow consumer, messages dropped") ErrTimeout = errors.New("nats: timeout") ErrBadTimeout = errors.New("nats: timeout invalid") ErrAuthorization = errors.New("nats: authorization violation") ErrNoServers = errors.New("nats: no servers available for connection") ErrJsonParse = errors.New("nats: connect message, json parse error") ErrChanArg = errors.New("nats: argument needs to be a channel type") ErrMaxPayload = errors.New("nats: maximum payload exceeded") ErrMaxMessages = errors.New("nats: maximum messages delivered") ErrSyncSubRequired = errors.New("nats: illegal call on an async subscription") ErrMultipleTLSConfigs = errors.New("nats: multiple tls.Configs not allowed") ErrNoInfoReceived = errors.New("nats: protocol exception, INFO not received") ErrReconnectBufExceeded = errors.New("nats: outbound buffer limit exceeded") ErrInvalidConnection = errors.New("nats: invalid connection") ErrInvalidMsg = errors.New("nats: invalid message or message nil") ErrInvalidArg = errors.New("nats: invalid argument") ErrInvalidContext = errors.New("nats: invalid context") ErrNoDeadlineContext = errors.New("nats: context requires a deadline") ErrNoEchoNotSupported = errors.New("nats: no echo option not supported by this server") ErrClientIDNotSupported = errors.New("nats: client ID not supported by this server") ErrUserButNoSigCB = errors.New("nats: user callback defined without a signature handler") ErrNkeyButNoSigCB = errors.New("nats: nkey defined without a signature handler") ErrNoUserCB = errors.New("nats: user callback not defined") ErrNkeyAndUser = errors.New("nats: user callback and nkey defined") ErrNkeysNotSupported = errors.New("nats: nkeys not supported by the server") ErrStaleConnection = errors.New("nats: " + STALE_CONNECTION) ErrTokenAlreadySet = errors.New("nats: token and token handler both set") )
Errors
var DefaultOptions = GetDefaultOptions()
DEPRECATED: Use GetDefaultOptions() instead. DefaultOptions is not safe for use by multiple clients. For details see #308.
NewInbox will return an inbox string which can be used for directed replies from subscribers. These are guaranteed to be unique, but can be shared and subscribed to by others.
RegisterEncoder will register the encType with the given Encoder. Useful for customization.
AuthTokenHandler is used to generate a new token.
type Conn struct { // Keep all members for which we use atomic at the beginning of the // struct and make sure they are all 64bits (or use padding if necessary). // atomic.* functions crash on 32bit machines if operand is not aligned // at 64bit. See Statistics // Opts holds the configuration of the Conn. // Modifying the configuration of a running Conn is a race. Opts Options // contains filtered or unexported fields }
A Conn represents a bare connection to a nats-server. It can send and receive []byte payloads.
Connect will attempt to connect to the NATS system. The url can contain username/password semantics. e.g. nats://derek:pass@localhost:4222 Comma separated arrays are also supported, e.g. urlA, urlB. Options start with the defaults but can be overridden.
Shows different ways to create a Conn
Code:
nc, _ := nats.Connect(nats.DefaultURL) nc.Close() nc, _ = nats.Connect("nats://derek:secretpassword@demo.nats.io:4222") nc.Close() nc, _ = nats.Connect("tls://derek:secretpassword@demo.nats.io:4443") nc.Close() opts := nats.Options{ AllowReconnect: true, MaxReconnect: 10, ReconnectWait: 5 * time.Second, Timeout: 1 * time.Second, } nc, _ = opts.Connect() nc.Close()
AuthRequired will return if the connected server requires authorization.
Barrier schedules the given function `f` to all registered asynchronous subscriptions. Only the last subscription to see this barrier will invoke the function. If no subscription is registered at the time of this call, `f()` is invoked right away. ErrConnectionClosed is returned if the connection is closed prior to the call.
Buffered will return the number of bytes buffered to be sent to the server. FIXME(dlc) take into account disconnected state.
ChanQueueSubscribe QueueSubscribeSyncWithChan.
ChanSubscribe will express interest in the given subject and place all messages received on the channel. You should not close the channel until sub.Unsubscribe() has been called.
Close will close the connection to the server. This call will release all blocking calls, such as Flush() and NextMsg()
ConnectedAddr returns the connected server's IP
Report the connected server's Id
Report the connected server's Url
DiscoveredServers returns only the server urls that have been discovered after a connection has been established. If authentication is enabled, use UserInfo or Token when connecting with these urls..
Flush will perform a round trip to the server and return when it receives the internal reply.
FlushTimeout allows a Flush operation to have an associated timeout.
Code:
nc, _ := nats.Connect(nats.DefaultURL) defer nc.Close() msg := &nats.Msg{Subject: "foo", Reply: "bar", Data: []byte("Hello World!")} for i := 0; i < 1000; i++ { nc.PublishMsg(msg) } // Only wait for up to 1 second for Flush err := nc.FlushTimeout(1 * time.Second) if err == nil { // Everything has been processed by the server for nc *Conn. }
FlushWithContext will allow a context to control the duration of a Flush() call. This context should be non-nil and should have a deadline set. We will return an error if none is present.
GetClientID returns the client ID assigned by the server to which the client is currently connected to. Note that the value may change if the client reconnects. This function returns ErrNoClientIDReturned if the server is of a version prior to 1.2.0.
IsClosed tests if a Conn has been closed.
IsConnected tests if a Conn is connected.
IsDraining tests if a Conn is in the draining state.
IsReconnecting tests if a Conn is reconnecting.
LastError reports the last error encountered via the connection. It can be used reliably within ClosedCB in order to find out reason why connection was closed for example.
MaxPayload returns the size limit that a message payload can have. This is set by the server configuration and delivered to the client upon connect.
NewRespInbox is the new format used for _INBOX.
NumSubscriptions returns active number of subscriptions.
Publish publishes the data argument to the given subject. The data argument is left untouched and needs to be correctly interpreted on the receiver.
PublishMsg publishes the Msg structure, which includes the Subject, an optional Reply and an optional Data field.
PublishRequest will perform a Publish() excpecting a response on the reply subject. Use Request() for automatically waiting for a response inline.
func (nc *Conn) QueueSubscribe(subj, queue string, cb MsgHandler) (*Subscription, error)
QueueSubscribe creates an asynchronous queue subscriber on the given subject. All subscribers with the same queue name will form the queue group and only one member of the group will be selected to receive any given message asynchronously.
func (nc *Conn) QueueSubscribeSync(subj, queue string) (*Subscription, error)
QueueSubscribeSync creates a synchronous queue subscriber on the given subject. All subscribers with the same queue name will form the queue group and only one member of the group will be selected to receive any given message synchronously using Subscription.NextMsg().
func (nc *Conn) QueueSubscribeSyncWithChan(subj, queue string, ch chan *Msg) (*Subscription, error)
QueueSubscribeSyncWithChan ChanQueueSubscribe.
Request will send a request payload and deliver the response message, or an error, including a timeout if no message was received properly.
RequestWithContext takes a context, a subject and payload in bytes and request expecting a single response.
Servers returns the list of known server urls, including additional servers discovered after a connection has been established. If authentication is enabled, use UserInfo or Token when connecting with these urls.
func (nc *Conn) SetClosedHandler(cb ConnHandler)
SetClosedHandler will set the reconnect event handler.
func (nc *Conn) SetDisconnectHandler(dcb ConnHandler)
SetDisconnectHandler will set the disconnect event handler.
func (nc *Conn) SetDiscoveredServersHandler(dscb ConnHandler)
SetDiscoveredServersHandler will set the discovered servers handler.
func (nc *Conn) SetErrorHandler(cb ErrHandler)
SetErrorHandler will set the async error handler.
func (nc *Conn) SetReconnectHandler(rcb ConnHandler)
SetReconnectHandler will set the reconnect event handler.
func (nc *Conn) Stats() Statistics
Stats will return a race safe copy of the Statistics section for the connection.
Status returns the current state of the connection.
func (nc *Conn) Subscribe(subj string, cb MsgHandler) (*Subscription, error)
Subscribe will express interest in the given subject. The subject can have wildcards (partial:*, full:>). Messages will be delivered to the associated MsgHandler.
func (nc *Conn) SubscribeSync(subj string) (*Subscription, error)
SubscribeSync will express interest on the given subject. Messages will be received synchronously using Subscription.NextMsg().
This Example shows a synchronous subscriber.
Code:
nc, _ := nats.Connect(nats.DefaultURL) defer nc.Close() sub, _ := nc.SubscribeSync("foo") m, err := sub.NextMsg(1 * time.Second) if err == nil { fmt.Printf("Received a message: %s\n", string(m.Data)) } else { fmt.Println("NextMsg timed out.") }
TLSRequired will return if the connected server requires TLS connections.
ConnHandler is used for asynchronous events such as disconnected and closed connections.
CustomDialer can be used to specify any dialer, not necessarily a *net.Dialer.
EncodedConn are the preferred way to interface with NATS. They wrap a bare connection to a nats server and have an extendable encoder system that will encode and decode messages from raw Go types.
func NewEncodedConn(c *Conn, encType string) (*EncodedConn, error)
NewEncodedConn will wrap an existing Connection and utilize the appropriate registered encoder.
func (c *EncodedConn) BindRecvChan(subject string, channel interface{}) (*Subscription, error)
BindRecvChan binds a channel for receive operations from NATS.
BindRecvChan() allows binding of a Go channel to a nats subject for subscribe operations. The Encoder attached to the EncodedConn will be used for un-marshaling.
Code:
nc, _ := nats.Connect(nats.DefaultURL) c, _ := nats.NewEncodedConn(nc, "json") defer c.Close() type person struct { Name string Address string Age int } ch := make(chan *person) c.BindRecvChan("hello", ch) me := &person{Name: "derek", Age: 22, Address: "85 Second St"} c.Publish("hello", me) // Receive the publish directly on a channel who := <-ch fmt.Printf("%v says hello!\n", who)
func (c *EncodedConn) BindRecvQueueChan(subject, queue string, channel interface{}) (*Subscription, error)
BindRecvQueueChan binds a channel for queue-based receive operations from NATS.
func (c *EncodedConn) BindSendChan(subject string, channel interface{}) error
BindSendChan binds a channel for send operations to NATS.
BindSendChan() allows binding of a Go channel to a nats subject for publish operations. The Encoder attached to the EncodedConn will be used for marshaling.
Code:
nc, _ := nats.Connect(nats.DefaultURL) c, _ := nats.NewEncodedConn(nc, "json") defer c.Close() type person struct { Name string Address string Age int } ch := make(chan *person) c.BindSendChan("hello", ch) me := &person{Name: "derek", Age: 22, Address: "85 Second St"} ch <- me
func (c *EncodedConn) Close()
Close will close the connection to the server. This call will release all blocking calls, such as Flush(), etc.
func (c *EncodedConn) Drain() error.
func (c *EncodedConn) Flush() error
Flush will perform a round trip to the server and return when it receives the internal reply.
func (c *EncodedConn) FlushTimeout(timeout time.Duration) (err error)
FlushTimeout allows a Flush operation to have an associated timeout.
func (c *EncodedConn) LastError() error
LastError reports the last error encountered via the Connection.
func (c *EncodedConn) Publish(subject string, v interface{}) error
Publish publishes the data argument to the given subject. The data argument will be encoded using the associated encoder.
EncodedConn can publish virtually anything just by passing it in. The encoder will be used to properly encode the raw Go type
Code:
nc, _ := nats.Connect(nats.DefaultURL) c, _ := nats.NewEncodedConn(nc, "json") defer c.Close() type person struct { Name string Address string Age int } me := &person{Name: "derek", Age: 22, Address: "85 Second St"} c.Publish("hello", me)
func (c *EncodedConn) PublishRequest(subject, reply string, v interface{}) error
PublishRequest will perform a Publish() expecting a response on the reply subject. Use Request() for automatically waiting for a response inline.
func (c *EncodedConn) QueueSubscribe(subject, queue string, cb Handler) (*Subscription, error)
QueueSubscribe will create a queue subscription on the given subject and process incoming messages using the specified Handler. The Handler should be a func that matches a signature from the description of Handler from above.
func (c *EncodedConn) Request(subject string, v interface{}, vPtr interface{}, timeout time.Duration) error
Request will create an Inbox and perform a Request() call with the Inbox reply for the data v. A response will be decoded into the vPtrResponse.
func (c *EncodedConn) RequestWithContext(ctx context.Context, subject string, v interface{}, vPtr interface{}) error
RequestWithContext will create an Inbox and perform a Request using the provided cancellation context with the Inbox reply for the data v. A response will be decoded into the vPtrResponse.
func (c *EncodedConn) Subscribe(subject string, cb Handler) (*Subscription, error)
Subscribe will create a subscription on the given subject and process incoming messages using the specified Handler. The Handler should be a func that matches a signature from the description of Handler from above.
EncodedConn's subscribers will automatically decode the wire data into the requested Go type using the Decode() method of the registered Encoder. The callback signature can also vary to include additional data, such as subject and reply subjects.
Code:
nc, _ := nats.Connect(nats.DefaultURL) c, _ := nats.NewEncodedConn(nc, "json") defer c.Close() type person struct { Name string Address string Age int } c.Subscribe("hello", func(p *person) { fmt.Printf("Received a person! %+v\n", p) }) c.Subscribe("hello", func(subj, reply string, p *person) { fmt.Printf("Received a person on subject %s! %+v\n", subj, p) }) me := &person{Name: "derek", Age: 22, Address: "85 Second St"} c.Publish("hello", me)
type Encoder interface { Encode(subject string, v interface{}) ([]byte, error) Decode(subject string, data []byte, vPtr interface{}) error }
Encoder interface is for all register encoders
EncoderForType will return the registered Encoder for the encType.
type ErrHandler func(*Conn, *Subscription, error)
ErrHandler is used to process asynchronous errors encountered while processing inbound messages.
Handler is a specific callback used for Subscribe. It is generalized to an interface{}, but we will discover its format and arguments at runtime and perform the correct callback, including de-marshaling JSON strings back into the appropriate struct based on the signature of the Handler.
Handlers are expected to have one of four signatures.
type person struct { Name string `json:"name,omitempty"` Age uint `json:"age,omitempty"` } handler := func(m *Msg) handler := func(p *person) handler := func(subject string, o *obj) handler := func(subject, reply string, o *obj)
These forms allow a callback to request a raw Msg ptr, where the processing of the message from the wire is untouched. Process a JSON representation and demarshal it into the given struct, e.g. person. There are also variants where the callback wants either the subject, or the subject and the reply subject.
type Msg struct { Subject string Reply string Data []byte Sub *Subscription // contains filtered or unexported fields }
Msg is a structure used by Subscribers and PublishMsg().
MsgHandler is a callback function that processes messages delivered to asynchronous subscribers.
Option is a function on the options for a connection.
ClientCert is a helper option to provide the client certificate from a file. If Secure is not already set this will set it as well.
func ClosedHandler(cb ConnHandler) Option
ClosedHandler is an Option to set the closed handler.
Dialer is an Option to set the dialer which will be used when attempting to establish a connection. DEPRECATED: Should use CustomDialer instead.
func DisconnectHandler(cb ConnHandler) Option
DisconnectHandler is an Option to set the disconnected handler.
func DiscoveredServersHandler(cb ConnHandler) Option
DiscoveredServersHandler is an Option to set the new servers handler.
DontRandomize is an Option to turn off randomizing the server pool.
DrainTimeout is an Option to set the timeout for draining a connection.
func ErrorHandler(cb ErrHandler) Option
ErrorHandler is an Option to set the async error handler.
FlusherTimeout is an Option to set the write (and flush) timeout on a connection.
MaxPingsOutstanding is an Option to set the maximum number of ping requests that can go un-answered by the server before closing the connection.
MaxReconnects is an Option to set the maximum number of reconnect attempts.
Name is an Option to set the client name.
func Nkey(pubKey string, sigCB SignatureHandler) Option
Nkey will set the public Nkey and the signature callback to sign the server nonce.
NkeyOptionFromSeed will load an nkey pair from a seed file. It will return the NKey Option and will handle signing of nonce challenges from the server. It will take care to not hold keys in memory and to wipe memory.
NoEcho is an Option to turn off messages echoing back from a server. Note this is supported on servers >= version 1.2. Proto 1 or greater.
NoReconnect is an Option to turn off reconnect behavior.
PingInterval is an Option to set the period for client ping commands.
ReconnectBufSize sets the buffer size of messages kept while busy reconnecting.
func ReconnectHandler(cb ConnHandler) Option
ReconnectHandler is an Option to set the reconnected handler.
ReconnectWait is an Option to set the wait time between reconnect attempts.
RootCAs is a helper option to provide the RootCAs pool from a list of filenames. If Secure is not already set this will set it as well.
Secure is an Option to enable TLS secure connections that skip server verification by default. Pass a TLS Configuration for proper TLS. NOTE: This should NOT be used in a production setting.
func SetCustomDialer(dialer CustomDialer) Option
SetCustomDialer is an Option to set a custom dialer which will be used when attempting to establish a connection. If both Dialer and CustomDialer are specified, CustomDialer takes precedence.
SyncQueueLen will set the maximum queue len for the internal channel used for SubscribeSync().
Timeout is an Option to set the timeout for Dial on a connection.
Token is an Option to set the token to use when a token is not included directly in the URLs and when a token handler is not provided.
func TokenHandler(cb AuthTokenHandler) Option
TokenHandler is an Option to set the token handler to use when a token is not included directly in the URLs and when a token is not set.
UseOldRequestStyle is an Option to force usage of the old Request style.
UserCredentials is a convenience function that takes a filename for a user's JWT and a filename for the user's private Nkey seed.
UserInfo is an Option to set the username and password to use when not included directly in the URLs.
func UserJWT(userCB UserJWTHandler, sigCB SignatureHandler) Option
UserJWT will set the callbacks to retrieve the user's JWT and the signature callback to sign the server nonce. This an the Nkey option are mutually exclusive.
type Options struct { // Url represents a single NATS server url to which the client // will be connecting. If the Servers option is also set, it // then becomes the first server in the Servers array. Url string // Servers is a configured set of servers which this client // will use when attempting to connect. Servers []string // NoRandomize configures whether we will randomize the // server pool. NoRandomize bool // NoEcho configures whether the server will echo back messages // that are sent on this connection if we also have matching subscriptions. // Note this is supported on servers >= version 1.2. Proto 1 or greater. NoEcho bool // Name is an optional name label which will be sent to the server // on CONNECT to identify the client. Name string // Verbose signals the server to send an OK ack for commands // successfully processed by the server. Verbose bool // Pedantic signals the server whether it should be doing further // validation of subjects. Pedantic bool // Secure enables TLS secure connections that skip server // verification by default. NOT RECOMMENDED. Secure bool // TLSConfig is a custom TLS configuration to use for secure // transports. TLSConfig *tls.Config // AllowReconnect enables reconnection logic to be used when we // encounter a disconnect from the current server. AllowReconnect bool // MaxReconnect sets the number of reconnect attempts that will be // tried before giving up. If negative, then it will never give up // trying to reconnect. MaxReconnect int // ReconnectWait sets the time to backoff after attempting a reconnect // to a server that we were already connected to previously. ReconnectWait time.Duration // Timeout sets the timeout for a Dial operation on a connection. Timeout time.Duration // DrainTimeout sets the timeout for a Drain Operation to complete. DrainTimeout time.Duration // FlusherTimeout is the maximum time to wait for write operations // to the underlying connection to complete (including the flusher loop). FlusherTimeout time.Duration // PingInterval is the period at which the client will be sending ping // commands to the server, disabled if 0 or negative. PingInterval time.Duration // MaxPingsOut is the maximum number of pending ping commands that can // be awaiting a response before raising an ErrStaleConnection error. MaxPingsOut int // ClosedCB sets the closed handler that is called when a client will // no longer be connected. ClosedCB ConnHandler // DisconnectedCB sets the disconnected handler that is called // whenever the connection is disconnected. DisconnectedCB ConnHandler // ReconnectedCB sets the reconnected handler called whenever // the connection is successfully reconnected. ReconnectedCB ConnHandler // DiscoveredServersCB sets the callback that is invoked whenever a new // server has joined the cluster. DiscoveredServersCB ConnHandler // AsyncErrorCB sets the async error handler (e.g. slow consumer errors) AsyncErrorCB ErrHandler // ReconnectBufSize is the size of the backing bufio during reconnect. // Once this has been exhausted publish operations will return an error. ReconnectBufSize int // SubChanLen is the size of the buffered channel used between the socket // Go routine and the message delivery for SyncSubscriptions. // NOTE: This does not affect AsyncSubscriptions which are // dictated by PendingLimits() SubChanLen int // UserJWT sets the callback handler that will fetch a user's JWT. UserJWT UserJWTHandler // Nkey sets the public nkey that will be used to authenticate // when connecting to the server. UserJWT and Nkey are mutually exclusive // and if defined, UserJWT will take precedence. Nkey string // SignatureCB designates the function used to sign the nonce // presented from the server. SignatureCB SignatureHandler // User sets the username to be used when connecting to the server. User string // Password sets the password to be used when connecting to a server. Password string // Token sets the token to be used when connecting to a server. Token string // TokenHandler designates the function used to generate the token to be used when connecting to a server. TokenHandler AuthTokenHandler // Dialer allows a custom net.Dialer when forming connections. // DEPRECATED: should use CustomDialer instead. Dialer *net.Dialer // CustomDialer allows to specify a custom dialer (not necessarily // a *net.Dialer). CustomDialer CustomDialer // UseOldRequestStyle forces the old method of Requests that utilize // a new Inbox and a new Subscription for each request. UseOldRequestStyle bool }
Options can be used to create a customized connection.
GetDefaultOptions returns default configuration options for the client.
Connect will attempt to connect to a NATS server with multiple options.
SignatureHandler is used to sign a nonce from the server while authenticating with nkeys. The user should sign the nonce and return the base64 encoded signature.
type Statistics struct { InMsgs uint64 OutMsgs uint64 InBytes uint64 OutBytes uint64 Reconnects uint64 }
Tracks various stats received and sent on this connection, including counts for messages and bytes.
Status represents the state of the connection.
type Subscription struct { // Subject that represents this subscription. This can be different // than the received subject inside a Msg if this is a wildcard. Subject string // Optional queue group name. If present, all subscriptions with the // same name will form a distributed queue, and each message will // only be processed by one member of the group. Queue string // contains filtered or unexported fields }
A Subscription represents interest in a given subject.
func (s *Subscription) AutoUnsubscribe(max int) error
AutoUnsubscribe will issue an automatic Unsubscribe that is processed by the server when max messages have been received. This can be useful when sending a request to an unknown number of subscribers.
Code:
nc, _ := nats.Connect(nats.DefaultURL) defer nc.Close() received, wanted, total := 0, 10, 100 sub, _ := nc.Subscribe("foo", func(_ *nats.Msg) { received++ }) sub.AutoUnsubscribe(wanted) for i := 0; i < total; i++ { nc.Publish("foo", []byte("Hello")) } nc.Flush() fmt.Printf("Received = %d", received)
func (s *Subscription) ClearMaxPending() error
ClearMaxPending resets the maximums seen so far.
func (s *Subscription) Delivered() (int64, error)
Delivered returns the number of delivered messages for this subscription.
func (s *Subscription) Drain() error
Drain will remove interest but continue callbacks until all messages have been processed.
func (s *Subscription) Dropped() (int, error)
Dropped returns the number of known dropped messages for this subscription. This will correspond to messages dropped by violations of PendingLimits. If the server declares the connection a SlowConsumer, this number may not be valid.
func (s *Subscription) IsValid() bool
IsValid returns a boolean indicating whether the subscription is still active. This will return false if the subscription has already been closed.
func (s *Subscription) MaxPending() (int, int, error)
MaxPending returns the maximum number of queued messages and queued bytes seen so far.
NextMsg will return the next message available to a synchronous subscriber or block until one is available. A timeout can be used to return when no message has been delivered.
NextMsgWithContext takes a context and returns the next message available to a synchronous subscriber, blocking until it is delivered or context gets canceled.
func (s *Subscription) Pending() (int, int, error)
Pending returns the number of queued messages and queued bytes in the client for this subscription.
func (s *Subscription) PendingLimits() (int, int, error)
PendingLimits returns the current limits for this subscription. If no error is returned, a negative value indicates that the given metric is not limited.
func (s *Subscription) QueuedMsgs() (int, error)
Queued returns the number of queued messages in the client for this subscription. DEPRECATED: Use Pending()
func (s *Subscription) SetPendingLimits(msgLimit, bytesLimit int) error
SetPendingLimits sets the limits for pending msgs and bytes for this subscription. Zero is not allowed. Any negative value means that the given metric is not limited.
func (s *Subscription) Type() SubscriptionType
Type returns the type of Subscription.
func (s *Subscription) Unsubscribe() error
Unsubscribe will remove interest in the given subject.
SubscriptionType is the type of the Subscription.
UserJWTHandler is used to fetch and return the account signed JWT for this user.
Package nats imports 26 packages (graph) and is imported by 207 packages. Updated 2019-06-08. Refresh now. Tools for package owners. | https://godoc.org/github.com/nats-io/go-nats | CC-MAIN-2019-43 | refinedweb | 4,532 | 50.84 |
#include <hallo.h> Martin Eriksson wrote on Tue Jan 15, 2002 um 05:26:55PM: >). I have to second this. My last impression of ReiserFS was: - needs less IO traffic for meta handling - means less! visible load on IDE systems - faster recursive searches - saves space. In our tests with /usr directories of typical systems, ReiserFS wasted <2% space. XFS wasted ~7% and Ext2/3 wasted 16.5 percent! (typical, with 4kB blocks) - Ext2/3 behave worse, Ext3 sometimes better, sometimes even more worse. The CPU load while massive disk write operations even sometimes makes my mouse and the window manager (which makes some IO handling periodicaly, I guess) freeze for few seconds. This did never happen with ReiserFS. > So what's some highlights on Ext3 vs. ReiserFS? I guess the Ext2 compability > is one large factor for using Ext3, but otherwise? - Stability. ReiserFS changed formats many times, often in incompatible ways. - Safeness. Ext3 should loose less data on crashes. - Same on hardware damages. In past, I had problems with different harddisks. e2fsck -c was very often successfully (means, could save what was not damaged), only if the directory node has been damaged, the file names sometimes got lost and I had to rename them. reiserfsck sucked at this point. Note there is also less reliable hardware - AFAIK on such systems Reiserfs sometimes is going broken. The situation may have changed with the recent ReiserFS code, but I would not trust them. My summary: use Ext3 for important data: /var, /home, /etc, / and ReiserFS for /usr and other parts which you can easily restore when something is broken. Gruss/Regards, Eduard. -- <Angel`Eye> installations anleitung für intelx86 richtig ? <Salz> Angel`Eye: Kommt auf deinen Rechner an. Wenn du die Antwort nicht weiß, ist sie ja. -- #debian.de | https://www.redhat.com/archives/ext3-users/2002-January/msg00069.html | CC-MAIN-2015-22 | refinedweb | 296 | 67.35 |
Is there a way to modify the java classpath in sublime text? I have appended a location to my .bashrc file. It all compiles fine in a terminal.
Using Ubuntu 10.10 with Build 2032 of Sublime Text 2.
.bashrc is read by bash only, so unless you've started Sublime Text 2 from bash, the variable won't be seen.
If you set the variable in .profile instead, then it should get picked up by the Display Manager, and thus inherited by Sublime Text 2 when it's started. Take a look at help.ubuntu.com/community/EnvironmentVariables for more information.
You can check (and set, too) the values of the env vars from within Sublime Text 2 by using os.environ in the console:
import os
os.environ | https://forum.sublimetext.com/t/java-classpath/1373 | CC-MAIN-2017-22 | refinedweb | 130 | 69.79 |
I'm working on an implementation of SCSH-style "process forms" for Guile, and I'm noticing occasional hangs. I think I have an understanding of root cause, and I'd like people to double-check my analysis. My code forks its process using the "primitive-fork" function. The function's return value indicates whether the current process is the parent or the child process. The parent and child have user-level data that start out identical but can vary independently thereafter: stacks and heaps. The parent and child have kernel-level data that are shared: file descriptors, and (crucially) mutexes. All we can do to stop sharing the kernel-level data is to drop our handles to the data. The BDW-GC implementation is configured to be thread safe, in case Guile runs multiple threads. Therefore per <>: "It causes the collector to acquire a lock around essentially all allocation and garbage collection activity." That means after the child process spawns, there is one kernel mutex controlling access to two heaps in two separate processes. If the child process needs to do work in the GC layer, it blocks: the signal delivery thread in the parent is holding the mutex, and will hold the mutex until it gets some data on its reporting pipe. This happens when a race condition ends up in the wrong order. Based on this comment from scm_fork() I should be seeing a warning when I fork with a running thread: scm_i_finalizer_pre_fork ();_display (scm_from_latin1_string ("warning: call to primitive-fork while multiple threads are running;\n" " further behavior unspecified. See \"Processes\" in the\n" " manual, for more information.\n"), scm_current_warning_port ()); (This is all Guile 2.2 code.) The call to scm_i_finalizer_pre_fork() killed off the finalization thread, so we're safe there: void scm_i_finalizer_pre_fork (void) { #if SCM_USE_PTHREAD_THREADS if (automatic_finalization_p) { stop_finalization_thread (); GC_set_finalizer_notifier (spawn_finalizer_thread); } #endif But nothing stops the signal delivery thread. In fact, scm_all_threads() explicitly skips the signal delivery thread; we don't get a warning: { /* We can not allocate while holding the thread_admin_mutex because of the way GC is done. */ int n = thread_count; scm_i_thread *t; SCM list = scm_c_make_list (n, SCM_UNSPECIFIED), *l; scm_i_pthread_mutex_lock (&thread_admin_mutex); l = &list; for (t = all_threads; t && n > 0; t = t->next_thread) { if (t != scm_i_signal_delivery_thread) { SCM_SETCAR (*l, t->handle); l = SCM_CDRLOC (*l); } n--; } *l = SCM_EOL; scm_i_pthread_mutex_unlock (&thread_admin_mutex); return list; } The signal delivery thread is running in order to support SCSH's "early" auto-reap policy, triggered by SIGCHLD. The alternative is the "late" policy, which triggers after garbage collections. That's not good for parents that do lots of spawning but very little garbage generation compared to their heap size. They end up with lots of zombies. One solution to support the "early" policy might be to tweak scm_fork() so it: 1. Blocks signals. 2. Records the current custom handlers. 3. Resets all handlers. 4. Kills the signal delivery thread. 5. Forks. 6. Starts the signal delivery thread in parent and child. 7. Re-loads the custom handlers in parent and child. 8. Unblocks signals. Does anyone have other possibilities? I don't think there's a safe, general solution for running "identical" finalizers in the parent and the child, so shutting down the finalizer in the child is the best we can do. Is it worth restarting just the parent's finalizer thread after forking? Other, independent, cleanup opportunities: - The docs for "primitive-fork" need to mention that calling "primitive-fork" shuts down finalizers for the parent and the child. - Calling “restore-signals” should stop any running signal delivery thread, to bring Guile back to a consistent state. Thanks, Derek -- Derek Upham address@hidden | http://lists.gnu.org/archive/html/guile-devel/2017-03/msg00109.html | CC-MAIN-2018-17 | refinedweb | 599 | 54.52 |
Communities
Getting logs for failed NSH script jobs.Rich Chiavaroli Nov 19, 2015 12:33 PM
Right now I'm trying to do this with a simple test. I have an NSH script job that I'm running against 2 servers. One will succeed and one will intentionally fail. What I'd like to be able to do is get the logs for the instance that failed from blcli. I was originally going to just parse the information from JobRun getLogItemsByJobRunId, but it doesn't seem like there's a way to tell which logs go with which execution of the script.
So from there I found getServersStatusByJobRun and getLogItemsByDevice, but I can't find any information on defining what the paramaters are that you pass in for getLogItemsByDevice. There is
sortParameter - com.bladelogic.om.infra.model.job.jobrun.LogItemSortParameter
sortOrder - com.bladelogic.om.infra.shared.db.QuerySortOrder
startIndex - Integer
endIndex - Integer
But I can't for the life of me find an example or more information on what format and content you need to pass for the first 2, and there no info on what the indexes are of and what they're used for.
Does anyone have more information on how to use this command or is there a different way I can isolate the logs for just the servers that errored in an NSH script job?
Thanks,
Rich
1. Re: Getting logs for failed NSH script jobs.Rich Chiavaroli Nov 19, 2015 2:36 PM (in response to Rich Chiavaroli)
For anyone else who's run into this, I found a solution. You can use the getLogItemsByDevice in the LogItems namespace. | https://communities.bmc.com/thread/138718 | CC-MAIN-2018-05 | refinedweb | 274 | 63.19 |
Taking this list of similar questions:
- How to set up JavaScript namespace and classes properly
- Javascript namespace declaration with function-prototype
- Best OOP approach to these two small JavaScript classes
I'd concluded there are two possible ways for implementing classes and instances in JS: using an inner function or using a prototype.
So let's say we have a Box class inside the namespace BOX_LOGIC with a simple code in it. I'm able to code the following:
BOX_LOGIC.Box = (function() { // private static var boxCount = 0; var classDefinition = function(x) { x = x || 0; var capacity = x; var id = ++boxCount; // public methods this.getCapacity = function() { return capacity; }; this.getId = function() { return id; }; this.add = function(weight) { weight = weight || 0; if (capacity >= weight) { capacity -= weight; } return capacity; }; }; return classDefinition; })();
As well as I'm able to code:
BOX_LOGIC.Box = (function () { var boxCount; var Box= function (x) { x = x || 0; this.capacity = x; this.id = ++boxCount; }; Box.prototype = { Constructor: Box, add: function (weight) { weight = weight || 0; if (this.capacity >= weight) { this.capacity -= weight; } return this.capacity; } }; return Box; })();
Mi question are: what is exactly the difference in using the Box prototype or not? is any approach better for any reason(cost, legibility, standard...)? Is in the second approach any way to emulate the
static idvariable? THX! | http://www.howtobuildsoftware.com/index.php/how-do/iBY/javascript-oop-closures-prototype-javascript-oop-designing-classes-correctly | CC-MAIN-2019-09 | refinedweb | 214 | 50.63 |
I have a nested list, named env, created in the constructor and another method to populate an element of the grid defined as below:
...
class Environment(object):
def __init__(self,rowCount,columnCount): env = [[ None for i in range(columnCount)] for j in range(rowCount) ] return env def addElement(self, row, column): self[row][column] = 0
...
Later in the code I create an instance of Environment by running:
myEnv = createEnvironment(6,6)
Then I want to add an element to the environment by running:
myEnv.addElement(2,2)
So what I expected to happen was that I would receive a new Environment object as a 6x6 grid with a 0 in position 2,2 of the grid. But that did not work.
I have two errors:
1) I am unable to return anything other than None from the init method.
2) The main issue us when trying to execute addElement(2,2) I get this error:
"TypeError: 'Environment' object does not support indexing.
I looked at the getitem and setitem methods but was unable to get them working over a multidimensional list. Is there a better data structure I should be using to create a grid? | https://www.daniweb.com/programming/software-development/threads/436886/python-nested-list-object-does-not-support-indexing | CC-MAIN-2017-13 | refinedweb | 195 | 51.38 |
Technical Articles
Use groovy script to extract attachment content from soap message in CPI
Today one customer called a soap api from a third party system. Some important information is in attachment of the soap message . Customer needs to extract message in soap message attachment . I had some test and successfully extract the data from soap message . Let me share the steps, which may help others .
I support the readers has installed Soap UI.
Let me share the steps :
Step 1 , Develope and deploy iflow in CPI .
Develope iflow
/* Refer the link below to learn more about the use cases of script. If you want to know more about the SCRIPT APIs, refer the link below */ import com.sap.gateway.ip.core.customdev.util.Message; import java.util.HashMap; def Message processData(Message message) { //Attach def attach = message.getAttachments(); def datahandler = attach.values()[0]; def content = datahandler.getContent(); def messageLog = messageLogFactory.getMessageLog(message); if(messageLog != null){ messageLog.setStringProperty("Logging", "Printing Payload As Attachment"); messageLog.addAttachmentAsString("Message#2", content.toString(), "text/plain"); } message.setBody(content); return message; }
After depoyment , we can find the iflow runtime URL and download the wsdl file with following screen shot .
Step 2, Test with Soap UI .
Get CPI runtime Client ID and Client Secret from CPI runtime instance service key
Test with Soap UI
We can find that the attachment content has been successfully extracted into response body .
Then End
Best regards!
Jacky Liu
Hello Jacky Liu.
Thanks for sharing and congrats for the great content.
Please, do you know how we can delete an attachment?
I see we have the method "removeAttachment(String id)", but I'm not sure how to get that ID.
I would appreciate any help from you.
Thank you!
Fellipe
Hi, Fellipe,
I can not find the methd removeAttachment(String id) for class interface Message in the follwoing linkage . .
Maybe you can try with the code to get the attachment key .
def attach = message.getAttachments();
def attachkey = attach.keys()[0];
Best regards!
Jacky Liu
Hi, Fellipe,
We can use the following code to get the key:
def attach = message.getAttachments();
def attachkey = attach.keySet()[0];
But the method message.removeAttachment() does not exist .
Best regards!
Jacky
Hello Jacky Liu.
Thanks for the answer.
I saw the removeAttachment() method in the Interface Message documentation of the package "org.apache.camel" (link).
In the package "com.sap.gateway.ip.core.customdev.utilI" I also didn't find.
Thank you for your attention and support.
Fellipe | https://blogs.sap.com/2022/06/24/use-groovy-script-to-extract-attachment-content-from-soap-message-in-cpi/ | CC-MAIN-2022-33 | refinedweb | 412 | 62.14 |
As much as developers might like to ignore it, SEO is still a crucial part of any website or web app. Applications and sites that are not easily indexed by search engines or poorly optimized will end up hidden behind pages and pages of search results. Now if you, a Vue.js developer, don’t want that to happen to your project, take a look at our tips for optimizing Vue.js sites and apps for the demanding eyes of search engine spiders.
🐊 Alligator.io recommends ⤵The Vue.js Master Class from Vue School
Heady Stuff
The first thing most developers think of when they think of SEO is stuffing their
<head> elements full of meta tags. So how would one do that with Vue? Enter vue-meta. (Okay, admittedly
vue-meta isn’t stable yet, it’s pretty powerful already.)
First off, install
vue-meta via Yarn or NPM.
Then, import and use it it in your Vue entrypoint:
import Vue from 'vue'; ... import Meta from 'vue-meta'; Vue.use(Meta); ...
Meta tags
Now in your components, you can add a
metaInfo property that contains the various bits you’ll want to inject into your
<head>:
<template> ... </template> <script> export default { ... metaInfo: { // Children can override the title. title: 'My Page Title', // Result: My Page Title ← My Site // If a child changes the title to "My Other Page Title", // it will become: My Other Page Title ← My Site titleTemplate: '%s ← My Site', // Define meta tags here. meta: [ {http-equiv: 'Content-Type', content: 'text/html; charset=utf-8'}, {name: 'viewport', content: 'width=device-width, initial-scale=1'}, {name: 'description', content: 'I have things here on my site.'} ] } } </script>
Social tags
It’s also a good idea for you to include relevant social media tags for every page, especially if you expect it to be shared on social media.
metaInfo: { ... meta: [ ... // OpenGraph data (Most widely used) {property: 'og:title', content: 'My Page Title ← My Site'}, {property: 'og:site_name', content: 'My Site'}, // The list of types is available here: {property: 'og:type', content: 'website'}, // Should the the same as your canonical link, see below. {property: 'og:url', content: ''}, {property: 'og:image', content: ''}, // Often the same as your meta description, but not always. {property: 'og:description', content: 'I have things here on my site.'} // Twitter card {name: 'twitter:card', content: 'summary'}, {name: 'twitter:site', content: ''}, {name: 'twitter:title', content: 'My Page Title ← My Site'}, {name: 'twitter:description', content: 'I have things here on my site.'}, // Your twitter handle, if you have one. {name: 'twitter:creator', content: '@alligatorio'} {name: 'twitter:image:src', content: ''}, // Google / Schema.org markup: {itemprop: 'name', content: 'My Page Title ← My Site'}, {itemprop: 'description', content: 'I have things here on my site.'}, {itemprop: 'image', content: ''} ] }
Canonical link
It’s entirely possible, especially for SPAs, that the URL that a user ends up on and the URL that represents that page on the server might be slightly different, or that someone might access instead of
my-site.com or vice-versa. Just in-case, you should put a canonical link in your head to instruct search engines to consider that URL as the intended URL for this page.
metaInfo: { ... link: [ {rel: 'canonical', href: ''} ] }
It’s not super important, at least for small sites, to have a sitemap, but a sitemap can be useful to indicate to search engines which pages you think are of particular relevance and importance on your site. You’ll either have to generate one somehow from your data or write it by hand, however.
An example (simple) sitemap:
<urlset xmlns="" xmlns: <url> <loc></loc> </url> <url> <loc></loc> </url> <url> <loc></loc> </url> <url> <loc></loc> </url> </urlset>
You can include the sitemap in
robots.txt by adding a line such as:
robots.txt
Mobile Optimizations
Google, at least, prefers sites that are mobile-optimized.
These are issues that would give you a mobile optimization warning:
- The
viewportmeta tag isn’t set. (See above.)
- The viewport width is fixed.
- The content requires horizontal scrolling.
- The font-size is too small.
- Touchable elements are too close together.
Google’s guide can give you some pointers on how to correct these issues.
You’d also get extra bonus points if your site is a PWA.
Other Issues
- You’ll take a hit in ranking if your site isn’t served over HTTPS or your HTTPS configuration is broken.
- Page speed is a significant factor these days in SEO, as several search engines are preferring sites that load in a few seconds over sites with potentially better content that are incredibly slow and bloated.
- If no one is linking to your site, it may take awhile for it to rise in search ratings. Even posting it on social media can help with that sometimes.
You can use Lighthouse to test for a wide variety of issues that might affect your search ranking.
Prerendering / SSR
Last but not least, an SPA is, by default, at an SEO disadvantage, because all URLs are handled by a single route, and crawlers will need to be able to run JavaScript to render the full page (an iffy process).
There are two methods commonly used to turn a SPA into a bunch of already-populated pages that present the data on the page before loading the SPA:
- Prerendering - The simpler of the two methods. Basically you have a browser automatically visit all the pages you want prerendered in your app during your build step, and it spits out whatever the resulting HTML is. You can pretty much drop it in to your existing build step.
- Server-Side Rendering - SSR is a much more complex process. It basically allows you to render your app on the server on-demand, but comes with a number of caveats and requires you to design your app with it in mind.
For the vast majority of sites, Prerendering is the simplest solution, but for highly dynamic sites, SSR might be preferred.
That's about it! If there's anything else you can think of that might help search engines rank your Vue.js project even higher, let us know! | https://alligator.io/vuejs/vue-seo-tips/ | CC-MAIN-2019-35 | refinedweb | 1,017 | 70.84 |
I will be updating this page shortly. The software is now called Internet Business Promoter and is a combination of Arelis and the SEO portion of the software. -Chris
Dear Christian Webmasters & Christian Businessmen:
Hello this is Chris Chandler, owner of Christian eBuy.com. I would like to highly recommend a new software that has helped us tremendously in our reciprocal link campaigns.
Reciprocal links are swapping hyperlinks between websites. If you have ever tried to swap links much, you know that it is a lot of work to find related urls (that are non-competing), contact the owner, install their link, and then verify that they have linked back to you. That is a lot of work! Well, there is finally a program that can do a lot of this work for you. It is Arelis. You can read more about it below or click here.
Try out this software for thirty days with this FREE Download.
PS. By the way… I have tried Zeus from Cyber-Robotics. I should have known from the name that it was not the one for me. I tried it and it was so clunky that I eventually stopped using it and went to the much easier to use Arelis. You will love Arelis! — Chris
An article I recently wrote on this awesome software….
Do You Want A 1/2 A Million Hits?
Christian Ebuy has grown by leaps and bounds in the last year
as we reach the one million mark in yearly traffic for the first time
due to reciprocal links. Today I want to share with you a powerful
concept that has helped fuel this kind of traffic… Reciprocal
Linking.
H
UGE TRAFFIC THROUGH RECIPROCAL LINKING
So you want huge traffic to your website huh? Everyone does. It really does not pay to just try a shot in the dark by submitting to the search engines and hoping the keywords on your site get noticed by the search engines. Today it takes more. It takes
reciprocal links.
Reciprocal links simply said is a “Link Swap”.
Swapping links between sites has been going on since the start
of the internet. It is the thing that makes the web a web. It interconnects us to millions of websites. Utilizing this concept can bring your company lots of traffic and hopefully lots of sales.
WANT A HALF A MILLION HITS FOR FREE?
Tired of paying Google or Overture, huge amounts of money just to send you traffic? Google Adwords charges at least 5 cents per click while Overture charges a minimum of 10 cents per clink!
Reciprocal linking can drive a huge amount of free traffic to your
site. For instance… Lets say that you have 500 links on other sites
that are bringing you 3 hits a day. That means you would be getting
1500 hits a day or 45,000 hits a month or 540,000 hits per year!
Advertising on Google alone at minimum bid, this amount of hits
would cost you $27,000 per year!
RECIPROCAL LINKING TAKES A LOT OF TIME DOESN’T IT?
I will not lie and tell you that reciprocal linking is quick and easy. It isn’t. It takes some time. But there is a tool that I use that makes finding, contacting, linking, to other websites much faster. It is a program called ARELIS.
ARELIS has been a real time saver for me because it will hunt down similar sites to mine (Christian… very important), and then
import the title, description, url, email info without having to visit the site manually. The robot in Arelis’ Reciprocal Link Software does it for you. Then you
have a simple email template that makes it easy to contact the website fast. Then the program will handle all the reciprocal link
requests and set up a link directory for your site. It is very easy to
use!
It is very easy and much faster than doing everything manually.
You will love it.
To find out more about ARELIS, go to…
Go there. I highly recommend this program. It can mean a 1/2 a million hits per year (or more) for your Christian website!
God Bless You!
Chris Chandler
Owner of Christian eBuy.com
Tags: arelis, arelis software, ibp, link directory, link trading, reciprocal linking, reciprocal links, trade links | http://www.christianebuy.com/software/arelis-link-trading-software.htm | crawl-002 | refinedweb | 722 | 83.25 |
What will we cover?
In this tutorial we will get familiar to work with DataFrames – the primary data structure in Pandas.
We will learn how to read a historical stock price data from Yahoo! Finance and load it into a DataFrame. This will be done by exporting a CSV file from Yahoo! Finance and load the data. Later we will learn how to read the data directly from the Yahoo! Finance API.
A DataFrame is similar to an Excel sheet. DataFrames can contain data in a similar way as we will see in this lesson.
Then we will learn how to use the index of the dates. This will be necessary later when we make calculations later on.
The first part of the tutorial will give the foundation of what you need to know about DataFrames for financial analysis.
Step 1: Read the stock prices from Yahoo! Finance as CSV
In this first lesson we will download historical stock prices from Yahoo! Finance as CSV file and import them into our Jupyter notebook environment in a DataFrame.
If you are new to CSV files and DataFrames. Don’t worry, that is what we will cover here.
Let’s start by going to Yahoo! Finance and download the CVS file. In this course we have used Apple, but feel free to make similar calculation on a stock of your choice.
Go to Yahoo! Finance write AAPL (ticker for Apple) and press Historical Data and download the CSV data file.
The CSV data file will contain Comma Separated Values (CSV) similar to this.
Date,Open,High,Low,Close,Adj Close,Volume 2020-03-02,70.570000,75.360001,69.430000,74.702499,74.127892,341397200 2020-03-03,75.917503,76.000000,71.449997,72.330002,71.773636,319475600 2020-03-04,74.110001,75.849998,73.282501,75.684998,75.102829,219178400 2020-03-05,73.879997,74.887497,72.852501,73.230003,72.666725,187572800 2020-03-06,70.500000,72.705002,70.307503,72.257500,71.701706,226176800
The first line shows the column names (Date, Open, High, Low, Close, Adj Close, Volume). Then each line contains a data entry for a given day.
Step 2: Read the stock prices from CSV to Pandas DataFrame
n Jupyter Notebook start by importing the Pandas library. This is needed in order to load the data into a DataFrame.
import pandas as pd data = pd.read_csv("AAPL.csv", index_col=0, parse_dates=True) data.head()
The read_csv(…) does all the magic for us. It will read the CSV file AAPL.csv. The AAPL.csv file is the one you downloaded from Yahoo! Finance (or from the zip-file downloaded above) and needs to be located in the same folder you are working from in your Jupyter notebook.
The arguments in read_csv(…) are the following.
- index_col=0 this sets the first column of the CSV file to be the index. In this case, it is the Date column.
- parse_dates=True this ensures that dates in the CSV file are interpreted as dates. This is important if you want to take advantage of the index being a time.
Step 3: Explore data types of columns and index
In the video lesson we explore the type of columns and index.
data.dtypes data.index
Which will reveal the data type and index of the DataFrame. Notice, that each column has its own data type.
Step 4: Indexing and slicing with DataFrames
We can use loc to lookup an index with a date.
data.loc['2020-01-27']
This will show the data for that specific date. If you get an error it might be because your dataset does not contain the above date. Choose another one to see something similar to this.
Open 7.751500e+01 High 7.794250e+01 Low 7.622000e+01 Close 7.723750e+01 Adj Close 7.657619e+01 Volume 1.619400e+08 Name: 2020-01-27 00:00:00, dtype: float64
A more advanced option is to use an interval (or slice as it is called). Slicing with loc on a DataFrame is done by using a starting and ending index .loc[start:end] or an open ended index .loc[start:], which will take data beginning from start to the last data.
data.loc['2021-01-01':]
This will give all the data starting from 2020-01-01. Notice, that there is no data on January 1st, but since the index is interpreted as a datetime, it can figure out the first date after.
Open High Low Close Adj Close Volume Date 2021-01-04 133.520004 133.610001 126.760002 129.410004 129.410004 143301900 2021-01-05 128.889999 131.740005 128.429993 131.009995 131.009995 97664900 2021-01-06 127.720001 131.050003 126.379997 126.599998 126.599998 155088000 2021-01-07 128.360001 131.630005 127.860001 130.919998 130.919998 109578200 2021-01-08 132.429993 132.630005 130.229996 132.050003 132.050003 105158200 2021-01-11 129.190002 130.169998 128.500000 128.979996 128.979996 100620900
Similarly, you can create slicing with an open-ended start.
data.loc[:'2020-07-01']
Another important way to index into DataFrames is by iloc[], which does it with index.
data.iloc[0] data.iloc[-1]
Where you can index from the start with index 0, 1, 2, 3, … Or from the end -1, -2, -3, -4, …
What is next?
Want to learn more?
This is part of the FREE online course on my page. No signup required and 2 hours of free video content with code and Jupyter Notebooks available on GitHub.
Follow the link and read more. | https://www.learnpythonwithrune.org/pandas-for-financial-stock-analysis/ | CC-MAIN-2021-25 | refinedweb | 944 | 85.59 |
Web components seem to be the rage in Dart-land of late, but I have almost no idea what they are. Sure, I could read excellent articles on the subject, but that's not how I learn best.
I start by updating my
pubspec.yamlto include web_ui:
name: scripts dependencies: hipster_mvc: any web_ui: any unittest: anyBut when I run
pub install, I am greeted with:
➜ app git:(web-components) ✗ pub install Resolving dependencies... Could not find package "hipster_mvc 0.2.4" at know that I published that, but it is not showing up in Dart Pub. Oh well, it's easy to re-publish:
➜ hipster-mvc git:(master) pub lish Publishing "hipster_mvc" 0.2.4: |-- .gitignore |-- LICENSE |-- README.asciidoc |-- lib | |-- hipster_collection.dart | |-- hipster_events.dart | |-- hipster_history.dart | |-- hipster_model.dart | |-- hipster_router.dart | |-- hipster_sync.dart | '-- hipster_view.dart |-- pubspec.yaml '-- test |-- hipster_events_test.dart '-- index.html Looks great! Are you ready to upload your package (y/n)? y hipster_mvc 0.2.4 uploaded successfully.Done and done. Now to install web_ui:
➜ app git:(web-components) ✗ pub install Resolving dependencies... Could not find package "logging" at... there are suspiciously fewer packages available in the pub tonight. It seems that something has gone wrong there. Hopefully this will not happen too often because I believe that I am completely blocked at this point.
So instead, I shift my attention to another question in need of answering: is it possible to have a whole book dashboard of my tests. I have been diligently extracting all code samples out into runnable tests. I can see the results of all tests within a chapter—either on the command line for non-browser chapters or in the browser for DOM-specific chapters. But what about putting them all together?
That turns out to be quite easy. The events chapter tests all have to run in the browser whereas I have been running the classes chapter tests from the command-line. To see both, I will need to run the tests in the least common denominator: the browser.
So I create a page to hold my tests:
<html> <head> <title>Dart for Hipsters Tests</title> <script type="application/dart" src="test.dart"></script> <script type="text/javascript"> // start dart navigator.webkitStartDart(); </script> </head> <body> <h1>Test!</h1> </body> </html>And, in the source'd
test.dart, I import my two test.dart chapter files:
import 'package:unittest/html_enhanced_config.dart'; import 'package:unittest/unittest.dart'; import 'events/test.dart' as Events; import 'classes/test.dart' as Classes; main () { useHtmlEnhancedConfiguration(); Events.main(); Classes.main(); }I have to declare both as libraries (starting the files with the library directive), which is not a problem since it will have no effect on the current uses. The
main()entry point in each of the chapter tests then becomes just another function in the imported libraries.
And, loading the combined tests up in my browser, I have two chapter's worth of tests passing at a glance:
It was a bummer not being able to mess about with web components tonight, but I am pretty happy to have a testing dashboard under way.
Day #620 | https://japhr.blogspot.com/2013/01/combined-tests-in-dart.html | CC-MAIN-2017-09 | refinedweb | 517 | 60.01 |
@Nebula,
@skol,
Problem is that the framework is currently lacking ability to nicely arrange bitmaps in the output spritesheet. This often results in excessing the boundaries you've already checked and seen in Flash Professional.
I updated the framework, actually quite remodelled it for the game I'm working on and added functionality that I find quite necessary for this tool.
It includes:
1) Ability to stack frames - quite important feature - usually makes the output spritesheet half the size.
2) Applying bin package algorithm to the output spritesheet - it is currently not the *best* optimal way to bin package things, but it is quite fast; and gives sufficiently good results I must say; Bin packaging is known as MaxRects algorithm for the guys who use Flash Professional.
3) All this results in ability to generate nearly as small as possible output spritesheet, so that as few spritesheets as possible are used.
@emibap: Please consider if you want me to publish those changes and I'll clean my code up as soon as I have time so that the framework could be updated.
Hi Martin,
I haven't touched this code for a long, long time. In fact I can't remember when was the last time I coded in AS3.
So please if you think that you can continue this, go ahead. To me it was a nice experiment but I never used it in a project, and it clearly needs more work.
Let me know if you want to push changes to my gitHub or if you want me to point to your forked branch in the beginning of the forum thread.
Cheers
Hey Martin, thanks for keeping up on developing this extension! Please keep us updated when you publish or push changes to emibap's.
Did you implement texture packing option in fromMovieClip function in Texture.fromBitmap call -- to correspond with Starling update. Basically, you can save some memory on packing textures (e.g. full screen background) with Context3DTextureFormat.COMPRESSED option.
Thanks, I'll keep you posted on any further updates...
@skol, I don't get what exactly you are talking about
Here is the method definition as I see it in docs:
public static function fromBitmap(data:Bitmap, generateMipMaps:Boolean = true, optimizeForRenderToTexture:Boolean = false, scale:Number = 1):Texture
are you talking about the optimizeForRenderToTexture property?
I'm talking about last param 'format' (that's become recently available in Starling) where you can now specify in which format to compress textures. Even though BRGA_COMPRESSED (i.e. ATF ) isn't supported on mobile, BRG_PACKED is supported -- so you save some memory on not encoding the alpha channel.
public static function fromBitmapData(data:BitmapData, generateMipMaps:Boolean=true,
optimizeForRenderToTexture:Boolean=false,
scale:Number=1, format:String="bgra"):Texture
in
Interestingly, adobe's docs mention only BGRA and COMPRESSED
Thank you skol,
I'll do effort to include this in the next release, once I have time to. Meanwhile I need to concentrate on our project. 🙂
I'll post here once I have updates so that we manage the new release.
@Skol,
any idea when this is going to become available in a stable Starling release?
@martin -- it's already there from 1.4 which was released yesterday! Just git pull Starling form github. Try with BRG_PACKED for backgrounds and you'll see GPU memory is off by 1-2 mb per full screen image.
Also, I pack them as rectangles in Fla (e.g. 512x512 or 1024x1024), which saves some processing and memory as well since 3.8 support for rectangle textures. Since the backgrounds are vectors, the result is crispy cool even on iPad 4. Man, I'm loving this vector thingy 🙂
So is this BGR_PACKED a real thing ? Is Context3D going to accept it? How is it represented as string - "packed"? There is no constant that represents this mode.
This is what I get when passing "packed" to the method
ArgumentError: Error #2008: Parameter textureFormat must be one of the accepted values.
at flash.display3D::Context3D/createTexture()
How do you mean 'a real thing'. Are you using latest Air 3.8 with latest Starling?
It works fine for me in my DTA fork.
From 3.8 beta release notes
Rectangle Texture Support
Rectangle Textures are now supported in BASELINE as well as BASELINE_EXTENDED profile. The texture formats supported for
Rectangle Textures are BGRA, BGR_PACKED and BGRA_PACKED. Details for usage can be found in the language reference.
To solve the problem with the low resolution, I make some changes in the file DynamicAtlas.as
Add in the top
import flash.display.StageQuality;
And instead of
_bData.draw(clip, _mat, _preserveColor ? clipColorTransform : null);
Use:
_bData.drawWithQuality(clip, _mat, _preserveColor ? clipColorTransform : null, null, null, true, StageQuality.BEST);
This work with Air 3.3 or above
Hi, I'm using this extension with great results in a game project, so thanks for building it, but I also keep running into the limitation that nested movieclips don't play in the cached version.
Would it be possible to add support for nested movieclips?
Another idea for improvement is that filters on the top-level movieclip are taken into consideration when bounds are determined. Right now for example a movieclip with a glow filter will appear clipped after caching because the glow-filter extends outside the calculated bounds of the movieclip.
i try to create texture atlas with swc. but when i trace all texture names, just show "instancexx_xxx", not the names of symbol in fla. i try to compare with sample swc, then on SheetMC, there was declarations
public var boy : MovieClip;
public var buttonSkin : MovieClip;
but when i "edit class" SheetMC on the fla, there are no declaration like that..
what should i do? can anyone teach me how i can make "right" texture atlas with swc so i can use it with this extension.
thank you
(sorry my bad english)
oh ok, forget my last stupid question.. i had found to give name of symbol
Hi, sorry if this could be a sily questione, but I haven't figured it out.
I'm using Dynamic texture atlas to load some parallax background tiles, but some of them gets loaded with some transparent pixels on the border, making the tile not seamless, any suggestions?
Here's a screenshot with disabled alpha channel:
I'm late to the party, but it looks like you need texture extruding on your repeated, tiled background texture. TexturePacker supports this, you might have to pre-rasterize just the repeating texture.
Thank you Kheftel, I'll try it
Although it has been passed a long time since the release of this extension I wanna say this is AWESOME!!
In my point of view, this extension is one of the few extensions which has changed completaly the way of build application using starling, mainly if we are targeting mobile applications.
VERY NICE!!!!! 😃
@andtankian thanks!
It's been years since the day I stopped making AS3, and frankly I thought that this extension wasn't production ready when I released it and abandoned it. Glad to know that you found it useful.
Cheers! | https://forum.starling-framework.org/d/48-dynamic-texture-atlas-generator-starling-extension/121 | CC-MAIN-2019-26 | refinedweb | 1,182 | 64.41 |
It seems like some code in safelite passes a file object to isinstance. By overriding the builtin isinstance function I can get access to the original file object and create a new one. Here is the code I used: from safelite import FileReader _real_file = None def _new_isinstance(obj,types): global _real_file if _real_file is None and obj.__class__.__name__ == 'file': _real_file = obj.__class__ return _old_isinstance(obj,types) _old_isinstance = __builtins__.isinstance __builtins__.isinstance = _new_isinstance FileReader('nul') f = _real_file('foo.txt','w') f.write('hello') f.close() -Farshid On Mon, Feb 23, 2009 at 12:10 PM, tav <tav at espians.com> wrote: > Hey all, > > As an attempt to convince everyone of the merits of my functions-based > approach to security, I've come up with a simple challenge. I've > attached it as safelite.py > > The challenge is simple: > > * Open a fresh Python interpreter > * Do: >>> from safelite import FileReader > * You can use FileReader to read files on your filesystem > * Now find a way to *write* to the filesystem from your interpreter > > Please note that the aim of this isn't to protect Python against > crashes/segfaults or exhaustion of resources attacks, so those don't > count. > > I'm keen to know your experiences even if you don't manage to write to > the filesystem -- and especially if you do! > > Dinner and drinks on me for an evening -- when you are next in London > or I am in your town -- to the first person who manages to break > safelite.py and write to the filesystem. > > Good luck and thanks! =) > >> If you block __closure__ and __globals__ on function objects you will get a >> semblance of a private namespace. That way you might (I have not thought >> this one through like securing the interpreter for embedding) be able to get >> what you need to safely pass in Python code through the globals of the code >> being executed. > > Brett, this is exactly what I do. You also need to restrict func_code. > The patch is simply for closing the other loopholes: > type.__subclasses__, GeneratorType.gi_frame and gi_code. All possible > in a patch of 6 lines of code thanks to Python's existing restricted > framework in the interpreter. > > Please review and accept =) > > * > * > > Thanks! > > -- > love, tav > > plex:espians/tav | tav at espians.com | +44 (0) 7809 569 369 > | @tav | skype:tavespian > > _______________________________________________ > Python-Dev mailing list > Python-Dev at python.org > > Unsubscribe: > > | https://mail.python.org/pipermail/python-dev/2009-February/086425.html | CC-MAIN-2017-13 | refinedweb | 394 | 64.91 |
Ruby Methods
Ruby methods are very similar to functions in any other programming language. Ruby methods are used to bundle one or more repeatable statements into a single unit.
Method names should begin with a lowercase letter. If you begin a method name with an uppercase letter, Ruby might think that it is a constant and hence can parse the call incorrectly.
Methods should be defined before calling them, otherwise Ruby will raise an exception for undefined method invoking.
Syntax:
def method_name [( [arg [= default]]...[, * arg [, &expr ]])] expr.. end
So you can define a simple method as follows:
def method_name expr.. end
You can represent a method that accepts parameters like this:
def method_name (var1, var2) expr.. end
You can set default values for the parameters which will be used if method is called without passing required parameters:
def method_name (var1=value1, var2=value2) expr.. end
Whenever you call the simple method, you write only the method name as follows:
method_name
However, when you call a method with parameters, you write the method name along with the parameters, such as:
method_name 25, 30
The most important drawback to using methods with parameters is that you need to remember the number of parameters whenever you call such methods. For example, if a method accepts three parameters and you pass only two, then Ruby displays an error.
Example:
#!/usr/bin/ruby def test(a1="Ruby", a2="Perl") puts "The programming language is #{a1}" puts "The programming language is #{a2}" end test "C", "C++" test
This will produce the following result:
The programming language is C The programming language is C++ The programming language is Ruby The programming language is Perl
Return Values from Methods:
Every method in Ruby returns a value by default. This returned value will be the value of the last statement. For example:
def test i = 100 j = 10 k = 0 end
This method, when called, will return the last declared variable k.
Ruby return Statement:
The return statement in ruby is used to return one or more values from a Ruby Method.
Syntax:
return [expr[`,' expr...]]
If more than two expressions are given, the array containing these values will be the return value. If no expression given, nil will be the return value.
Example:
return OR return 12 OR return 1,2,3
Have a look at this example:
#!/usr/bin/ruby def test i = 100 j = 200 k = 300 return i, j, k end var = test puts var
This will produce the following result:
100 200 300
Variable Number of Parameters:
Suppose you declare a method that takes two parameters, whenever you call this method, you need to pass two parameters along with it.
However, Ruby allows you to declare methods that work with a variable number of parameters. Let us examine a sample of this:
#!/usr/bin/ruby def sample (*test) puts "The number of parameters is #{test.length}" for i in 0...test.length puts "The parameters are #{test[i]}" end end sample "Zara", "6", "F" sample "Mac", "36", "M", "MCA"
In this code, you have declared a method sample that accepts one parameter test. However, this parameter is a variable parameter. This means that this parameter can take in any number of variables. So above code will produce following result:
The number of parameters is 3 The parameters are Zara The parameters are 6 The parameters are F The number of parameters is 4 The parameters are Mac The parameters are 36 The parameters are M The parameters are MCA
Class Methods:
When a method is defined outside of the class definition, the method is marked as private by default. On the other hand, the methods defined in the class definition are marked as public by default. The default visibility and the private mark of the methods can be changed by public or private of the Module.
Whenever you want to access a method of a class, you first need to instantiate the class. Then, using the object, you can access any member of the class.
Ruby gives you a way to access a method without instantiating a class. Let us see how a class method is declared and accessed:
class Accounts def reading_charge end def Accounts.return_date end end
See how the method return_date is declared. It is declared with the class name followed by a period, which is followed by the name of the method. You can access this class method directly as follows:
Accounts.return_date
To access this method, you need not create objects of the class Accounts.
Ruby alias Statement:
This gives alias to methods or global variables. Aliases can not be defined within the method body. The alias of the method keep the current definition of the method, even when methods are overridden.
Making aliases for the numbered global variables ($1, $2,...) is prohibited. Overriding the built-in global variables may cause serious problems.
Syntax:
alias method-name method-name alias global-variable-name global-variable-name
Example:
alias foo bar alias $MATCH $&
Here we have defined foo alias for bar and $MATCH is an alias for $&
Ruby undef Statement:
This cancels the method definition. An undef can not appear in the method body.
By using undef and alias, the interface of the class can be modified independently from the superclass, but notice it may be broke programs by the internal method call to self.
Syntax:
undef method-name
Example:
To undefine a method called bar do the following:
undef bar | http://www.tutorialspoint.com/cgi-bin/printversion.cgi?tutorial=ruby&file=ruby_methods.htm | CC-MAIN-2015-35 | refinedweb | 911 | 61.26 |
A Little History or Why NFS?
File shares on computer networks are as old as the concept of a network itself. The idea of being able to access data across a wire by multiple machines was created not long after the first network was created. When the PC industry took off in the 1980’s file share became commonplace among most businesses, both large and small. The ubiquitous “file server” was a mainstay in most businesses from this time through the 2010s. Even now, the concept still lives on as it evolved to cloud-based storage options that serve much of the same purpose.
During the 1980s and 1990s, several different file sharing protocols emerged for networks from different vendors. There was SMB from Microsoft that shipped as part of Windows for Workgroups and Windows NT, the IPX based NCP from Novell that was hugely popular for business networks, and the NFS protocol that originated from Sun Microsystems. Unlike SMB and NCP however, NFS went on to be released as an open standard and was widely adopted by the UNIX community on systems like BSD and Linux. It remained a rather obscure file-sharing system with the SMB and NCP dominating the market until Novell fell out of favor and Linux rose in popularity as a server-based operating system. Through this rise, it became a staple among networks that used Linux hosts for sharing files. Because of its rise in popularity along with Linux, support for the protocol even among cloud vendors providing storage as a service remains a priority to help maintain backward compatibility with older applications that are being migrated to the cloud.
NFS on Azure
On Azure, there are two primary ways to get NFS as a service. The first one is through Azure NetApp Files, a service that was built with a partnership between NetApp and Microsoft to provide file shares as a service for large data sets. The other implementation is for less performant, but highly scalable workloads on Azure Blob Storage. Before Microsoft added this feature, mounting Blob Storage as part of a file system was only possible through Blobfuse. This approach is still valid for some use cases, but NFS allows for protocol-level access to blob storage, so any NFS client can mount Blob Storage as part of the client’s file system, including Windows, now that it has an NFS client.
To setup NFS on Blob Storage, there are a few things that have to be enabled for the subscription. To enable, you’ll need the Azure CLI installed on your local machine or you can access it through Cloud Shell in the Azure portal. Once Azure CLI is installed and you’ve logged in, run the following two commands. The first enables NFS on Blob Storage, and the second then enables hierarchical namespaces (HNS) which is needed for the NFS service to work.
az feature register --namespace Microsoft.Storage --name AllowNFSV3
az feature register --namespace Microsoft.Storage --name PremiumHns
After running the commands, wait for about 15 minutes. Once these are enabled. You can now set up an NFS share on a Blob Storage account.
In the Azure Portal, create a Storage Account.
On the Basics blade of the Storage Account, the main settings to watch for are the Performance setting and the Account Kind. These must be set to Premium and BlockBlobStorage respectively.
On the Networking blade, make sure that you choose Public endpoint (Selected Networks) or Private endpoint. This is needed for security. You will then need to configure what network you want to use with the Storage Account. Everything else is not enabled.
On Data protection, no items are selectable so leave this blade as is.
On the Advanced blade, ensure that Secure Transfer required is disabled, Hierarchal namespaces is enabled, and NGS v3 is enabled.
You can add tags if you like on the Tags blade.
On the Review + create blade, click the Create button. This will create the Storage Account.
Once the Storage Account has been completed, open the Storage Account in the Azure Portal and then click on Containers on the Overview blade. Here, click + Container to add a new container. You can name it whatever you want.
Mounting in Windows
On Windows, the first thing you will need to do is add the Windows Client for NFS. To do this, open Control Panel, navigate to Programs and Features, Click on Turn Windows features on or off, then find the Services for NFS group, expand it, then check the box next to Client for NFS. This will install the client for NFS on Windows.
If you want to enable write access to the NFS share, you need to create two registry settings. You can do this by launching PowerShell and running the following two commands. Once this is done, you need to reboot or restart the NFS service.
New-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\ClientForNFS\CurrentVersion\Default -Name AnonymousUid -PropertyType DWord -Value 0 New-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\ClientForNFS\CurrentVersion\Default -Name AnonymousGid -PropertyType DWord -Value 0
Now, you can mount the Storage Account. To do this, run the following command in a Command Prompt (CMD).
mount -o nolock STORAGEACCOUNT.blob.core.windows.net:/STORAGEACCOUNT/CONTAINER Q:
Replace STORAGEACCOUNT with the name of your storage account in both places and then replace CONTAINER with the name of the container you created in your storage account. You can replace Q: with whatever drive letter you want or use * to let Windows pick one.
Mounting on Linux
Mounting on Linux is simple, but you’ll need to have an NFS client install first. Some distros have this automatically installed, but others will need to install it.
Once it’s installed, create a mountpoint with mkdir. You may need sudo if you aren’t a root user or don’t have permissions.
mkdir /mnt/mystuff
After creating the mountpoint, mount the Storage Account with the mount command.
mount -o sec=sys,vers=3,nolock,proto=tcp STORAGEACCOUNT.blob.core.windows.net:/STORAGEACCOUNT/CONTAINER /mnt/mystuff
Replace STORAGEACCOUNT with the name of your storage account in both places and then replace CONTAINER with the name of the container you created in your storage account. The last parameter is the mountpoint you created on the file system with mkdir.
When to Use?
Blob Storage as a storage solution offers a low-cost option for storing data in the cloud. However, the storage does come with some limitations and caveats. Using NFS on Blob Storage will work for many workloads that don’t require demanding IOPS (input/output operations per second). For more demanding workloads, consider using Azure Files or Azure NetApp files for better performance.
Conclusion
NFS on Blob Storage is still a preview feature, but once it does GA, it has many use cases that will help older applications take advantage of the cost savings of Blob Storage and without the headaches of maintaining a file server. | https://www.wintellect.com/using-nfs-with-azure-blob-storage/ | CC-MAIN-2021-39 | refinedweb | 1,161 | 62.88 |
Hi,
Today we are excited to announce the launch of AppCode 3.4 EAP and the first build is already available on our confluence page. Please note that a patch from the release version will not be available until AppCode 3.4 gets stable. This EAP does not require an active license, so you can use it for free until the build expiration date.
Swift
This build delivers the following features and improvements:
- Parsing, completion and resolve for types conforming to OptionSetType protocol (OC-12078):
- Parsing, completion and resolve for Self type (OC-12913):
- Set value in Swift debugger for Core Data objects (OC-12896):
- Resolve for enum members in if-case statement (OC-12878)
- Resolving enum initialisers (OC-12639) and parsing named arguments in tuple patterns (OC-12985)
- Fix for Swift Structure View freeze (OC-11526)
C++
Now the Quick Documentation popup (available via F1) also shows documentation for lambda expressions (but mind the remaining problem CPP-5491), namespace aliases (CPP-682) and explicit instantiation. This EAP build also addresses some problems with quick documentation in C++, like the internal error that would previously occur while fetching documentation for anonymous class/struct/enum.
Source directories management
New context menu called Mark directory as is available for folders in Files view:
- Mark directory as excluded. You can choose this option for 2 different cases. First is when you want to remove some directory contents from Inspect Code, Find in Path (⇧⌘F) or Search Everywhere (Double ⇧) results. By default these actions are executed not only on files included into Xcode project, but on all files that are located in the project root folder (except build directories like DerivedData). Second is when you have a source folder included into your Xcode project and you don’t want AppCode to index it. AppCode indexes all directories listed in your Xcode project in order to provide you with accurate code completion, navigation, refactorings and other smart features, but sometimes the source folder can be too big and indexing can become too expensive – in this case you can tell AppCode to manually exclude such folders from indexing.
- Mark directory as library. If you have framework sources included into your Xcode project (or workspace), you may want to disable refactorings for it and take control over navigation and search options. If you mark some folder as a library, refactorings for sources in this folder will be disabled, as will code generation options and completion. By default, results from this folder will not be shown for Navigate to File, Class or Symbol actions. However, if you still want to navigate to the library sources, you can simply tick “Include non-project items/symbols/files” and the corresponding items will be shown in the navigation dialog.
- Mark directory as project sources. In some situations this action can also be helpful – for example, if you want to get navigation and completion for some sources located in your project’s folder but not included into the currently opened Xcode project.
Version control
A couple of new features are included into this build:
- By-word difference highlighting in Diff viewer:
- Checkout with Rebase Git action, helpful in case you want to rebase a feature branch on master in one click:
Xcode compatibility
In one if the recent blog posts about AppCode 3.3.3 RC we’ve mentioned that there were some critical issues with debugger when using it with Xcode 7.3 beta 2. These issues should be fixed in this EAP build, so you can use it with the latest Xcode beta.
Note, that starting from AppCode 3.4 EAP minimal Xcode version supported by AppCode will be limited to Xcode 7.2. To use AppCode with earlier Xcode versions (for example, Xcode 7.1.1), please install AppCode 3.3.3.
Java Runtime Environment used with AppCode
IntelliJ Platform has migrated to Java 8 as the target platform. In practical terms this means the following:
- AppCode won’t start under JDK versions older than 8. In general it shouldn’t be a problem for you, since AppCode installer contains an appropriate bundled JDK version.
- In case you’ve switched the Java version used for running AppCode to a non-bundled one (via Switch IDE boot JDK…) and then imported these settings while starting the AppCode 3.4 EAP, you may receive the ‘unsupported Java version’ error. To fix the problem simply delete ~/Library/Preferences/AppCode34/appcode.jdk. In future versions we’ll try to handle this situation automatically (IDEA-149618).
- Plugin writers will be able to use Java 8 features in their plugins.
- The annoying issue with Java2D Queue Flusher thread crashing is fixed in this JDK version.
And more:
- Support for RTL languages (Arabic and Hebrew) added to the editor.
- CoffeeScript and Stylus plugins bundled in AppCode.
- Improved UI for Attach to local process… action:
The full list of improvements and fixes is available here.
Download AppCode 3.4 EAP build 144.3600, give it a try and report issues to our tracker or share your feedback in comments!
Your AppCode team
JetBrains
The Drive to Develop
Yay! *woot* 😀
Thank you! Its finally looking like there is some light at the end of this Swift tunnel
This all looks great. I know the AppCode team is unlikely to be responsible… but those new 3D-effect scrollbars are really bad
There were no changes for scrollbars in this build. Could you please make a screenshot?
Yes – please see the image here:
Thanks, we see the problem, seems to be an affect from platform changes. For the moment – old look is available if you change scroll behaviour to “When scrolling” in System Preferences.
Much better – thanks.
This appcode hangs on Building symbols on a project with ~1000 files. 3.3 worked, although parsing was very slow.
Could you please try to increase Xmx value in appcode.vmoptions file as described here and let us know if it helps in your case?
Tried -Xmx2400 instead of -Xmx1200 and got same result. With -Xmx4800 it finally worked but took more than 20 minutes to complete
Tried on MacBook Pro (Retina, 15-inch, Mid 2014) 2.2 GHz Intel Core i7 16Gb | https://blog.jetbrains.com/objc/2016/02/appcode-3-4-eap-opens/?replytocom=109814 | CC-MAIN-2019-43 | refinedweb | 1,030 | 62.78 |
Install Synchronator
I know this is an old issue, but I can't really work out what to do. I just got a new iPad and I am trying to install Synchronator. I know I have to update dropbox and the apparently also request (which is now 2.9.1).
But it just doesn't work.
Does anyone has clear instructions how to realize this (with Stash).
The strange thing is that my old iPad has requests 2.9.1 and it all seems to work. So do I really have to upgrade requests.
I have also noticed that Stash now installs in site-packages-3 whereas the old version used site-packages. Is that intended behaviour?
@upwart StaSh version
0.7.0chooses the 'site-packages*' directory depending on the python version you used to start StaSh. There is a '-6' argument for 'pip' to enforce the use of 'site-packages'.
There is no -6 flag in pip.py. I checked the code and it will always install in site-packages-2 or site-packages-3.
Do I miss something?
I have finally managed to install Synchronator on a pristine Pythonista install. Just for reference for other users, I show here the instructions:
Set default interpreter to 2.7
Install import requests as r; exec(r.get('').text)
Launch stash
(check latest versions with pip versions package)
pip install urllib3==1.23
pip install requests==2.19.1
pip install dropbox==9.0.0
move all folders from site-packages-2 to site_packages
Set default interpreter to 3.6
Get Synchronator from GitHub
Install Synchronator
Optionally change the horrible colors the scheme of Synchronator
There is no -6 flag in pip.py. I checked the code and it will always install in site-packages-2 or site-packages-3.
Do I miss something?
Oops, my mistake. The
-6flag was added in the latest StaSh dev version, so the stable version does not contain that flag yet. If you want to update, use
selfupdate -f dev.
Set default interpreter to 2.7
I know that this reply is a bit late, but you do not need to set your default interpreter. You can also open
launch_stash.py, long-press the run button and select Run with Python 2.7.
Also, if you just want the latest version of a package, there should be a
pip update <package>command.
- markhamilton1
I have been doing a substantial amount of debugging on Synchronator and have discovered that requests tends to be the problem. Don't get me wrong, it is a wonderful module, but it has introduced dependencies that make it tricky to use in Pythonista.
First, Synchronator is dependent on the dropbox and requests modules. HOWEVER, requests is dependent on a number of modules that MUST be there before it can run. These are certifi, chardet, idna, and urllib3. Install the latest updates of these FIRST.
Once these are installed you should be able to install requests. If you ALREADY have requests installed, it is possible that it will prevent the other modules from installing. If you encounter this uninstall requests and install the other modules first. Then reinstall requests.
I was able to do all of this with the Stash module from within Pythonista.
Just a side note, all of these modules are Python 3 compatible so they can be moved into the site-packages directory.
At this point be sure to QUIT the Pythonista app and restart it. Now you should be able to run Synchronator.
This fixes a number of the issues people have reported, that were due to old versions of the requests module.
In addition I have fixed Synchronator to preserve the case of the directories that it copies to/from Dropbox.
Sorry for the delay on my part getting to these issues.
I have successfully been using Synchronator for sometime now but recently I started to have a problem on my iPhone with version 1.8. I downloaded the latest version 1.11 and now I am getting a different error. Can someone help me diagnose the problem?
Dropbox File Syncronization *
Cannot Find State File -- Creating New Local State
Updating From Dropbox 149, in execute_delta
results = dbx.files_list_folder(path='', recursive=True)
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages-2/dropbox/base.py", line 1618, in files_list_folder
None,
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages-2/dropbox/dropbox.py", line 274, in request
timeout=timeout)
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages-2/dropbox/dropbox.py", line 365, in request_json_string_with_retry
timeout=timeout)
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages-2/dropbox/dropbox.py", line 449, in request_json_string
timeout=timeout, 505, in post
return self.request('POST', url, data=data, json=json, * 462, in request
resp = self.send(prep, **send 574, in send
r = adapter.send(request, */adapters.py", line 371, in send 566, in urlopen
timeout_obj = self._get 309, in _get_timeout
return Timeout.from_float 155, in from_float
return Timeout(read=timeout, connect 98, in init
self._connect = self._validate_timeout(connect, 'connect') 128, in _validate_timeout
"int or float." % (name, value))
ValueError: Timeout value connect was Timeout(connect=30, read=30, total=None), but it must be an int or float.
Did you check all the versions of modules, as I described in an earlier message?
Yes, I thought I had all the correct versions installed but I just redid some and now the iPad can run Synchronator just fine. However, on the iPhone I redid some installs and now there is a problem with 'import requests' in that it seems to be missing chardet. If I try pip update chardet or pip install chardet, I get the message No module Chardet. Catch-22?
OK, I deleted the site-packages version of requests and did all of the installs per @markhamilton1 and now Synchronator runs for a bit and then crashes with:
Traceback (most recent call last):
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents//site-packages-2/Synchronator/Synchronator.py", line 403, in <module>
check_remote(dbx, state)
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents//site-packages-2/Synchronator/Synchronator.py", line 282, in check_remote
state.execute_delta(dbx)
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents//site-packages-2//site-packages-2//site-packages-2-2/dropbox/base.py", line 1175, in files_download_to_file
None,
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages-2/dropbox/dropbox.py", line 296, in request
user_message_locale)
dropbox.exceptions.ApiError: ApiError('1905da0107ff33cb011b4305be613b5f', DownloadError(u'path', LookupError(u'not_found', None)))
It's interesting that I never installed requests, certifi, idna, or chardet on the iPad yet Synchronator runs fine. On the iPhone those installs seem to be necessary, yet it crashes.
It looks like the iPad is running Synchronator v1.8 (works) and iPhone has v1.11 (crashes).
I tried deleting Synchronator and starting all over again on the iPhone following the directions above. Synchronator starts and begins Updating from Dropbox, downloads a dozen files and then the script dies. The traceback is as follows:/dropbox/base.py", line 1175, in files_download_to_file
None,
File "/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages/dropbox/dropbox.py", line 296, in request
user_message_locale)
dropbox.exceptions.ApiError: ApiError('da9c4c00582c7cfa99818f98393be092', DownloadError('path', LookupError('not_found', None)))
I would really like to get this working (reliably) on the iPad and iPhone. Can someone please help?
Can anyone please tell me what the problem is here or suggest how I can debug it? Synchronator (v1.11) gets to this point after downloading some files and then fails with the api error.
Looks like she synchronator is trying to download a file that doesn't exist in Dropbox. Why not fire up
import pdb
pdb.pm()
And figure out which file it is trying to download..
Alternatively it might be saying that your destination path doesn't exist - you'd have to look at the code to see specifically what the issue is
Seems
pathneeds to be the full remote Dropbox path. Maybe synchronator needs to know how you have your Dropbox folders set up ..
pdb.pm()
/private/var/mobile/Containers/Shared/AppGroup/A7D4C56F-A77A-4D88-87AC-A52286C0CF04/Pythonista3/Documents/site-packages/dropbox/dropbox.py(296)request()
-> user_message_locale)
(Pdb)
I thought it was possible for me to sync my iPhone and iPad to the same Dropbox directory so that any changes to one would be reflected in changes to the other but perhaps I can't do that?
pdb lets you enter a debugging state, that lets you walk up the stack frame, interrogating variables, etc.
for instance here i would be interested in you pressin
ua few times until you are at line 242 in Synchronator:
self.download_remote(dbx, entry_path, '-- Not Found Locally')
then typing
print(entry_path)
(press q to exit pdb)
Alternatively, add a print(entry_path) before that line, and then we can see which(if any) files succeed, and which one failed, then figure out which one failed.
if you are saying it works for a while, then craps out, it may be you are violating a dropbox rate api, and need to add some time.sleep's between each file.
I did what you said and the Print(entry_path) shows Examples/Calculator.py/Calculator.py
AFAICT that file is not on the iPhone nor is it in the Dropbox backup.
I can replace everything on the iPhone with the Dropbox backup (which is from the iPad) but I don't know of an option in Synchronator to do that.
hmm. you could just try/except around the line throwing the failure you are getting, so at least the valid files get restored.
Do you have an Examples/Calculator.py? | https://forum.omz-software.com/topic/5031/install-synchronator | CC-MAIN-2022-40 | refinedweb | 1,667 | 58.58 |
I am having a form which takes some value as input, and I am processing the input and returning the required output. Now when I tried to display the output it not displaying on the webpage.
The following is my forms.py:
class CompForm(forms.ModelForm):
class Meta:
model = Comp
fields = ('inp',)
def index(request):
form = CompForm(request.POST or None)
context = {
'form': form,
}
print context
if form.is_valid():
...
...
outData = "The values you gave is correct"
errData = "The values you gave is incorrect"
print context
context['outData'] = outData
context['errData'] = errData
print context
return render(request, 'comp/index.html', context)
{% extends "comp/base.html" %}
{% load crispy_forms_tags %}
{% block content %}
<div class="row">
<div class="col-md-8 col-md-offset-2">
<form method="post" action="">
{% csrf_token %}
{{ form|crispy }}
<input class="btn btn-primary" type="submit" name="Submit" />
</form>
</div>
</div>
{% if outData %}
{{ outData.as_p }}
{% endif %}
{% if errData %}
{{ errData.as_p }}
{% endif %}
{% endblock %}
outData
errData
You are trying to called the method
as_p on strings which doesn't make sense.
as_p() is a helper method on form instances to make it easier to render them in the template so you need:
{{ form.as_p }}
you can also use
as_table and
as_ul
You can read more in the documentation | https://codedump.io/share/4OH5DTe99xD9/1/django---template-tags-not-working-properly-after-form-validation | CC-MAIN-2017-04 | refinedweb | 204 | 57.98 |
Package: wnpp Severity: wishlist Owner: "Adeodato Simó" <dato@net.com.org.es> Package name : python-debian Description : python modules to work with Debian-related data formats So, uhm, hi all. I've had this in mind for about a couple weeks now, and I kinda like the idea, but I also wanted to run it by some list, so I'm doing an ITP/RFC. martin f. krafft mentioned yesterday on IRC a similar idea, which prompted me to write this mail. I. The trigger ----------- I've recently started two small projects in Python (debcache and deb2bzr) that deal with quite a bit of Debian-related data . In both, I've ended up with local copies of two fine python modules (authors CC'ed): - debian_support.py by Florian Weimer, available in the secure-testing Subversion repository [1]. The pieces I used were the 'ed-patches support', for updates to Packages files with the pdiff method, and the very sweet Version class, that implements dpkg --compare-versions in Python (but uses python-apt if available). [1] svn://svn.debian.org/secure-testing/lib/python/debian_support.py - deb822.py by dann frazier and John Wright, which has an IPT of its own, #380173. This file provides support for parsing rfc822-like files, with extra goodies like support for continuation lines (e.g. Description), and whitespace-separated-fields-in-fields (e.g. Files section in dsc and changes files). II. The what, and the possible what ------------------------------- The idea is to have a package where stuff like this can be collected: python files coming from different sources that are made available for other packages to depend on. In this scheme, the maintainer does little more than notice updates and upload updated versions (or lets authors do that themselves if they so wish). I'm CC'ing the authors of the two files above to know what they'd think of their module being incuded in the collection, particularly dann and John, who were intending to upload it in a separate package. Another possibility, probably more useful in terms of standardizing a bit programming Debian stuff in python, would be to have some time spent in integrating those files that come from different sources into something consistent, and general enough as to be useful to almost everybody. This, of course, would require that a person with time in their hands, and preferably Python knowledge and Debian insight, would step up to "maintain/write parts of" such integrated library. Like always, I guess all of us would like to use/see such library, but nobody can really commit time to writing it. There must be lots of code out there, though, that'd just need to be put together, I'd say. III. The plan -------- After writing the above, I have a bit more clear what I'd like to do, probably with modifications after receiving input on the list: * upload soonishly a python-debian package with the two files mentioned above, and any others that may get mentioned in the thread. These modules would be available in the "debian_bundle" or "debian.bundle" namespace: `from debian_bundle import deb822`. * if somebody steps up to drive the implementation of that "integrated debian python library", let them take it from there, and transfer maintenance of the above package if they so wish. If not, I'll create a bzr branch somewhere and will wait for code to merge, or for inspiration to write something myself. Will probably also create a mailing list somewhere, to drop a mail when something of interests gets merged in. After a while, either the branch will be dead, or there'll be something interesting in it. If the latter, uploading that to be provided under the "debian" namespace can be discussed, or maybe debian_v0 / debian.v0. Cheers, -- Adeodato Simó dato at net.com.org.es Debian Developer adeodato at debian.org Listening to: Maximilian Hecker - Daylight | https://lists.debian.org/debian-devel/2006/08/msg00274.html | CC-MAIN-2016-07 | refinedweb | 652 | 59.64 |
User:JWSchmidt/Blog/15 September 2008
Contents
My talk[edit]
Near the top of my user talk page it says:
The bad with the good. If you have a complaint about something I have done, please feel free to let me know what is on your mind. I strive to assume good faith and improve my behavior in response to honest criticism. For example, I often like to explore the boundary between what is socially acceptable and what is outrageous. If something I have done upsets you, please let me know. Also, I am sometimes blunt and and terse and my actions might seem needlessly confrontational. Let me know when I "cross the line" and start to disrupt the atmosphere of collaboration rather than support it.
After SB Johnny went out of his way to let me know that he refused to tell me what was on his mind, he told me that this is what was on his mind and that I had requested that page. In fact, what I requested is stated at the top of my user talk page: "Let me know when I 'cross the line' and start to disrupt the atmosphere of collaboration rather than support it." By refusing to use my user talk page to tell me what was on his mind, SB Johnny demonstrated what he means by "It is felt that lesser options than this review have already been exhausted".
When SB Johnny drew my attention to this, I asked him, " now the question is, do you still refuse to discuss things?". The expected answer came as soon as I tried to join the discussion and it was announced that somebody owned that page, and I was not allowed to join the discussion.
My fork[edit]
Since McCormack wouldn't let me edit his page, I've moved to this page. Please feel free to join me for OPEN discussion at the fork page --JWSchmidt 10:26, 15 September 2008 (UTC)
Day 1 Reflections[edit]
So far I have had a chance to read three of the cases and start to respond to them. Below are short summaries...click on the links such as "case 1 details" in order to see more detailed comments from me on each case.
case 1 details. My learning project about deletionism was not appreciated. However, the learning resource was about the idea that Wikiversity should welcome the contributions of new users and help them learn how to edit. Deleting the good faith contributions of new Wikiversity participants is not welcoming. Other people prefer to delete the contributions of new Wikiversity participants and they can often be heard calling such contributions "garbage". I prefer to welcome new users and expand new pages.
case 2 details. Some people wanted to use a Wikipedia deletion template according to Wikipedia rules for deletion. I fixed the template to conform to Wikiversity deletion policy.
case 3 details. There is one Wikiversity participant who does not want to provide a link at the top of the Main Page from the word "students" to the main Wikiversity student portal page. I think Wikiversity should have such a link.
General reflections. The view of Wikiversity provided by Michael, SBJ, Cormac, and McCormack is rather alarming. It is a view of Wikiversity that does not mesh with reality. It will take me many hours to go through the charges and sort them out for the Wikiversity community. At the rate I work, I estimate it will take approximately three weeks to complete this project. I suppose at some point a few people will bother to examine the charges and they will see the extent to which these authors have misrepresented events in order to depict my editing in the worst possible light. It is really quite boring and sickening to participate in this process of answering to these twisted charges. However, I suppose this was inevitably the only way to sort things out at Wikiversity. I hope this process leads to a constructive discussion about the motivation and editing history of McCormack. McCormack has called me troll and I believe he would do anything within his powers to damage me, which largely amounts to putting on public display these twisted cases and charges. Dear reader: this is sickening stuff, but please try to read along. I know most of you care deeply about Wikiversity and that makes it hard to look at a witch hunt taking place within what we hope will become a center for scholarship. I know that some of you have been made uneasy by some of my learning projects. I still request that you discuss with me any issues you have with respect to my editing. Use my talk page. Come to #wikiversity-en and chat (however, see the next paragraph below. Special thanks to those of you who do take the time to talk to me and help develop Wikiversity resources with me. As always, it is a joy to collaborate with you. Eventually this process will end and we can get back to more interesting types of learning projects. Keep learning the wiki way!
UPDATE: I was banned from #wikiversity-en without warning, discussion or a reason given. This ban on my participation in #wikiversity-en is a clear violation of channel ops power. You can still find me in #wikiversity. I was banned from #wikiversity-en by User:SB Johnny who also blocked me from editing Wikiversity in order to prevent me from responding to all the false and distorted charges he made against me. His bad block was eventually overturned by the Wikiversity community, but I remain banned from #wikiversity-en. User:SB Johnny also used his false and distorted charges to attract the attention of a Steward and have my custodianship stripped from me. This was another abuse of his power since there was no reason to remove my custodial status and certainly no community consensus for such a move. As time permits, I will continue to respond to the false and distorted charges that have been made against me. --JWSchmidt 16:04, 19 October 2008 (UTC)
Day 2 Reflections[edit]
I could not really work today because of this. Everything else seems unimportant.
There was an interesting session today in the #wikiversity-en chat channel. Ottava Rima was able to initiate an exchange of views between McCormack and myself. I learned that I had intimidated him by my editing style. I apologized for intimidating him. Hopefully this is a start towards getting us to the point where we can talk things out.
I also had a chance to read Learning from conflict and incivility/Jade Knight. So I started a conversation with User:Jade Knight. Hopefully our dialog will increase mutual understanding. 1, 2, 3, 4.
I again ask that if you have a complaint about something I have done, please feel free to let me know what is on your mind. If you have written about your complaint on some page other than my user talk page, then I probably have not seen it. I really do think it is helpful for people to come talk to me one-on-one when they do not like something I have done. Eventually I will have the chance to read everything here, but it will take a while.
Day 3 Reflections[edit]
Another day during which it is essentially impossible to think and work (see this and this).
While I've only gotten through case #3, I was asked to look at case 34 out of sequence. I was interested to learn that I am "an aggrieved Wikipedian". I feel the need to make another page to add to my collection that includes JWSchmidt is a Troll and Campaign for the inclusion in Wikipedia of religious views expressed as science. "enemies at Wikipedia and the foundation" <-- I demand that the four authors of this charge list my enemies. Other than one banned Wikipedian who has stalked me in real life, I do not know of any such enemies. I invite the Wikiversity community to read this. I spent weeks discussing with Moultan the fact that if he could not give up his interest in the real world identities of wiki users then he would be blocked from editing Wikiversity. I repeatedly asked him not to discuss the real world identities of wiki users while in #wikiversity-en. I will never apologize for my scholarly collaborations and various learning projects I have engaged in with Moulton or any of my other wiki friends. Yes, I have failed to turn Moulton away from his interest in the real world identities of wiki users. I take full responsibility for my failure. I did my best.
Day 4 reflections[edit]
case 4 details. I stand by my position that Wikiversity can decide for itself what is allowed on Wikiversity user pages.
cases 5 & 6. I just noticed that some cases are missing. It makes me wonder what we are not being shown. Given the absurd charges that we have been shown, what must have been in #5 and #6?
case 7 details. I made good faith edits to improve a template.
I've spent a significant amount of time trying to think of ways to both protect the good faith contributions of Wikiversity participants and prevent Wikiversity from filling up with stub pages. I still think that welcome templates are a good start. I recently tried to start some discussion on this idea which involves a special "Training:" namespace where stub pages could be used as learning exercises for Wikiversity participants who are learning how to edit.
I spoke with User:Emesee on IRC channel #wikiversity-en and I thanked him for agreeing to remain as a custodian.
Update. User:Emesee was one of the few Wikiversity custodians to stand up and resist the attacks that have been made on Wikiversity. For his trouble, he had his custodianship stripped away without community consensus. More comments on this sad turn of events can be found at this page. --JWSchmidt 16:11, 19 October 2008 (UTC)
Day 5 reflections[edit]
More bad news. --JWSchmidt 13:33, 19 September 2008 (UTC)
Restart[edit]
I was blocked from editing Wikiversity before I could respond to all of the false and distorted charges that have been made against me in the review. Note: there was never a valid reason for the block. I thank those honorable Wikiversity participants who spoke out against this bad block and who were able to get me unblocked. During the time I was blocked, additional false charges have been made against me. The effort continues to use these false charges to "justify" blocking me from editing, banning me from #wikiversity-en and removing my custodianship status.
At this time, due to real world commitments, I have limited online time. Since my return to editing, I posted some of my thoughts about what is currently happening at Wikiversity at User:JWSchmidt/Blog/10 October 2008. As time permits, I will continue the sickening task of responding to all the false and distorted charges that have been made against me. --JWSchmidt 18:10, 16 October 2008 (UTC)
Please continue this thread at User:JWSchmidt/Blog/19 October 2008. | https://en.wikiversity.org/wiki/User:JWSchmidt/Blog/15_September_2008 | CC-MAIN-2018-09 | refinedweb | 1,876 | 71.14 |
number_display 2.0.1
number_display #
Display number smartly within a certain length.
final display = createDisplay(length: 8); display(-254623933.876) // result: -254.62M
To display data in a width-limited component, this function will smartly help you to convert number to a certain chart length. To be simple, plain, flexible and accurate, the conversion follow this rules:
- result chart length will never overflow length
- replace null, nan or infinity to placeholder
- use locale string with commas ( 1,234,222 ) as possible ( configurable )
- trim number with units ( 1.23k ) when length is limited
- convert scientific notation ( 1.23e+4 ) to friendly form
- no decimal trailing zeros
Usage #
In version 2.* we only export a
createDisplay function for users to custom their
display function. So the real display function has only one input:
value . This separates the configuration and usage, which is more simple and clear.
import 'package:number_display/number_display.dart'; final display = createDisplay( length: 8, decimal: 0, ); print(display(data));
The complete configuration params are listed in the next section .
If the length overflow, the trimming rules in order are:
- omit the locale commas
- slice the decimal by the room left
- trim the integer with number units ( k, M, G, T, P )
- if the
lengthis >= 5, any number can be trimmed within it. If it's less than 5 and input number is too long, display will throw an exception.
Conversion examples:
createDisplay(); null => '' double.nan => '' -123456789.123456789 => '-123.456M' '123456' => '123,456' -1.2345e+5 => '-123,450'
With some configs:
createDisplay( comma: false, placeholder: '--' ); null => '--' 123456 => '123456'
Configurations #
length
( default: 9 )
The max length the result would be. length should no less then 5 so that any number can display ( say -123000 ) after trim.
decimal
( default: 2 )
The max decimal length. Note that this is only a constraint. The final precision will be calculated by length, and less than this param. There will be no decimal trailing zeros.
placeholder
( default: '' )
The result when the input is neither string nor number, or the input is NaN, Infinity or -Infinity. It will be sliced if longer than length param.
comma
( default: true )
Whether the locale string has commas ( 1,234,222 ), if there are rooms.
1.0.0 #
2019-02-07
- Init this package.
1.0.1 #
2019-02-07
- Add some documents.
2.0.0 #
2019-07-30
- Simplify APIs, details in README.md.
- Optimize performance.
- Add unit test.
- Remove decimal trailing zeros.
2.0.1 #
2019-07-31
- Enlarge SDK requirement to ">=2.1.0 <3.0.0".
example/main.dart
import 'package:number_display/number_display.dart'; final display = createDisplay(length: 8); main(List<String> args) { print(display(-254623933.876)); // result: -254.62M }
Use this package as a library
1. Depend on it
Add this to your package's pubspec.yaml file:
dependencies: number_display: :number_display/number_display.dart';
We analyzed this package on Sep 10, 2019, and provided a score, details, and suggestions below. Analysis was completed with status completed using:
- Dart: 2.5.0
- pana: 0.12.21
Platforms
Detected platforms: Flutter, web, other
No platform restriction found in primary library
package:number_display/number_display.dart.
Health suggestions
Format
lib/number_display.dart.
Run
dartfmt to format
lib/number_display.dart. | https://pub.dev/packages/number_display | CC-MAIN-2019-39 | refinedweb | 527 | 52.05 |
Visual Studio developers have enjoyed the speed and consistency of visual designers for controls since the pre-.NET days of Visual Studio. In the world of Microsoft Office Server 2007 Web Part development, developers have no visual designer available for the development of WebParts. This means dynamically loading controls or concatenating a large number of strings in order to render even the simplest controls. (One could also use XSLT, but that discussion is for another day). We are not quite ready to give up the intuitive and speedy development visual designers offer.
Visual Studio does offer the ability to design User Controls, including Web User Controls. But these controls cannot be used as SharePoint WebParts and personally, I want to do just that. This article will introduce the concept of creating distinct components (Web Particles) that together provide the full benefit of SharePoint WebParts while still allowing the use of the familiar and productive visual designers available to Web User Control developers. I refer to these components (tongue in cheek) as "WebParticles" since each one is just a portion of the functionality ultimately provided by the WebPart..
In Visual Studio, create a new ASP.NET Web Application (new web site will NOT work for this exercise). For the project name, enter SmartParticles*.
Since we are developing this part for SharePoint, we will need a reference to SharePoint.dll. If you are developing on a machine having MOSS or SharePoint Services installed, this file is typically located in the %CommonProgramFiles%\Microsoft Shared\Web Server Extensions\12\ISAPI Directory. In my case the expanded path is C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\ISAPI\Microsoft.SharePoint.dll. If you are developing on a machine not having SharePoint or MOSS, you will need to copy this file along with Microsoft.SharePoint.Search.dll and Microsoft.SharePoint.Search.xml from the same directory to a directory on your local computer. In either scenario, select the Microsoft.SharePoint.dll and set a reference to it in your project. Visual Studio will include the proper files in your project output.
Next, add a Web User Control file to your project and name it WebParticleControl.ascx.
In the control designer, add three Textboxes, a drop down Control, a Label and two Buttons as follows:
I also created a table to organize the controls and labels for the text boxes, but that exercise is optional.
Double-click the Submit button to generate the stubbed-out
btnSubmit_Click event handler in the code-behind file (WebParticleControl.ascx.cs). If you cannot see this file, ensure that "Show All Files" is toggled on in Solution Explorer:
In the
btnSubmit_Click event handler, enter this code:
string _response = "Hello {0} {1} from {2}, {3}! Please reset the form!"; string szState = ddlState.SelectedValue; lblResults.Text = string.Format(_response, txtFirstName, txtLastName, txtCity, szState);
Double-click
btnReset to generate the Click handler and enter this code in the
bntReset_Click handler:
txtCity.Text = ""; txtFirstName.Text = ""; txtLastName.Text = ""; ddlState.SelectedIndex = 0;
Next, add a class file to your project named WebParticle.cs.
To summarize this class, it will inherit from the
Microsoft.SharePoint.WebPartPages.WebPart and override the
CreateChildControls and
RenderContents methods to load and render the ASCX Web Control we created in the preceding steps. This class will inherit from the
Microsoft.SharePoint.WebPartPages.WebPart class, so you will need to add the correct
using directive to your namespace or class section.
using Microsoft.SharePoint.WebPartPages;
Set the inheritance of the class to WebPart:
public class WebParticle: WebPart
I have defined two properties which together determine the location from which to load the associated Web Control ASCX file. If you wish to simply inherit from this class, just override these property declarations, one of which defines the source directory and the other defines the filename hosting your control.
protected string UserControlPath = @"~/usercontrols/"; protected string UserControlFileName = @"webparticlecontrol.ascx";
Next, the class will override the
CreateChildControls method to load the Web Control. In this method, the control is loaded from the source file by the Page property inherited from
System.Web.UI.Control via
Microsoft.SharePoint.WebPartPages.WebPart. The Page property allows programmatic access to the underlying ASP.NET Page instance hosting our WebPart in SharePoint.
protected override void CreateChildControls() { try { // load the control ... this could require GAC installation // of your DLL to avoid File.IO permissions denial exceptions _control = this.Page.LoadControl(UserControlPath + UserControlFileName); // add it to the controls collection to wire up events Controls.Add(_control); } catch (Exception CreateChildControls_Exception) { _exceptions += "CreateChildControls_Exception: " + CreateChildControls_Exception.Message; if (AlwaysBubbleUpExceptions) { throw; } }//end catch finally { base.CreateChildControls(); }//end try/catch/finally block }//end protected override void CreateChildControls()
Next, we will override the
RenderContents method which is specific to the
WebPart class from which we inherit. This method was chosen because in the life cycle of SharePoint web pages, by the time this method is called all prerequisite processing will have taken place, including the creating and assignment of SharePoint variables and the
CreateChildControls method. There is no need to call
EnsureChildControls here since child controls will always exist when this method is called by the SharePoint ASP engine.
protected override void RenderContents(HtmlTextWriter writer) { // not much to do here except to programmatically and cleanly // handle exceptions try { base.RenderContents(writer); } catch (Exception RenderContents_Exception) { _exceptions += "RenderContents_Exception: " + RenderContents_Exception.Message; if (AlwaysBubbleUpExceptions) { throw; } } finally { if (_exceptions.Length > 0 && AutoWriteExceptions) { writer.WriteLine(_exceptions); } }//end try/catch/finally }//end protected override void RenderContents(HtmlTextWriter writer)
We are not quite ready to build our class. Since we intend this WebPart and Web User Control to live in Microsoft Office SharePoint Server and the Global Assembly Cache, we will need to assign a Strong Name key and sign the control. In Solution Explorer, right-click the SmartParticles project node and select Properties. The Project Property Pages appear. Select the Signing tab from the choices on the left. Check the "Sign the assembly" box and select <New...> from the "Choose a strong name key file" drop down list.
Enter "SmartParticles.snk" in the "Key file name" field. Uncheck the box marked "Protect my key file with a password" unless, of course, you want to password-protect your key file (not a bad idea).
Click "OK". The SmartParticles.snk Strong Name Key file is added to your project. Now, build the project using the Visual Studio Build menu.
Creating a SharePoint WebPart is relatively simple compared to deploying one. Since we are using the WebParticle approach, we have to deploy both an ASCX file and the compiled DLL that contains the supporting class for the ASCX Web User Control and the class that will actually be the SharePoint WebPart. Here is a summary of what we need to do in order to deploy our WebParticles:
publicKeyTokenproperty of our assembly
SafeControlentries for each of our classes in SharePoint's web.config file
Use the Visual Studio Build menu to build your project.
First you will need to ensure that your target SharePoint web site has an UserControls directory. If not, create it. Then copy the ASCX file from your project directory to your SharePoint UserControls directory.
The Global Assembly Cache (GAC) is a special folder located at %WINDIR%\Assembly where %WINDIR% is the full path to your Windows folder (such as C:\Windows or C:\Winnt). Use Windows Explorer to copy your DLL into the GAC folder.
Remember adding a Strong Name Key to our project? The result of this is that our Assembly is strongly named, meaning is has a Public Key token. Microsoft came up with this strategy to combat "DLL Hell" that used to plague COM/COM+ Developers back in the day. If you've never heard of DLL Hell, it means that Microsoft has done a very good job in their efforts to make our lives easier. I'm not complaining, but there is one more thing they could have done for developers: give us the ability to view our project's public key token directly in Visual Studio. Maybe my next project will be an add-in... Anyway, there are two ways you can discover your DLL's public key token. Since we copied our assembly into the GAC, the public key will be plainly visible to us if we look. Just use Windows Explorer to browse to your C:\Windows\Assembly folder (or %WINDIR%\Assembly if Windows is not installed in the default location). Scroll down and find the SmartParticles assembly:
As you can see, our version information and Public Key Token are plainly visible. Still, you will have to copy it into a text file by hand for our next step. Alternatively, you can use .NET Reflector by Lutz Roeder at to browse to your assembly's DLL file and read out the Assembly information and Public Key Token with no hassles and the ability to cut and paste.
If you built the project with the Strong Name Key included with the source code, you have it easy: just copy the lines below onto your clipboard.
SmartParticles, Version=1.0.0.0, Culture=neutral,PublicKeyToken=8e2900508c69349a
We have two tasks that require this information. First, we must let SharePoint know that our control is Safe. To do this, we will need to edit the web.config file of our SharePoint site. Use your favorite text editor to browse for and open your site's web.config file. You will see a section named "SafeControls" with a number of default entries provided by Microsoft. You will need to add the following entries under "SafeControls":
<SafeControls> ....various Microsoft entries..... <SafeControl Assembly="SmartParticles, Version=1.0.0.0, Culture=neutral, PublicKeyToken=8e2900508c69349a" Namespace="SmartParticles" TypeName="WebParticle" Safe="True"/> <SafeControl Assembly="SmartParticles, Version=1.0.0.0, Culture=neutral, PublicKeyToken=8e2900508c69349a" Namespace="SmartParticles" TypeName="WebParticleControl" Safe="True"/> <SafeControl Assembly="SmartParticles, Version=1.0.0.0, Culture=neutral, PublicKeyToken=8e2900508c69349a" Namespace="SmartParticles" TypeName="*" Safe="True"/> </SafeControls>
Replace the
PublicKeyToken with the token from your assembly (if you did not use the included
StrongNameKey file).
You would think that would be enough but, no, SharePoint still does not know enough about your types to load them. It does not check the SafeControl section until it loads the Assembly using Reflection. First, it must understand how and where to load your assembly. You could place your assembly in your Share Point's bin folder, but then you would have two copies to update each time you built or modified your assembly. Best to leave it in one place, the GAC, and keep things simple. The way to do this is to tell SharePoint about your assembly and the way to do that is to add an assembly reference to the web.config file. Every ASP.NET web.config file has a compilation section, and SharePoint is no exception. Find the compilation section of your SharePoint site's web.config file. Beneath it you will see an assemblies section with at least an entry for SharePoint beneath it. Add a node for your assembly using the same information from the assembly that you discovered earlier:
SmartParticles, Version=1.0.0.0, Culture=neutral, PublicKeyToken=8e2900508c69349a
Here are the entries, replace the public key token if needed.
<compilation batch="false" debug="false"> <assemblies> <add assembly="Microsoft.SharePoint, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" /> <add assembly="SmartParticles, Version=1.0.0.0, Culture=neutral, PublicKeyToken=8e2900508c69349a" /> </assemblies> </compilation>
A WebPart xml file is a very simple, structured text file with the minimum information needed to add your WebPart to the WebPart gallery in SharePoint. Use Visual Studio to add an XML file to your project. Name the file SmartParticles.WebPart:
Paste the following code into your XML file:
<?xml version="1.0" encoding="utf-8" ?> <webParts> <webPart xmlns=""> <metaData> <type name="SmartParticles.WebParticle, SmartParticles, Version=1.0.0.0,Culture=neutral, PublicKeyToken=8e2900508c69349a" /> <importErrorMessage>Cannot import this Web Part.</importErrorMessage> </metaData> <data> <properties> <property name="Title" type="string">SmartParticles Web Part</property> <property name="Description" type="string">A demonstration using WebParticles in a SharePoint WebPart</property> <property name="ChromeType">TitleOnly</property> <property name="ChromeState">Normal</property> <property name="ItemLimit" type="int">15</property> <property name="ItemStyle" type="string">Default</property> </properties> </data> </webPart> </webParts>
WebPart files can be much larger and complex, but this simple file illustrates our simple web part. The sections that are important for our demonstration are the type section and the Title and Description property sections. In the type name section, you must enter the name of your
WebPart class, in this case SmartParticles.WebParticle, followed by the assembly information we have already copied twice into web.config. You can put any strings you want into the Title and Description properties. The string that is in the Title property becomes the default title for your WebPart when it is added to a SharePoint page. Save your changes and close the file.
Next, we need to import (or upload) into SharePoint the WebPart file we created in the previous section. You will need to be a SharePoint administrator to perform this task. If you have a dedicated SharePoint Administrator upon whom you can offload this task, you are lucky. If not, browse to your SharePoint site. Under "Site Actions" select Site Settings, Modify All Site Settings.
On the Site Settings page, under Galleries, click Web Parts
In the Web Part Gallery, click Upload, then Upload Document:
In the form that appears, browse to your Project folder for your SmartParticles.WebPart file, then click Upload to upload it. When it has uploaded, the Web Part Gallery Edit Item page is displayed. You will see (and can change, if you like) the information entered into your WebPart XML file. In the Group section, I recommend added your WebPart to a non-Default group to make it easier to find. There are a lot of WebParts that come with Microsoft Office SharePoint Server 2007 directly out of the box!
When you are done, click "OK". You will be returned to the Web Part gallery where you will see that your part has been installed. It will be decorated with the "New!" splash.
You can now test that your WebPart is installed by clicking its name (as shown in the preceding figure). This will take you to the Web Part Preview page. Here, as the name implies, you can preview your part; you cannot test your Web Part's functionality in the Web Part Preview page. For example, if you click the buttons in the Preview, the page will reload and nothing else will happen. Just thought I would let you know so you wouldn't freak out about it.
If your WebPart blew up or would not install, verify that you followed all of the procedures in order before wailing and gnashing your teeth (or contacting your humble narrator). Don't worry, there is a short, but hopefully effective, troubleshooting guide near the end of this document.
To test or use your WebPart, you will need to add it to a SharePoint page just like you would any other WebPart. This will be very simple since we have added our WebPart to the Web Part Gallery. To summarize:
This is what SharePoint is all about. So easy a caveman user can do it! [would have put a caveman graphic here, but do not like lawyers banging on my doors]
Under site actions, select Edit Page.
Click on a zone and select "Add Web Part". The Add Web Part dialog will be displayed:
Scroll down and find the
SmartParticles Web Part, select it and click "Add". Publish your page so everyone can see it. Your web part will now be fully functional on your SharePoint page.
* Yes, it is a take-off on SmartPart, the excellent tool for SharePoint created by Jan Tielens, et al.
If, like me, you run your Visual Studio from My Documents, when you copy files from this location on an NTFS partition using Copy and Paste in Windows Explorer, you also copy the ACL (Access Control List) with these files. Files in My Documents, including these, are not accessible by SharePoint. When you copy files from this location into your SharePoint site directory if they are both on the same volume (logical drive such as C:\), the permissions will also be copied and SharePoint will not be able to load either the DLL or the ASCX files. You will get the ubiquitous "Access Denied" message in SharePoint which is not very helpful. For more information about ACL copy problems, see. Fortunately, there are a couple of easy workarounds. The easiest is to work on a separate volume such as another hard drive. Alternatively, copy the ASCX to another hard drive and then to your SharePoint directory of choice. You may only want to do this if you are getting the Access Denied error. Then again, better to prevent than solve problems.
Be sure you added an assembly reference to your assembly in Share Point's web.config file. Did you add your assembly to the GAC? If you did both of these things, try adding your assembly to the bin folder of your Share Point site.
Verify that you have added a
SafeControl entry in Share Point's web.config file. See "Access Denied or File.IO Permissions exceptions".
Ensure that this line is present in your Class's
CreateChildControls method.
Controls.Add(_control);
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Answer
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Admin | http://www.codeproject.com/KB/sharepoint/WebParticles.aspx | crawl-002 | refinedweb | 2,896 | 56.15 |
Writing Junit tests for Java classes in Eclipse and Netbeans IDE are super easy, and I will show you with that later in this JUnit tutorial. Before that, let’s revise what is unit test and why should you write them. Unit test is to test smaller unit of code, e.g. methods. Writing unit test to test individual unit of code is one of the best development practice and helps to find bug earlier in development cycle. Though there are other unit testing framework available in Java e.g. TestNG, JUnit has it’s own place among Java developers. IMHO code review and unit testing are two most important practices for improving code quality and should always be followed during software development. Sad thing is that not every developer follows it; some programmer don’t write unit test due to ignorance and others due to laziness. Any way, it’s just start which take time, once you start writing unit tests, you will automatically start enjoying it. I have seen Java developers testing there code with main() method, but now they prefer to test them with JUnit testcases. I agree few initial tests are difficult because of knowledge and inertia and best way to approach is to start with simplest of JUnit tests. In this JUnit tutorial, I will show you how to write and execute JUnit test from Eclipse and Netbeans, two popular Java IDE. By the way, if you are looking for any good book on JUnit and unit testing, you should look Pragmatic Unit Testing in Java with JUnit, it's an amazing book and teaches a lot about both JUnit and unit testing in Java.
JUnit 3 and JUnit 4 testing framework
JUnit frameworks is popular from quite a sometime now and there are two popular versions available in form of JUnit 3.8, known as JUnit 3 and JUnit 4. Working of both versions are same, as you create testcases, testsuite and execute them. Main difference between JUnit 4 and JUnit 3 is that, JUnit4 is based on annotation feature of Java 1.5 and easy to write, while JUnit 3 uses “test” keyword, to identify test methods. What is bonus in terms of writing JUnit tests for Java program is that, two of most popular Java IDE, Eclipse and Netbeans has inbuilt support and provides easy interface and infrastructure to create and execute JUnit tests for Java classes. In this JUnit 4 tutorial, we will see step by step guide for writing JUnit test in Eclipse and Netbeans with simple example of Calculator. Our Calculator class has methods add() and multiply() for addition and multiplication, I have used variable arguments of Java 1.5 to implement these methods, so that they can accept any number of parameter.
How to write JUnit tests in Eclipse
1. Create a New Java Project called JUnitExample.
2. Create a Java class Calculator in project which should have add() and multiply() method.
3. Right click on Java class and click on create Junit testcase
How to execute JUnit tests in Eclipse
Right Click --> Run As --> Junit Test
This will run all the JUnit tests declared in this class and will pass if all the test run successfully and pass the condition tested by various assert statement and fail if any of JUnit tests failed. Eclipse will print stack trace and hyper link to the failed test and you can go and fix the problem.
Why.
How to write JUnit tests in Netbeans
Junit support in Netbeans is also great and seamless. Here is the steps to create JUnit test in Netbeans
1. Create a New Java Project called JUnitExample.
2. Create a Java Class Calculator in project which should have add() and multiply() method.
3. Now Select a Java Class --> Right click --> Tools --> Create Junit tests
this will create Junit test class for all the methods of selected Java class.
How to execute Junit tests in Netbeans
Executing JUnit tests in Netbeans is much simpler than it was in Eclipse. Go to your Junit test class and right click and select run File option. This will execute all the JUnit tests on File and show the result in console. As earlier test will be pass if all test method passes otherwise it will fail. Netbeans also shows complete stack trace and hyperlink of failed test cases.
Code
Here is complete code example of, How to write unit test in Java using JUnit framework. In this example, we have a Java class called Calculator, which has two methods add() and multiply() and takes variable arguments. In this JUnit tutorial, we will write JUnit testcases, to test these two methods.
/**
* Simple Java Calculator with add and multiply method
*/
public class Calculator {
public int add(int... number) {
int total = 0;
for (int i : number) {
total += i;
}
return total;
}
public int multiply(int... number) {
int product = 0;
for (int i : number) {
product *= i;
}
return product;
}
}
Following class CalculatorTest is our JUnit test class, it contains two methods testAdd() and testMultiply(). Since we are using JUnit 4, we don’t need to use prefix test, but I have used that to make test methods explicit. @Test annotation is used by JUnit 4 framework to identify all test cases. If you are new to JUnit 4, then see this post to learn more about JUnit 4 annotations. By the way when we run this class as JUnit Test, it will show how many test cases pass and how many failed. If all the test cases pass then it will show green bar, otherwise red bar to indicate failure.
import static org.junit.Assert.*;
import org.junit.Test;
/**
* JUnit Test class for testing methods of Calculator class.
*/
public class CalculatorTest {
@Test
public void testAdd() {
Calculator calc = new Calculator();
assertEquals(60, calc.add(10,20,30));
}
@Test
public void testMultiply() {
Calculator calc = new Calculator();
assertEquals(6000, calc.multiply(10,20,30));
}
}
That’s all on How to write unit test in Java using JUnit framework in Eclipse and Netbeans. JUnit testing framework is is very useful for writing and executing unit test for Java classes and it can also be integrated into build system by using ANT and Maven, which means you can all your tests automatically at build time. By the way since many project have there JUnit test running during build process, it’s good to keep unit test short and quickly executable to avoid lengthy build. See JUnit best practices guide more unit testing practices. Also start using Junit 4 annotations, they have made job of writing unit tests much easier.
Recommended Book: Pragmatic Unit Testing in Java with JUnit
Recommended Book: Pragmatic Unit Testing in Java with JUnit
16 comments :
Very interesting articles, I've read them for a while and I've learned a lot of useful things and tricks.
I think a mistake has slipped into this one; please check the test for multiply method, is calling the add method instead of multiply.
@Anonymous, good catch :), it should call multiply method, correct now.
Testing with main method is not a bad idea either, but yes it doesn't tell whether you test is successful or not, until you use assertion provided by JDK.
Not sure if you have intentionally done this to find the error in junit test case, but shouldn't product be initialized to 1 instead of 0 in multiply() method ?
I am looking for a unit test case which tests the program which is written for reading HTML from any website and save it to any file(.txt).
Can you help?
How to create suite of Unit test in JUnit 4 verison?
Should be this.
0*10*20*30 is still a goddamn zero.
public int multiply(int... number) {
int product = 1;
for (int i : number) {
product *= i;
}
return product;
}
Right. In multiply must product = 1
?? | http://javarevisited.blogspot.com/2013/03/how-to-write-unit-test-in-java-eclipse-netbeans-example-run.html?showComment=1362256114659 | CC-MAIN-2015-35 | refinedweb | 1,309 | 61.46 |
I have been editing on a sound wave recently and found it interesting to see the visualization of the sounds that are part of the waveform. We have all made mp3 players that showed the waveform live like so:
I would like to be able to show the spectral display as the sound is playing and have it move in the background. This is from Adobe Audition and it does not support follow the cursor. The cursor moves from left side of the screen to the right side of the screen.
I want the cursor to stay locked in the center of the screen and the spectral display (red background) to move from right to left as the sound is played back.
Before I reinvent the wheel is there an app that does this (free - this is for a single video)? If not is there an AS3 library or project that already does this? In the past you could throw a mouse at your office and hit a guy who wrote a sound visualizer.
If nothing is out there anyone want to help code this?
I'm not sure I understand the effect you want to achieve
is it something like that ?
see Andre Michelle's Sound Spectrumsources are available:
There are two things I'm trying to do: Display the sound wave spectrum in real time and have it scroll by (so I have to read ahead a bit).
Here is an example. The sound is playing back but I am manually using the scroll bar to keep the cursor in the same place (not doing a very good job of it).
The top half of the screen is the form of the sound wave in time (green). The bottom half is the spectral frequency display (red). I am interested in reading a sound wave and displaying that area in real time.
How I understand spectral frequency area is that the bright red shows the concentration of the sound wave. The top on the vertical scale is the high frequency and the bottom is the low frequency. The faster the frequency of the sound wave the higher the pitch. The slower the sound wave frequency the lower the pitch.
I know you know this but for someone else sound is simply the vibration of pressure through a medium such as air or water.
Thanks for the link. I'll take a look.
OK I've kind of got something working. The code gave me a starting point but most of the work is done by compute spectrum. Here is what I've got so far:
It's pretty rough. Notes below code.
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx=""
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:
<fx:Script>
<![CDATA[
import mx.events.FlexEvent;
import mx.events.ResizeEvent;
import mx.utils.ColorUtil;
private var sound: Sound;
private var soundChannel: SoundChannel;
private var bytes: ByteArray;
private var peaks: BitmapData;
private var displace: Matrix;
private var rect: Rectangle;
public var soundArray:Array = [];
public var peakBitmap:Bitmap;
public var isPlaying:Boolean;
protected function windowedapplication1_applicationCompleteHandler(event:FlexEvent):void
{
sound = new Sound();
sound.addEventListener( IOErrorEvent.IO_ERROR, onIOError );
sound.load( new URLRequest( 'song1.mp3' ) );
soundChannel = sound.play(0, 100);
isPlaying = true;
bytes = new ByteArray();
peaks = new BitmapData( stage.stageWidth, stage.stageHeight, false, 0xFFFFFFFF);
rect = new Rectangle(0, 0, width, height);
peaks.fillRect(rect, 0x0);
displace = new Matrix();
//displace.tx = 2;
//displace.ty = -1;
rect = new Rectangle( 0, 0, 1, 0 );
peakBitmap = new Bitmap( peaks ) ;
component.addChild( peakBitmap );
stage.addEventListener( Event.ENTER_FRAME, onEnterFrame );
stage.addEventListener( KeyboardEvent.KEY_UP, windowedapplication1_keyUpHandler);
}
private function onEnterFrame(event:Event):void {
var value:Number;
var values:Array = [];
var xPosition:int;
var yPosition:int;
var color:uint;
var centerX:int;
var maxDisplayWidth:int= 100;
if (peaks.height!=height || peaks.width!=width) {
rect = new Rectangle(0, 0, width, height);
peaks.fillRect(rect, 0x0);
}
SoundMixer.computeSpectrum(bytes, true, 0);
// get current sound values
for (var i:int; i < 256 ; i++ ) {
value = bytes.readFloat();
if (value>1) {
// value is supposed to be -1 to 1 and it's showing 1.28...??
}
values.push(value);
}
centerX = width/2;
//peaks.lock();
xPosition = centerX;
peaks.scroll(-1,0);
// draw sound sample - vertical position
for (var j:int; j < 256; j++) {
value = values[j];
yPosition = height+-j;
if (value==0) {
color = 0;
}
else {
color = ColorUtil.adjustBrightness2(0xFF0000, value*100);
}
peaks.setPixel(xPosition, yPosition, color);
}
}
private function onIOError( event: IOErrorEvent ): void
{
}
protected function component_resizeHandler(event:ResizeEvent):void
{
rect = new Rectangle(0, 0, width, height);
if (peaks) {
peaks.fillRect(rect, 0x0);
}
}
protected function windowedapplication1_keyUpHandler(event:KeyboardEvent):void
{
if (event.keyCode==Keyboard.SPACE) {
if (!isPlaying) {
sound.play(0);
isPlaying = true;
trace("play");
}
else {
soundChannel.stop();
isPlaying = false;
trace("stop");
}
}
}
]]>
</fx:Script>
<mx:UIComponent
</s:WindowedApplication>
Notes: * It doesn't show the nice gradient from red to white. It appears to be mostly all red or white. * It only shows left channel* It does not fill the height of the view* It app is resized it breaks* It is scrolling the pixels off the screen. What concerns is there on long duration sounds?* The sound values are sometimes above 1.0 when the values from computeSpectrum should be between -1.0 to 1.0??? Consistent values around 1.28...* There's no zoom support or increase of levels
Edit: If I change the stretch factor to 2 (computeSpectrum) and increase the frame rate I can get a larger view with more updates but at a lower quality (gif is really compressed). | https://discuss.as3lang.org/t/as3-sound-visualizer-app-or-code/1298 | CC-MAIN-2018-51 | refinedweb | 911 | 67.35 |
We saw
over a decade ago
(my goodness I've been doing this way too long)
that the
AdjustWindowRect and
AdjustWindowRectEx functions
do not take menu wrapping into account because they don't
take a window handle parameter,
so they don't know what menu to test for wrapping.
Still, they are useful functions if you aren't worried about
menu wrapping
because they let you do window size calculations without
a window handle (say, before you create your window).
But those functions take a proposed client rectangle and return the corresponding non-client rectangle by inflating the rectangle by the appropriate borders, caption, scroll bars, and other non-client goo. But how do you go the other way? Say you have a proposed window rectangle and you want to know what client rectangle would result from it?
AdjustWindowRect and
AdjustWindowRectEx can do that too.
You just have to apply a negative sign.
The idea here is that we use the
AdjustWindowRectEx
function to calculate how much additional non-client area gets
added due to the styles we passed.
To make the math simple, we ask for a zero client rectangle,
so that the resulting window is all non-client.
We pass in the empty rectangle represented by the dot in the middle,
and the
AdjustWindowRectEx expands the rectangle
in all dimensions.
We see that it added ten pixels to the left, right, and bottom,
and it added fifty pixels to the top.
(Numbers are for expository purposes.
Actual numbers will vary.)
From this we can perform the reverse calculation: Instead of expanding the rectangle, we shrink that the top and left are subtracted, so that the two negative signs cancel out.
That doesn't sound like the function doing the inversion…
@henke37
My psychic commenting powers tell me you're engaging in pedantry.
@xor88 But then your helper function has to perform memory allocation. In C# one doesn't care about memory ownership (i.e. who is responsible for deleting it), but in C one must. It is beneficial for simple helper methods to not participate in the management of memory. In this case memory management is left to the caller.
The C version could return a copy without performing memory allocation, by returning the struct by value. In C++ you even have the return value optimization, which eliminates the copy on return (and I believe the copy from the return value into a new stack object can also be elided). In this case the copy would have only been four words anyway.
Of course this isn't always a solution. If you have a bigger structure, the function is being called in a tight loop, and the RVO doesn't save you (e.g. if you're updating an existing object instead of creating a new one on the stack), then returning by value may not be sensible. In this particular case these are unlikely to apply to any caller, but we'd need a time machine anyway.
The RECT functions typically accept separate input and output parameters. Here's a more idiomatic implementation:
BOOL UnadjustWindowRectEx(
_Out_ LPRECT pShrunk,
LPCRECT pOriginal,
DWORD dwStyle,
BOOL fMenu,
DWORD dwExStyle)
{
RECT rc;
SetRectEmpty(&rc);
BOOL fRc = AdjustWindowRectEx(&rc, dwStyle, fMenu, dwExStyle);
if (fRc) {
pShrunk->left = pOriginal->left – rc.left;
pShrunk->top = pOriginal->top – rc.top;
pShrunk->right = pOriginal->right – rc.right;
pShrunk->bottom = pOriginal->bottom – rc.bottom;
}
return fRc;
}
This would (equally idiomatically) be called by passing the same pointer to the first two args:
RECT rc = …;
// shrink rectangle
if (!UnadjustWindowRectEx(&rc, &rc, …)) { … }
// rectangle is now shrunk
This makes it clear that no memory is being allocated, and that the RECT is being modified in-place. It does place a burden on the called function not to read from the input after it's written to the output, since they might be the same RECT!
> The RECT functions typically accept separate input and output parameters
A counterexample to this general trend is AdjustWindowRectEx itself, which takes a single input/output parameter. So it makes sense for UnadjustWindowRectEx to do the same.
I bet TCM_ADJUSTRECT was invented after developers learned (from AdjustWindowRect) that opposite operation also sometimes needed.
So…. we're taking this interesting tidbit of math as a chance to observe that two different languages, with different expectation of how memory is handled, end up with different "best practices" and that neither is a good fit for the other. Better late than never, I suppose.
> We saw over a decade ago (my goodness I've been doing this way too long)
Then this is probably a good time to say thank you for ten years of consistent and consistently high quality writing. I can only hope that Microsoft sees the immense value in your blog archives (as well as others at Microsoft) and ensures it stays online and available even long after you stop writing.
Coincidentally, Eric Lippert also just celebrated (perhaps "recognized" is a better word!) his 10th anniversary of blogging. Both of you are fantastic writers and your sites a pleasure to read. Thank you!
Having used C# for years in a functional style, viewing idiomatic C is quite a contrast. In C# I'd probably have created a new rectangle and returned directly that expression, or put it into a fresh variable. I wouldn't have modified *prc or overwritten it.
Even if I had wanted to use the return-value-by-out-param style I'd have create a fresh rect and assigned it to *prc instead of mutating its members.
> We saw over a decade ago (my goodness I've been doing this way too long)
Which means that you've been part of my daily routine for 10 years as I haven't missed a single article since… wow, that's a weird thought! Can't imagine the withdrawal symptoms should you ever decide to stop… so cheers for the next 10 years :-)
But what if the window manager one day decides to use different styles of window decoration for different window sizes? E.g., it could place the title bar on the side for very narrow windows. Or the close button in the center if the window is exactly square. Then your UnadjustWindowRectEx would be wrong.
The other approach is to simply create a window of the desired size and style and use ClientToScreen and GetClientRect on it.
@Sven2: "Then your UnadjustWindowRectEx would be wrong."
Then wouldn't AdjustWindowRectEx return the correct coordinates for the "new" style? If so, then I fail to see how the Unadjust code would be wrong.
@Brian_EE
I think Sven was saying that different styles might be used – so the non-client area for a square, 0x0 window may have a different "shape" (be narrower or wider, in general) than the non-client area for a window of whatever size was passed to UnadjustWindowRectEx.
@Damien: In the same way Windows doesn't support transactions for the file system any longer, Windows doesn't support transactions for the windowing system either. Windows does never guarantee that the border size and other system global decoration settings hasn't changed between the AdjustWindowRect* and CreateWindows* functions calls.
>Note that the top and left are subtracted, so that the two negative signs cancel out.
Dear Raymond, happy to read your article.
This way of representing the geometry of the window, I also think the best.
So use myself in my native utilities for many years, here are the screenshots for examples:…/htspy.png (see "w-cl: [3,22, -3, -3]"),…/printlayered.jpg (see "rtdif: [4,23, -4, -4]"). | https://blogs.msdn.microsoft.com/oldnewthing/20131017-00/?p=2903 | CC-MAIN-2017-34 | refinedweb | 1,265 | 61.77 |
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.
All other parts:
Part 2 use Preload/Prefetch to boost load time
Part 4 Image optimisation
Part 5 Web font optimisation
Time to see what we can do for our old friend JavaScript. So let’s begin.
With more and more hosting providers supporting HTTP/2, it’s becoming a good time to switch to this protocol instead and benefit from its multiplexed nature. What it means in terms of performance is that we don’t need to bundle all of our JavaScript into large bundles to reduce the number of calls to server.
With HTTP/2 designed to handle large number of requests, you can now increase the number of files required to render the page. Not too much tho:
Too much of a good thing is a bad thing.
As I mentioned before, JavaScript, like CSS is a render blocking element. This simply means the browser needs to wait for it to load and execute before it can parse the rest of the
HTML document.
This hugely increases our First Meaningful Pain. In order to fix this issue we can use two of the features which are not used by many people but are very effective.
When you use a
<script> to load a JavaScript file, it interrupts the parsing of the document. Browser fetches the resource, executes this and then continues on paring:
Asyncattribute
The
Async attribute is used to indicate that this resource can be executed asynchronously. The parsing doesn’t need to be halted, it can be done right after the resource is fetched from network and is ready.
<script async
This attribute can be used only on external JavaScript files. The file would be downloaded in parallel and once the download is finished, the parsing is paused for the script to be executed:
Deferattribute
The
Defer attribute is used to tell the browser to execute this script after parsing the whole document.
<script defer
Like
Async this file gets downloaded in parallel but the execution only happens when the whole
HTML document is parsed:
At the end remember to put all of your
script tags right at the end of the
body to prevent more delay in parsing your
HTML.
As for the browser support, fortunately these attributes are fully supported by all of the major ones.
Most of the modern sites will bundle all of their JavaScript into one, resulting in an increase in load time and suffering from load performance.
Code splitting allows you to split your application code into separate chunks and lazy load them when needed. This also means minimum required code to client and improve the page load time.
You can split your code in three areas:
Vendor code like Angular, React, moment, etc. can be separated from your main code. Webpack has full support for this and other methods. This technique allows you to have better control over cache invalidation of your bundles whenever your app or vendor code changes independently of one another.
This is something every app should do.
This technique separates your code by entry points in your app. These points are where bundlers like webpack start from, when they build a dependency tree of your app.
This is bar far the easiest way to split code, but it is manual and has some pitfalls:
This technique is not suitable for when you have client side routing or when you have a mix of server side rendering and a single page app.
Separate code when dynamic
import are used. This is the best option for single page applications. Having different modules for different routes in your SPA is an example of this.
This is one of many times when you hear me say it depends (I am a consultant after all 😉). If your app has many routes with isolated functionality and heavily uses frameworks and libraries, this answer is most probably YES.
However, it is up to you to decide whether you need it or not by your own understanding of your app structure and code.
If you use
npm or other package management systems for your dependencies, then you will have a lot of extra and unneeded files in your buid folder.
When using a framework or a library, make sure you investigate wether they have separate modules you can import and if yes, only import what you need.
For instance, let’s assume you are using underscore, but only use
groupBy,
shuffle, and
partition. Most people import the whole library like this:
import * as _ from 'underscore'
Instead of this, you could just import what you need:
import { groupBy, shuffle, partition, } from 'underscore'
This way you only bring what your need and the bundlers will take care of the rest for you. Your total package size and as a result your page load time will decrease.
Ok, enough about the size, let’s see where else we can improve our performance.
Many times you have to add an event listener to do something, like listening to page scroll. Then we forget that the listener fires every time the event is triggered.
window.addEventListener('scroll', function() { console.log('page scrolled') })
In the above example, the message is printed into console whenever you scroll. Imagine you have some heavy operation in that callback function, this would turn into a big performance bottleneck.
If you can’t remove that event listener and use a different approach, then you can use either
debounce or
throttle to alleviate the situation.
This feature enforces a function call to not happen until some time has passed since it’s last call. For example, call the function if 100 millisecond has passed from it’s last call.
Look at this implementation from underscore:
const debounce = (func, delay) => { let inDebounce return function() { const context = this const args = arguments clearTimeout(inDebounce) inDebounce = setTimeout( () => func.apply(context, args), delay ) } }
Now we can debounce our event listener for every 100 millisecond:
var efficientScrollListener = debounce( function() { console.log('page scrolled') }, 100 ) window.addEventListener( 'scroll', efficientScrollListener )
Throttling is similar to debounce but different since it will enforce the maximum number of times a function can be called over a period of time. For example execute this function once every 100 millisecond.
Here is a simple implementation:
const throttle = (func, limit) => { let inThrottle return function() { const args = arguments const context = this if (!inThrottle) { func.apply(context, args) inThrottle = true setTimeout( () => (inThrottle = false), limit ) } } }
Now we can throttle our scroll event listener:
var efficientScrollListener = throttle( function() { console.log('page scrolled') }, 100 ) window.addEventListener( 'scroll', efficientScrollListener )
I hope I have given you enough information on just some of the areas you can focus to improve your applications performance when using JavaScript. If you would like to have other topics covered please comment below and I will add them here or in another post.
And as always don’t forget to share the ❤️. | https://yashints.dev/blog/2018/10/12/web-perf-3/ | CC-MAIN-2019-22 | refinedweb | 1,142 | 60.75 |
Open File Action
By Geertjan-Oracle on Aug 20, 2012
Let's create a simple NetBeans Platform application for opening files. We assume we need an "Open File" action, rather than using the Favorites window to open files, which would work just as well, if not better.
- Use the NetBeans Platform Application template in the New Project dialog to create a skeleton NetBeans Platform application.
- Add a new module and set dependencies on Datasystems API, File System API, Lookup API, Nodes API, UI Utilities API, and Utilities API.
- In the new module, define the class below:
import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.File; import org.openide.awt.ActionID; import org.openide.awt.ActionReference; import org.openide.awt.ActionRegistration; import org.openide.cookies.OpenCookie; import org.openide.filesystems.FileChooserBuilder; import org.openide.filesystems.FileUtil; import org.openide.loaders.DataObject; import org.openide.loaders.DataObjectNotFoundException; import org.openide.util.Exceptions; import org.openide.util.NbBundle.Messages; @ActionID(category = "File", id = "org.mycore.OpenFileAction") @ActionRegistration(displayName = "#CTL_OpenFileAction") @ActionReference(path = "Menu/File", position = 10) @Messages("CTL_OpenFileAction=Open File") public final class OpenFileAction implements ActionListener { @Override public void actionPerformed(ActionEvent e) { //The default dir to use if no value is stored File home = new File(System.getProperty("user.home")); //Now build a file chooser and invoke the dialog in one line of code //"user-dir" is our unique key File toAdd = new FileChooserBuilder("user-dir").setTitle("Open File"). setDefaultWorkingDirectory(home).setApproveText("Open").showOpenDialog(); //Result will be null if the user clicked cancel or closed the dialog w/o OK if (toAdd != null) { try { DataObject.find(FileUtil.toFileObject(toAdd)). getLookup().lookup(OpenCookie.class).open(); } catch (DataObjectNotFoundException ex) { Exceptions.printStackTrace(ex); } } } }
- Add the "image" module, which is in the "ide" cluster, in the Libraries tab of the application's Project Properties dialog.
Run the application. Choose File | Open File and then browse on disk to the files of your choice. Depending on whether you have support for the related file type, e.g., you're able to open image files because of the "image" module added above, the file will open in the application's editor mode.
Read this related blog entry for a different approach!
How do you combine this with your own FileType (e.g. AbcFileType) so that the file selected is opened in an appropriate editor, your own?
Håkan
Posted by guest on April 02, 2013 at 12:38 PM PDT #
Hi Hakan, the file should automatically open in your own editor. Nothing needs to be done for that. Go to the New File dialog, select your file on disk, and then it will be opened in the editor you created for it.
Posted by Geertjan on April 15, 2013 at 02:09 PM PDT #
Hi!, thank for your post
please, I have a problem loading xml-file "java.lang.IllegalArgumentException: We expect CloneableEditorSupport in org.openide.nodes.FilterNode$FilterLookup@106d267"
Posted by Javier on May 22, 2014 at 03:45 PM PDT #
Hi Javier,
I just got the same error message.
The solution is to add the "XML Multiview Editor" module to your platform app project.
right click on your platform app project -> properties -> libraries -> ide -> check XML Multiview Editor -> clean and build
Nico
Posted by guest on May 30, 2014 at 02:52 PM PDT #
BTW: this class is not necessary at all.
Add the User Utilities module in the ide section and you have an image viewer without a single line of code.
Nico
Posted by Nico on May 30, 2014 at 02:57 PM PDT # | https://blogs.oracle.com/geertjan/entry/open_file_action | CC-MAIN-2016-44 | refinedweb | 592 | 50.94 |
Greetings to all!
Faced with the problem of passing user events to the child element. I want to pass it through the attributes method, but it refuses to digest it
If you shove events directly into the template, the button also refuses to work
Greetings to all!
Faced with the problem of passing user events to the child element. I want to pass it through the attributes method, but it refuses to digest it
If you shove events directly into the template, the button also refuses to work
Welcome to the Vue Forum, @Flareon!
Your BaseButton isn’t emitting the click up to its parent. Try this:
// Basebutton.vue <template> <button @ ....
Perhaps a better way is to automatically pass ALL events back up to the parent:
// Basebutton.vue <template> <button v- ....
You can emit it to Root and listen to the event in the parent example in child you use this.$root.$emit(‘eventName’) and in parent this.$root.$on(‘eventName’)
or you can use the boring way by emiting like this in child this.$parent.$parent.$emit(‘eventName’)
or you can first emit the value to your first parent and again emit the value from the first parent to its above parent like in child this.$emit(‘eventName’,value) and in parent1 you do this.$on(‘eventName’,functio(val){
this.$emit(‘eventName1’,val)
}) and recieve it iin parent2 like this this.$on(‘eventName1’,function(val1){
console.log('recieved value is: ',val1)
})
You can use a simple event.bus and pass the event
Read this:
But depending on your use perhaps using Vuex… all depends.
make a simple event bus…
import Vue from 'vue' export const EventBus = new Vue()
and in component
this.$bus.on(do something)
Thank you!
I was really worried about the fact that when issuing a click on a button and passing it to TodoListItem, and then to TodoList, two click events occurred in the debugger.
However, your third method allowed only one event to be triggered. It’s wonderful!
I’m going to read more about $listeners. And I’m sorry for my English.
No worries…
Not 100% sure so you might need to find out but you can use a hook like beforeDestroy() or what ever to destroy the listener
bus.$off();
As far as I know, event bus is discouraged.
There’s another alternative, in case of nested components, which doesn’t need event emision passthrough nor an event bus: to provide a method from the grandparent and inject it to the grandchild. The grandchild will have access to this method in which data from the grandparent will be modified.
Two things to consider:
This is an example I made. I use a counter, which in reality is app state and in real world should be managed by Vuex, but imagine it represented something related to components instead, such as a flag to open/close a slide: | https://forum.vuejs.org/t/how-do-i-pass-an-event-to-two-parents-up/111901 | CC-MAIN-2022-05 | refinedweb | 484 | 64.91 |
Details¶
support for simple lists as mapping keys by transforming these to tuples
!!omapgenerates ordereddict (C) on Python 2, collections.OrderedDict on Python 3, and
!!omapis generated for these types.
Tests whether the C yaml library is installed as well as the header files. That library doesn’t generate CommentTokens, so it cannot be used to do round trip editing on comments. It can be used to speed up normal processing (so you don’t need to install
ruyamland
PyYaml). See the section Optional requirements.
Basic support for multiline strings with preserved newlines and chomping ( ‘
|’, ‘
|+’, ‘
|-’ ). As this subclasses the string type the information is lost on reassignment. (This might be changed in the future so that the preservation/folding/chomping is part of the parent container, like comments).
anchors names that are hand-crafted (not of the form``idNNN``) are preserved
merges in dictionaries are preserved
adding/replacing comments on block-style sequences and mappings with smart column positioning
collection objects (when read in via RoundTripParser) have an
lcproperty that contains line and column info
lc.lineand
lc.col. Individual positions for mappings and sequences can also be retrieved (
lc.key('a'),
lc.value('a')resp.
lc.item(3))
preservation of whitelines after block scalars. Contributed by Sam Thursfield.
In the following examples it is assumed you have done something like::
from ruyaml import YAML yaml = YAML()
if not explicitly specified.
Indentation of block sequences¶
Although ruyaml doesn’t preserve individual indentations of block sequence items, it does properly dump:
x: - b: 1 - 2
back to:
x: - b: 1 - 2
if you specify
yaml.indent(sequence=4) (indentation is counted to the
beginning of the sequence element).
PyYAML (and older versions of ruyaml) gives you non-indented scalars (when specifying default_flow_style=False):
x: - b: 1 - 2
You can use
mapping=4 to also have the mappings values indented.
The dump also observes an additional
offset=2 setting that
can be used to push the dash inwards, within the space defined by
sequence.
The above example with the often seen
yaml.indent(mapping=2, sequence=4, offset=2)
indentation:
x: y: - b: 1 - 2
The defaults are as if you specified
yaml.indent(mapping=2, sequence=2, offset=0).
If the
offset equals
sequence, there is not enough
room for the dash and the space that has to follow it. In that case the
element itself would normally be pushed to the next line (and older versions
of ruyaml did so). But this is
prevented from happening. However the
indent level is what is used
for calculating the cumulative indent for deeper levels and specifying
sequence=3 resp.
offset=2, might give correct, but counter
intuitive results.
It is best to always have
sequence >= offset + 2
but this is not enforced. Depending on your structure, not following
this advice might lead to invalid output.
Inconsistently indented YAML¶
If your input is inconsistently indented, such indentation cannot be preserved. The first round-trip will make it consistent/normalize it. Here are some inconsistently indented YAML examples.
b indented 3,
c indented 4 positions:
a: b: c: 1
Top level sequence is indented 2 without offset, the other sequence 4 (with offset 2):
- key: - foo - bar
Positioning ‘:’ in top level mappings, prefixing ‘:’¶
If you want your toplevel mappings to look like:
library version: 1 comment : | this is just a first try
then set
yaml.top_level_colon_align = True
(and
yaml.indent = 4).
True causes calculation based on the longest key,
but you can also explicitly set a number.
If you want an extra space between a mapping key and the colon specify
yaml.prefix_colon = ' ':
- : 23445 # ^ extra space here - : 944
If you combine
prefix_colon with
top_level_colon_align, the
top level mapping doesn’t get the extra prefix. If you want that
anyway, specify
yaml.top_level_colon_align = 12 where
12 has to be an
integer that is one more than length of the widest key.
Document version support¶
In YAML a document version can be explicitly set by using:
%YAML 1.x
before the document start (at the top or before a
---). For
ruyaml x has to be 1 or 2. If no explicit
version is set version 1.2
is assumed (which has been released in 2009).
The 1.2 version does not support:
sexagesimals like
12:34:56
octals that start with 0 only: like
012for number 10 (
0o12is supported by YAML 1.2)
Unquoted Yes and On as alternatives for True and No and Off for False.
If you cannot change your YAML files and you need them to load as 1.1
you can load with
yaml.version = (1, 1),
or the equivalent (version can be a tuple, list or string)
yaml.version = "1.1"
If you cannot change your code, stick with ruyaml==0.10.23 and let me know if it would help to be able to set an environment variable.
This does not affect dump as ruyaml never emitted sexagesimals, nor octal numbers, and emitted booleans always as true resp. false
Round trip including comments¶
The major motivation for this fork is the round-trip capability for comments. The integration of the sources was just an initial step to make this easier.
adding/replacing comments¶
Starting with version 0.8, you can add/replace comments on block style collections (mappings/sequences resuting in Python dict/list). The basic for for this is:
from __future__ import print_function import sys import ruyaml yaml = ruyaml.YAML() # defaults to round-trip inp = """\ abc: - a # comment 1 xyz: a: 1 # comment 2 b: 2 c: 3 d: 4 e: 5 f: 6 # comment 3 """ data = yaml.load(inp) data['abc'].append('b') data['abc'].yaml_add_eol_comment('comment 4', 1) # takes column of comment 1 data['xyz'].yaml_add_eol_comment('comment 5', 'c') # takes column of comment 2 data['xyz'].yaml_add_eol_comment('comment 6', 'e') # takes column of comment 3 data['xyz'].yaml_add_eol_comment('comment 7', 'd', column=20) yaml.dump(data, sys.stdout)
Resulting in:
abc: - a # comment 1 - b # comment 4 xyz: a: 1 # comment 2 b: 2 c: 3 # comment 5 d: 4 # comment 7 e: 5 # comment 6 f: 6 # comment 3
If the comment doesn’t start with ‘#’, this will be added. The key is the element index for list, the actual key for dictionaries. As can be seen from the example, the column to choose for a comment is derived from the previous, next or preceding comment column (picking the first one found).
Config file formats¶
There are only a few configuration file formats that are easily readable and editable: JSON, INI/ConfigParser, YAML (XML is to cluttered to be called easily readable).
Unfortunately JSON doesn’t support comments, and although there are some solutions with pre-processed filtering of comments, there are no libraries that support round trip updating of such commented files.
INI files support comments, and the excellent ConfigObj library by Foord and Larosa even supports round trip editing with comment preservation, nesting of sections and limited lists (within a value). Retrieval of particular value format is explicit (and extensible).
YAML has basic mapping and sequence structures as well as support for ordered mappings and sets. It supports scalars various types including dates and datetimes (missing in JSON). YAML has comments, but these are normally thrown away.
Block structured YAML is a clean and very human readable format. By extending the Python YAML parser to support round trip preservation of comments, it makes YAML a very good choice for configuration files that are human readable and editable while at the same time interpretable and modifiable by a program.
Extending¶
There are normally six files involved when extending the roundtrip capabilities: the reader, parser, composer and constructor to go from YAML to Python and the resolver, representer, serializer and emitter to go the other way.
Extending involves keeping extra data around for the next process step, eventuallly resulting in a different Python object (subclass or alternative), that should behave like the original, but on the way from Python to YAML generates the original (or at least something much closer).
Smartening¶
When you use round-tripping, then the complex data you get are already subclasses of the built-in types. So you can patch in extra methods or override existing ones. Some methods are already included and you can do:
yaml_str = """\ a: - b: c: 42 - d: f: 196 e: g: 3.14 """ data = yaml.load(yaml_str) assert data.mlget(['a', 1, 'd', 'f'], list_ok=True) == 196 | https://ruyaml.readthedocs.io/en/latest/detail.html | CC-MAIN-2022-40 | refinedweb | 1,400 | 55.54 |
This question comes out of the discussion on tuples.
I started thinking about the hash code that a tuple should have. What if we will accept KeyValuePair class as a tuple? It doesn't override the GetHashCode() method, so probably it won't be aware of the hash codes of it's "children"... So, run-time will call Object.GetHashCode(), which is not aware of the real object structure.
Then we can make two instances of some reference type, which are actually Equal, because of the overloaded GetHashCode() and Equals(). And use them as "children" in tuples to "cheat" the dictionary.
But it doesn't work! Run-time somehow figures out the structure of our tuple and calls the overloaded GetHashCode of our class!
How does it work? What's the analysis made by Object.GetHashCode()?
Can it affect the performance in some bad scenario, when we use some complicated keys? (probably, impossible scenario... but still)
Consider this code as an example:
namespace csharp_tricks { class Program { class MyClass { int keyValue; int someInfo; public MyClass(int key, int info) { keyValue = key; someInfo = info; } public override bool Equals(object obj) { MyClass other = obj as MyClass; if (other == null) return false; return keyValue.Equals(other.keyValue); } public override int GetHashCode() { return keyValue.GetHashCode(); } } static void Main(string[] args) { Dictionary<object, object> dict = new Dictionary<object, object>(); dict.Add(new KeyValuePair<MyClass,object>(new MyClass(1, 1), 1), 1); //here we get the exception -- an item with the same key was already added //but how did it figure out the hash code? dict.Add(new KeyValuePair<MyClass,object>(new MyClass(1, 2), 1), 1); return; } } }
Update I think I've found an explanation for this as stated below in my answer. The main outcomes of it are:
- Be careful with your keys and their hash codes :-)
- For complicated dictionary keys you must override Equals() and GetHashCode() correctly. | http://ansaurus.com/question/102690-how-does-c-figure-out-the-hash-code-for-an-object | CC-MAIN-2018-39 | refinedweb | 313 | 57.16 |
5. Privileged groups and memberships
How many users are in elevated groups? Companies with good security have a bare minimum, bad ones have insane numbers, and top-notch companies have none. For example, in Active Directory shops, I like to see a handful (or less) of permanent members in the Enterprise Admins and Domain Admins groups, more commonly, I've been in companies with hundreds of members in these groups. Heck, each year I find a company that has the Authenticated Users group as a member of their highest-privileged groups, and it's been that way for ages. I also review sensitive and shared directories for excessive permissions.
6. Lifecycle management
Good lifecycle management is worth its weight in gold. Lifecycle management starts by making sure every object in a namespace (such as Active Directory, DNS, and so on) is needed before it's added. An owner is always assigned; if anyone has any questions, everyone can easily see who to contact. But my quick litmus test is to see if they regularly remove old members when that object or member is no longer needed. Lots of companies are great at the process control for adding items, but horrible at following up afterward, especially on deprovisioning.
7. Security hardening
I always take a quick look at basic security settings on workstations and servers. Do they have the basic recommended security settings enabled, are settings tighter than normal, or have they made their computers weaker? I don't care about a misconfigured setting here and there, but you want to see a pattern of strength and protection.
8. Authentication sophistication
Although the protection provided by smartcards, RSA tokens, and other two-factor authentication methods are often oversold, any authentication method beyond plain log-on passwords is a positive. It means the company is interested in preventing easy authentication credential theft. If they only use passwords, I have two questions out of the gate: Are the passwords long and complex (or at least long)? And do they use the strongest available authentication hashes and protocols? If not, the looters have already paid many visits, most likely.
9. Configuration consistency
You want to see consistency for all the items listed so far. Hackers thrive on inconsistency. Inconsistency is how most compromises happen. Consistency takes resolve from start to finish, beginning with consistent images and builds and instructions. You need consistent processes and watchful change and configuration controls. I see consistency when I survey multiple computers and find the same programs installed on the same roles: no more software, no less. I see consistency when I see the same directory structure and folders: no more and no less. I see the same management and monitoring tools. Consistency is the backbone of all security recommendations. Even if a company has security gaps, if I see consistency (in both the good and the bad), I know the company will have an easier time closing holes and becoming more secure. Rampant inconsistency could well mean that everything I find or recommend will be nearly useless.
10. Up-to-date education
Lastly, I like to see good, up-to-date, end-user and staff education. Does the end-user education include the latest threats or are company newsletters still warning about untrusted websites, file attachments, and macro viruses?
You might hire me for a few weeks to analyze your environment. But the truth is that my first impression forms right after I check a few computers. And my first impressions are rarely wrong.
This story, "Secure or not? 10 spot checks will tell you," was originally published at InfoWorld.com. Keep up on the latest developments in network security and read more of Roger Grimes' Security Adviser blog at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter. | http://www.infoworld.com/d/security/secure-or-not-10-spot-checks-will-tell-you-197928?page=0,1 | CC-MAIN-2013-48 | refinedweb | 635 | 55.44 |
Ryan is a software engineer for Siebel Systems. He can be contacted at ryan@ ryanstephens.com.
In theory, comparing two relational data sets is straightforward. The problem statement is simple enough: Given two data sets, A and B, measure how similar they are. But here is where the apparent simplicity begins to fade-what does "similar" mean?
The definition of similarity depends on the sort of differences you want to capture. Two (or more) data sets can differ in both magnitude and content. For example, B may contain many more rows than A, and that is worth knowing, but the rows also may or may not contain combinations of values similar to those in A, and that is worth knowing, too.
If you want to capture such differences, you can start with a simple approach. Match up unique keys in the two tables, count the number of columns that contain unequal values, and report the average number of differences. Find the difference in the number of rows in each data set to capture any difference in magnitude. This will give you a rough idea of how similar two data sets are.
This approach may be sufficient for some data sets, but it has a few shortcomings. To begin with, it does not work when both data sets do not share common unique keys-which rows do you compare? It also lacks a general scheme for comparing relative similarity in data sets of different size; the average column difference is data dependent.
Thus, in finding a solution to this problem, there are two competing goalsmeasure similarity without imposing requirements on the data (such as unique keys), and provide an intuitive way to represent the difference. It would also be nice if the solution requires only enough information about the data to make accurate measurements, and is therefore general enough to apply to a variety of data types.
In this article, I show how borrowing techniques from the field of Information Retrieval lets you measure the similarity between data sets efficiently, accurately, and with minimal development.
Information Retrieval & Computational Geometry
Information Retrieval (IR) is a field devoted primarily to efficient, automated indexing and retrieval of documents. There are a variety of sophisticated techniques for quickly searching documents with little or no human intervention. A survey of those techniques is beyond the scope of this article (see "Matrices, Vector Spaces, and Information Retrieval" by M. Berry, SIAM Review Volume 41, No. 2, 1999 for a great tour of them), but the common thread in many of them is that they are based on a geometric representation of data called the "vector space model."
In the vector space model, documents are represented by vectors (arrays of numbers) in a high-dimensionality vector space. This representation is possible by imposing a few simplifications on the putative notion of a "document." First, since most documents are simply ordered sets of words, ignore the word order and you are left with sets of words (sets that allow duplicates, that is). Next, to make things simpler still, replace each unique word with a word/frequency pair, where the frequency indicates the frequency of that word in the current document. Despite this seeming oversimplification, word frequencywithout regard for orderstill retains a significant amount of information about a document's contents.
Take this one step further and decouple the word-frequency pairs. An easy way to do this is to have a vector of words as your "dictionary." Then you can represent documents as integer vectors, where an entry at a given index contains the frequency in that document for the word at the same index in the dictionary. So if dict[5] in the dictionary is "hiking" and doc[5] in my document vector is "7," it means that the document represented by doc[] contains the word "hiking" seven times.
This is where geometry comes in. Now that you have a vector of n integers, you have a point in n-dimensional space. Consider a simple dictionary that contains only two words: "running" and "swimming." It might look like this:
dict[0] = "running"
dict[1] = "swimming"
Now imagine that you have a document (say a magazine article) that has the word "running" three times and "swimming" twice. That vector would look like:
doc[0] = 3
doc[1] = 2
Figure 1 provides a visual representation of this, which is a vector in a two-dimensional space.
Other documents with the same terms would be represented by vectors in the same space and would appear as other points on the 2D vector space. Documents that are similar, based on relative word frequency, appear closer to one another than those that do not. Therefore, you can use a couple of standard geometric measures to measure how "close" two vectors are, which is their respective documents' similarity: Euclidean distance and cosine.
Euclidean distance, which involves the square root of the sum of the squares of the differences (see Figure 2), is a good measure of the magnitude of the difference between the two documents. For example, if you have document A that contains "running" 20 times and "swimming" zero times, and another document B that contains "swimming" 30 times and "running" zero times, the two documents have a distance of about 36. If, on the other hand, document C contains "running" 15 times and "swimming" twice, the distance to A is about 5. Intuitively, this makes sensedocuments that use the same words roughly the same number of times are probably more similar than those that don't.
This doesn't capture the whole picture though. In the same example, what if document B contains the word "running" 100 times? Intuitively, it should be very similar to document A because both documents are clearly more about running than anything else, but using the distance formula, you are still 80 units away. This is not right.
The cosine measure takes care of this. The cosine treats both vectors as unit vectors by normalizing them, then gives you a measure of the angle between the two vectors; see Figure 3. The notation ||x|| means the vector norm, which is
xTx. Now revisit the aforementioned example. With vectors d1{20,0} and d2={0,30}, the cosine=0, which means these two vectors are perpendicular (regardless of their length). Table 1 contains the possible values for cosine and their directional meanings.
Similarly, suppose d1 represents a magazine article and d2 a book. With d1={3,2} and d2={305,220}, the cosine is 0.9993, which means these two vectors are pointing almost exactly in the same direction and, therefore, the two documents are similar in content. Intuitively, the cosine measure preserves the ratios of terms relative to one another.
There are a couple of items worth pointing out here. First, based on the descriptions above, cosine appears to be a much better measure. It provides an accurate, intuitive measure of similarity without regard for magnitude. But magnitude is important. If one data set is 10 times the size of the other (and this is something, based on the type of data you are dealing with, that you may want to measure), cosine will not tell you.
Second, there is one problem with using frequency as the numerical basis for this: What about frequently used words that carry little or no meaning? Words like "and," "or," "the," and so on, will have extremely high frequencies and therefore significantly affect the similarity measures, but tell you nothing about a given document. Not surprisingly, there are a number of weighting schemes used in IR that neutralize these terms so they don't skew the results. This will not be a problem in this article's techniques, but the schemes for dealing with these approaches are elegant.
Now that the basis for IR similarity measures has been set, you can investigate how to recast the data set similarity problem as a geometric problem.
Recasting the Problem
As is often the case in programming and computer science, representing one problem as another enables a whole class of solutions.
Think of a relational data set as a document. Each unique column/value pair is a term and the number of occurrences of it in a given data set is its frequency. With a little bookkeeping code and a handful of simple data structures, you can use the geometric formulas just described to measure similarity between data sets.
Before you do anything else, figure out what your data sets look like. Determining which tables and columns you are going to compare will be (and should be) the most time-consuming task in this whole exercise. For simplicity, I assume you are comparing two identical tables. Additionally, the data sets in this article should be simple SELECT statements. You can, of course, include multiple tables in your data sets using joins, but doing so adds more complexity.
Just as in comparing documents, not all terms are useful. I mentioned earlier how words like "and" and "the" are useless when comparing documents. The same goes for data sets: If most records in a data set have the same value, then it does little good when comparing them. Unique terms, at the other extreme, are equally useless when comparing two data sets. To jump back to the magazine article analogy, suppose the "running" and "swimming" articles were written by different authors. If I know the first article contains the first author's name twice and the second one contains the second author's name three times, this tells me nothing about the similarity of the articles' content because they are unique to each document.
Apply this same intuition to data sets. Use columns that contain heterogenous, evenly distributed values, but that are not unique. For example, if one of the data sets you want to compare contains, say, 100,000 rows, a good candidate column for this technique may hold five or 10 different values, each with a significant number of rows. You can get a feel for data distribution with SQL's COUNT and GROUP BY clauses. Say you want to see the distribution of the TYPE column on a FIELD table; you could do it like this:
SELECT DISTINCT TYPE, COUNT(TYPE)
FROM FIELD
GROUP BY TYPE
This produces the breakdown of the data distribution in Figure 4(a). This data is sufficiently evenly distributed, though not perfect. It is somewhat skewed toward the TEXT, BOOL, and ID values, but there are enough of the other types to make it a useful column. For the sake of comparison, a column with poor distribution may look like Figure 4(b). This sort of distribution is not completely useless, but chances are that other columns have more meaningful data. The goal of this analysis is to find columns that characterize the data, and because of that, a column's usefulness is partially subjective. You know what the data in your table are used for, so it may be that a heavily slanted distribution is okay. Generally speaking, however, more evenly distributed column values contribute more to your similarity measures.
What I have described is a best-guess, eyeball approach to analyzing data distribution. If you want a solid mathematical measure of data distribution, see the accompanying text box entitled "Entropy."
Once you have examined the data distribution for each of the columns in your data sets, you should know which columns will be useful in comparing them. The next step is transforming this data into a geometric representation.
Before you use IR techniques on relational data sets, you have to transform the data into a different representation. Thus, this is the critical step in this exercise.
From the previous explanation of similarity measures, you already know that you need to convert this data into a frequency vector format. The pseudocode for doing so is straightforward:
for each row
for each column
make a key of the column name and value
add the key to the dictionary if it's not there already
increment the corresponding index in the doc vector
This algorithm uses two structuresa dictionary and an integer vector. The dictionary does two things. First, it keeps track of the terms. A term, for our purposes, is a unique column name/value combination. The dictionary has a single entry for each of them. Second, it makes manipulation of the document vectors easier and more efficient. Each index in the doc vector corresponds to a term in the dictionary.
There is one dictionary and as many document vectors as there are data sets to be compared. Build each document vector by examining each term in the data set, looking it up in or adding it to the dictionary and getting the index of it in the process, then incrementing the corresponding index in the document vector for each occurrence of the term.
All of this is easy to do with C# and a handful of the ADO.NET classes. My DataSource class (available electronically; see "Resource Center," page 5) uses the classes OdbcConnection, OdbcCommand, and OdbcDataReader in the System.Data namespace to do all the database work, and ArrayLists for the dictionary and document vectors. Take note of the SqlToDocument method. It executes a SQL statement against the current data source, then converts the results to a dictionary/frequency vector format. Listing One is the most important part of the code.
Create each of your document vectors with SqlToDocument like this:
myDS1.SqlToDocument( sql1, dict, doc1 );
myDS2.SqlToDocument( sql2, dict, doc2 );
Once you have created both document vectors, the transformation is complete. Now you have two frequency vectors that are in sync with the dictionary, or to put it another way, the indices of each vector refer to the same term. Measure their similarity with Euclidean distance or cosine:
double dist = ds1.Distance( doc1, doc2 );
double cos = ds1.Cosine( doc1, doc2 );
At this point, you have your distance or cosine measure. So what now? It depends on what types of data differences you want to measure.
The Results
If you use the techniques described so far, you have two numbers, distance and cosine, that each tell something about the difference between the data sets. Distance indicates the magnitude of the difference and cosine reports the similarity of the data in each of the data sets. Both numbers describe important aspects of the relationship between data sets.
Consider the case just described, where you have a magazine article and a book about the same topic. In terms of data sets, the "book" data set would have rows with the same combination of values, but with more of them. The corresponding vectors may look like Figure 5.
Cosine tells you that the vectors point in roughly the same direction and that the documents are therefore similar in content, and distance will tell you that one is much larger than the other. You can use the two values together to infer the relationship between the two data sets.
When you use more than three terms, the corresponding vectors are not something you can visualize, but the calculations work regardless. Cosine and Euclidean distance work for any number of dimensions.
Conclusion
One technique won't work for everybody so experiment and see what sort of calculation makes the most sense for your data. For example, for one of my applications, I had to use a different approach to distance by normalizing it to some basis and then using that normalized value. I did this by using one vector as the baseline and calculating its distance from the origin. I then calculated the distance between the two vectors and reported that distance as the percentage of the baseline distance. This let me get an idea of what a value for distance means, in terms of the size of the baseline vector.
You can use this and similar approaches based on the type of data you are using and the kinds of differences you want to measure. The two complementary measurement calculations permit effective comparison of data quantity and quality, and with some experimentation, you should be able to tailor it to suit your particular needs.
DDJ
while (reader.Read()) { for (int j = 0; j < reader.FieldCount; j++) { name = reader.GetName( j ); val = reader.GetValue( j ).ToString(); key = name + "|" + val; idxDict = dict.IndexOf( key ); if (idxDict < 0) { idxDict = dict.Add( key ); doc.Insert( idxDict, 1 ); } else { idxKey = dict.IndexOf( key ); freq = (int)doc[idxKey]; freq++; doc[idxKey] = freq; } } }Back to article | http://www.drdobbs.com/architecture-and-design/information-retrieval-computational-geo/184405928 | CC-MAIN-2014-42 | refinedweb | 2,749 | 53.51 |
P-12C PilotThe Flight Simulator experience and other tangential thoughts Community 7.1.12.36162 (Build: 7.1.12.36162)2007-04-07T18:43:00ZI made the jump to Windows Live Spaces<P>There.</P> <P>I don't plan to update this blog any more, so head on over to the new space and check it out.</P> <P><A href=""></A></P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C the Cockpit of your Favorite Aircraft.</P> <P>Susan has written a blog post about how to do this and used our Cessna 172 as an example. See her blog post <A class="" title=herehere</A>.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C ESP<P>I was going to post about Microsoft ESP but after reading <A class="" title="Phil's post" href="" mce_href="">Phil's post</A> I'm not sure I can add much value...</P> <P>I guess I'll give more examples that might help you understand the opportunity.</P> <P.</P> <P.</P> <P>Maybe you are really good at building scenery objects and creating animations and effects. Some of the agencies will need scenery that can be animated into a damaged or destroyed visual. Maybe you could work with one of the ESP partners to help create new content.</P> <P.</P> <P>I expect most individual contributors in our community will not pursue ESP as a business opportunity. However some FS development companies will use ESP, and maybe you could partner with one of them as a vendor.</P> <P>If you haven't seen the official Microsof ESP website <A class="" title="here it is." href="" mce_href="">here it is</A>.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Need an Aircraft Developer.</P> <P> Here is a link to the job followed by the job description.</P> <P> <A href=""></A></P> <P> SOFTWARE DESIGN ENGINEER:<BR>Description:<BR. <BR><BR>Required experience:<BR>Experience in physical modeling, C/C++ programming, and the ability to work in a highly motivated team environment are required.<BR><BR>Educational experience: <BR>BS (or equivalent) degree in Computer Science, Computer Engineering or Aeronautical Engineering. <BR><BR>Desirable Experience:<BR>Previous game industry development experience working on physics engine is preferred. Background in aeronautical engineering, real world aviation and feedback control systems would be desirable as well as being trained as a pilot and being familiar with the Flight Simulator SDK.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C a Beta Tester<P>With all the great screenshots of FSX Accleration being generated and shared on various forums, a lot of users are inquiring about getting onto the beta program.</P> <P>First of all, it's too late for FSX Acceleration. The beta for Acceleration will be shut down soon, so there isn't any point in joining it. If you want to be considered for the Train Sim 2 beta, then you should use the fs_ideas e-mail alias to sell yourself to us.</P> <P>We won't open a beta for FS11 for a long time so it's too early to apply for that.</P> <P>When users/developers for any beta program we look for the following:</P> <UL> <LI>How the user interacts with the community (how active in forums, how helpful they are with other users, whether or not they can logically evaluate issues without being overly emotional about it, etc)</LI> <LI>If they are developers of add-on products</LI> <LI>If an existing beta member that is particularly good is willing to recommend the user for the beta</LI></UL> <P>Being a beta tester isn't an easy job. First of all it's purely on a volunteer basis with the only thing you receive being the opportunity to see product before it's released and a final copy of the software (assuming policies don't change). You must be active on the beta forums or filing bugs to stay on the beta long-term. You have to put up with some nasty bugs and will likely have to install and uninstall software rerpeatedly and remove third party add-ons.</P> <P>Honestly it can be a pretty painful process and for some when you see a bug that might impact you negatively, it can be quite stressful as well (especially if we resolve it as won't fix or postponed).</P> <P.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Screenshots<P>Just thought you might like to see some screenshots from the final bits of Acceleration. The beta team gets to run the final code as part of their participation and we are allowing them to post screenshots from that final version. Check it out!</P> <P><A href=""></A></P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C You to Acceleration Partners<P>Although this information is quietly and publically included in the credits (under the help menu "about" section) I want to call out the great work from the companies and individuals that created content for Acceleration or contributed to helping us do the same.</P> <P.</P> <P.</P> <P>Sibwings created the P-51D Mustang for us and I think it turned out great. I know the owners of the Mustangs we depict in Acceleration are very happy with the way it looks in Acceleration.</P> <P.</P> <P.</P> <P>Of course our internal team worked very hard to integrate all of this content into Acceleration, fixed many bugs in the end game and did a great job in a short development cycle!</P> <P!</P> <P>I hope you enjoy what we have all created.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C're Done!<P.</P> <P>Now I can focus on designing FS11 which I've been working on part-time for awhile.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Day 5<P>I'm a bit late with this, but Sunday's racing was awesome. It was touch and go that racing would continue for the weekend at all, but thankfully racing continued.</P> <P. </P> <P.</P> <P.</P> <P.</P> <P!</P> <P>It was a week of mixed feelings. Great excitement for the event, fantastic racing, great reception for Acceleration, all tempered by great sadness for the tragic loss of life. Blue skies to the pilots and my heart goes out to the families they have left behind.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Day 4 (Saturday)<DIV dir=ltr><FONT face=Tahoma color=#000000 size=2>Just a quick note to say that we are getting a great reception at the Reno Air Races. The multiplayer races being run every hour in the "public" booth are full every time with a crowd watching from the sidelines. I have primarily been working in the VIP area, but I went to the public booth today and it was great to see the users getting into racing so much. Later in the day we organized a "champions" race where the best of the best users got to race against Brandon and I. They had been practicing to try and beat my best time and one of them had done so the previous day (by .5 seconds) so he was very confident he could beat me in a race.</FONT></DIV> <DIV dir=ltr><FONT face=tahoma size=2></FONT> </DIV> <DIV dir=ltr><FONT face=tahoma size=2>Ryan Leeward (grandson of Jimmy whose P-51 Cloud Dancer we modeled) and his mother and father attended the race with Ryan as one of the race pilots. This race was really close but I worked my way from fourth to first by the end of the race. What a close finish with Brandon finishing in second!</FONT></DIV> <DIV dir=ltr><FONT face=tahoma size=2></FONT> </DIV> <DIV dir=ltr><FONT face=tahoma size=2>The racers desperately wanted to race again so we oranized another race. This time I was on fire with the best performance to date. I was a full 5 seconds ahead of everyone else on the course and set a new course record. Matt, the user that had beaten my previous best time was pretty upset at himself for not finishing better. The Leewards were very impressed with the performance and it was very cool feeling the comraderie they were sharing with us.</FONT></DIV> <DIV dir=ltr><FONT face=tahoma size=2></FONT> </DIV> <DIV dir=ltr><FONT face=tahoma size=2>Interestingly the users that were getting most into the racing had never met before this event, but have become friends as a result. Eric has commented several times at how rewarding it is to see users enjoy what we have spent a year creating. It's also very rewarding to see people new to Flight Sim reacting so positively.</FONT></DIV> <DIV dir=ltr><FONT face=tahoma size=2></FONT> </DIV> <DIV dir=ltr><FONT face=tahoma size=2>The VIP area has been getting more and more busy over the days with many of the race teams stopping by to try out the product. Brandon was working with a retired Navy pilot that nailed his first carrier landing attempt. He was pretty excited about it. We had a helicopter fan come in so I had him try the slingload tutorial and I was amazed at how well he handled the loads.</FONT></DIV> <DIV dir=ltr><FONT face=tahoma size=2></FONT> </DIV> <DIV dir=ltr><FONT face=tahoma size=2>It was really important to me and I assume for the rest of the team to have a good day yesterday. Friday the races were suspended after a series of fatal crashes which is why I didn't make a Reno Day 3 post. The mood at the races was very somber to say the least. Yesterday helped turn that around.</FONT></DIV> <DIV dir=ltr><FONT face=Tahoma></FONT> </DIV> <DIV dir=ltr><FONT face=Tahoma>Today we will run more races, and the Leewards are interested in having a Cloud Dancer team only race so I need to set that up. In the afternoon I get to watch the remaining final heats which is always fun.</FONT></DIV><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Day 2<P.</P> <P.</P> <P>I am most impressed with <A class="" title="Mike Singer" href="" mce_href="">Mike Singer</A>.</P> <P>We ran several multi-player races in the public display with some proud moments for some of the racers as they win a race or get a good race time/speed. As the crowds increase it will be interesting to see how the races go.</P> .</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Ready to go in Reno<P>Well.</P> <P!</P> <P <A class="" title=MotoartMotoart </A>have decorated the booth with some fantastic aviation furniture.</P> <P. </P> <P>If you are interested in following the racing head over to <A class="" title="Warbird Aero Press" href="" mce_href="">Warbird Aero Press</A> or <A class="" title=AAFOAAFO</A> and check out the forums.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C World<P>Or maybe the world just has some really crazy people in it...</P> ).</P> <P.</P> <P>Anyway I called 911 and my wife to make sure people knew there was a lunatic by the gate. I have to say I was pissed off for hours after that.</P> <P>What a strange morning...</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Acceleration Preview<P><A class="" title=GamespotGamespot</A> has a pretty nice writeup on FSX Acceleration with a bunch of screenshots if you're interested.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C and FSX Acceleration<P.</P> <P.</P> <P.</P> <P.</P> <P.</P> <P.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Acceleration in Private Beta<P>Many beta testers are already aware that we have entered our beta testing phase, but some may not be aware. If you are a beta tester for us, then please visit the beta forums and participate. We look forward to your feedback.</P> <P>If you're not a beta tester, I appologize for leaving you out in the cold on this one.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C'm Feeling a bit Chatty<P>Not as chatty as Hal mind you. If you haven't been reading Hal's blog, you've really got to see what he has been up to at AirVenture in Oshkosh. Well worth the read and he has a lot to say about it.</P> .</P> <P.</P> <P.</P> <P.</P> <P."</P> <P.</P> <P.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C FSX Acceleration Trailer<P>Mike has managed to get our video up on fsinsider. Get to the site <A class="" title=herehere</A>.</P> <P>Apparently there were some technical issues getting the HD version posted as it was too large, so they are working on getting that resolved.</P> <P>Let us know what you think of it!</P> <P>Added note: This video uses a relatively new version of Windows Media Viewer and some users may not have the right video codec to see it (my laptop included). <A class="" title=HereHere</A> is a link to more information about the codec although I haven't yet found a direct update to get it...</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Simulator X Acceleration at E3<P>E3 has begun and speculation has started regarding our expansion pack. If you've been checking my blog periodically, you already know how excited I am about it! There has been a <A class="" title=videovideo</A> posted on GameSpot but it's worth noting that this video is a compilation of b-roll material we shot while in the studio producing our primary trailer which I think is much cooler. I think that trailer will be released on <A class="" title=fsinsiderfsinsider</A> after it's officially shown at E3 (in other words I don't know exactly when). What you won't see in the trailer is material on the <A class="" title=EH-101EH-101</A>...</P> <P.</P> <P...</P> .</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C"Launch Event" in Reno This Year<P>If you read this blog much, you'll know I'm a big fan of the <A class="" title="Reno National Championship Air Racing" href="" mce_href="">Reno National Championship Air Racing</A> event held every September. Like many years past I will be there taking in the sights and sounds of the fastest motorsport on earth.</P> <P (<A class="" title=RARARARA</A>) and the <A class="" title="T-6 Racing Association" href="" mce_href="">T-6 Racing Association</A> "<A class="" title="Grace 8" href="" mce_href="">Grace 8</A>" (note the <A class="" title=PMDGPMDG</A> and <A class="" title=AVSimAVSim</A> logos). This year Grace 8 is getting a new livery matching what it wore in it's WWII squadron. I'm looking forward to seeing it.</P> <P>We plan to have a display area near the main gate where we will be conducting multi-player races with whomever wants to participate as well as a special location in the pit area which <A class="" title=MotoArtMotoArt</A> is helping us setup. Hopefully we will have some races with the real air racing pilots as well, which would be fun to participate in.</P> .</P> <P> See you there!</P> <P mce_keep="true"> </P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C "Miss America"<P>Let me be clear here, I'm talking about the P-51D Mustang "Miss America," not the human variety...</P> <P>I've always wanted to go for a ride in a Mustang, and I wasn't sure I ever would, but today I can say I've not only flown in a Mustang, but I actually flew a Mustang!</P> <P>It's been an awesome weekend. First the Indy 500, then yesterday I stopped in Oklahoma City to visit with Brent Hisey, the owner and pilot of Miss America. When I called him from the airport he said, "I sent you an e-mail saying the weather was crummy and I had to take care of something else, so I didn't know you were coming." I hadn't checked my e-mail the previous day as I was at the race track all day and I knew the weather was lousy as I decended through IMC into Oklahoma City, but I was there so I wanted to connect anyway.</P> <P>Brent was a wonderful host and he picked me up from the airport and drove me to Wiley Post airport where his Oklahoma Flying Museum is located. Inside sat "Miss A" in all her beautiful glory just begging to fly. We chatted a little standing next to her and some of the crew came by to say hello as well. Everyone was really nice and full of great information about air racing and mustangs in particular. Only a few years ago Brent had to put her down in the desert in an emergency landing badly damaging the aircraft. After seven months of intense work this crew rebuilt almost all of Miss America to be a basically new aircraft. And honestly she looks and feels new.</P> <P>With the inclement weather I offered to show them FSX and the expansion pack. I really wanted to see what they thought of the course and how it was working. Of course Murphy's Law was in force and I couldn't run for some reason, so I kicked off a re-build and we chatted about air racing and flying for 30-40 minutes while the laptop crunched away on all the bits.</P> <P>Finally we were up and running and I flew the course in a Mustang using the mouse to fly (not my favorite, but I didn't have a joystick). Intentionally allowed my engine to be destroyed blowing most of the pistons along the way and they were pleased with the simulation. With their feedback on the engine and failures I think we can get it a lot more realistic as well. I can happily report that they seemed genuinely impressed with everything they saw. Brent made comments like "That looks exactly like what I see on the course, even the ground rush looks amazing." Some of the crew were amazed to see all the details around the course saying "There's the guard base, and there's so and so's hangars." This is exactly the kind of feedback I was hoping to get and it felt really good to get high praise from the guys that really know racing at Reno. I had them take the controls and after getting used to the mouse, they did a credible job flying around.</P> <P>Brent bless his heart was busy checking the weather, and when we finished up on the laptop he asked "Well do you want to go flying?" I'm sure he knew the answer and I jumped at the chance to go up. The weather had miraculously improved and he was willing to give me a taste of the real thing. I put on my relief band (helps to control nausea) just in case he got a bit crazy with some G's and headed for the plane.</P> <P>I twisted my way into the backseat and I got a breifing on how to get strapped into the parachute and seat harness, then received instructions on how to bail out if it came to that with the caveat that the only way we're going to bail out is if we are on fire! Believe me the last thing I want to do is bail out of a priceless Mustang. I was very pleased to see that Miss America has dual controls... I'm thinking, I wonder if Brent is trusting enough to let me fly...</P> <P>Brent started her up and after a few seconds we went from the tumping of a Harley to the smooth purr of a Rolls Royce Merlin. By now the sun was starting to leak through the clouds and like all bubble canopies it get's pretty hot. Considering the radiator lines run under the cockpit between the belly scoop and the engine, there is a lot of heat radiating up through the floor boards. During the runup and takeoff the canopy is closed and it really does get hot in there. Thankfully nausea wasn't a problem or I would have been in trouble.</P> <P>After the runup he taxied out to the runway and we bolted into the air. What a rush with all that power up front, and this was a stock engine! I love this airplane and I can see why pilot's love it so much. So we wewre up and running and I was runnign the new HD camcorder all the while. Unfortunately I can't look at the view screen and fly at the same time or I will get sick, so I kept the screen closed. This was the first time I used this camcorder and I've now learned that the telephoto control is very sensitive. Most of my video is unusable because the camera was zoomed all the way in! Damn technology... I figure that out on our approach to land so I did get some good stuff, but not the coolest shots that I thought I was getting.</P> <P>Brent scooted along under the clouds then pulled up and over the top through a small hole. Wow, here I am in a hotrod Mustang punching holes in the sky. Then he offers to let me fly. So I juggle with the camcorder a bit and take the stick. This airplane is as smooth as butter and easy to fly with neutral stability. Put it in a bank and she just stays there. Command a change in attitude and she is ready to respond. Whenever I fly someone elses plane I am very cautious (especially if I can't see where I'm going) and do very shallow turns and make my way up to steeper ones, and aerobatics are out of the question. As I steepened the banks the airplane was still really easy to fly and required no rudder input to maintain coordinated flight and it was easy to stay at altitude. Of course I couldn't really see the gauges very well, so I'm sure they weren't perfect turns, but they felt good to me. I commented on it to Brent and he said at racing speeds he starts turns with the rudder to keep the nose from rising.</P> <P>I was starting to feel guilty burning up gas and knowing Brent had other things to do that day, so I gave up the controls and Brent started giving me more of a taste of what a Mustang feels like. He started the descent to the airport dodging clouds along the way and accelerating to much higher speeds coming downhill. What a rush zipping past clouds and between them. It was so cool. We never exceeded much more than 2 G's the whole time and it was exhilerating! He did a military style approach coming over the runway and breaking right to the downwind in a steep turn to bleed off some speed. On short final with gear down and full flaps the airplane is going downhill fast with the nose low, then a quick flare and a nice wheel landing.</P> <P>This was by far the best airplane ride I have ever experienced. Thank you Brent and Miss America for a memory I will never forget!</P> <P>Now it will be even more fun when the Miss America livery is ready on our Mustang and I take to the Reno course.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Trip to the Indy 500<P>Life is good :)</P> <P>My brother, father and I made the trek to Indianapolis for the Indy 500 this year. It was the first time for all of us although we have watched it on TV every year as a family thing. My dad has always wanted to go and my brother surprized him with an expense paid trip Christmas present. They had different airfare than I so I traveled alone, and I almost didn't make it at all (I'll get to the good stuff in a minute).</P> <P>Brandon kindly dropped me off at the airport and I was sitting at the gate when American Airlines cancelled my flight due to weather issues in Chicago. Off to baggage claim to get my suitcase, then back up to ticketing to see what options I had. Of course by then the line to resolve the issues was an hour long, American was freaking out, and the wait on hold for customer service was over 30 minutes. I booked the flight through Expedia, so I called their 800 number. Thankfully I wasn't on hold very long, but they said they couldn't (or rather wouldn't) help me and I had to deal with the airline. Well American Airlines told the crowd at large that if you lived in Seattle, you may as well just go home and come back tomorrow because there was no way we would get a flight. Nice. No options whatsoever.</P> <P>Back to Expedia... Still unwilling to help, but they did offer up that they booked the whole trip through United Airlines and that I should go talk with them. I walked to the opposite end of the ticketing area and to my surprize there was no line of any kind in their area. United hadn't cancelled any flights to Chicago... When I started talking to the ticket agent, he said there was nothing he could do and that I would have to talk with Expedia. Here we go again with a wild goose chase. At this point I was ready to cancel the whole thing as United was fully booked all weekend. To my surprize as we were chatting about this dillema, he sounded encouraging that I stood a good chance going standby on a United flight. In case I did make it, we sent my luggage all the way to Indianapolis so it would be there when I arrived. Amazingly I did make it onto that flight and was off to Chicago.</P> <P>The United ticket agent told me what flight to go for and was trying to get me onto the standby list for that flight, but American hadn't released me from the booked flight from Chicago to Indy yet so he couldn't but would keep trying. After running through the terminal in Chicago about 2 miles I found that both flights to Indy were delayed about 2 hours. I asked the gate agent if I was on the list and she confirmed I was, so I thought I was in pretty good shape, then she said I was 36th in line out of 50+ people on standby. So I sat around and waited not expecting to be called at all, then the last name they called to get on that flight was Lange. Woo Hoo, I was going to make it on the flight! Then two of us showed up at the counter. Damn, who would have expected there would be two Langes waiting on standby for the same flight. Turns out I wasn't really on the standby list afterall.</P> <P>There was one more flight to Indy that I could take before having to go the route of a rental car and a 4 hour drive. So I tried to get on standby for that United flight. All I had was my boarding pass for the previous flight and my boarding pass for the cancelled American flight. So, the attendent (who was not in a good mood through any of this), said, sorry, I can't help you, call American.</P> <P>After being on hold for over 30 minutes and while the flight was boarding, the previously grumpy agent worked with her supervisor and basically gave me a ticket so I could get there. I finally arrived in Indianapolis about 3:00 AM.</P> <P>The scale of the Indianapolis Motor Speedway doesn't translate when watching TV. This place is huge! The stands are large and when you look from one end of the front stretch to the other end they look small. I think you could fit at least 6 major football stadiums inside the infield of the course.</P> <P>The weather was pretty nice on Friday for "Carb Day" and Saturday when we took in the racing museum and just walked around to the various tents and such. However Sunday was a different story. We woke up to pooring rain and uncertainty on the part of the weather reporters. By the time we got to the track the rain was now light, and hopes were rising. When we sat in the stands it had stopped raining entirely but was still solid overcast. It took more than 2 hours to dry the track, but with the race starting at 1:00 they were on-schedule.</P> <P>I've been to several auto races including a couple of Indy car events at Portland International Raceway, but I had never seen these cars at full speed. When they are doing over 220 mph on the front stretch they are going by so fast you can't read their race number most of the time. It was difficult to know what was really going on with lead changes even though many of the passes were right in front of us just before turn one. Many of those passes had the cars tires inches from each other as they pulled in front of another car. In once case the wheels touched and marco Andretti was launched into the air and flew upside down for while. he was on the backstrech so we witnessed that one on the jumbotrons. I was cheering for Danika Patrick, one of the three female drivers in the race. She get's a lot of attention, and probably deserves it. She held third place for a long time and at one point she was in second place for several laps. Some drivers would get toward the lead by not pitting when the leaders would pit, but Danika was part of the lead pack the entire race. I think it would have been really cool if she had won the race. </P> <P>After about 106 laps it started pooring again and it rained for about 40 minutes then they spent a little over 2 hours drying the course again. Back to racing again, the teams knew it could start raining again at any time, so they were going all out in a sprint strategy instead of looking at it as an endurance race. Those were amazing laps as the cars were always close together and there was a lot of passing on every lap. It was the most exciting Indy racing I have every seen, and being there in person made it that much more awesome.</P> <P>As it turned out it did start raining again and this time even harder than the first two downpoors. They called the race and the winner Dario Franchitti won by taking the risk of not pitting when the other leaders did even though he didn't have enough fuel to do more than a few more laps. They gambled on the rain and they won the race. It's not that he wasn't fast though as he was one of the fastest drivers in the field.</P> <P>Overall it really was an amazing experience and I'm very glad I didn't listen to American Airlines and go home.</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C's New!<P>There.</P> <P.</P> <P.</P> <P!</P> <P).</P> <P>.</P> <P).</P> <P>Thanks for reading and being patient with my lack of attention lately!</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C Shift+Z Information<P>I've been meaning to blog about this forever, and now I finally will. In FSX we implemented the ability to customize the information shown at the top of the screen when you press "shift+z."</P> <P>In the [CONTROLS] section of fs.<BR><BR>Under each of the sub-sections described above are variable names followed by =X,X where the X's are numbers. These numbers define the line and placement on the line. So - </P> <P>[TextInfo.1]<BR>Latitude=1,1<BR>Longitude=1,2<BR></P> <P>means that on the first press of shift+z the latitude will be displayed on line one in the first spot on the line and Longitude will be displayed on the same line just to the right of latitude.</P> <P>In the example below, on the third press of shift+z, there are six different values on the first line and four values on the second line. </P> <P>[TextInfo.3]<BR>Latitude=1,1<BR>Longitude=1,2<BR>Altitude=1,3<BR>Heading=1,4<BR>AirSpeed=1,5<BR>WindDirectionAndSpeed=1,6<BR>FrameRate=2,1<BR>LockedFrameRate=2,2<BR>GForce=2,3<BR>FuelPercentage=2,4<BR> </P> <P>You can have as many lines of information as you want on any given press of shift+z, but you do need to be aware of how much horizontal space a given line will take up across the screen.</P> <P.</P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Latitude<?xml:namespace prefix = o<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">LatitudeDec<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">LatitudeHex<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Longitude<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">LongitudeDec<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">LongitudeHex<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Altitude<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">AltitudeAgl<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Heading<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">HeadingHex<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">HeadingTrue<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; BACKGROUND: red; FONT-FAMILY: 'Arial','sans-serif'; mso-highlight: red"></SPAN><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"><o:p></o:p></SPAN></P><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Airspeed<o:p></o:p></SPAN> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">TrueAirspeed<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">WindDirectionAndSpeed<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">WindSpeed<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">WindDirection<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">FrameRate<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">LockedFrameRate<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">GForce<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">FuelPercentage<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">FuelRemainingGallons<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">FuelRemainingPounds<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">VerticalSpeed<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">AngleOfAttack<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">VideoDevice<o:p></o:p></SPAN></P> <P class=MsoNormal<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">AverageFrameRate<o:p></o:p></SPAN></P> <P mce_keep="true"> </P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C the Pylons in Reno<P.</P> <P.</P> <P.</P> <P...</P><div style="clear:both;"></div><img src="" width="1" height="1">P-12C | http://blogs.technet.com/b/p-12c_pilot/atom.aspx | CC-MAIN-2014-23 | refinedweb | 6,435 | 59.33 |
I realize this problem and solutions are all over StackOverflow like here however I'm still unable to make this work.
Most of the examples say that I just need to multiply the row by the width and add the column meaning the location (4, 3) in a 4x4 square grid would become (3 * 4 + 4) or 16. So far so good.
The examples say to get back the coordinates, I should divide the index by the number of rows for x and get the modulo of the index for y. For the example above, that should be...
int x = 16 / 4; int y = 16 % 4;
But this works for some values, and not others. In this case, when I get back the coordinates after converting to an index, I get (4,0). This makes sense since 4 goes into 16 evenly so I must be missing something basic.
Here's some test Java code that I've created for trying to figure this out. I should mention that I'm indexing started at 1 so the first square in the upper left corner is 1,1 and the last square would be 4,4.
public class Test { int size; public Test(int size) { this.size = size; } public int toIndex(int x, int y) { return x * this.size + y; } public int[] toCoordinates(int index) { int coordinates[] = new int[2]; coordinates[0] = index / this.size; coordinates[1] = index % this.size; return coordinates; } public static void main(String[] args) { int testSize = 4; Test test = new Test(testSize); for (int i = 1; i <= testSize; i++) { for (int j = 1; j <= testSize; j++) { int index = test.toIndex(i, j); int coordinates[] = test.toCoordinates(index); System.out.println(index + " == " + coordinates[0] + "," + coordinates[1]); } } } }
The output of the current code is
5 == 1,1 6 == 1,2 7 == 1,3 8 == 2,0 9 == 2,1 10 == 2,2 11 == 2,3 12 == 3,0 13 == 3,1 14 == 3,2 15 == 3,3 16 == 4,0 17 == 4,1 18 == 4,2 19 == 4,3 20 == 5,0 | http://www.howtobuildsoftware.com/index.php/how-do/b9a/java-arrays-matrix-2d-unable-to-convert-between-1d-and-2d-array-values | CC-MAIN-2018-22 | refinedweb | 343 | 70.53 |
Recent posts by Connelly Home modified by Connelly2012-09-14T21:59:51Z2012-09-14T21:59:51ZConnelly to your wiki! This is the default page, edit it as you see fit. To add a new page simply reference it within brackets, e.g.: [SamplePage]. The wiki uses [Markdown](/u/connelly/wiki/markdown_syntax/) syntax. [[project_admins]] [[download_button]]>[PATCH] PyOpenGL binary compatibility on Windows2008-04-26T01:04:02Z2008-04-26T01:04:02ZConnelly<div class="markdown_content"><p>Freeglut attempts to be binary compatible with GLUT. However, renaming freeglut.dll to glut32.dll causes PyOpenGL-3.0.0b1 to break.</p> <p>This can be fixed by:</p> <p>1. Modifying the freeglut Visual Studio 2005 project to use the __stdcall calling convention.</p> <p>2. Applying the attached patch to add stub functions for __glutInitWithExit, __glutCreateWindowWithExit, __glutCreateMenuWithExit, and export these plus glutMouseWheelFunc (the reason I installed freeglut in the first place was to use the mouse wheel).</p> <p>Now building a release and debug DLL causes freeglut to work with PyOpenGL-3.0.0b1, as a drop-in replacement for glut32.dll. And the mouse wheel works!</p></div>Class allocation on stack2007-06-01T00:48:59Z2007-06-01T00:48:59ZConnelly<div class="markdown_content"><p>This is probably a lot of work, but on the off chance that it is not much work, I thought I'd make the request that user-defined classes be allocated on the stack if they contain a special class attribute such as __stack__ = True.</p> <p>I tried editing the SS output for the PyGmy ray tracer to see how hard it would be to allocate vec() on the stack -- it's hard! (I didn't succeed because passing a stack allocated vec() to the tuple2(...) constructor failed with the error "cannot pass objects of non-POD type `class vec' through `...'; call will abort at runtime.")</p> <p>In any case, I was mostly just interested in Mark's opinion on whether this is worth implementing; if so and if it gives a significant speed increase then I might implement it.</p></div>abs() does not call __abs__()2007-05-31T23:30:57Z2007-05-31T23:30:57ZConnelly<div class="markdown_content"><p>Calling abs() on a custom class does not call the __abs__() method:</p> <p>class C:<br /> def __abs__(self):<br /> return 1.0</p> <p>print abs(C())</p> <p>Note that "print -abs(C())" should also work.</p></div>linkUrl broken2007-04-01T18:58:29Z2007-04-01T18:58:29ZConnelly<div class="markdown_content"><p>If I download FlowPlayer 1.15 binary distribution, modify the default playList in FlowPlayer.html as follows:</p> <p><param name="flashvars" value="config={ <br /> ...<br /> playList: [ { url: 'out.flv', linkUrl='foo'} ]<br /> }" /></p> <p>The clip no longer plays. Removing linkUrl causes the clip to play again, so I know this is not a problem with my .flv video. Using <a href="" rel="nofollow"></a> also does not fix the problem.</p> <p>I conclude that linkUrl when used with flashvars is broken.</p> <p>I'd normally try using an older version of FlowPlayer to fix this bug without downloading a Flash compiler, but I can't find the old FlowPlayer releases. Can the old FlowPlayer releases can be put back online, or have they been removed due to space limitations on SF?</p></div>Add tostring(), topil(), fromstring(), frompil()2007-02-13T13:34:32Z2007-02-13T13:34:32ZConnelly<div class="markdown_content"><p>I added tostring(), topil(), fromstring(), frompil() methods to the Bitmap class. Then I noticed that there is a from_string() method which already exists in the Bitmap class (I didn't see it because it didn't show up in the documentation). This patch is also diff'ed against the "post-templated" source and text files as opposed to the "pre-templated" source and text files (as I didn't realize that the C file was the output of a templating process). In general frustration, I am submitting this patch, so that either (a) You can tell me, "No this API is entirely wrong; here's how to change it" and I can resubmit; (b) You can use this code as a reference to develop your preferred API; or (c) You can remove the undocumented from_string() and just incorporate the patch as-is. Let me know what your preferences are.</p> <p>From the patched documentation:</p> <p>* fromstring(str, mode, w, h, s, stride=-1) -> Bitmap<br /> Static method, creates a bitmap from a string of raw color data. Here mode<br /> should be one of 'RGB', 'RGBA', 'ARGB', 'BGR', 'BGRA', 'ABGR', w and h are<br /> the size of the raw image, and s is a string with the contents of the raw<br /> image. By default, it is assumed that rows are packed in without any extra<br /> padding; to change this, supply the stride argument, which specifies the size<br /> in bytes of each row.</p> <p>* frompil(img) -> Bitmap<br /> Static method, creates an alpy Bitmap from a Python Imaging Library (PIL)<br /> Image.Image instance. The conversion is done in RGB format, so any alpha<br /> channel will be lost.</p> <p>PIL is only required if this method is called; it is not required in general<br /> for alpy.</p> <p>* tostring(mode='RGB', stride=-1) -> str<br /> Converts a bitmap to a raw string of color data. Here mode should be one of<br /> 'RGB', 'RGBA', 'ARGB', 'BGR', 'BGRA', 'ABGR'. By default, it is assumed that<br /> rows are packed in without any extra padding; to change this, supply the stride<br /> argument, which specifies the size in bytes of each row.</p> <p>* topil() -> Image.Image instance<br /> Converts a bitmap to a Python Imaging Library (PIL) Image.Image instance.<br /> The conversion is done in RGB format, so any alpha channel will be lost.</p> <p>PIL is only required if this method is called; it is not required in general<br /> for alpy.</p></div>slerp(): shortest path2006-05-14T21:10:12Z2006-05-14T21:10:12ZConnelly<div class="markdown_content"><p>The quaternion slerp() currently may give either the shortest-path or the <br /> longest-path interpolation. It seems that either slerp() should give the <br /> shortest-path interpolation, or else provide a boolean option (e.g. slerp<br /> (shortest=True)) so that the shortest path may be chosen.</p></div>Fix bug where class_ instances are created before GC_INIT()2006-04-23T02:14:53Z2006-04-23T02:14:53ZConnelly<div class="markdown_content"><p>First, thanks Mark for creating shedskin. It looks like a pretty cool <br /> compiler.</p> <p>When I use SS on the following Python source:</p> <p>class C:<br /> pass</p> <p>It generates the following (incorrect) C++ code:</p> <p>namespace __a__ = {<br /> class_ *cl_C = new class_("C", 19, 19);<br /> ...</p> <p>The problem here is that GC_INIT() has not yet been called, and the <br /> class_() constructor calls str(), which is a garbage collected type.</p> <p>Maybe this doesn't cause problems on some systems, but on my <br /> computer (Windows XP, Mingw 3.4.2, Python 2.4.1, GC 6.7), it causes <br /> the generated program to crash on startup. In other words, if SS is <br /> used on any Python file that creates a class, then the generated C++ <br /> program will crash.</p> <p>One simple fix is to generate C++ code like:</p> <p>namespace __a__ = {<br /> class_ *cl_C = NULL;<br /> void __init_classes() {<br /> cl_C = new class_("C", 19, 19);<br /> }<br /> int __main() {<br /> __init_classes();<br /> ...<br /> }</p> <p>The provided patch modifies ss.py so that the (above) correct C++ <br /> code is generated.</p></div> | https://sourceforge.net/u/connelly/profile/feed.atom | CC-MAIN-2017-47 | refinedweb | 1,284 | 64.2 |
This is your resource to discuss support topics with your peers, and learn from each other.
12-14-2010 12:59 AM
hii,,
I am developing a application in which there is need of connection timeout..But how we will check the timeout without blackberry MDS service available on that mobile..Means that if that mobile is not using BES services and using Wifi or GPRS for net connection........Please help......
Solved! Go to Solution.
12-14-2010 02:16 AM
hello,
In blackberry by default connection timeout is ConnectionTimeout=1200000 mili seconds.
if u want to customize in ur application place ;ConnectionTimeout=1200000 with ur webpage/data request.
for e.g.;ConnectionTim
If u find that answer helpful, do not forget to click on kudos button.
Regards
12-14-2010 02:23 AM
if you are using DirectTCP for http connection
AFAIK this method will not work.
12-14-2010 03:48 AM
The problem is coming by using ";ConnectionTime
12-14-2010 06:12 AM
As far as I know, setting connection timeout via a suffix string is only supported for BES connections. I believe the official way to do it is to cast you connection to SocketConnectionEnhanced and use setSocketOptionEx.
That said, regardless of timeout, calling the webservice 8-10 times should not cause a failure as you have described. I strongly suspect a bug in your logic, I would guess that you do not close the connection properly.
You might find the code in this Thread useful:
At the very least this will help you add tracing code to your own connection, so that you log the processing properly and so can tell us exactly what problem you are seeing. "It doesn't connect" is not a very useful problem description, unfortunately.
12-15-2010 01:45 AM
Hi Peter_Strange....I have checked the Connection Thread throught the application but the problem is only coming while using ConnectionTime out...As said by Vivart i thik i need solution for the DirectTCP for http connection Timeout...can anyone give me a sample code for that.... thaks in advance...
12-15-2010 04:58 AM
As noted in my previous post, but with a spelling correction....
"I believe the official way to do it is to cast your connection to SocketConnectionEnhanced and use setSocketOptionEx."
12-16-2010 12:10 AM - edited 12-16-2010 12:13 AM
I have tried that also....I am using this code for webservice calling....
import java.io.IOException; import java.io.OutputStream; import java.io.InputStream; import javax.microedition.io.Connector; import javax.microedition.io.HttpConnection; public class ConnectionThread extends Thread { boolean start = false; boolean stop = false; String url; String data; public boolean sendResult = false; public boolean sending = false; String requestMode = HttpConnection.POST; public String responseContent; public void run() { while (true) { if (start == false && stop == false) { try { sleep(20); } catch (InterruptedException e) { e.printStackTrace(); } } else if (stop) { return; } else if (start) { http(); } } } int ch; private void getResponseContent( HttpConnection conn ) throws IOException { InputStream is = null; is = conn.openInputStream(); int len = (int) conn.getLength(); if ( len > 0 ) { int actual = 0; int bytesread = 0; byte[] data = new byte[len]; while ( ( bytesread != len ) && ( actual != -1 ) ) { actual = is.read( data, bytesread, len - bytesread ); bytesread += actual; } responseContent = new String (data); } else { while ( ( ch = is.read() ) != -1 ) { } } } private void http() { System.out.println( url ); HttpConnection conn = null; OutputStream out = null; int responseCode; try { conn = (HttpConnection) Connector.open(url); conn.setRequestMethod(requestMode); out = conn.openOutputStream(); out.write(data.getBytes()); out.flush(); responseCode = conn.getResponseCode(); if (responseCode != HttpConnection.HTTP_OK) { sendResult = false; responseContent = null; } else { sendResult = true; getResponseContent( conn ); } start = false; sending = false; } catch (IOException e) { start = false; sendResult = false; sending = false; } } public void get(String url) { this.url = url; this.data = ""; requestMode = HttpConnection.GET; sendResult = false; sending = true; start = true; } public void post(String url, String data) { this.url = url; this.data = data; requestMode = HttpConnection.POST; sendResult = false; sending = true; start = true; } public void stop() { stop = true; } }
In
conn = (HttpConnection) Connector.open(url);
I tried to use that SocketConnection still its creating problem.....Can u tell me where to use it exactly...
12-16-2010 04:18 AM
There is more information and sample code here:
12-16-2010 04:49 AM
I am using OS version4.5 only...
Is there some another way out for this problem.... Plz help... | https://supportforums.blackberry.com/t5/Java-Development/Connection-Timeout-Problem/m-p/679717 | CC-MAIN-2017-04 | refinedweb | 719 | 58.99 |
This C# code detects a CD-ROM being inserted into the CD-ROM drive of a PC. In order to interact with the CD-ROM, you need to use Windows Management Instrumentation (WMI). The .NET Framework provides two sets of classes for interaction with WMI. The
System.Management Namespace provides access to management information and events about the system. The
System.Management.Instrumentation Namespace provides classes to expose management information and events of an application to WMI.
using System; using System.Management; namespace CDROMManagement { class WMIEvent { static void Main(string[] args) { WMIEvent we = new WMIEvent(); ManagementEventWatcher w = null; WqlEventQuery q; ManagementOperationObserver observer = new ManagementOperationObserver(); // Bind to local machine ConnectionOptions opt = new ConnectionOptions(); opt.EnablePrivileges = true; //sets required privilege ManagementScope scope = new ManagementScope( "root\\CIMV2", opt ); try { q = new WqlEventQuery(); q.EventClassName = "__InstanceModificationEvent"; q.WithinInterval = new TimeSpan( 0, 0, 1 ); // DriveType - 5: CDROM q.Condition = @"TargetInstance ISA 'Win32_LogicalDisk' and TargetInstance.DriveType = 5"; w = new ManagementEventWatcher( scope, q ); // register async. event handler w.EventArrived += new EventArrivedEventHandler( we.CDREventArrived ); w.Start(); // Do something usefull,block thread for testing Console.ReadLine(); } catch( Exception e ) { Console.WriteLine( e.Message ); } finally { w.Stop(); } } // Dump all properties public void CDREventArrived(object sender, EventArrivedEventArgs e) { // Get the Event object and display it PropertyData pd = e.NewEvent.Properties["TargetInstance"]; if (pd != null) { ManagementBaseObject mbo = pd.Value as ManagementBaseObject; // if CD removed VolumeName == null if (mbo.Properties["VolumeName"].Value != null) { Console.WriteLine("CD has been inserted"); } else { Console.WriteLine("CD has been ejected"); } } } } }
Note… In order to use the
System.Management namespace in .NET 2, you will need to add a reference to the System.Management.dll. This can be done in the IDE by right-clicking on the project in the solution explorer and choosing Add Reference… from the list. The DLL is on the first tab towards the end of the list of items.
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The first public release of Preset Command is now available.
Preset:
This plugin is technically pre-release so please create a GitHub Issue if anything breaks.
Looks like a nice addition to have. Unfortunately it ( still ) can not be installed via Package Control. Will have to check it out in the next few days to come.
You can install almost any GitHub or BitBucket hosted plugin via package control, even if it hasn't been added to the repository.
Honestly, I think this is one of the most underutilized features in Package Control.
It's a great trick, this. (Although, unfortunately, there are issues with this method for plugins that try to access their own files in ST3.) But like most of the ST ecosystem, it's not well documented. I think this is the most common help I've provided in these forums. It would be great if there was somewhere to link to. Maybe a documentation initiative with a low bar of entry. Or is there something along these lines that I'm not aware of? Maybe something like @tito's bugtracker: an empty project with a Git Wiki.
/sorry for the OT mini-rant
documented here: wbond.net/sublime_packages/package_control/usage
You should make an issue request on those projects for a completely ST3 compatible branch. These plugins should be using "sublime.load_resource()" to retrieve contents. If they want the same branch for both ST2 and ST3, they would just need a simple module like this.
def get_resource(package_name, resource, encoding="utf-8"):
packages_path = sublime.packages_path()
content = None
if int(sublime.version()) > 3013:
try:
content = sublime.load_resource("Packages/" + package_name + "/" + resource)
except IOError:
pass
else:
path = os.path.join(packages_path, package_name, resource)
if os.path.exists(path):
with codecs.open(path, "r", encoding=encoding) as file_obj:
content = file_obj.read()
return content
Anyways, getting away from the new plugin announcement. Though, perhaps the plugin will need to do something similar. Just took a look at the plugin and noticed the use of sublime.load_settings(). This returns a Settings object, not a string, so the plugin will fail when it runs. It would be great of jps could make the settings object iterable so this plugin could just look at the keys of interest rather than checking all of the keys in the default settings file.
This isn't the case anymore. I was originally using load_resource() but it's not supported in ST2 so I went to try out load_settings() which I dropped until I have something a little more feature complete and stable. So for now I've gone back to load_resource() and will be ST3-only for the foreseeable future. The uniterable settings object was a little odd for sure, I didn't exactly need to use it when loading the items for the quick panel but I've since made changes to improve the object handling. Updates will come quickly so I'm not going to post every time I potentially break something.
If you want it to be both ST2 and ST3 compatible, you can try something like that code snippet I posted. ST2 settings are much simpler as all the settings will exist in the Packages folder. In ST3, these can be in the executable directory, installed packages directory, or packages directory. Though you will have to manually remove comment strings in ST2.
That's fine, I just thought it was in a stable state since you made an announcement about it, but it's not a huge issue that it wasn't. If you think you will be committing broken code, consider creating a dev branch to work on. This is especially important if you want people to install via package control. Package control will grab the latest version of your master branch by default. You probably don't want broken versions being used by end users. | https://forum.sublimetext.com/t/new-plugin-preset-command/10011 | CC-MAIN-2016-36 | refinedweb | 644 | 66.64 |
I'm completely lost on most of this discussion, but thought I'd pop in with
couple ideas that may or may not be applicable:
1) In CXF, all the subclasses of AbstractDataBinding already have a
namespaceMap in them where the use CAN (not require) configure prefixes in if
they want. It might be good to push them into jettison. Keeps them
consistent between soap/json.
2) You might be able to loop through the schemaCollection for all the
namespaces up front to avoid the DOM thing. Doesn't solve the real prefix
mapping issue though. You could at least make it predictable by sorting the
namespaces and assigning them ns# based on the sorting order.
If I think of more, I'll happily speak up. :-)
Dan
On Sat September 5 2009 1:52:10 pm Benson Margulies wrote:
> Well, so, I've been working on the soggy saga of JAX-RS + Aegis + Jettison.
> I won't repeat other recent messages too much.
>
> Aegis likes to write namespaces. There is no option to use it unqualified.
>
> Jettison is really weak on namespaces. It someone to know all the
> namespaces and prefixes in advance of creating a StaX stream. That's not
> very realistic for Aegis.
>
> Jettison doesn't write out the definition of namespaces for you. You tell
> it that namespace X maps to prefix P, and it writes strings of the form
> P.qqqq, and never writes a definition of P.
>
> I have danced around all of this by making the JAX-RS Aegis provider write
> to DOM first, and then collect all the namespace prefixes, and then push it
> to jettison. I have no idea how to make the read side work consistently in
> any non-brittle way. Given that any sort of object, in any package, could
> turn up as a subclass, there's just no way to know what all the namespaces
> will be in advance. More to the point, when reading, seeing 'ns3.bloop',
> there's no way to tell what namespace should go with ns3. Very simple cases
> work where there's only one namespace.
>
> This might be addressed by prefixing an actual namespace map, and reading
> it. Alternatively, we could use a completely different scheme for handling
> namespaces than Jettison. Instead of adding prefixes to the element names,
> put them all in attributes (say, well, 'xmlns' attributes, by URI). Then we
> wouldn't lose any information.
>
> It could be argued that this combination is just a really bad idea. If you
> want JSON, you want a binding that can do unqualified elements. And if the
> DOSGi gang wants to avoid JAX-B that badly, perhaps someone from in there
> would like to add unqualified support to Aegis?
>
--
Daniel Kulp
dkulp@apache.org | http://mail-archives.apache.org/mod_mbox/cxf-dev/200909.mbox/%3C200909081628.18433.dkulp@apache.org%3E | CC-MAIN-2018-26 | refinedweb | 459 | 74.08 |
BZOJ 3524: [POI2014]KUR-Couriers
[POI2014]KUR-Couriers
题目描述
Byteasar works for the BAJ company, which sells computer games.
The BAJ company cooperates with many courier companies that deliver the games sold by the BAJ company to its customers.
Byteasar is inspecting the cooperation of the BAJ company with the couriers.
He has a log of successive packages with the courier company that made the delivery specified for each package.
He wants to make sure that no courier company had an unfair advantage over the others.
If a given courier company delivered more than half of all packages sent in some period of time, we say that it dominated in that period.
Byteasar wants to find out which courier companies dominated in certain periods of time, if any.
Help Byteasar out!
Write a program that determines a dominating courier company or that there was none.
输入输出格式
输入格式：
The first line of the standard input contains two integers,
and
(
), separated by a single space, that are the number of packages shipped by the BAJ company and the number of time periods for which the dominating courier is to be determined, respectively.
The courier companies are numbered from
to (at most)
.
The second line of input contains
integers,
(
), separated by single spaces;
is the number of the courier company that delivered the
-th package (in shipment chronology).
The
lines that follow specify the time period queries, one per line.
Each query is specified by two integers,
and
(
), separated by a single space.
These mean that the courier company dominating in the period between the shipments of the
-th and the
-th package, including those, is to be determined.
In tests worth
of total score, the condition
holds, and in tests worth
of total score
.
输出格式：
The answers to successive queries should be printed to the standard output, one per line.
(Thus a total of
lines should be printed.) Each line should hold a single integer: the number of the courier company that dominated in the corresponding time period, or
if there was no such company.
输入输出样例
说明
题解：
就是一个主席树模板。。
1 #include<bits/stdc++.h> 2 using namespace std; 3 4 const int maxn=5e5+5; 5 6 struct node{ 7 int sum,l,r; 8 }t[maxn*21]; 9 int n,m,root[maxn],cnt=1; 10 11 void bt(int &now,int x,int l,int r) 12 { 13 t[cnt++]=t[now]; 14 now=cnt-1; 15 t[now].sum++; 16 if(l==r) 17 return ; 18 int mid=(l+r)>>1; 19 if(x<=mid) 20 bt(t[now].l,x,l,mid); 21 else 22 bt(t[now].r,x,mid+1,r); 23 } 24 25 int query(int i,int j,int x,int l,int r) 26 { 27 if(l==r) 28 return l; 29 int mid=(l+r)>>1; 30 if(2*(t[t[j].l].sum-t[t[i].l].sum)>x) 31 return query(t[i].l,t[j].l,x,l,mid); 32 if(2*(t[t[j].r].sum-t[t[i].r].sum)>x) 33 return query(t[i].r,t[j].r,x,mid+1,r); 34 return 0; 35 } 36 37 int main() 38 { 39 scanf("%d%d",&n,&m); 40 root[0]=0; 41 for(int i=1;i<=n;i++) 42 { 43 int x; 44 scanf("%d",&x); 45 root[i]=root[i-1]; 46 bt(root[i],x,1,n); 47 } 48 for(int i=1;i<=m;i++) 49 { 50 int l,r; 51 scanf("%d%d",&l,&r); 52 printf("%d\n",query(root[l-1],root[r],r-l+1,1,n)); 53 } 54 return 0; 55 } | https://www.cnblogs.com/Hammer-cwz-77/p/8705805.html | CC-MAIN-2019-30 | refinedweb | 615 | 62.98 |
Running websites can be difficult with all the overhead of creating and managing Virtual Machine (VM) instances, clusters, Pods, services, and more. That's fine for larger, multi-tiered apps, but if you're only trying to get your website deployed and visible, then it's a lot of overhead.
With Cloud Run, the Google Cloud implementation of Knative, you can manage and deploy your website without any of the overhead that you need for VM- or Kubernetes-based deployments. Not only is that a simpler approach from a management perspective, but it also gives you the ability to scale to zero when there are no requests coming to your website.
Not only does Cloud Run bring serverless development to containers, but it can also be run either on your own Google Kubernetes Engine (GKE) clusters or on a fully managed platform as a service (PaaS) solution provided by Cloud Run. You'll test the latter scenario in this codelab.
The following diagram illustrates the flow of the deployment and Cloud Run hosting. You begin with a Docker image created via Cloud Build, which you trigger in Cloud Shell. Then, you deploy that image to Cloud Run with a command in Cloud Shell.
Prerequisites
- General familiarity with Docker (See the Get started section of Docker's website.)
What you'll learn
- How to build a Docker image with Cloud Build and upload it to gcr.io
- How to deploy Docker images to Cloud Run
- How to manage Cloud Run deployments
- How to set up an endpoint for an app on Cloud Run
What you'll build
- A static website that runs inside a Docker container
- A version of this container that lives in Container Registry
- A Cloud Run deployment for your static website
What you'll need
- A Google Account with administrative access to create projects or a project with project-owner role
Self-paced environment setup
If you don't already have a Google Account, then you must create one. Then, sign into the Google Cloud Console and click Project > Create project.
Remember the project ID, which is automatically populated under your project name. The project ID is a unique name across all Google Cloud projects, so the name in the screenshot has already been taken and will not work for you. It will be referred to later as
PROJECT_ID.
Next, you need to enable billing in the Cloud Console to use Google Cloud resources and enable the Cloud Run API.
Enable the Cloud Run API
Click Navigation menu ☰ > APIs & Services > Dashboard > Enable APIs And Services. .
Search for "Cloud Run API," then click Cloud Run API > Enable.
Running through this codelab shouldn't cost you more than a few dollars, but it could be more if you decide to use more resources or if you leave them running (see Clean up at the end). For more information, see Pricing.
New users of Google Cloud are eligible for a $300 free trial.
Cloud Shell
While Google Cloud and Cloud Run can be operated remotely from your laptop, you'll use Cloud Shell, a command-line environment running in Google Cloud. The environment is preconfigured with all the client libraries and frameworks that you.
Given that you're deploying an existing website, you only need to clone the source from your repository, so you can focus on creating Docker images and deploying to Cloud Run.
Run the following commands to clone the repository to your Cloud Shell instance and change to the appropriate directory. You'll also install the Node.js dependencies so that you can test your app before deployment.
cd ~ git clone cd ~/monolith-to-microservices ./setup.sh
That clones your repository, changes to the directory, and installs the dependencies needed to locally run your app. It may take a few minutes for the script to run.
Do your due diligence and test your app. Run the following command to start your web server:
cd ~/monolith-to-microservices/monolith npm start
Output:
Monolith listening on port 8080!
You can preview your app by clicking Web Preview
and selecting Preview on port 8080.
That opens a new window where you can see your Fancy Store in action!
You can close this window after viewing the website. To stop the web-server process, press
CONTROL+C (
Command+C on Macintosh) in the terminal window.
Now that your source files are ready to go, it's time to Dockerize your app!
Normally, you'd have to take a two-step approach that entails building a Docker container and pushing it to a registry to store the image for GKE to pull from. However, you can make life easier by using Cloud Build to build the Docker container and put the image in Container Registry with a single command! To view the manual process of creating a Dockerfile and pushing it, see Quickstart for Container Registry.
Cloud Build compresses the files from the directory and moves them to a Cloud Storage bucket. The build process then takes all the files from the bucket and uses the Dockerfile, which is present in the same directory for running the Docker build process. Given that you specified the
--tag flag with the host as gcr.io for the Docker image, the resulting Docker image will be pushed to the Container Registry.
First, you need to make sure that you have the Cloud Build API enabled. Run the following command to enable it:
gcloud services enable cloudbuild.googleapis.com
After the API is enabled, run the following command in Cloud Shell to start the build process:
gcloud builds submit --tag gcr.io/${GOOGLE_CLOUD_PROJECT}/monolith:1.0.0 .
That process takes a few minutes, but after it>/monolith:1.0.0 SUCCESS
To view your build history or watch the process in real time, you can go to the Cloud Console, then click Navigation menu ☰ > Cloud Build > History. There, you can see a list of all your previous builds, but there should only be the one that you created.
If you click on the Build id, you can see all the details for that build, including the log output. You can view the container image that was created by clicking the link next to Image.
Now that you containerized your website and pushed it to Container Registry, it's time to deploy to Cloud Run!
There are two approaches for deploying to Cloud Run:
- Cloud Run (fully managed) is the PaaS model where the entire container lifecycle is managed. You'll use that approach for this codelab.
- Cloud Run for Anthos is Cloud Run with an additional layer of control, which allows you to bring your clusters and Pods from GKE. For more information, see Setting up Cloud Run for Anthos on Google Cloud.
Command-line examples will be in Cloud Shell using the environment variables that you set up earlier.
Command line
Run the following command to deploy your app:
gcloud run deploy --image=gcr.io/${GOOGLE_CLOUD_PROJECT}/monolith:1.0.0 --platform managed
You'll be asked to specify which region you'd like to run in. Select the region closest to you, then accept the default suggested service name (monolith).
For testing purposes, allow unauthenticated requests to the app. Enter
y at the prompt.
Verify deployment
To verify that the deployment was created successfully, run the following command. It may take a few moments for the
Pod status to be
Running:
gcloud run services list
Select [1] Cloud Run (fully managed).
Output:
SERVICE REGION URL LAST DEPLOYED BY LAST DEPLOYED AT ✔ monolith us-east1 <your url> <your email> 2019-09-16T21:07:38.267Z
The output shows you several things. You can see your deployment, as well as the user that deployed it (your email address) and the URL that you can use to access the app. Looks like everything was created successfully!
Open the URL provided in the list of services in your web browser and you should see the same website that you locally previewed.
Now, deploy your app again, but this time adjust one of the parameters.
By default, a Cloud Run app will have a concurrency value of 80, meaning that each container instance will serve up to 80 requests at a time. That's a big departure from the functions as a service (FaaS) model, in which one instance handles one request at a time.
Redeploy the same container image with a concurrency value of 1 (only for testing purposes) and see what happens.
gcloud run deploy --image=gcr.io/${GOOGLE_CLOUD_PROJECT}/monolith:1.0.0 --platform managed --concurrency 1
Answer the subsequent questions as you did the first time. Once the command is successful, check Cloud Console to see the result.
From the Cloud Run dashboard, click the monolith service to see the details.
Click the Revisions tab. You should see two revisions created. Click monolith-00002 and review the details. You should see the concurrency value reduced to 1.
]
Although that configuration is sufficient for testing, in most production scenarios you'll have containers supporting multiple concurrent requests.
Now, restore the original concurrency without redeploying. You can set the concurrency value to the default of 80 or 0, which will remove any concurrency restrictions and set it to the default max (which happens to be 80 at the time of this writing).
Run the following command in Cloud Shell to update the current revision:
gcloud run deploy --image=gcr.io/${GOOGLE_CLOUD_PROJECT}/monolith:1.0.0 --platform managed --concurrency 80
Notice that another revision has been created, that traffic has been redirected, and that the concurrency is back to 80.
Your marketing team asked you to change the home page of your company's website. They think it should be more informative of what the company is and sells. In this section, you'll add some text to the home page to make the marketing team happy!
It looks like one of your developers already created the changes with the filename
index.js.new. You can simply copy that file to
index.js and your changes should be reflected. Follow the instructions to make the appropriate changes.
Run the following commands, copy the updated file to the correct filename, and print its contents to verify the changes:
cd ~/monolith-to-microservices/react-app/src/pages/Home mv index.js.new index.js cat ~/monolith-to-microservices/react-app/src/pages/Home/index.js
The resulting code should look like this:
/* from "react"; import { makeStyles } from "@material-ui/core/styles"; import Paper from "@material-ui/core/Paper"; import Typography from "@material-ui/core/Typography"; const useStyles = makeStyles(theme => ({ root: { flexGrow: 1 }, paper: { width: "800px", margin: "0 auto", padding: theme.spacing(3, 2) } })); export default function Home() { const classes = useStyles(); return ( <div className={classes.root}> <Paper className={classes.paper}> <Typography variant="h5"> Fancy Fashion & Style Online </Typography> <br /> <Typography variant="body1"> Tired of mainstream fashion ideas, popular trends and societal norms? This line of lifestyle products will help you catch up with the Fancy trend and express your personal style. Start shopping Fancy items now! </Typography> </Paper> </div> ); }
You updated the React components, but you need to build the React app to generate the static files. Run the following command to build the React app and copy it into the monolith public directory:
cd ~/monolith-to-microservices/react-app npm run build:monolith
Now that your code is updated, you need to rebuild your Docker container and publish it to Container Registry. You can use the same command as earlier, except this time you'll, you'll use that image to update your app with zero downtime.
The changes are completed and the marketing team is happy with your updates! It's time to update the website without interruption to users.
Cloud Run treats each deployment as a new revision, which will be brought online then have traffic redirected to it.
Follow the next sets of instructions to update your website.
Command line
From the command line, you can redeploy the service to update the image to a new version with the following command:
gcloud run deploy --image=gcr.io/${GOOGLE_CLOUD_PROJECT}/monolith:2.0.0 --platform managed
Verify deployment
Validate your deployment update by running the following command:
gcloud run services describe monolith --platform managed
The output looks like this:
apiVersion: serving.knative.dev/v1alpha1 kind: Service metadata: annotations: client.knative.dev/user-image: gcr.io/my-cloudrun-codelab/monolith:2.0.0 ...
You'll see that your service is now using the latest version of your image deployed in a new revision.
To verify your changes, navigate to the external URL of your Cloud Run service again and notice that your app title has been updated.
Run the following command to list the services and view the IP address if you forgot it:
gcloud run services list
Your website should now display the text that you added to the home page component!
Delete Container Registry images
#
Delete Cloud Build artifacts from Cloud Storage
#
Delete Cloud Run service
gcloud run services delete monolith --platform managed
You deployed, scaled, and updated your website with Cloud Run. | https://codelabs.developers.google.com/codelabs/cloud-run-deploy | CC-MAIN-2020-50 | refinedweb | 2,182 | 62.38 |
java.lang.Object
org.netlib.lapack.Sorml2org.netlib.lapack.Sorml2
public class Sorml2
Following is the description from the original Fortran source. For each array argument, the Java version will include an integer offset parameter, so the arguments may not match the description exactly. Contact seymour@cs.utk.edu with any questions.
* .. * * Purpose * ======= * * SORML(k) . . . H(2) H(1) * * as returned by SGELQF.,M) if SIDE = 'L', * (LDA,N) if SIDE = 'R' * The i-th row must contain the vector which defines the * elementary reflector H(i), for i = 1,2,...,k, as returned by * SGELQF in the firstGELQF. * * * * ===================================================================== * * .. Parameters ..
public Sorml2()
public static void sorml2(java.lang.String side, java.lang.String trans, int m, int n, int k, float[] a, int _a_offset, int lda, float[] tau, int _tau_offset, float[] c, int _c_offset, int Ldc, float[] work, int _work_offset, intW info) | http://icl.cs.utk.edu/projectsfiles/f2j/javadoc/org/netlib/lapack/Sorml2.html | CC-MAIN-2017-51 | refinedweb | 142 | 58.28 |
Im working on an rpg project heres the files :
main.cpp
new_game:new_game:Code:#include <cstdlib> #include <iostream> #include <conio> #include "new_game.h" #include "load.h" #include "help.h" using namespace std; int main(){ int answer; main_menu: cout << "RPG Game\n\n\n"; cout << "1) New Game\n"; cout << "2) Load Game\n"; cout << "3) Help\n"; cout << "4) Exit\n\n"; cout << "Selection(1 to 5):"; cin >> answer; if (answer == 1){ clrscr(); new_game(); }else if (answer == 2){ clrscr(); int load(); }else if (answer == 3){ clrscr(); help (); goto main_menu; }else if (answer == 4) { exit(1); }else { cout << "\nYou entered an incorrect key.\n"; system ("PAUSE"); clrscr(); goto main_menu; } system("PAUSE"); }
help:help:Code:#include <cstdlib> #include <iostream> #include <conio> using namespace std; int health = 100; int magic = 60; int armour = 5; int attack = 3; int gold = 120; int new_game (){ clrscr(); cout << "Health:" << health << "Mana:" << magic << "Armour:" << armour << "Attack:" << attack << "\n"; system("PAUSE"); }
No load game, i use int loadgame and i know its there but the program doesnt touch it.No load game, i use int loadgame and i know its there but the program doesnt touch it.Code:#include <iostream> #include <cstdlib> #include <conio> using namespace std; int help () { clrscr(); cout << "This is the help file\n"; system ("PAUSE"); clrscr(); }
So heres my problem. With my help and with my newgame functions it will not let me use clrscrn(); so i cant clear the screen. It also doesnt pick up any spaces i put in the armour/health/gold section.
I have no idea why its doing this as it will clear screen in some parts of the code like after the pause in help file when you hit enter. Thanks in advance | https://cboard.cprogramming.com/cplusplus-programming/106250-my-game-wont-clear-screen.html | CC-MAIN-2017-13 | refinedweb | 284 | 75.24 |
View Complete Post
I have three reorder lists on a page, one does not want to work. It is no different to the others, but is behaving like it is not enabled.
All working fine in IE 7 + 8.
Any ideas appreciated :)
Ive been stuck on this one for a month:
So I have a custom control that has a list of textboxes, and a button that will dynamically add a new textbox to the list.
So I have an addTextbox() function, that will do something like
TextbBox t = new TextBox()
then I add it to the page. So adding a new textbox works fine, but I have values that I want to put into each textbox and upon each page load, the values get replaced. What I need to do is get the textboxes from the viewstate so I can use their values for other textboxes, but since they are created anonymously, im not sure how I can do that. I tried to get the unique name and put all of them into an arraylist, then upon the next page load, load the names from the list, but the unique name isnt unique. Thanks
Can ...
Application has generated a exception that could not be handled.
Process id=0xb0c (2828), Thread id=0x910 (2320).
Click OK to terminate the application
Click CANCEL to debug the application.
Now ive dont all of that, when i click OK the message just disapears all the way, but when I click
CANCEL a differnt message appears. It says,
No Debugger found.
Registered JIT debugger is not avilable. An attempt to launch a JIT debugger with the following command resulted in a error code of 0x2 (2). Please heck computer settings.
Cordbg.exe !a 0b0c
Click on retry to have the proess wait while attaching a debugger manually.
Click on Cancel to ab
Hi,? created a Resource Dictionary in x86 architecture and it worked perfectly until i tried building it in x64. The error Im getting is:
Undefined CLR namespace. The 'clr-namespace' URI refers to a namespace 'Client.Controls' that is not included in the assembly. C:\Users\[USER]\Documents\Visual Studio 2010\Projects\Client\Client\Resources\Label.xaml
The ResourceDictionary looks as followed:
<ResourceDictionary
xmlns=""
xmlns:x=""
xmlns:
I have a class with the
Hall of Fame Twitter Terms of Service Privacy Policy Contact Us Archives Tell A Friend | http://www.dotnetspark.com/links/10017-problems-with-net4-control-gac-reference.aspx | CC-MAIN-2017-04 | refinedweb | 396 | 72.36 |
An Enhancement to NanoXML, the Extremely Compact Java XML Parser
An Enhancement to NanoXML, the Extremely Compact Java XML Parser
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Learn how to stop testing everything every sprint and only test the code you’ve changed. Brought to you by Parasoft.
The proliferation of XML for data interchange and configuration file format have resulted in numerous open-source Java XML Parser libraries (left image). Indeed, Java includes its own full-fledged XML library obviating the need to download additional XML library. However, the in-built and majority of open-source Java XML Parsers tend to suffer from few considerable issues like complexity and bloated size, and this tend to be normal rather than exceptional.
This is because the majority of Java XML Parsers are designed for enterprise usage and therefore the support for latest XML technologies like XPATH, SCHEMA are built, and combined with their complexity give Java a undeserved bad name). bundle it with mobile, applet, desktop solution that will be downloaded and deployed.
NanoXML
NanoXML is just the perfect Java XML Parser solution for those who value ease of use, simplicity and compactness. As its name implies, it is unprecedentedly lightweight and compact in size, taking less than 50kb (after modification) in space while still retaining important functionality ( a far cry from megabyte-size Java XML Parsers). Even though its development becomes inactive since 2003, its current version is still very much useful for processing simple XML stuff. It may not support the advanced technologies like XPATH, SCHEMA, however it is definitely capable of holding its own through its rich and easy API for searching, adding, updating and removing XML tag and attributes.
The reasons that I prefer NanoXML over competing solutions are because it is very simple to use, extremely compact, very fast and most importantly, it is much easier to extend its feature due to ‘lesser advanced’ features. Its compactness is particularly enticing for application that need to be downloaded over the web. In fact, NanoXML becomes a important component for those current projects I working now. This includes replacing the XML handling mechanism in gwtClassRun currently using string manipulation with NanoXML as having Java XML Parser will make XML processing more robust and easier to maintain.
Enhancement
Despite NanoXML in its current version 2.2.3, is a very useful library, it could definitely be made more flexible. Few caveats of NanoXML remain in this version that might deter its usage. Currently it ignores all comment in XML. Another problem is that adding of tag element can only be added to the last position. These limitations may deter others from considering it as a viable solution.
After failure to receive a response from the author over the request for those desired features, I ended up ‘hacking’ the source code and build those desired features. So after hours of dabbling with the code, the following ‘critical’ features are finally added.
- Parsing and generation of comment
- Adding tag element in specific position
See example section.
Download
The modified codes and binary are available for download
Rename the file to nanoxml-224.zip because WordPress.com does not allow zip file to be stored in its service.
For documentation and support, please check the NanoXML’s original site.
For those who are interested to learn and use NanoXML, they can download through the following site (Click on the image)
Note that the last official version is version 2.2.3 . Since I have modified the code, I unofficially distinguished it by making it version v2.2.4 without official approval from the author (After failure to receive reply from email)
Note that the changes is only made for nanoxml-2.2.3.jar file, not the lite or SAX version
Example
For those who want to learn about NanoXML and the use of ‘enhanced’ features, the following is the example.
test.xml
<root name=”main”> <child name=”me1″/> <child name=”me2″/> <child name=”me3″/> </root>
XmlTest.java
import net.n3.nanoxml.*; import java.io.File;); } }
Result
After running the code against the testfile, the output should display:
<root name=”main”> <!–This is new child–> <newChild att1=”me1″ att2=”me2″/> <child name=”me2″/> <child name=”me3″/> </root>
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Since I started write my first block of code, I heard from many developers that commenting is useless and it's a type of apology to write a bad code, but after working in a big projects with a big team, the only thing I can say is: Not commenting your code is narcisist and excludes beginners, by the way, who said your code is so good and obvious as you think it is? Yeah, your mind.
During your work, probably you faced a function that you asked yourself: "-What the hell is even that?". Many of us experienced this situation, even with our own code after some weeks far from the project. Now, imagine if instead of you have to waste your time, searching through the houndreds of files for the right function you need to put hands on, you could have just comment your code telling the function purpose, its params and what it should return. Life could be a dream, right?
Also, we cannot asume the everybody think like us and we are being so obvious. People have different ways to analyze things, we have people that are less experienced or even have mental health conditions like, anxiety and ADDH, and that makes the process of understand some pieces of code even harder. Should we just exclude them because we can't use one single minute to comment our complexity? I think we shouldn't.
The question is not about if you should comment your code or not, but is what you need to comment in your code and how it should be done.
Write a clean and easily readable code is unegotiable, and you get better on this with experience, but you can also write clean and good comments, so it can be used as a reference for you and the others, and it do not make you a bad programmer, on the contrary!, It makes you a better professional,your code will be easily maintainable, plus, you're ensuring that no matter the level of who enters on your team, they'll get it faster and start working on the project, and if you have to leave your job, the devs that comes after you will be grateful and thanks you everyday before they going to bed. (okay, I'm not so sure about this last part).
“Programs must be written for people to read and only incidentally for machines to execute.” - Hal Abelson - MIT Professor.
Recommended reads:
Best practices for writing code comments
What's the best way to document JavaScript?
Discussion (106)
It's never 'useless', but it can be overkill.
If code is written well (good variable & function names, clear logic), then it should be fairly obvious from reading it what it does. In cases where the logic is a little hard to follow then some comments can be very helpful. It can be a tricky balance - you don't want absolutely no comments ever, but at the same time, commenting absolutely everything just to try and cater for every possible skill level is also not a good idea.
If code is written well, and is uncommented - then it is probably the assumption of the team (as presumably the code has passed code review) that it is already understandable enough. If a new developer comes to this code and does not understand it, the best solution would be to consult a team member who does, and get them to explain it. This will have the dual benefit of increasing the junior developer's understanding, and making the team aware that there may be an issue with the code being too impenetrable in places.
And that's just it: Everybody thinks their code is well written. But most of the time it isn't near as good as the writer thinks it is. When I look at code that I wrote just 6 months ago I can see that it's not as good as the code I write today. I'm always learning improving.
If they can't write clean and readable code, why would you think that they can write clear and understandable comments?
I wish people wrote clean and readable code. Most of the code I read is crap. I must admit I don't have much experience reading comments.
Sadly, most devs aren't very good. Just like most doctors, lawyers, bricklayers, actors, barbers, politicians. Most people are mediocre at what they do. By definition, actually. Mediocre means average. Average isn't very good, usually.
But if a person can't even write decent code, I find it unlikely that they are going to write understandable comments in a natural language (much harder -- ask any writer), or, more importantly, that they are going to be diligent enough to keep that comment in sync with the code.
And my experience -- closing in on three decades -- bears that out. If you think code is bad, read the comments. They are almost always awful.
What's needed, really, is not comments but good code reviews by talented leaders who ensure that code is clean and readable before it goes into production. Which would also help to teach coders to write readable code in the first place.
But that might take time, right? We never have time to do it right. We only have time to write comments that we wouldn't have needed if we'd done it right, and then pay a bigger penalty down the road when the comments and code are incompatible and everything is a mess. Ever seen any code like that?
You made that up. Nobody is that bad. I did get a chuckle out of it.
It was a joke. But it's not as far off as you might think. :-)
I consider comments as documentation. If a programmer does not document their code... I don't have energy to finish that sentence.
Comments are a shit way to document code. The best way is in the code itself. So if your code is self-documenting, then you have documented your code. The only excuse for comments is that you had to do something in the code that you can't figure out how to make clear without a comment.
Maybe it's a workaround. Maybe you're just not that good. That's why we have teams -- so they can show you how to write better code.
In short, comments are generally where mediocre coders document their failure to write understandable code. It's either that, or the comments are redundant and probably just get out of sync.
So one could say that the more you comment your code, the more you're willing to admit that you don't write very good code. And if that's the case, then I guess comments are better than nothing. But why not learn to be a better coder or take up a different profession?
But hey, black and white condemnations like yours are all the rage these days. Maybe see a doctor, though, about your anemia?
It is always surprising how many devs confuse their personal preferences and pet peeves as scientific arguments and absolute judgements. And then boast about it.
Apologies. Sir, I do not condemn self documenting code. Most of the code I write is self documenting. We agree that bad code is bad code. You make a solid argument that comments don't improve bad code.
I generally use comments in a couple of ways. One is when I am writing a function or method, I write the steps out in plain English as comments before I implement them. Then I remove redundant comments. Some comments I leave because some things are nuanced and not obvious.
The second way is explaining, usually to my future self, why I did something a particular way, not what the code is doing, because well, I'm not as smart as I think I am. Even then, most of those comments are from my future self to my future future self to save time the next time I have to modify it.
Third, is explaining somebody else's code for instance, where they used a variable or parameter named "id" where id could be the column of one of 6 tables, and refactoring is not an option because it's spaghetti code in a huge legacy codebase.
I'm interested in your work flow. You're a teacher. I'm a student. How do you do it?
Sorry, I misread your last comment as saying that all code had to be commented. I rarely comment my code.
Instead I:
function returnFalse() { return false }
this, typically in callback functions (anywhere you might use
const self = this)
any
typenot
interface-- interfaces are mutable
unknownin production code
Also:
index.ts(x)or
mod.ts(x)
import not from "~utilities/not"
notfunction and use that
import typefor type imports, it's cleaner
appsfolder
utilitiesfolder (for generic utilities such as
not,
pipe,
identity)
servicesfolder for any bespoke services (i.e., not in an npm or deno module) such as authentication
modulesfolder for any reusable modules (e.g., generic components, icons)
import doIt from "~apps/TicTacToe/utilities/doIt"rather than
import doIt from "../../utilities/doIt"
In the
appsfolder, I have "micro-apps". These are standalone apps. Everything bespoke to that app is in that folder. Everything outside of that folder is generic and reusable.
So, for example, I may have a
services/useGraphQLfolder that provides a hook for using GraphQL, but it takes a config and returns
queryand
mutationfunctions. So the actual URL, query, variables, etc. are provided where they are used. None of this is hard coded in the
useGraphQLhook. (And I don't bother with Apollo -- a simple POST request returning JSON works fine.)
Inside the
appsfolder, I might have a micro-app called, I dunno,
TicTacToe. The hierarchy of that folder and its subcomponents would follow the hierarchy of the components, for example:
The benefit of this is that:
.tsxending tells me it is using JSX (I am forced to use React usually, though I prefer SolidJS or even plain vanilla TS -- deno gives me JSX for free)
<TicTacToe />) elsewhere in the app
I do not care how short a file is. Why would I? For some reason, many devs fear files. I don't get it. Why would I make a 1000-line file full of named exports when I could make a well organized folder tree with maybe 20 files, each of which contains a single function? If I need to view multiple functions at once, I can open them in side-by-side tabs.
Here is an example of the
notfunction I mentioned, from production code:
That is the entire file! Three lines. Here is a somewhat longer one:
That replaces an entire dependency (on "classnames")! You can see pretty easily, I think, that it takes an object with CSS class names as the keys and booleans as the values, and then includes only those that are true, concatenating them into a space-separated string. And if that's not enough to be clear, then in the very same folder is the test:
Other than a few polyfills for
Intland
Temporal,
fetch, and
uuid, my app uses only React, XState, and, sadly, Auth0.js (not my choice).
I write my own code, including utility functions, and reuse it from app to app, improving it as I get better (and the language improves). So yes, I write my own
pipefunction, and often
map,
filter,
find,
reduceand more (wrapping the JS methods where appropriate).
That means that I know practically my whole code base (an argument for vanilla TS). It means that to the greatest extent possible, no one else has code in my code base, which means better security, better reliability, etc.
It means that when things break, I know where they broke and why they broke, and I can fix them rather than waiting for the owners to get around to fixing them and releasing a patch.
It means that I am highly motivated to keep my code base simple, not to bulk it up with unnecessary and bloated dependencies.
It means that most of my files can be seen in full without scrolling.
And if my code needs further documentation, I try to put it in those README.md files right in the folder (README means GitHub will automatically display them).
That's just a start, but I hope it answers your question at least a little.
Lots of devs violently disagree with one or another of the above, and I have done all of these things differently over the years, but this is the methodology that has stood the test of time. I'm sure it can be improved still further, and significant changes in language, framework, or library might make adaptations necessary, but I can say that of the many people I've taught this too, none have gone back to their old ways. It's simple, and it works.
YMMV.
Good answer. That's more than I expected. It will take me some time to digest it all.
I struggle keeping my functions short. 50 - 100 lines is not unusual for me. Three line functions always make me second guess myself, "Should I inline this"?
Earlier, I was thinking to myself "I bet he uses readme files".
Your use of utilities is fascinating. I have some functions that I seem to redefine over and over in different projects. This a good way to organize then and not redefine them.
I've used the folder/index.* naming convention in one project. It confuses me a bit and make my tabs too wide when I get several files open at once.
The temporal polyfill is interesting.
I like writing vanilla js for much the same reasons you use vanilla TS.
Good Night
@chasm
Just wanted to say that I agree with almost every statement. I have made very similar experiences during my time as a software developer and have come to very similar conclusions. Most of the things are in line with Uncle Bob's Clean Code. Thank you for the detailed elaboration!
+1 I couldn't have said it better myself
thanks
I've never in my years of education been told (except from that student who doesn't want to comment their code) that commenting/documenting code is "useless". Oh my! Documenting your code teaches beginners what you're doing. Not documenting at all excludes them because....how are they supposed to understand if you don't explain it in plain english? I bet the developer himself/herself won't even remember what the program he or she wrote does five or six months down the line without documentation. Who is it harming? True productivity, team work, and efficiency? Or just their ego and arrogance?
If you keep naming your classes, methods, parameters and variables consistently and their names express their purpose, your code without comments is easy to understand even for beginners.
Sometimes comments are necessary to describe and point to code that does not work in an expected way, and you have implemented strange looking workaround. For example some libraries, used in your project may have side-effects and wrong behavior and to overcome these problems, you have to write strange-looking code. And in this case comment helps to understand what is going on.
I totally agree on this. I write and read mostly deep learning Python code. Therefore, I understand the pain when reading undocumented inputs. Documenting these code not only teaches the beginners SOTA but also save time of running the code again just to determine what is the correct shape of a Tensor.
But if you have beginners in a project, you can not rely a decision on this, which affects how the whole project and code is build. Again, just to provide an example, you would need to maintain the comments, if you do not, these will rather harm the process of understanding.
It is possibly a better approach to on-board and support beginners well. Allow them to contact and ask you whenever they need help. Be their mentor and teach them to work with the code like an experienced developer, do not create "code for the beginners" with comments all over the place.
Yep fully agree. It isn't harming anyone, but more so creating an inclusion to new people and beginners.
My golden rules:
Add a summary at the top of a function about what it does.
This way I do not have to read and mentally parse your functions code to understand what it does.
This does not apply to very simple functions where the function name can describe everything like
removeLastCharacter(). But
calculateSingularityProbability()might win by some description.
Add comments to reduce mental work
If some line(s) are really complicated, add a short comment above describing what it does.
Add comments to explain hidden knowledge
Why are you doing array.pop() twice here without any appearant reason? Well, because I do know that the array always contains two empty entries at the end, which we don't want.
If you write the code, you have that knowledge at hand. Your team member might not. And you, looking at that code in 2 month wont remember either.
I have to say, I disagree.
calculateSingularityProbability()is already a pretty good summary, isn't it? It shouldn't be necessary to describe formally what the function does exactly because, well, that's exactly what code is: a formal description of behavior.
If you write code that you think is hard to read and needs a comment then why don't you change the code instead of adding a comment? This is like creating a product with a crappy UX and then writing a descriptive manual instead of fixing the UX.
Why don't you wrap the double
array.pop()in a function named
removeEmptyArraysAtTheEnd()? Shorter functions, single responsibility maintained and description inside the function title. No risk of "changing the function but forgetting to change the comment".
In my opinion, writing comments is the last resort and should almost never be done. Instead, keep functions very short (10 -30 LOC) and parameter count low. I recommend reading Uncle Bob's "Clean Code".
I prefer reading one line of comment in human language than having to read 10 - 30 lines of machine language and parse it in my head to figure out whats going on.
I read that book. Also many others. 👍
Don't you prefer to read one function title that describes on a high level in human readable language what's inside the function? Basically the same that would be in the one comment line?
We went full circle to my initial comment. Yes, there are simple function where all they do fits into the function name.
Since functions are composed from other functions no matter how much you break things up, you will end up with something more complex. And the case will be even worse since I now have to scan all over the place nd go down rabbit holes to understand whats going on inside.
I also mentioned that its depending on the cases. You cannot generalize the topic.
I understand what you're saying. I would argue, though, that only because you add a layer of abstraction to something, it doesn't mean that you need to understand every detail of the layer below to understand the abstraction. I would even say that's the purpose of abstraction.
So when you compose 5 functions in a new function, you don't need to read the code of the 5 child functions if they have a descriptive name.
If I wrap five HTTP requests in a repository, I don't need to understand the HTTP request logic to refactor the repository. I can stay in this layer of abstraction because I separated all the logic into smaller pieces.
I would argue that if a function does more than fits in the function name, the function does too much. If it's only one responsibility, it can be usually described in a short title.
But we may have made different experiences and we will possibly not come together and agree here and this is fine :).
Agreed big, and so few developers know that I always hear those words and I can't argue.
Best line ever:
"Not commenting on your code is narcissist and excludes beginners, btw."
"Who said your code is as good and obvious as you think it is? Yeah, your mind." Yes Yes Yes a lot of developers say it and yes it's only good in your mind even the seniors will struggle with undocumented code.
Although I do see your point, and I myself tend to "over comment" my own code, there is a valid argument to the code being self documented. Interestingly, with a "meta programming" language, such as our Hyperlambda, the code literally is self documented, due to the abilities of the programming language to extract meta data from the code, being able to intelligently understand what each snippet of code does, to the point where you can write stuff that's logically similar to the following (pseudo code).
Of course the above is pseudo code, but still a perfectly example of something easily achieved with a "meta programming language", resulting in that your "comments" literally becomes its code, and information about what the code does can be dynamically extracted using automated processes, allowing you to easily understand everything your code actually does, without having a single comment in your code base.
Still, kind of out of fear from possibly being wrong, I tend to document my code (too much) ... :/
I love self-documenting "What does the code do" but I have yet to see self-documenting "Why does it do it?"
"Why" is a question that has nothing to do with the implementation. It has something to do with the requirements. These come from the stake holders. They should document the requirements somewhere else, not in the code. If the code is the single source of truth for the requirements of your software, then you're doing something wrong.
"Why did I choose to use this mapping method? Because in exploring the options this was the most performant."
That's never something you'll see in requirements somewhere and is ideally situated near the code you wrote.
If it's really a matter of performance, then I agree. However, in today's web applications, performance on such a low level is almost never a concern. From what I've learnt, it almost always boils down to IO in a loop or other nested loops with cubic complexity.
Apart from that: readability > performance. Unless you're working in game industry or doing other low level stuff.
I've spent a long-time in open source. The one thing that invariably remains…the source code (and it's git history). All other things rot and decay far faster.
So, include whatever comments can help provide contextual support of the local "state" of the code.
In addition, one must consider that placing way finding comments in a code-base are of high value.
There have been a few cases, where past decisions/specs were lost but we still had code. I don't want to go and "backfill" those specs, so I'll write a note saying "This is my understanding given what I've been able to piece together."
Okay, maybe I am viewing it too much from a business perspective. It seems like there are a lot more specs from a non-technical view there. This somehow eliminates the need for specs inside code.
If you use comments as way to communicate with other developers working on the same code base and have no real communication channel outside of that, then I can better understand the necessity!
We're both looking at the same "elephant" but from different perspectives. The code is the most accurate representation of the product. It says exactly what the product is. There will invariably be cases where the intention of the code will be hidden in a private Slack channel, a lost email, or even an unrecorded Zoom meeting.
The code is the product and provides the most reliable place to "pin" a way finding comment/annotation.
Specs inside code are…treacherous. A URL in the code to that spec? Gold!
Good point, but I was speaking of the ability to runtime extract semantic data about what the code does, not reading the code itself ...
But you've got a very good point ...
I intend to write a full post about this sometime, but here are my thoughts in summary.
Self-documenting code doesn't exist because the purpose of documentation is different from what clean code gives you. Cleanly written code makes it trivial to understand how the code functions — nothing surprises you, the code isn't hard to follow or constructed of spaghetti, chunks of it fit neatly in your memory and it doesn't require you to go back-and-forth too often. You understand both the implementation and the abstraction quickly and cleanly. It exposes all of the how and most of the what, but what it doesn't necessarily do is explain all of the why.
Sure, well-written clean code with properly named functions and properties etc. can help expose the why, but it still requires you to do several iterative readings in any sizeable codebase to grasp the original business intent — namely, why does this code exist at all? What purpose does it serve?
That's where documentation steps in. Documentation should expose as much of the why as possible, and some of the what, without focusing at all on the how, since how it is implemented is quite literally implementation detail, and is subject to change even without the original business intent changing. The why changes very rarely, and also requires the least comprehensive documentation (the type of documentation that Agile tries to avoid) which is quick to read and grasp.
In my experience, pretty much every programmer I've met who has clamored for "don't write documentation, write self-documenting code" has parroted this statement because they didn't want to spend the time it takes to write documentation in the first place, not because they genuinely believe trawling through the code trying to tenuously grasp the intent of its writing is better than reading a short document about it.
I've always found this to be a pretty egotist attitude. "My code is so good you shouldn't need help to understand it".
I've learnt there's a balance in commenting. There are really 3 use cases:
And what is not egoist about thinking that a comment is so good that every reader should get what the corresponding code does? If you know by yourself that your code might be hard to read, then why don't you refactor it instead of adding an explanation? Reminds me of products with manuals that nobody reads. Always asked myself why they don't make the product of intuitive usage instead of writing a manual. Apple was the first big company to understand this.
Yes, but that's not so much because I didn't comment the code, as that I didn't write clean, readable code in the first place. If the bit of my wetware that needed to light up at the time to tell me to comment it had actually been doing its job I'd have written it better anyway!
Mostly, I'm on your side in this. I like commenting things. I like having a standard doc comment at the top of every function, even if it's "obvious".
However, I've had colleagues who don't, and their arguments are usually something like, "now you have to update two things", i.e. whenever you make a code change you need to make sure the comments and documentation match, and it's way too easy to forget. In fact, how many times have you seen the same comment repeated because someone's copied a component from one file to another to use as a kind of boilerplate, even though it has an entirely new purpose now?
I guess that it is necessary some context, but to make it short:
better this
I'm so happy to see so rich discussion here in my article! Thank you so much devs.
I don't think leaving out comments excludes beginners. Quite the opposite. Writing too much waste into your code sets a bad example. And I've seen more redundant comments than useful ones in codebases I worked on (including my own).
My favourite to this day is:
Does this look beginner friendly to you?
If you do want to comment stuff, please write proper JavaDoc / JSDoc / whatever-Doc. That's what it's there for.
@desc,
@property/s and
@returns.
And if you want to go bonkers, at least be so kind and do so in your automated test suites. You can even use
@seein your production code base. And everybody wins.
Great article! Writing comments about what your code does can be helpful. But, I've learned that writing too many comments can be excessive.
The line I always take with students I mentor is that I don't need a comment to tell me what the code is doing, because I can read the code just fine, and most of that can be encoded in variable and function names, like
frobnicate_the_input_array()and
input_array_to_frobnicate. I need comments to tell me why it's doing that, and particularly why you're not doing it a different way.
"But requirements and statements of purpose don't belong in the code! They should be in other requirements documents." As a developer, I have ready access to the code I'm working on, not the requirements docs, and I especially don't have anything to connect
frobnicate_the_input_arrayto a requirements doc saying that the input array needs to be frobnicated, or to a later decision saying that it needs to be frobbed in reverse order. That's what I need a comment for.
This is a straw man argument. I don't know a single developer who never writes a comment. The argument is over whether you should comment everything, or just when a comment is needed, which is inversely proportional to the amount of clean, readable, and easily understandable code you write. The argument is not that you should never comment your code.
If you have to make up a straw man argument, then your credibility as an authority is undermined.
"There are two hard problems in computing: cache invalidation, and naming things".
Naming things is hard, which sometimes leads to comments. For the longest time I was a proponent of comments, and it is what was drilled into me growing up. I never heard about them being "useless" or that they should be avoided until the mid 2010s. Now I try to be pragmatic about them: and always consider "does this comment bring value?" "If so, could the code be changed to make the comment unnecessary?"
My reasoning about this, including some pet peeves and "uselessness" is in one of my old blog posts. The counter argument (use docstrings / doc-comments if your language has them) is in another.
Meta:- I should clean these up a bit and post on DEV...
Guy who write the code usually don't have enough distance (and often not enough skill where, documenting is an animal in its own right!) to document the same.
I encourage devs to ask questions, and document code they come across when they don't get it (hopefully, after they figure it out). This means that, the meandering effort you refer, of figuring what it really does... Somebody, in my experience, have to do this at least once.
Most, "horse did, horse mouth documented" code I come across - the docs in there paraphrase the code - dead weight which I promptly delete in a separate commit (sneering is not productive, removing dead weight is)
Good comments often signal bad code. Guy suddenly realized some danger with their code, wrote a comment and moved on cause no time to fix. Which is perfectly fine. They save somebody else the trouble of falling into a trap, and boost the confidence of the time-endowed person who are going to fix the code, and delete the signpost.
I'd much rather a
// bad codecomment than nothing - because I respect my co-workers. If something looks twisted and isn't labeled bad/clumsy I'll assume its crooked for a reason, whereas sometimes it's not.
Part of being an API designer (and much code isn't "API" just grease) is having a knack for roleplaying as a beginner, and adopt the TLDR mentality of somebody who need to understand something, but are lacking the time and dedication to do verbose let alone code.
Not all code that needs documenting is bad, but writing code that people just get without much effort (and if possible reading signatures NOT the code) is a good smell.
Ok so there are like 100 comments that I honestly won't read (I was eager to read the first 10 but got tired at 5).
What whas that? It's honesty. We all should practice it when coding, because we know what we are doing at the time of coding whatever but we should be honest and think that "My future me will love to see comments on this code".
"Yeah but there are functions that are SOLID and don't need comments because blah blah"
I had the exact same conversation with a colleague the other day so let's mimic it:
Is it straightforward, isn't it?
But how do you know what it returns?
"But Joel, it returns a user, A USER!"
Nope, it returns a Promise that hopefully will retrieve a user (as long as it exists in the DB).
And me and you, and the rest of the team will love having this information without the need of Ctrl+Click over the function name to see what is doing behind the scenes.
So when you are about to use this function you get:
Here it is! Inference! Beloved inference.
Moreover if you use TS pragma
at the top of your JS file it will use TS when it's important, in dev time.
Without adding TS as project dependency plus without the extra bundle time of compiling/transpiling TS into JS.
It will use JSDoc to type-check your functions and variables. VSCode will handle it out of the box.
So if you try to do something like passing a string it will correctly complain like that:
Look how cool it looks like!
It looks even cooler in VSCode as it changes the color for the JSDoc when properly written:
Sooner or later I receive either a "you are right" or a "you were right" about that.
I had been in enough projects to say that this is a must.
I've been ignoring this, because I'm tired of the "conventional wisdom (or a straw-man version) says X, but I oppose that" genre of article. However, there are a couple of points to make.
First, as I hinted, nobody really says not to document your code. No (serious) programming language lacks a way to write comments, and several try to shift the focus to the comments, so-called literate programming.
That said, comments are almost universally an admission of failure---the "I don't actually know how this works, so don't touch it" style---or vapid descriptions that have nothing to offer beyond repeating what the code does...or, rather, they repeat what the code did when it was first written, but haven't received an update since then. How much time in your career has reading a comment saved you?
The problem is that "comment your code" implies the latter, inserting comments that follow the code. "This assigns the current total to the
totalvariable." "Loop over the array indices." "Increment
iby one." Not only are those comments useless, but they make maintenance more difficult, because someone needs to always double-check to make sure that the comments reflect the code...but you already have the code.
Rather, you want to comment the project, from within the code. For some examples.
If, instead of covering that kind of ground, your comment explains the syntax, though, then you should rewrite the code instead of writing the comment. If the comment explains what the variable name means, rename the variable, instead. Those comment the code, and no developer should be forced to read them...
There are certainly scenarios where writing comments can be useful, though I would also argue that you should not use comments as a cruch. Anywhere your logic is complicated by all means write a comment, but if your logic is not complicated you should focus on giving the write name to your function. For example.
But comments don't make much sense in the following example
First preference in my opinion should be to name things properly, use the single responsibility principle as much as possible and then if logic is still complicated then add comment.
It's a balance. If creating code for demos/illustrative purposes, definitely need more comments. Otherwise, think 2x before putting long comments. Usually, I will add a comment if I found that I screwed up more than a couple of times b/c I forgot the same thing. That's a good spot to put a warning comment or something like that.
Also, add comments when there is a better approach, like a refactor, but we are not doing now b/c of time shortage, for instance. Like a:
// TODO. You can even do comments that kind of assign for someone else like:
// TODO{john.smith}They can search for their name, etc. Probably can connect to some type of workflow that will automatically generate assigned issues using the comment in GitHub.
I always argue for documentation comments, and against random comments.
*Doc, if it's written well is always welcome. One line comments before a function call of the same name are generally terrible!
First, if you start using comments to explain your code, you will have to maintain these as well. Guess what, this likely will not happen everytime, because people need to always keep in mind to do this whenever something in code changes.
Second, code can be self-explaining without the need to look for a certain function. Usually the naming and how you build the whole project helps a lot and maybe sometimes it is necessary to see, what other functions are called, too. But if you cannot understand it without looking for many other places in the project, maybe something different is wrong and the issue is not missing comments. These would rather patch the issues, not solve them.
I am not asking for to not comment, but usually there are only a few special cases, which actually need comments and this can be very specific to the technologies chosen.
Is it just me or feels the "mental health" and "inclusion" part again just following a trend? I would not say it is wrong (I am totally with you in sense of, that not everybody is the same and we need to respect and support each other), but I do not see, how the commenting part has to be necessarily connected to this.
You can have high quality comments and that helps a lot navigating codebases.
There's usually a lot of context behind the decisions for some routing and for code that has to be read a lot (99% of it) they help.
For enterprise apps that have been touched by lots of people (most of them already gone), comments are valuable. I've found important warnings/explanations and it's saved me hours that are spent in better ways.
Comments are async communication and expand context beyond the mere computer instructions.
Write comments if you need "external" context to understand "what the heck" this piece of code is doing - by "external context" I mean knowledge/info that can't be derived from that piece of code (function, method, class, module) itself.
I do not agree in some parts, your code is changes, the comments often not. once you found several times a comment which lied to you, you start to ignore them. then you have often autognerated code for your linter and pipelines and setter etc which often is also teaches you "just ignore it". if your code has many stuffs which is just boilerplate or self explained you start to ignore even more the comments. so if you have code parts which is ignored by others, then people will do not take care of it since noone relies on it.
if you have a code which usually has no comments but then you find here and there one line with a comment which describes why it is there, then this is very usefull. you need sometimes comments, describing a regular expression or a method which do nothing or something weird but in general for most cases your code should be readable and understable enough. i changed in my editor the comment color to red or even pink. and if i see too many of this color which is useless, i just delete it because it hurts to look at it. and if i find a comment which is required, the bright pink color reminds me to read it because it is an important part there
and if you leave your job, make sure have ENOUGH, unit, implementation and e2e tests (also more unit tests than impl. and more than e2e follow the pyramide) which runs FAST and can tell you RELIBALE that your project or at least the critical parts of it are running without failure.
I have seen code with too many comments. Something like five lines of code having 5 lines of comments each, which really breaks the flow of reading code for such a simple function. That being said, I think it's important to describe the purpose of each block of code with some standard format. It also helps some IDEs provide you with infirmatiomnon mouse over, which is incredibly helpful. So that being said, I try (and usually fail) to use my comments like so:
I use comments in the code very sparingly and only to tell the story about the reasoning behind the code if that should not be obvious even to a beginner.
I'm very liberal with elaborate JSDoc blocks above my API interfaces, though.
Too many comments are not just useless, they're detrimental to legibility, and are a typical feature of poorly designed code
As a rule of thumb:
Feeling completely lost in someone else's code is not at all correlated with amount of comments, it's associated with poorly designed code
There are only two disadvantages to writing comments. First, and least important, is the column inches it may take up. Annoying, at best. Decent IDEs will collapse such a comment if asked.
Second, however, is that, like code, comments can become stale and therefore misleading or unhelpful. This is very serious. Comments must be updated as part of the code they describe should that code ever change. Because comments are code.
Not writing and maintaining comments is narcissistic and brazenly hostile to a) others who read your code trying to figure out what you meant to do and b) yourself down the road a few years should you have to do the same thing as (a).
By the way, not writing unit tests is also unforgivable and an "armed assault" on others just as is (a) above.
Most of my comments are for me 6 months from now when I will be asked to debug or modify the code again, and I surely will ask myself "what the heck was I thinking when I wrote this"? It happens to me all the time.
I'm dealing with 20 years worth of legacy code - some methods have 20 - 30 optional parameters and almost no comments anywhere - it takes hours to make even minor changes because the person who wrote it thought it was so obvious what their code does. And then on top of that, single and 2 letter variables names all over the place... Refactoring that mess is a nightmare of technical debt.
If you don't comment your code you are some combination of lazy, narcissist, and noob or someone who just thinks that they are smarter than everybody else, and you may well be. But the people that wrote the mess I'm fixing weren't that smart - but they thought they were.
Sometimes people say comments are "distracting". But I've always made the syntax highlighter make them light grey so I can tune them out visually if I want to focus just on the code.
That being said.. I've been through enough nightmares to know the value of good comments. I'd definitely say any comment is better than none. But in my experience code very rarely has comments (when not written by my team).
I believe there needs to be a balance. It's hard for me to believe that one can achieve the highest standards of readability in a production-level application with no comments. If written well, code will explain everything related to how stuff is happening. But based on my experience, there's always a need to document "why". And code often fails to achieve that without comments.
I think it's a quite known fact that real-world apps need to sometimes take paths that aren't intuitive, you would insert if-else in your function possibly destroying the single responsibility principle, because of business needs.
A comment explaining the purpose of what your code is doing is always welcomed.
Here's a talk by Sarah Drasner on Code comments, can check out if interested.
First please don't promote wrong things!
I honestly didnt know where to start arguing so i won't and I will give you another perspective.
Being in a real world project with multiple teams or devs working on it is complex enough. If for whatever function or line you need to comment might as well change jobs. This is not scalable at all. We have all sorts of tools at are disposal. Typescript, unit tests, automation tests, documentation of features (not blocks of code) function complexity tools.
Commenting means one of the two things when code isn't self explanatory that you are doing too many things or you aren't giving correct variable, class, function names so things needs to be explained. Again this isn't ok. This needs to be corrected. Leaving a comment will solve the situation at that moment. What about when someone refactors that piece of code. The chances of the comments being updated accordingly are slim to none
When you read code you need to understand it. Having comments negates the purpose of readable code and allows windows of badly written code because "well it was difficult so i have added a comment". but then another dev comes to enhance the functionality and will either read the comment and understand nothing because most likely it's an essay which makes no sense so he starts reading the code and again makes no sense of it so he starts debugging line by line till he understands it. If you can write good comments and bad code then ask someone to help you write in a way that's readable. If your content is short and still have to write it, seriously look at your code and find out why you need to comment it. Something so wrong. Sit and think plan or what you want. Finally and most importantly unit tests are your documentation of your class or module. If you don't understand the code in place read the unit tests which should have good description of functionality not a comment which will be deprecated in the first iteration.
Don't use comments as an excuse to write tens or even hundreds of lines code cause the only thing that you are adding to is complexity for the next developer to have to read through and try and change which will most likely lead to a refactoring.
If what whatever reason you meant documentation in your topic this is completely different and i couldn't agree more with you but i don't think you do.
Please don't promote bad practices cause if others adopt what you suggest repos will double in size :p
Good practices and conventions are what allow self-documenting code. Not your mind. I wouldn't advise a newbie to avoid comments. Naturally someone who starts out doesn't know anything about architecture. There is already a structure and pattern for everything we want to do.
After thinking and experimenting with this a lot, I'm convinced the rules are simple.
Inline comments only answer "why". What, where, who and how should be represented in the code by correct encapsulation and naming.
Comment external interfaces so they show in the editor. For example, a function should have the parameters commented, a class needs the constructor commented. This comment should never contain the name of the variable/parameter.
Comment after a bug fix, to avoid falling in the same error again.
That's it. Excessive commenting is lies waiting to happen.
I think that people missed a point in Uncle Bob's book about this topic. He did say that writing comments is an excuse for bad code, but he did mention somewhere that it's OK to add a comment if a certain function or block wouldn't be obvious to others if for example there is no way to make it better.
The function name should convey its purpose. Same for the params. When I see a docblock above a function it usually means one of 2 things. 1. The comment is entirely redundant or 2. The function doesnt have single responsibility.
Except in config files I've never seen a comment that told me more than the code itself. The inverse however is true. I've seen a lot of outdated comments that no longer convey the purpose of the code, or even comments that flat out lied, because they were copy pasted from somewhere else and not updated properly.
IMHO docblocks make devs lazy. Focus on writing good clean code (there are books about that if you're interested) don't waste everyone's time writing comments ;p
One problem with the commenting code I see is that when you write "what" code does then you are gonna use commenting as excuse to write bad code. Like "Hey, that code smells", "Ya, but I have comment which explains all". And you don't feel the need to write better code.
Well... I don't agree!
I respect your opinion and I believe that if is a team standard you should follow that.
But in my opinion, if you write clean code you don't need to write comments. In fact, it makes the code unreadable.
Of course, comments are allowed when you think the code it's not selfexplanatory and writing a comment is a better solution to explain some code.
I usually add comments when I fix a bug and there is no way that my code can explain why that code is added. So I only add a comment with a link reference to the issue. Or sometimes when I add a utility function that needs some small comments and why the code is written in that way.
You have to keep in mind, that writing comments, means that you have to maintain them too! And that means, whenever you change the code, you have to update the comment too which is tricky if you write many comments because usually code have dependencies on other parts of the code and then you will end-up maintaining a comment that is written elsewhere which might have no relation to the code you changed.
Another reason is that adding many comments makes the code verbose and sometimes you will think that removing all the comments makes it easier to follow the flow of the code and/or read the code.
I have worked on a project which was full of comments and was the worst experience ever for me.
Personally, I always try to avoid writing comments, and if I see that a component is way too complex, I prefer writing a "component.readme" file explaining the complex topics that need to be explained for that component.
Another important part of not having comments, is Git. If I fail to understand something in a file, I simply look at the histofy of that file. Many times it has helped me understand what I was looking for.
I think if you have to make comments to say what your code is doing, then it probably wasn’t written to be readable.
Comments are good as long as they aren’t unnecessary comments like commented out code.
Generally I don’t like having comments at all, because they sort of keep the code looking messy.
Good variable names indicate what concepts are involved. Clean code can document the execution model (what the code is and how it functions) but code itself can not explain "why" a certain routine had been chosen in favour of others.
From an engineering perspective the "why" is important to reason about the code on a higher level than just the few lines in front of the eyes.
From my experience with reading many many open source project code I can only say: the more comments explain what's going on, including well written jsDoc, the better it was to create a PR to that code.
For me, the necessity to add comments to code is a smell. If you realize, your code might be hard to understand, then why don't you refactor the code instead of adding a manual? And what makes you think that the manual is understandable if you're incapable of writing understandable code?
Do you think Apple would ever give out a bloated manual for their products? Or do they just create products that are intuitive?
Also, I don't agree that code is more maintainable if it's commented. What if there are changes to the code and/or the comment and suddenly the code and the comment have contradictory statements. Which do you trust - the code or the comment. And when people realize something like this happens, they stop trusting the comments inside the code and it becomes a mess all over the place.
There is a reason why we can name classes, functions and variable. Because they are supposed to be descriptive. Why don't we use this opportunity to write self-documenting code instead of relying on a meta layer like comments?
I've never heard in a decade of software that comments are useless. They're the LAST step though. Identifiers and types should provide as much information as possible. Then comments only when there are gaps.
Comments should generally say WHY not just what you're doing. IE I had to add a bug fix that wasn't merged into an older version of jQuery that we were self-hosting. I had a big giant comment of What I did and WHY I did it.
I've had some jobs where they avoided comments more than others. I agree that often one's code isn't as readable as they think it is. Comments of high level logic do add value because people forget and code review doesn't always force great naming.
I think a lot of this whole "code should be self-documenting" critique of comments implicitly assumes that comments are used to document WHAT the code does.
But I find generally find the most useful comments talk about WHY the code does what it does. Which the code does not do, no matter how good the variable names or the structure is. Especially in enterprise code bases with hundred of thousands of lines och code.
It is completely obvious what deleteLastRowInTableIfSecureFlagIsSet() does. But why? If the system is re-architected to no longer use secureFlag, what should happen here? If there is a bug related to the function, what is actually the correct behaviour? If we switch from SQL to a key-value store that doesn't have a "last row" what should happen?
So IMO a rule of thumb is that good code comments explain WHY, not WHAT. And in that light this whole debate misses the point.
I think people is just taking things literally. The people who told you comments = bad were just parroting what they read online and didn't fully understand.
There is a place and time for comments. IMO, they should be the exception and not the rule though, or at least the coding standards should aim for that.
It's much better to have a small, self-documenting method, but it's also very damn important to have a good, descriptive, multiline comment in a chunk of complex, messy code.
Just use your brain people, there is no silver bullet.
An emphasis on self-explanatory code should still be the key.
Writing out params is verbose and possibly trivial, unless they are not clearly defined. For Javascript, Typescript is really helpful in achieving this, but it shouldn't come at a cost of adopting poor naming conventions. More likely, code's context and purpose is more useful as a comment, rather than a technical explanation of individual variables.
Ultimately, it's up to the team to agree on maintainable code practices, adhere to them, and ensure code readability.
More often I have seen comments that led me to spend time wondering what it means and in the end find out I've just wasted my time because it was outdated. Comments are used when it's too complex to read.. then the real problem is that it's too complex and should be simplified. Comments should be rarely seen and explain the "why" it was done this way. Explain why you had write this exotic solution.
You have pretty strong points in your article. I noticed popular programming languages such as PHP are evolving on this point, though. For example, named parameters self-document the code. Union types allow skipping verbose PHPDoc annotations.
IDE can map such features and auto-complete parameters. Probably more efficient than multiple lines of description.
However, nothing is magic, and IT likes catchy slogans and bold statements like "Do not comment your code, it should be self-documentated."
I think it's misleading. The right statement would be "write your comments carefully" or "use comments with caution."
I really appreciate comments that explain the dev's point of view or specific constrainsts that leaded to particular choices. There are always pros and cons, and it's easy to judge someone else's code without the context.
When you run into a function that is hard to read, after you get the job of understanding it, do a refactor in such a way that the next time you come across that function, it's easy to read. No, need to do comments if you invest in code improvement. And code improvment is investment as comment writing is debth.
I think comments are valuable, but only if the comments come first. Outline what you plan to code first will give you focus to ensure a better outcome than the other way around.
I found when devs comment after, the comments tend to describe what the code does instead of what is the intent or the "big picture".
Well, in my opinion, your code should be as readable as any english paragraph. Which, at times, is not achieved, so you can add some not-so-obvious comments for that. But the focus should be writing clean and readable code. | https://practicaldev-herokuapp-com.global.ssl.fastly.net/jssantana/do-not-comment-your-code-it-should-be-self-documentated-well-i-dont-agree-2n59 | CC-MAIN-2022-27 | refinedweb | 10,107 | 71.44 |
Opened 7 years ago
Closed 7 years ago
#24419 closed New feature (fixed)
Provide an easy way to test email connection
Description
When configuring django to send emails through an SMTP server, there are usually many different settings to try to get it to work. I've written a management command that just sends an email to make testing the settings easier. I'm wonder if there's any interest in including this command in django?
Here's the command:
Change History (8)
comment:1 Changed 7 years ago by
comment:2 Changed 7 years ago by
I don't see much advantage to a management command compared to opening a shell and invoking
send_mail() as you see fit (besides saving some keystrokes).
comment:3 Changed 7 years ago by
From the mailing list thread:
Russ: "However, the counterpoint to that is that you can't just reload settings, so you have to retype (or rely on command history). I agree the benefit is marginal, but I think it's a nice enough convenience, and it's not going to be a major maintenance overhead, so I think it's probably worth including."
aRkadeFR: "But if I take a step back, these commands (for my projects) are only here to test that my SMTP settings are well setup. Thus, the test sending email is quite unnecessary, I would like a check that connects to the SMTP server (if the emails settings are setup else do nothing) when the application starts. (I don't know if there's something like saying to a SMTP server: am I allowed here? without sending an actual email)"
Tom (reply to aRkadeFR): "In Simple Mail Transfer Protocol terms, it definitely is (EHLO, MAIL FROM, RCPT TO, then disconnect without sending DATA). But SMTP is not the only mail backend, and smptlib does not expose that level of connection detail - it will merely raise a different exception type if any of those commands do not return 250 status."
comment:4 Changed 7 years ago by
comment:5 Changed 7 years ago by
Please review
comment:6 Changed 7 years ago by
Did you consider the comments from the mailing list thread about testing SMTP settings only without sending a mail? If it's feasible and not too difficult, I find that a bit more useful than simply duplicating
send_mail().
comment:7 Changed 7 years ago by
Something like this throws an error when SMTP creds are wrong:
from django.core import mail from django.core.mail.backends.smtp import EmailBackend def _check_mail_settings(self): connection = mail.get_connection() if isinstance(connection, EmailBackend): connection.open()
But I think this should be a new ticket/feature. This ticket, to me, is really about sending an actual mail. Could I propose a new ticket to create
testconnections (like @imgraham suggested) that's to test other connections (cache, ...) as well?
The django developers list is usually the best place to discuss new features.
My thoughts on your code:
Maybe it would be more useful to try to mimic the unix mail/sendmail commands, so you can use it even for non testing situations. | https://code.djangoproject.com/ticket/24419 | CC-MAIN-2022-33 | refinedweb | 521 | 57.3 |
Modify the format.
Is there a guideline/code style describing it? If so, would be nice to add the link.
And I'd suggest you to put the detailed document to the rst instead of code comments -- because users usually read documents.
nit: remove the blank line.
No need to put utility functions/variables inside the class, you can define them in an anonymous namespace in the implementation file, the same below.
nit: remove extra trailing ===
Use completed statements fopen("filename", "re"); to do the fix verification. The same below.
You can use a shorter string here -- It is sufficient as we have a completed message check in the first CHECK-MESSAGES.
Adding 'e' is like adding the "O_CLOEXEC". The reason is the same with part1(). Added more text in doc.
Inline one and move the other and the variable to anonymous namespace.
The fix will mark the corresponding argument and suggest the fix like:
fopen("filename", "r");
^~
re
fopen("filename", "r");
^~
re
Is this clear to show the fix?
How about if (const auto* ModeStr = dyn_cast<StringLiteral>(...))?
remove the trailing ., clang-tidy message is not a sentence.
And we can simplify the code like: diag(...) << FD << FixItHint::CreateReplacement(ModeRange.getSourceRange(), ReplacementText);
We may not need this utility function, see my comment on your part 2.
CHECK-FIXES is not used to check the message of the fix. It is used to check the code after the generated-fix is applied. So here should be // CHECK-FIXES: fopen("filename", "re");.
url format fix in doc.rst
We'd prefer early return in llvm, and with that the flag "MayHaveE" can be removed.
I think you can use ModeArg->getSourceRange().
Moreover, as ModeRange is used only once, you can ModeArg->getSourceRange() directly in FixtItHint below.
You can use Twine here which is more efficient: (getSourceText(...) + " \"" + Twine(Mode) + "\"").str().
The same below.
One comment on test, otherwise looks good.
What if str = "re" here? Seems to me the check will omit this case. Would be nice to add this test case.
rename the check.
Summary should be updated. s/android-fopen-mode/android-cloexec-fopen/ | https://reviews.llvm.org/D33747 | CC-MAIN-2020-05 | refinedweb | 353 | 70.19 |
In 12th tutorial, we have seen Introduction to Methods and in 13th part, we have seen Classes in C#. Methods are simple storage units and stores code only, Classes are slightly bigger storage units and can store methods. Now Namespaces are giant storage units, which can save anything in them i.e. classes, methods, namespaces etc. So, let’s have a look at them in detail:
Introduction to Namespaces in C#
- Namespaces are giant code storage units, can be referred as libraries in C#, and are used for optimization & orientation of the code.
- Namespaces are included in the project with the help of using directive at the top.
- If you look at our previous codes, then you will find using Systems; at the top of your code, basically this Systems is a namespace and with the help of using directive, we have included it in our project.
- Console, which we use for printing our data, is a member of this System Namespace.
- Our whole project is also placed between { } brackets of namespace TEPProject.
Why we need namespaces ?
- Using Namespace, we can organize the code pretty well, it doesn’t have much impact in simple projects but in complex projects, you can’t ignore namespaces.
- Throughout our course, we have discussed classroom data and in C# Classes lecture, I have asked you to get data of all classes of a school and now in namespace case, think of data coming from all schools of British School System.
- So, in bigger projects, there’s always a need to make different teams, which will be working on separate code departments.
- In such cases, each team can create project with its own namespace and at the end you can use all those namespaces in your Main code and can get access to its functions etc. without disturbing each other’s code.
Creating Namespaces in C#
- So, now let’s create two namespaces in our project for two different schools, named as SchoolA & SchoolB, as shown in below figure:
- In above figure, you can see our first namespace structure is: Namespace SchoolA > Class TeamA > Method printSchoolName.
- Our second namespace structure is: Namespace SchoolB > Class TeamB > Method printSchoolName.
- Now in my Main function, which is in TEPProject Namespace, I am calling both of these printSchoolName Method.
- In order to invoke the method in first namespace, I have used dot operator and the sequence is SchoolA.TeamA.printSchoolName();
- For the second namespace, I have placed using SchoolB; at the top of the code and now we can call TeamB class directly and that’s why I have used TeamB.printSchoolName(); to invoke method in second namespace.
- So, we can use namespaces using these two ways and I prefer the second one as it makes the code smooth, we don’t need to write SchoolB every time.
Create Project for Namespaces in C#
- Now you got the idea of what are namespaces and how to use them in C#.
- So now it’s time to create separate projects for these two namespaces and you will see our code will become clear & simple.
- Right click on your Project’s Name in Solution Explorer and then click on Add and then click on New Item, as shown in below figure:
- When you click on New Item, a new window will open and here you need to select C# class, as shown in below figure:
- I have given it a name SchoolA.cs and then click Add Button.
- Similarly, I have created a new project for second namespace SchoolB.cs and now my Solution Explorer is shown in below figure:
- Both of my projects’ codes and Main file code are shown in below figure:
- Now you can see in the above figure that our codes are now quite simple & clear and we have created separate files for our new namespaces.
- C# Classes created in separated files and namespaces are now accessible in our Main Function.
So, that was all about Namespaces in C#, I hope you have understood the main idea. In our next tutorial, we will have a look at Inheritance in C#. Till then take care and have fun !!! 🙂 | https://www.theengineeringprojects.com/2019/11/introduction-to-namespaces-in-c-sharp.html | CC-MAIN-2021-43 | refinedweb | 690 | 75.44 |
If you're exhibiting at a gaming trade show, you want to be sure your booth stands out from the crowd. Take a look at these 6 great trade show display ideas that will ensure your booth is the center of attention. Read more →
Guns of Icarus Online is a team-based airship combat game made by Muse Games. This game is expanding upon their idea from Guns of Icarus, another game made by Muse Games, and making it a multiplayer experience. Guns of Icarus online is another Kickstarter baby. It got $25,000 more than it asked for, which is fantastic. The only two questions are: does it soar off successfully into the distance or crash and burn before it even lifts off? Lets find out.
I’m going to start with graphics. The graphics in this game are actually really good for an indie game. I was really happy with how the game looked. When a ship blows up in the sky, it looks really amazing. It adds to the satisfaction of blowing up an enemy ship. The other animations aren’t really that great. I would say mediocre at best. Swinging your wrench as an engineering seems a bit awkward. That doesn’t take too much away from the great looking texture quality though. I really like the style of the graphics too. It is a steam-punk world again, which seems to be really popular these days. I like it though. I don’t think it has over stayed its welcome yet. I am not sure why, but the graphics style reminds me a bit of the movie Hugo. Maybe it is just because all of the turning gears.
Lets talk about character creation. There are three classes that the player can play in Guns of Icarus Online Gunner, Engineer, and Captain. The player can customize the look of each of the three classes. There is one catch though. The player has to pay real life money to buy different clothing for each class. If the player chooses not to pay for clothes in a first person game like most of us with brains will, then their character will be forced to wear the same clothes all the time. By the way, you can’t change the face of your character at all, so the only way your characters will look different is if you change their gender. All the males in the game look exactly the same as other males, and all the females look exactly the same as other females. The only things you can “customize” are hair color, eye color, skin color, and facial details. Now, I know what you are thinking, “Zach won’t changing the facial details change the look of your character?” Well, reader you would think that would be the case, but all changing the facial details of your character does is add scars. So, all players in the game look like their related, but some of them just look like they stayed in a tanning bed a bit too long. The whole character creation and store in this game just seems like a waste of time. Their aren’t even that many items in the store. Most of the items are hats, and I don’t see why I can’t unlock these things by ranking up or by crafting like in Team Fortress 2 since I already put $20 towards the game. It just has greed written all over it because they put this out on launch day. If the game had been out for awhile then they put the store in, I would of been more acceptance towards it. Putting a in-game store in a non-free to play game on launch day is just greedy. There is no way I am paying $6 for clothes on my character when most of the time people aren’t even looking at my character. People are usually too busy spotting enemy ships or looking at the thing they have to repair, and you can’t even see how cool your character looks. It is a first person game. If they wouldn’t of wasted their time on the store and character creation, maybe the game-play would of been better.
The game-play in this game is quite interesting. You join a team of 4, and try to survive the onslaught from other ships while also trying to blow the other team’s ships out of the sky. There can be as many as 8 ships in the sky of one battle. There are only two game modes right now team death match and conquest. Team Death match is self explanatory. In Conquest, the objective is to capture and hold places on the map to gain points towards winning. As I said before, you can play as three different classes in this game a Gunner, Engineering, and Captain. You can mix and match as many of these classes as you want in your team of 4. Hell, you could have 4 captains on one team if you wanted too. I would not recommend that though. Anyways, back to the classes. The Gunner mans the turret just like you would expect him or her too. The Engineer repair things that get damaged on the ship, and the Captain pilots the big airship. To be honest, I was a little worried that the game-play was going to suck after I saw the quality of the character creation and store. I was pleasantly surprised though. This game is truly a cooperative game, which is one thing that I really like about it. This game accepts that in a truly team-based experience not everyone’s role can be equal. Just like in football the Quarterback’s role is more
import than the kicker’s most of the time until it comes down to the winning field goal. Well, in Guns of Icarus Online the Captain’s role is more important most of the time until your hull gets damaged and catches on fire. At that moment, the Engineer’s role would be more important. Since each class is so different, lets talk about the game-play of each separately. Lets talk about the captain first. The Captain is the most important role on the ship. He or she pilots the ship, which is extremely hard to pilot. You are looking in a first person view when you pilot the big airship, which was really hard for me to get use to at first. I played the beta of this game, and one of the things I didn’t like about it was that their was no practice mode to improve your piloting skills. Well, Muse Games added a practice mode to the game, which is good because the only way you could practice your piloting skills in the beta was to hop in the captain’s role and piss off your team mates by trial and error. Now that there is a practice mode, you don’t have to grief people to get better at piloting the airships. Over all piloting the airship is pretty fun. Next, lets talk about the gunner. The Gunner was my least favorite role of all. The gunner is really boring to play in my opinion. You just sit there on your gun and shoot at the other ship. You have to lead your shots, which makes it a little bit more fun I guess, but it isn’t even satisfying until to see the ship blow up. I don’t feel like I am doing damage to the ship until I see it actually fall out of the sky. Probably because I can put a whole round into the balloon of the air ships, and it never gets damage. I also wish that you could pin point out things on the ship to aim at. The guns feel awkward to turn too. Some of them only turn a little bit, which leaves you looking straight ahead almost all of the time. So, the only thing you can do is wait for the captain to line up the ship and click. I just didn’t like to play the gunner it wasn’t for me. I think I enjoyed my experience as the Engineer the most. The Engineers job, as I said earlier, is to repair everything that gets damaged during battle. As an Engineer, you don’t just sit around and wait for the ship to get damaged. The Engineering has a hammer that he can hit the guns with to give them a buff. Don’t ask me how that logic works. That is just what you do. It gives a buff to damage, reload time, and health, which is pretty good. You can change your load out in this game to anything you want, but the most sensible items to pick for the engineering is a wrench for repairs, buff hammer for buffs, and a fire extinguisher to put out those nasty fires. Believe me. When you are under attack, there are a lot of fires to put out. I don’t know what it was, but I found a lot of enjoyment being the only reason my ship was still flying around in the air. See, the combination of classes that my team liked to run was two gunners, one pilot, and one engineer. So, I had to put out all the fires, and repair everything that got damaged, which was a lot of fun to me. I really really like the feeling of team work that you get from the game. There is nothing like the struggle of losing with a group of people, but then at the end you pull together and with a combined effort you destroy the other ships for a win. Unfortunately that is the only enjoyment I get out of the game-play. If you aren’t playing with friends or people that have good team skills, then the game just isn’t fun. Another complaint that I have about the game is that the roles of each class are really plain and repetitive. After you have won a couple of games as each role, it just seems like every game is the same thing for each class. You shoot stuff as the gunner, you repair stuff as an engineer, and you fly the ship as a captain every single game. It gets really old after a couple of games, and the games aren’t even that long. So, I cannot play this game for more than an hour at a time if that. I just get bored of it if I do. I like the feeling of team work this game gives you, but when that wears off it gets really old really fast. The game-play is good for a little while, but it isn’t deep enough to keep me playing.
In conclusion, Gun of Icarus Online is a really good looking game game that can be fun for about an hour. After the feeling of team work wears, the game tends to lose its charm. I definitely cannot recommend if you are a lone wolf. If you don’t play with friends or cooperate well as a team, you aren’t going to have fun. All of the satisfaction that comes out of this game, comes from the truly cooperative experience. I don’t know if that is a good enough selling point though. This game was a really good idea. I just wish they would of pulled it off better. I would love to see a game like this pulled off really well as a team-based space combat game. I think that would be awesome. It could of been a great game, but it just didn’t get executed well enough. | https://www.leviathyn.com/2012/11/01/guns-of-icarus-online-review/ | CC-MAIN-2018-30 | refinedweb | 1,983 | 80.62 |
How do you learn to work with PowerShell, the .NET Framework, your .NET DLLs, third-party .NET DLLs, and other Microsoft and non-Microsoft libraries? In this chapter, I’ll step you through how to load DLLs and discover the types, properties, and methods that you can call during a live interactive session.
When you’re working with the .NET Framework, your best friend is the MSDN Library (). It’s an essential source of information for developers using Microsoft tools, products, technologies, and services.
For example, if I search for “programmatically put data on the clipboard MSDN,” I find the page “Clipboard Class (System.Windows)” (). This page details all the information I need—specifically the assembly needed to load (
PresentationCore), the fully qualified type name (namespace and class) needed to call
System.Windows.Clipboard, and a list of the methods that are available to use.
To kick this section off, we’ll create a PowerShell function to put the text “Hello World” on the clipboard. I’ll show you how to use
Get-Member to list out method names at the command line so you can discover them in your current session. This is a convenient technique that can speed development when you need to find out what methods exist on an object you are using.
For this example, if you are using PowerShell v2 you’ll need to start with the ...
No credit card required | https://www.oreilly.com/library/view/windows-powershell-for/9781449322694/ch08.html | CC-MAIN-2019-18 | refinedweb | 236 | 65.83 |
Details
Description
Currently we only support retention by dropping entire segment files. A more nuanced retention policy would allow dropping individual messages from a segment file by recopying it. This is not currently possible because the lookup structure we use to locate messages is based on the file offset directly.
To fix this we should move to a sequential, logical offset (0,1,2,3,...) which would allow deleting individual messages (e.g. 2) without deleting the entire segment.
It is desirable to make this change in the 0.8 timeframe since we are already doing data format changes.
As part of this we would explicitly store the key field given by the producer for partitioning (right now there is no way for the consumer to find the value used for partitioning).
This combination of features would allow a key-based retention policy that would clean obsolete values either by a user defined key.
The specific use case I am targeting is a commit log for local state maintained by a process doing some kind of near-real-time processing. The process could log out its local state changes and be able to restore from this log in the event of a failure. However I think this is a broadly useful feature.
The following changes would be part of this:
1. The log format would now be
8 byte offset
4 byte message_size
N byte message
2. The offsets would be changed to a sequential, logical number rather than the byte offset (e.g. 0,1,2,3,...)
3. A local memory-mapped lookup structure will be kept for each log segment that contains the mapping from logical to physical offset.
I propose to break this into two patches. The first makes the log format changes, but retains the physical offset. The second adds the lookup structure and moves to logical offset.
Here are a few issues to be considered for the first patch:
1. Currently a MessageSet implements Iterable[MessageAndOffset]. One surprising thing is that the offset is actually the offset of the next message. I think there are actually several uses for the current offset. I would propose making this hold the current message offset since with logical offsets the next offset is always just current_offset+1. Note that since we no longer require messages to be dense, it is not true that if the next offset is N the current offset is N-1 (because N-1 may have been deleted). Thoughts or objections?
2. Currently during iteration over a ByteBufferMessageSet we throw an exception if there are zero messages in the set. This is used to detect fetches that are smaller than a single message size. I think this behavior is misplaced and should be moved up into the consumer.
3. In addition to adding a key in Message, I made two other changes: (1) I moved the CRC to the first field and made it cover the entire message contents (previously it only covered the payload), (2) I dropped support for Magic=0, effectively making the attributes field required, which simplifies the code (since we are breaking compatibility anyway).
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Updated the patch. This patch fixes the remaining failing tests and correctly handles compressed messages.
This patch is ready for review.
I am going to begin phase two of this, implementing the logical offset management in Log.
Thanks for patch v1. Overall, the log format change is reasonable. Some comments:
1. MessageAndOffset: nextOffset is not correct for compressed messages. Currently, in the high-level consumer, after iterating each message, the consume offset is moved to the offset of the next message. So, if one consumes a message and then commits the offset, the committed offset points to the next message to be consumed. We could probably change the protocol to move the consumer offset to the offset of the current message. Then, the caller will need to commit the offset first and then consumes the message to get the same semantics.
2. Message:
2.1 The comment of the message has a bug. Payload should have (N- K - 10) bytes.
2.2 In constructor, should we assert that offset is btw 0 and bytes.length-1? Also, just to be clear that offset and size are for the payload, should we rename bytes, offset and size to something like payload, payloadOffset and payloadSize?
2.3 computeChecksum(): can use MagicOffset for both starting offset and length
2.4 remove unused import
3. MessageSet: Fix the comment in second line "A The format".
4. ByteBufferMessageSet: remove unused comment
5. Log:
5.1 append(): For verifying message size, we need to use the shallow iterator since a compressed message has to be smaller than the configured max message size.
5.2 append(): Compressed messages are forced to be decompressed and then compressed again. This will introduce some CPU overhead. What's the increase in CPU utilization if incoming messages are compressed? Also, for replicaFetchThread, it can just put the data fetched from the leader directly into the log without recomputing the offsets. Could we add a flag in append to bypass regenerating the offsets?
5.3 trimInvalidBytes(): There is a bug in the following statement: messages.size should be messages.sizeInBytes.
if(messageSetValidBytes == messages.size) {
6. javaapi.ByteBufferMessageSet: Java users shouldn't really be using buffer. So, we don't need the bean property.
7. PartitionData: Do we need to override equal and hash since this is already a case class?
8. ZkUtils.conditionalUpdatePersistenPath(): This method expects exception due to version conflict. So there is no need to log the exception.
9. SyncProducerTest: remove unused imports
10. How do we handle the case that a consumer uses too small a fetch size?
Great feedback, thanks.
1. Good point about nextOffset. I think this is slightly tricky to fix. I think I will ignore this problem and work on phase 2 which will fix that issue by making nextOffset=offset+1. This means taking both patches at once which will be a bit big. Sound feasible?
2-4 Good feedback
5.1. Good point.
5.2. I will do a little micro-benchmark on decompression/re-compression. Yes, we can definitely avoid this for the replica fetcher thread. Depending on how much we want to optimize that path there are a lot of options. On the extreme side of total trust I think it might actually possible to do FileChannel.transferTo directly from the socket buffer, though there are complications around metrics and hw mark. I think for now it makes sense to just skip decompression. One question: let's say recompression turns out to be expensive, there are two options: (1) do not set internal offsets (as today), (2) eat the cost and recommend snappy instead of gzip. Personally I prefer (2) since I think we need to fix the correctness bugs, but I am open to implementing either if there is a consensus.
5.3. Good catch
6. OK
7. I am not sure. We had a custom implementation of equals but no hashcode which I think was likely wrong. We can remove both, but I would want to figure out why we added the equals.
8-9. OK
10. Ah, forgot to add that. I think the right thing is just to check (currentDataChunk.messages.size > 0 && currentDataChunk.buffer.size == fetchSize) throw Exception() in the ConsumerIterator. The only thing to consider is that this means there is no check for the simpleconsumer.
Actually, there is another thing.
11. We need to change DefaultEventHandler to put the key data into messages sent to the broker. Also, Producer currently can take any type as key, do we want to restrict it to bytes or do we want to define a serializer for key too?
Thanks for the patch ! The log format change doesn't interfere with replication as of this patch. A few comments in addition to Jun's -
1. CompressionUtils: How about re-using the ByteBufferMessageSet.writeMessage() API for serializing the compressed message to a byte buffer ?
2. ByteBufferMessageSet.scala, FileMessageSet: Can we use MessageSet.LogOverhead instead of 12 for byte arithmetic ?
3. ConsumerIterator
The nextOffset issue for compressed message sets will get resolved when we actually use the sequential logical offsets. With that, the advantage is that the consumer will be able to fetch a message even if it is inside a compressed message. Today, there is no good way to achieve this unless we have level-2 message offsets for compressed messages. Even if we cannot make that change in time for replication, we can take this change and leave the message set iterator to return the next offset (valid fetch offset), just like we do today. So, either way, we are covered here.
This patch is incremental from the previous one. I will rebase and provide an up-to-date patch that covers both phases, but this shows the new work required to support logical offsets.
I think I have addressed most of the comments on the original patch, except:
1. I have put off any performance optimization (avoiding recompression for replicas, memory-mapping the log, etc). I would like to break this into a separate JIRA and write a reasonable standalone Log benchmark that covers these cases and then work against that. I have several other cleanups I would like to do as well: (1) get rid of SegmentList, (2) move more functionality in Log into LogSegment.
2. I am not yet storing the key in the message, this may change the produce api slightly so i think this should be a seperate JIRA too.
3. Neha--I change most of the uses of magical numbers except where the concrete number is more clear.
Here is a description of the new changes.
- Offset now always refers to a logical log offset. I have tried to change any instances where offset meant file offset to instead use the terminology "position". References to file positions should only occur in Log.scala and classes internal to that.
- As in the previous patch MessageAndOffset gives three things: (1) the message, (2) the offset of THAT message, and (3) a helper method to calculate the next offset.
- Log.append() is responsible for maintaining the logEndOffset and using it to assign offsets to the messageset before appending to the log.
- Offsets are now assigned to compressed messages too. One nuance is that the offset of the wrapper message is equal to the last offset of the messages it contains. This will be more clear in the discussion of the offset search changes.
- Log.read now accepts a new argument maxOffset, which is the largest (logical) offset that will be returned in addition to the maxSize which limits the size in bytes.
- I have changed Log.read to now support sparse offsets. That is, it is valid to have missing offsets. This sparseness is needed both for the key-retention but also for the correct handling of compressed messages. I will describe the read path in more detail below.
- I moved FileMessageSet to the package kafka.log as already much of its functionality was specific to the log implementation.
- I changed FetchPurgatory back to use a simple counter for accumulated bytes. It was previously re-calculating the available bytes, but because this now is a more expensive operation, and because this calculation is redone for each topic/partition produce (i.e. potentially 200 times per produce request), I think this is better. This is less accurate, but since long poll is a heuristic anyway I think that is okay.
- I changed the default suffix of .kafka files to .log and added a new .index file that contains a sparse index of offset=>file_position to help efficiently resolve logical offsets.
- Entries are added to this index at a configurable frequency, controlled by a new configuration log.index.interval.bytes which defaults to 4096
- I removed numerous instances of byte calculations. I think this is a good thing for code quality.
Here is a description of the new read path.
1. First log tries to find the correct segment to read from using the existing binary search on log segments. I modified this search slightly in two ways. First we had a corner case bug which only occurred if you have two files with successive offsets (unlikely now, impossible before). Second, I now no longer check ranges but instead return the largest segment file less than or equal to the requested offset.
2. Once the segment is found we check the index on that segment. The index returns the largest offset less than or equal to the requested offset and the associated file position in the log file. This position represents a least upper bound on the position in the file, and it is the position from which we begin a linear search checking each message. The index itself is just a sorted sequence of (offset, position) pairs. Complete details are in the header comments on kafka.log.OffsetIndex.scala. It is not required that all messages have an entry in the OffsetIndex, instead there is a confgurable frequency in terms of bytes which is set in LogSegment. So, for example, we might have an entry every 4096 bytes. This frequency is approximate, since a single message may be larger than that.
3. Once we have a greatest lower bound on the location we use FileMessageSet.searchFor to search for the position of the first message with an offset at least as large as the target offset. This search just skips through the file checking the offset only.
Okay attached a fully rebased patch that contains both phase 1 and phase 2 changes.
Three preliminary comments from Neha while she does deeper interogations:
- Would be nice if the DumpLogSegment tool also dumped the contents of the index file
- This patch implicitly assumes file segments are limited to 2GB (I use a 4 byte position pointer in the index). Turns out this isn't true. Proposed fix is to limit log segments to 2GB.
- We decided the corner case with sparse messages at the end of a segment isn't really a corner case as it effects compressed messages too. So I will fix that in the scope of this patch.
2 additions to the preliminary comments -
- 3 unit tests fail on patch v2 -
- It will be nice for maxIndexEntries to be a configurable property on the server
Thanks for patch v2. Some more comments:
20. Log:
20.1 findRange(): Add to the comment that now this method returns the largest segment file <= the requested offset.
20.2 close(): move the closing } for the for loop to a new line.
20.3 bytesSinceLastIndexEntry is only set but is never read.
20.4 append(): This method returns the offset of the first message to be appended. This is ok for the purpose of returning the offset to the producer. However, when determining whether all replicas have received the appended messages, we need to use the log end offset after the messages are appended. So, what we should do is to have append() return 2 offsets, one before the append and one after the append. We use the former in producer response and use the latter for the replica check. To avoid complicating this patch further, another approach is to, in the jira, have append return the log end offset after the append and use it in both producer response and replica check. We can file a separate jira to have append return 2 offsets.
20.5 read(): The trace statement: last format pattern should be %d instead of %s.
20.6 truncateTo(): The usage of logEndOffset in the following statement is incorrect. It should be the offset of the next segment.
segments.view.find(segment => targetOffset >= segment.start && targetOffset < logEndOffset)
20.7 There are several places where we need to create a log segment and the code for creating the new data file and the new index file is duplicate. Could we create a utility function createNewSegment to share the code?
21. LogSegment: bytesSinceLastIndexEntry needs to be updated in append().
22. FileMessageSet.searchFor(): The following check seems to be a bit strange. Shouldn't we use position + 12 or just position instead?
while(position + 8 < size) {
23. OffsetIndex:
23.1 In the comment, "mutable index can be created to" seems to have a grammar bug.
23.2 mmap initialization: The following statement seems unnecessary. However, we do need to set the mapped buffer's position to end of file for mutable indexes.
idx.position(idx.limit).asInstanceOf[MappedByteBuffer]
23.3 append(): If index entry is full, should we automatically roll the log segment? It's ok if this is tracked in a separate jira.
23.4 makeReadOnly(): should we call flush after raf.setLength()? Also, should we remap the index file to the current length and make it read only?
24. LogManager.shutdown(): log indentation already adds LogManager in the prefix of each log entry.
25. KafkaApis:
25.1 handleFetchRequest: topicDatas is weird since data is the plural form of datum. How about topicDataMap?.
26. Partition: There are a few places that the first character of info log is changed to lower case. The current convention is to already use upper case.
27. javaapi.ByteBufferMessageSet: underlying should be private val.
28. DumpLogSegment: Now that each message stores an offset, we should just print the offset in MessageAndOffset. There is no need for var offset now.
29. FetchedDataChunk: No need to use val for parameters in constructor since this is a case class now.
30. PartitionData:
30.1 No need to redefine equals and hashcode since this is already a case class.
30.2 initialOffset is no longer needed.
31. PartitionTopicInfo.enqueue(): It seems that next can be computed using shallow iterator since the offset of a compressed message is always the offset of the last internal message.
32. ByteBufferMessageSet: In create() and decompress(), we probably should close the output and the input stream in a finally clause in case we hit any exception during compression and decompression.
33. remove unused imports.
The following comment from the first round of review is still not addressed.
10. How do we handle the case that a consumer uses too small a fetch size?
New patch with a few new things:
I rebased a few more times to pick up changes.
WRT Neha's comments:
- I made maxIndexEntries configurable by adding the property log.index.max.size. I did this in terms of index file size rather than entries since the user doesn't really know the entry size but may care about the file size.
- For the failing tests: (1) The message set failure is due to scalatest not handling parameterized tests, i had fixed this but somehow it didn't make it into the previous patch. It is in the current one. testHWCheckpointWithFailuresSingleLogSegment is a timing assumption in that test. Fixed it by adding a sleep
. The producer test failure I cannot reproduce.
- Wrote a test case using compressed messages to try to produce the corner case at the end of a segment. But actually this turns out not to be possible with compressed messages since the numbering is by the last offset. So effectively our segments are always dense right now. As such I would rather wait until I refactor segment list to fix it since it will be duplicate work otherwise.
- Turns out that log segments are limited to 2GB already, via a restriction in the config. Not actually sure why this is. Given this limitation one cleanup that might be nice to do would be to convert MessageSet.sizeInBytes to an Int, which would remove a lot of casts. Since this is an unrelated cleanup I will not do it in this patch.
- I added support to DumpLogSegment tool to display the index file. I had to revert Jun's change to check that last offset=file size since this is no longer true.
Jun's Comments:
First of all, this is an impressively thorough code review. Thanks!
20.1 Made the Log.findRange comment more reflective of what the method does. I hope to remove this entirely in the next phase.
20.2 Fixed mangled paren in close()
20.3 bytesSinceLastIndexEntry. Yes, good catch. This is screwed up. This was moved into LogSegment, but the read and update are split in two places. Fixed.
20.4 append(): "We need to have both the begin offset and the end offset returned by Log.append()". Made Log.append return (Long, Long). I am not wild about this change, but I see the need. I had to refactor KafkaApis slightly since we were constructing an intermediate response object in the produceToLocalLog method (which was kind of weird anyway) so there was only one offset and since this is an API object we can't change it. I think the use of API objects in the business logic is a bit dangerous for this reason.
20.5 Fixed broken log statement to use correct format param.
20.6 truncateTo(): The usage of logEndOffset in the following statement is incorrect. Changed this to use Log.findInRange which I think is the intention.
20.7 "There are several places where we need to create a log segment and the code for creating the new data file and the new index file is duplicate. Could we create a utility function createNewSegment to share the code?" Good idea, done. There is still a lot more refactoring that could be done between Log and LogSegment, but I am kind of putting that off.
21. LogSegment: "bytesSinceLastIndexEntry needs to be updated in append()." Fixed.
22. FileMessageSet.searchFor() fixed bad byte arithmetic.
23. OffsetIndex:
23.1 Fixed bad english in comment
23.2 mmap initialization: Yes, this doesn't make sense. The correct logic is that the mutable case must be set to index 0, and the read-only case doesn't matter. This was happening implicitly since byte buffers initialize to 0, but I switched it to make it explicit.
23.3 append(): "If index entry is full, should we automatically roll the log segment?" This is already handled in Log.maybeRoll(segment) which checks segment.index.isFull
23.4 makeReadOnly(): "should we call flush after raf.setLength()?" This is a good point. I think
what you are saying is that the truncate call itself needs the metadata to flush to be considered stable. Calling force on the mmap after the setLength won't do this. Instead I changed the file open to use synchronous mode "rws" which should automatically fsync metadata when we call setLength. The existing flush is okay: I verified that flush doesn't cause the sparse file to desparsify or anything like that. "Also, should we remap the index file to the current length and make it read only?" Well, this isn't really needed. There is no problem with truncating a file post mmap, but I guess making the mapping read-only could prevent corruption due to any bugs we might have so I made that change.
LogManager
24. "log indentation already adds LogManager in the prefix of each log entry." Oops.
25. KafkaApis:
25.1 "handleFetchRequest: topicDatas is weird since data is the plural form of datum. How about topicDataMap?" Changed to dataRead (I don't like having the type in the name).." Agreed, accidentally removed this; added it back.
26. "Partition: There are a few places that the first character of info log is changed to lower case. The current convention is to already use upper case." Made all upper case.
27. "javaapi.ByteBufferMessageSet: underlying should be private val." Changed.
28. "DumpLogSegment: Now that each message stores an offset, we should just print the offset in MessageAndOffset. There is no need for var offset now." Removed.
29. "FetchedDataChunk: No need to use val for parameters in constructor since this is a case class now." Wait is everything a val in a case class? I made this change, but don't know what it means...
30. PartitionData:
30.1 "No need to redefine equals and hashcode since this is already a case class." Yeah, this was fixing a bug in the equals/hashcode stuff due to the array that went away when i rebased. Removed it
30.2 "initialOffset is no longer needed." I think PartitionData is also used by ProducerRequest. This is a bug, but I think we do need the initial offset for the other case. Until we separate these two I don't think I can remove it.
31. "PartitionTopicInfo.enqueue(): It seems that next can be computed using shallow iterator." Ah, very nice. Changed that.
32. "ByteBufferMessageSet: In create() and decompress(), we probably should close the output and the input stream in a finally clause in case we hit any exception during compression and decompression." These are not real output streams. I can close them, but they are just arrays so I think it is just noise, no?
33. "remove unused imports." Eclipse doesn't identify them, will swing by.
34. "How do we handle the case that a consumer uses too small a fetch size?" Added a check and throw for this in ConsumerIterator.
Ran system test, passes:
2012-10-02 14:11:50,376 - INFO - ======================================================
2012-10-02 14:11:50,376 - INFO - stopping all entities
2012-10-02 14:11:50,376 - INFO - ======================================================
2012-10-02 14:12:43,105 - INFO - =================================================
2012-10-02 14:12:43,105 - INFO - TEST REPORTS
2012-10-02 14:12:43,105 - INFO - =================================================
2012-10-02 14:12:43,105 - INFO - test_case_name : testcase_1
2012-10-02 14:12:43,105 - INFO - test_class_name : ReplicaBasicTest
2012-10-02 14:12:43,105 - INFO - validation_status :
2012-10-02 14:12:43,105 - INFO - Leader Election Latency - iter 2 brokerid 3 : 49636.00 ms
2012-10-02 14:12:43,105 - INFO - Validate leader election successful : PASSED
2012-10-02 14:12:43,106 - INFO - Unique messages from consumer : 850
2012-10-02 14:12:43,106 - INFO - Validate for data matched : PASSED
2012-10-02 14:12:43,106 - INFO - Unique messages from producer : 850
2012-10-02 14:12:43,106 - INFO - Leader Election Latency - iter 1 brokerid 2 : 354.00 ms
Thanks for patch v3. We are almost there. A few more comments:
40. Log.append: It seems that it's easier if lastOffset returned is just nextOffset instead of nextOffset -1. Then, in KafkaApis, we can just pass end, instead of end+1 to ProducerResponseStatus.
41. OffsetIndex: When initializing mmap, if the index is mutable, shouldn't we move the position to the end of the buffer for append operations?
42. KafkaApis: It's useful to pass in brokerId to RequestPurgatory for debugging unit tests.
43. DumpLogSegments: Currently, the message iterator in FileMessageSet will stop when it hits the first non parsable message. So, we need to check if at the end of the message iteration, location == FileMessageSet.sizeInBytes(). If not, we should report the offset from which data is corrupted.
44. ConsumerIterator: The check for guarding small fetch size doesn't work. This is because in PartitionTopicInfo.enqueue(), we only add ByteBufferMessageSet that has positive valid bytes. We can log an error in PartitionTopicInfo.enqueue() and enqueue a special instance of FetchedDataChunk that indicates an error. In ConsumerIterator, when seeing the special FetchedDataChunk, it can throw an exception.
29. Yes, all parameters in the constructor in a case class are implicitly val.
There is another issue:
45. ConsumerIterator: Now that we index each message inside a compressed message, we need to handle the case when a fetch request starting on an offset in the middle of a compressed message. In makeNext(), we need to first skip messages whose offset is less than currentDataChunk.fetchOffset. Otherwise, the consumer would get duplicates. We probably can do this in a followup jira since currently the consumer can get duplicates on compressed messages too.
Here is a new patch that addresses these comments. I also did an incremental diff against the previous patch so you can see the specific changes for the below items (that is
KAFKA-506-v4-changes-since-v3.patch)
Also rebased again.
40. I actually disagree. It is more code to add and subtract, but I think it makes more sense. This way we would say the append api returns "the first and last offset for the messages you appended" rather than "the first offset for the messages you appended and the offset of the next message that would be appended". This is not a huge deal so I can go either way, but I did think about it both ways and that was my rationale.
41. My thinking was that there were only two cases: re-creating a new, mutable index (at position 0) and opening a read-only index. In reality there are three cases: in addition to the previous two you can be re-opening an existing log that went through clean shutdown. I was not handling this properly and in fact was truncating the index on re-open, so the existing entries in the last segment would be unindexed. There are now two cases for mutable indexes. Recall that on clean-shutdown the index is always truncated to the max valid entry. So now when we open an index, if the file exists, I set the position to the end of the file. If the file doesn't exist I allocate it and start at position 0. The recovery process well still re-create the index if it runs, if the shutdown was clean then we will just roll to a new segment on the first append (since the index was truncated, it is now full).
43. I removed that feature since the iterator only has the offset not the file position. However after thinking about it I can add it back by just using MessageSet.entrySize(message) on each entry and use the sum of these to compare to the messageSet.sizeInBytes. Added that.
44. Changed the check to be the messageSet.sizeInBytes. This check was really meant to guard the case where we are at the end of the log and get an empty set. I think it was using validBytes because it needed to calculate the next offset. Now that calculation is gone, so I think it is okay to just use messageSet.sizeInBytes. This would result in a set with 0 valid bytes being enqueued, and then the error getting thrown to the consumer. The fetcher would likely continue to fetch this message set, but that should be bounded by the consumer queue size.
45. The behavior after this patch should be exactly the same as the current behavior, so my hope was to do this as a follow up patch.
Also: Found that I wasn't closing the index when the log was closed, and found a bug in the index re-creation logic in recovery; fixed both, and expanded tests for this.
Patch v4 looks good overall. A couple of remaining issues:
50. testCompressionSetConsumption seems to fail transiently for me with the following exception. This seems to be related to the change made for #44.
kafka.common.MessageSizeTooLargeException: The broker contains a message larger than the maximum fetch size of this consumer. Increase the fetch size, or decrease the maximum message size the broker will allow.
at kafka.consumer.ConsumerIterator.makeNext(ConsumerIterator.scala:87)
51. ConsumerIterator: When throwing MessageSizeTooLargeException, could we add the topic/partition/offset to the message string in the exception?
Rebased again and fixed the above issues to make v5
50. I looked into this. It is slightly subtle. The problem was that validBytes is cached in a local variable, and the incremental computation was done on the member variable in ByteBufferMessageSet. The next problem was that AbstractFetcherThread and the ConsumerIterator could both be calling this at the same time, which would lead to setting validBytes to 0 and then iterating over the messages to count the bytes. If the check and the computation occurred at precisely the same time it is possible for validBytes to return essentially any value. The fix is (1) avoid mucking with the MessageSet once it is handed over to ConsumerFetcherThread.processPartitionData, and (2) use a local variable to compute the validbytes, this way even if we do have future threading bugs the worst case is that we recompute the same cached value twice instead of accessing a partial computation (we could also make the variable volatile, but that doesn't really add any additional protection since we don't need precise memory visibility).
51. Done.
Thanks for patch v5.
50. There is still a potential issue in that shallowValidByteCount is a long and long value is not guaranteed to be exposed atomically without synchronization in java. So, 1 thread could see a partially updated long value. Thinking about this, since ByteBufferMessageSet is not updatable, is it better to compute validBytes once in the constructor?
51. ConsumerIterator: Could you include currentDataChunk.fetchOffset in the message string in MessageSizeTooLargeException? This will make debugging easier.
Since this is a large patch, it would be good if someone else takes a closer look at it too. At least Neha expressed interests in taking another look at the latest patch.
50. It can actually only take Int values, so I don't think this can happen. I will file a follow-up clean-up issue to change sizeInBytes to be an Int (I had mentioned that earlier in the thread) since this anyways leads to innumerable safe-but-annoying casts to int. I think this is better than pre-computing it because in many cases we instantiate a ByteBufferMessageSet without necessarily using validBytes.
51. Yes, I will add this as part of the checkin.
I will free up tomorrow after Grace Hopper conference is over. Would like to take another closer look at the follow up patches. If you guys don't mind, please can we hold this at least for this weekend ?
It is really hard/error-prone to keep this patch alive and functioning, I basically spend half of each day on rebasing then debugging the new bugs i introduce during rebasing. Could we do it as a post commit review? I am totally down to fix/change things, but the problem is each new change may take a few iterations and meanwhile the whole hunk has to be kept alive. In an ideal world I would have found a way to have done this in smaller pieces, but it is kind of a cross-cutting change so that was hard.
What we can do is to hold off committing other conflicting patches for now and have this patch more thoroughly reviewed. If there are no major concerns, we can just commit the patch and have follow-up jiras to address minor issues. Neha, do you think that you can finish the review by Saturday?
Rebasing is painful for sure, especially since 0.8 is moving quite fast. I think the other patches in flight are either small or otherwise straightforward to rebase as they don't have significant overlap. So it seems holding off all check-ins until after this weekend would work for everyone right?
jkreps-mn:kafka-git jkreps$ git pull
remote: Counting objects: 72, done.
remote: Compressing objects: 100% (37/37), done.
remote: Total 42 (delta 26), reused 0 (delta 0)
Unpacking objects: 100% (42/42), done.
From git://git.apache.org/kafka
0aa1500..65e139c 0.8 -> origin/0.8
Auto-merging core/src/main/scala/kafka/api/FetchResponse.scala
CONFLICT (content): Merge conflict in core/src/main/scala/kafka/api/FetchResponse.scala
Auto-merging core/src/main/scala/kafka/api/ProducerRequest.scala
CONFLICT (content): Merge conflict in core/src/main/scala/kafka/api/ProducerRequest.scala
Auto-merging core/src/main/scala/kafka/consumer/ConsumerFetcherThread.scala
Auto-merging core/src/main/scala/kafka/server/AbstractFetcherThread.scala
CONFLICT (content): Merge conflict in core/src/main/scala/kafka/server/AbstractFetcherThread.scala
Auto-merging core/src/main/scala/kafka/server/KafkaApis.scala
CONFLICT (content): Merge conflict in core/src/main/scala/kafka/server/KafkaApis.scala
Auto-merging core/src/main/scala/kafka/server/ReplicaFetcherThread.scala
Auto-merging core/src/test/scala/unit/kafka/api/RequestResponseSerializationTest.scala
Auto-merging core/src/test/scala/unit/kafka/producer/SyncProducerTest.scala
Auto-merging core/src/test/scala/unit/kafka/utils/TestUtils.scala
Automatic merge failed; fix conflicts and then commit the result.
Rebased patch and improved error message for the MessageSizeTooLargeException.
Btw, which svn revision does patch v5 apply correctly on ?
I have to mention that there is a possibility that some of my comments are not related to this patch directly, but were found while inspecting the new code closely
Since you know the code better, feel free to file follow up JIRAs
1. Log
1.2 In findRange, the following statements runs the risk of hitting overflow, giving incorrect results from the binary search -
val mid = ceil((high + low) / 2.0).toInt
Will probably be better to use
val mid = low + ceil((high - low)/2.0).toInt
1.3 It seems that there are only 2 usages of the findRange API that takes in the array length . We already have an API that covers that use case - findRange[T <: Range](ranges: Array[T], value: Long) and this is used by a majority of API calls.
We can make the findRange method that has the actual binary search logic private and changes the 2 use cases in Log.scala to use the public method that assumes the array length.
1.4 In truncateTo, it is possible that the log file was successfully deleted but the index file was not. In this case, we would end up an unused index file that is never deleted from the kafka log directory.
1.5 In loadSegments, we need to rebuild any missing index files. Or it will error out at a later time. Do we have a follow up JIRA to cover this, it seems like a blocker to me.
2. LogManager
2.1 numPartitions is an unused class variable
3. FileMessageSet
3.1. In searchFor API, fix comment to mention that it searches for the first/least offset that is >= the target offset. Right now it says search for the last offset that is >= target offset
3.2 The searchFor API returns a pair of (offset, position). Right now, it does not always return the offset of the message at the returned position. If the file message set is sparse, it returns the offset of the next message, so the offset and position do not point to the same message in the log. Currently, we are not using the offset returned by the read() API, but in the future if we do, it will be good for it to be consistent.
3.3 In searchFor API, one of the statements uses 12 and the other uses MessageSet.LogOverhead. I think the while condition is better understood if it said MessageSet.LogOverhead.
4. LogSegment
4.1 It is better to make translateOffset return an Option. That way, every usage of this API will be forced to handle the case when the position was not found in the log segment.
4.2 I guess it might make sense to have all the places that uses this segment size to a an Int instead of Long.
5. ConsumerIterator
Right now, while committing offsets for a compressed message set, the consumer can still get duplicates. However, we could probably fix this by making the ConsumerIterator smarter and discarding messages with offset < fetch offset.
6. ReplicaFetcherThread
When the follower fetches data from the leader, it uses log.append which re-computes the logical message ids. This involves recompression when the data is compressed, which it is in production. This can be avoided by making the data copy from leader -> follower smarter
7. MessageCompressionTest
There are 2 unused imports in this file
8. ByteBufferMessageSet
8.1 There are 3 unused imports in this file
8.2 The return statement in create() API is redundant
9. OffsetIndex
9.1 The last return statement in indexSlotFor is redundant
9.1 The first return statement in indexSlotFor can be safely removed by using case-match or putting the rest of the logic in the else part of if-else block.
10. Performance
Performance test to see the impact on throughput/latency if any due to this patch. What I am curious about is the performance impact due to the following, which are the changes that can impact performance as compared to pre
KAFKA-506 -
10.1 Recompression of data during replica reads
10.2 Recompression of data to assign correct offsets inside a compressed message set
10.3 The linear search in the file segment to find the message with a given id. This depends on the index interval and there needs to be a balance between index size and index interval.
10.4 The impact of making the log memory mapped.
10.5 Overhead of using the index to read/write data in Kafka
11. KafkaApis
Unused imports in this file
Just to summarize so that we understand the follow up work and also the JIRAs that got automatically resolved due to this feature. Please correct me if I missed something here -
Follow up JIRAs
1. Retain key in producer (
KAFKA-544)
2. Change sizeInBytes() to Int (
KAFKA-556)
3. Fix consumer offset commit in ConsumerIterator for compressed message sets (
KAFKA-546)
4. Remove the recompression involved while fetching data from follower to leader (
KAFKA-557)
5. Rebuild missing index files (
KAFKA-561)
6. Add performance test for log subsystem (
KAFKA-545)
7. Overall Performance analysis due to the factors listed above
JIRAs resolved due to this feature
1. Fix offsets returned as part of producer response (
KAFKA-511)
2. Consumer offset issue during unclean leader election (
KAFKA-497)
Hi Neha, here are some comments on your comments and a patch that addresses the comments we are in agreement on.
1. Log
1.2, 1.3 True. This problem exists in both OffsetIndex and Log, though I don't think either are actually possible. In Log this requires one to have 2 billion segment files, though, which is not physically possible; in OffsetIndex one would need to have ~2 billion entries in an index, which isn't possible as the message overhead would fill up the log segment first. I am going to leave it alone in Log since that code I want to delete asap anyway. I fixed it in the OffsetIndex since that code is meant to last.
1.4. This logic is a little odd, I will fix it, but actually this reminds me of a bigger problem. If file.delete() fails on the log file, the presence of that log file will effectively corrupt the log on restart (since we will have a file with the given offset but will also start another log with a parallel offset that we actually append to--on restart the bad file will mask part of the new file). Obviously if file.delete() fails things are pretty fucked and there is nothing we can do in software to recover. So what I would like to do is throw KafkaStorageException and have Partition.makeFollower() shut down the server. What would happen in the leadership transfer if I did that?
1.5 Filed a JIRA for this.
LogManager
2.1 Deleted numPartitions (not related to this patch, I don't think)
FileMessageSet
3.1 Good catch, fixed.
3.2 Right, so I return the offset specifically to be able to differentiate the case where I found the exact location versus the next message. This is important for things like truncate. I always return the offset and corresponding file position of the first offset that meets the >= criteria. So either I am confused, or I think it works the way you are saying it should.
3.3 Well, but the code actually reads and Int and Long out of the resulting buffer, so if MessageSet.LogOverhead != 12 there is a bug, so we aren't abstracting anything just adding a layer of obfuscation. But, yes, it should be consistent, so changed it.
LogSegment
4. LogSegment
4.1 I don't want to allocate an object for each call as this method is internal to LogSegment. I will make it private to emphasize that.
4.2 I agree, though we have had the 2gb limit for a while now so this isn't new. We repurposed
KAFKA-556 for this.
5. ConsumerIterator
Agreed. Broke this into a separate issue since current state is no worse than 0.7.x. JIRA is
KAFKA-546.
6. ReplicaFetcherThread
Agreed this was discussed above. JIRA is
KAFKA-557.
7. Only IDEA detects this, which I don't have. So can't help on this.
8. ByteBufferMessageSet
8.2 Fixed
9. OffsetIndex
9.1 Fixed
9.2 This is true but I think it would be more convoluted. Simple test and exits make it so you don't have to add another layer of nesting.
10 Agreed, of the various things on my plate I think this is the most important. Any issues here are resolvable, but we need to first get the data.
This patch is identical to the previous Neha related patch except that now in the event that a log segment can't be deleted we throw KafkaStorageException. In KafkaApis.handleLeaderAndISRRequest we catch this exception and shutdown the server.
+1. Looks good and thanks for addressing the late review comments. One minor comment -
The following error statement is slightly misleading. The broker could either be in the middle of becoming a leader or a follower, not necessarily the former.
fatal("Disk error while becoming leader.")
Ah, nice catch. Changed it to "Disk error during leadership change."
Checked in with the change.
I think you missed a change to KafkaETLContext. It needs:
diff --git a/contrib/hadoop-consumer/src/main/java/kafka/etl/KafkaETLContext.java b/contrib/hadoop-consumer/src/main/java/kafka/etl/KafkaETLContext.java
index bca1757..9498169 100644
— a/contrib/hadoop-consumer/src/main/java/kafka/etl/KafkaETLContext.java
+++ b/contrib/hadoop-consumer/src/main/java/kafka/etl/KafkaETLContext.java
@@ -205,7 +205,7 @@ public class KafkaETLContext {
key.set(_index, _offset, messageAndOffset.message().checksum());
- _offset = messageAndOffset.offset(); //increase offset
+ _offset = messageAndOffset.nextOffset(); //increase offset
_count ++; //increase count
return true;
or something similar. As it stands it'll run forever...
Add key to message and reorder some fields
Bump up Message magic number to 2
Add offset to MessageSet format
Make MessageAndOffset contain the current offset and add a nextOffset() method to get the next offset
Some misc. cleanups (delete some obsolete files, fix bad formatting)
There are still two problems with this patch:
1. Not handling offsets properly in compressed messages
2. Unit test failures in LogRecoveryTest | https://issues.apache.org/jira/browse/KAFKA-506 | CC-MAIN-2017-09 | refinedweb | 7,832 | 65.73 |
Hi
I just started learning a bit of arduino. I had a year of coding class a few years back but it wasn’t super great. Other than that its the first code i have ever written.
I’m doing an guide by elegoo (the most complete arduino starter kit) and decided to try and fiddle around a bit. I want a servo motor to turn on when i press a button and turn off when i press it again. The state should also be indicated by an LED.
Later i plan to add the function of reading out the servo motor angle and having another LED light up when its between “50 and 70 degree” or whatever.
How can i improve on this code? I read everywhere that goto statements are shit and you should avoid using them, but i don’t have the knowledge and understanding to find a different solution yet. Any other things you want to point out are appreciated, but my main interest is how to fix the goto situation.
#include <Servo.h> //servo library //define pins #define red 8 #define butt 7 #define serv 9 //define initial states int ledstate = 0; boolean buttstate = false; int i = 20; boolean check = false; int servspeed = 10; //create servo object Servo myservo; void setup() { pinMode (red, OUTPUT); pinMode (butt, INPUT_PULLUP); analogWrite (red, ledstate); myservo.attach (serv); //attach servo object to servo pin } void loop() { checkforbutt(); onoff(); } boolean checkforbutt () { boolean checked = false; //has it been checked? if (digitalRead(butt) == LOW) { if (buttstate == true) { buttstate = false; } else { buttstate = true; } //LED shows if button is true or false if (buttstate == true) { ledstate = 255; analogWrite (red, ledstate); } else if (buttstate == false) { ledstate = 0; analogWrite (red, ledstate); } boolean checked = true; //if button was pressed, its true to get out of the loops in onoff delay (200); //wait so the button isn't pressed twice by pressing it too long return checked; } } void onoff () { here: //label to get out of loops //Servo is on or off if (buttstate == true) { //turn the servo from left to right for (i; i <= 180; i++) { myservo.write(i); delay (servspeed); check = checkforbutt(); if (check == true) { //if the button has been pressed, its supposed to stop moving, haven't found a way to do it differently. It would always complete the if statement first goto here; } } for (i; i > 19; i--) { myservo.write(i); delay (servspeed); check = checkforbutt(); if (check == true) { goto here; } } } }
I went through some iterations to get here. First i had everything in the loop function but I couldn’t check for input while the servo motor ran. I tried different things to end the loops, including trying to call the onoff function again if the buttoncheck was true. But it kept completing the if statement of the motor running before actually stopping. So in the end i did that stupid boolean checked and goto thing. Now it works but i know it isn’t optimal.
PS: i starts with 20 because the servo is doing weird things if lower, even though its supposed to go from 0 to 180
i don’t have a button that works like a switch, thats why i tried to code my own from a normal button. I know thats not optimal either, but im learning
so i think its not too bad of an exercise
I appreciate any help! I feel like being corrected on what i thought might be a good idea would really teach me a lot | https://forum.arduino.cc/t/how-can-i-improve-this-code/662038 | CC-MAIN-2022-33 | refinedweb | 580 | 73 |
Europeans!
An Oldies but Goodies!
Old IPC Files
In the name of all Mini Skirt Wearing Gals,
The point here, is not that Palestinian got to accept that they lost
their land! Israel perfectly agreed & already gave them the West bank
& Ghaza Strip. Palestine does officially exist & they have their own
land & flag & government, but obviously to agree on a long lasting
peace between Arafat & Barrack was not good enough for the Rag Heads!
Arafat rejected the peace plan that Barrack had on the table & that
is the best that Palestinians will ever get. Arafat lost his chance,
simply because PLO, Hamas, Al Jihad, Al Puss & Al WUS, & Al Vagina &
the rest of the Arab Palestinian Terror Groups do not get satisfied
with the West bank! They want to dump Israel in the sea of
Mediterranean!
This dangerous political ideology (Islam) knows no limitation nor
boundaries. Islam is 10 times worst than Nazism, ask us Persians, we
have the first hand experience being the victim of Islam for 23 years
since 1979!
United States is the only power standing behind Israel. If it was up
to European Bloody Socialists, like the French Whores cigarette
smoking wanna be intellectuals, German Pigs who sell their mothers
for a dollar, British Wheelers & Dealers who openly deal with Islamic
Republic on the cost of the people of Iran's blood, Italian rats who
open their Asses foe anyone who gives them some oil, or Spanish
bastards who gave a new meaning for the word
Liberalism, ...........they would all stand & gladly watch 6 million
Israelis get mass murdered just like W.W.II.
European Union is more like an old Whore who never ever stood by
United States in sanctioning Iran or any other Terrorist nation!
European Union are dealing billions of dollars with Iran & all the
money goes to Mullahs private bank accounts in Cayman or Canada, some
in Swiss!
The only European Sub Whores who partially stood by USA, was UK. The
worst of them are Germans. They do not give a flying Fandango about
Human Rights of over 30,000 Iranian Opposition who so far are
slaughtered by IRI. As long as they get the cheap oil, best of Iran's
Caviar, Pistachio, Carpet, Natural Gas, Uranium, Copper, Fruits, Food
Products, Caviar Fish, Tuna, & a dozen more goods, very cheap, they
are fine with Mullahs pillaging Iran for another 23 years.
It is amazing that number one fruits & vegetables of Iran are in
German, & French Markets & for the elite in Tehran & other large
cities. Number two fruits are for the Middle Class in Iran & the rest
of Iranian population can chew on Mullahs Schlong all day long!
Iranians can starve to death & Germans get the best of Iran's Fruits
& Vegetables, cause Europeans do not have Jack Shiite on their own, &
the fruit prices are sky high! As far as Europe cares, our people can
all join Allah in heavens, as long as Germany, France, England &
Italy will remain the Top Four Trade partners with Mullahs & steal
our resources for a dime or a nickel!
European Union is always screaming very loud for human rights but
when it comes down to action, they protect terrorist's rights over
hard working decent people!
European Union are like little whores who never stand behind USA when
US needs their moral support, but for GOD sake, if the Europe is in
trouble, like W.W.II or W.W.I or @ USSR's time, all these little
Shitsu European nations start begging & blowing USA's balls to send
troops, arms & money to save their little Socialist Asses!
If it wasn't because of USA, all these Shitsu European nations would
be Marching in the streets, singing Siege Heil, under Nazi jack boots
& if not so, then under Bolshevik Red Armies boots!
The whores that Europeans are, everytime they need help, they love
USA, but when USA needs moral support, they chow the finger to USA!
Thank God that USA never needs Jack Shiite from any of these European
Bloody Socialist Whores. USA does not need their military support,
economical support, or political support. They only thing that USA
cares is for them, to @ least support the war against Terrorism,
morally, & the whores that Europeans are, they cannot even do that!
Last year, when I was in Europe, I proudly wore a costume T Shirt
that I got made & on it, there was an AMERICAN FLAG & it said "Blow
Me, I am American!"
I wore this all over there, specially where they hate America most,
like in France! And the big heavy duty son of a bitch that I am
walking with my gang, the puny Socialist bastards would just suffer
giving me & my crew dirty looks & not having any balls to do
something about it! I love controversy, I live for controversy. Every
time I go to Europe, on purpose, I wear Football Jerseys or some kind
of American Flag T shirt to piss these shitsus off! I can hear them
with their socialist intellectual looks, cigarettes in the mouth &
long hair pointing to each other & mumbling "Here comes another
Capitalist Pig" or "another American Red Neck" or "Here comes another
Illiterate Hick Yankee" or so on..... but Do I give a Rats Ass?! Of
course not! And I will do it again next year, this time I wear a
football Jersey of Pittsburgh Steelers & the Steelers Cap backward on
my head too! Anything to piss the European bloody Socialists off!
As far as I care, if Europeans care so much about Palestinian Rights,
give them Versay or Windsor, maybe Koln Dom or Central Berlin, so
they can all come over there with their Rags on the heads, baggy
Pajamas, turbans, Islamic Flip Flops, & toilet pitcher (Aftabeh) &
camp in Moulin Rouge or Picadely!
People critic G. W. Bush on his Axis of Evil speech, when he openly
made a speech for Persian New Year & thanked Persian Americans for
being such powerful force in American Economy & he welcomed people of
Iran's struggle against the Axis of Evil & the Islamic Regime! People
who critic G W, have no bloody clue of American politics & that his
Axis of Evil has nothing to do with the people of Iran, Iraq or N.
Korea! Liberals just like to open the mouth & drop something, no
matter how illiterate, yet they just have to drop something or give
a "Parazit" (Persian).
I do not know, what is the worst:
A God Damn Socialist European Humanitarian, Environmentalist Waco,
Militant Pro Animal rights Activist
or
A Bloody God Damn X European Socialist who used to live in Europe &
now living in USA as a Neo Democrat Liberal?!?!?!
Thats like a double whammy! A Socialist Liberal Democrat! Praise the
lord o mighty, halle luya!
Gag me with the spoon, choke me with a coke bottle, even make me
French kiss Arafat, but please don't make me sit next to a God Damn
European Socialist who just migrated to America & is about to become
an American Citizen & cannot wait to join the Democratic Party & a
few Pro Animal Rights & Environmentalist groups! You know, the type
that would go all the way against digging Alaska for oil, so we can
rely on our own oil rather than sucking Arab Bone?! The kind who
would rather to save Alaska & the planet for Minks, & Raccoons, but
to let the human beings die out?! The type, that would give the trees
of Alaska the perfect love & care, & not to cut them, but to let us
import wood for double price from some God Damn Canadian Company?!
You know who I am talking about don't you? The type who would rather
to pay a buck ninety-five @ the gas station for Arab oil, but to have
a clean Alaska!
Well, I rather for Allah to send a thunder & lightning from the sky
to hit me in the rectum & shock me stiff, than to sit & listen &
suffer in silence to one of these left over hippies from 60's posing
as the University Official, Dean or maybe the president! Just make me
the personal bitch in a prison full of big boned Negroes, yet do not
make me listen to half an hour of speech from one of these
Educational Liberal X European Bastards!
Hey, all this made me think! Hmmmmmmm, by the way, all these
characteristics are present in my old buddy Pantea from London! and
she is about to become an American Citizen! Oh lord, help me get over
this! I think I run away to Africa for a while, you know, @ least
during the time that she will do the ceremony & the pledge of Legion
to the Star Spangled Banner & the US Flag!
Just kidding, just pulling Pantea's shorts, a bit!
Oki Doki, enough Rhetoric from me, gots to go bye byes.
Evil going under,,,under......under.....way beneath.......
Evil over & out
sign
^-^
^¿~
-v- | http://www.iranpoliticsclub.net/club/viewtopic.php?f=9&t=309&p=1289 | CC-MAIN-2018-05 | refinedweb | 1,490 | 66.17 |
SCLK Required Reading
Abstract
Introduction
References
Support for New Missions
Detection of Non-native Text Files
The Basics
SCLK rates
SCLK kernels
Partitions, briefly
Converting between SCLK strings and ET or UTC
Using encoded SCLK
Encoded SCLK
Ticks
Partitions
SCLK Conversion Functions
Distinguishing Between Different Clocks
Clock Types
Clock type-specific functions
Spacecraft-Specific Parameters
The SCLK Kernel File
Partition boundaries
Clock type assignment
Clock type-specific parameters
Expanding the system: What NAIF must do
An Example Using SCLK Functions
SCLK01
Conforming spacecraft clocks
Type 1 SCLK format
Galileo SCLK format
Mars Global Surveyor SCLK format
Voyager SCLK clock format
Type 1 SCLK conversion
Conversion algorithms
Type 1 SCLK functions
The type 1 SCLK kernel file
Kernel ID assignment
Parallel time system code assignment
SCLK type assignment
Format constant assignments
Time coefficients
Partition boundaries
Sample SCLK kernels
Appendix: Document Revision History
May 27, 2010
April 1, 2009
March 02, 2008
December 21, 2004
February 2, 2004
April 12, 1999
Top
Last revised on 2010 MAY 27 by E. D. Wright.
The SCLK system is the component of SPICE concerned with spacecraft
clock correlation data.
The spacecraft clock is the onboard time-keeping mechanism that triggers
most spacecraft events, such as shuttering of a camera. Since telemetry
data are downlinked with this clock's time attached to it, spacecraft
clock time (SCLK--pronounced ``s-clock'') is the fundamental time
measurement for referencing many spacecraft activities.
It is natural, then, that SCLK have an important role in the CSPICE
system. In fact, all C-kernel pointing data are referenced to SCLK.
CSPICE contains functions to convert between SCLK and other standard
time systems, such as Ephemeris Time (ET) and Universal Time Coordinated
(UTC).
The suite of SCLK functions has been designed to easily accommodate
future missions. A later section describes how the system might be
easily expanded to incorporate new spacecraft clocks..
In this section, we present a minimal subset of facts about the CSPICE
SCLK system that you can get by with and still use the system
successfully.
Most of the complexity of dealing with SCLK time values arises from the
fact that the rate at which any spacecraft clock runs varies over time.
As a consequence, the relationship between SCLK and ET or UTC is not
accurately described by a linear function; usually, a piecewise linear
function is used to model this relationship.
The mapping that models the relationship between SCLK and other time
systems is updated as a mission progresses. While the change in the
relationship between SCLK and other systems will usually be small, you
should be aware that it exists; it may be a cause of discrepancies
between results produced by different sets of software.
SCLK files conform to a flexible format called ``NAIF text kernel''
format. The SPICE file identification word provided by itself on the
first line of a text SCLK file is ``KPL/SCLK''. Both the NAIF text
kernel format and SPICE file identification word are described in detail
in the Kernel Required Reading document, kernel.req.
To use any of the SCLK conversion functions, your program must first
load a SCLK kernel file. The code fragment
furnsh_c ( <name of the SCLK kernel file goes here> );
In addition, you will usually need to load a leapseconds kernel. For
some missions, conversions between SCLK and ET will require that both an
SCLK and a leapseconds kernel be loaded. The code fragment
furnsh_c ( <name of the LEAPSECONDS kernel file goes here> );
Normally, you will load these kernels at just one point in your
application program, prior to using any time conversion functions.
Details concerning the kernel pool are covered in the KERNEL required
reading document, kernel.req.
The lifetime of each mission is divided into intervals called
``partitions.'' Partitions are time intervals during which the
spacecraft clock advances continuously. Every time that a discontinuity
in a spacecraft clock's readout values occurs, a new partition is
started. Discontinuities may consist of positive jumps, in which the
spacecraft clock's readout ``skips'' ahead, or negative jumps, in which
the spacecraft clock regresses.
The fact that a spacecraft clock may regress raises the possibility that
the clock may give the same reading at two or more different times. For
this reason, SCLK strings in CSPICE are prefaced with partition numbers.
The partition number is a positive integer followed by a forward slash,
for example
4 /
An example of a Galileo SCLK string with a partition number is
1/100007:76:1
The time known as ``spacecraft event time'' (SCET) is usually UTC. You
must verify that this is the case for your spacecraft.
To convert a SCLK string to a double precision ET value, you can use the
function call
scs2e_c ( sc, clkstr, &et );
scs2e_c ( sc, clkstr, &et );
timout_c ( et, pictur, lenout, utc );
The inverse conversion is performed by the code fragment
str2et_c ( utc, &et );
sce2s_c ( sc, et, lenout, clkstr );
The CSPICE C kernel (CK) system tags CK data with SCLK times. Within the
CK system, these time tags are encoded as double precision numbers. To
look up CK data, you will need to supply encoded SCLK time tags to the
CK reader functions.
You can obtain encoded SCLK values from SCLK strings via the function
scencd_c. The code fragment
scencd_c ( sc, clkstr, &sclkdp );
Encoded SCLK values can be converted to strings using the code fragment
scdecd_c ( sc, sclkdp, lenout, clkstr );
sce2c_c ( sc, et, &sclkdp );
A parallel routine sce2t_c converts ET to encoded SCLK, rounding the
result to the nearest integral tick.
The inverse conversion is provided by the routine sct2e_c, which is
called as follows:
sct2e_c ( sc, sclkdp, &et );
There is a special function that is used for encoding ``tolerance''
values for the CK readers. (See the CK Required Reading, ck.req,
document for a discussion of the CK readers.)
The code fragment
sctiks_c ( sc, clkstr, &ticks );
All of the concepts used in this section are discussed in greater detail
in the following sections of this document.
The fundamental representation of SCLK in the CSPICE system is a double
precision numeric encoding of each multi-component count. Encoding SCLK
provides the following advantages:
To convert a character representation of an SCLK count `sclkch' to its
double precision encoding `sclkdp', use the function scencd_c (Encode
SCLK):
scencd_c ( sc, sclkch, &sclkdp );
scdecd_c ( sc, sclkdp, lenout, sclkch );
Later chapters describing clock types give complete details on clock
string formats for spacecraft clocks supported by the CSPICE Toolkit.
The units of encoded SCLK are ``ticks since spacecraft clock start,''
where a ``tick'' is defined to be the shortest time increment
expressible by a particular spacecraft's clock.
An analogy can be drawn with a standard wall clock, showing hours,
minutes, and seconds. One tick for a wall clock would be one second. And
a wall clock time of
10:05:50
10(3600) + 5(60) + 50 = 36350
As in the case of the wall clock, the length of time associated with a
tick varies as the clock rate varies.
Since not all spacecraft clocks are the same, the particular time value
for one tick varies from spacecraft to spacecraft. For Mars Global
Surveyor, for instance, one tick is equivalent to approximately four
milliseconds. For Galileo, it's about 8 1/3 milliseconds.
In addition to representing spacecraft clock readings, ticks can be used
to represent arbitrary epochs. In order to minimize discretization
error, ``continuous'' (non-integral) tick values are supported:
ephemeris times may be converted to non-integral ticks via the function
sce2c_c.
Conversion of spacecraft clock strings to ticks always produces integral
tick values.
One desirable feature of encoded SCLK is that it increases continuously
throughout the course of the mission. Unfortunately, real spacecraft
clocks do not always behave so nicely. A clock may reset to a lower
value, rendering certain counts ambiguous. This might happen if the
clock has reached its maximum expression, or because of a power surge. A
clock may also jump ahead.
Any time one of these discontinuities occurs, we say that SCLK time has
entered a new partition. The partitions must be accounted for when
encoding and decoding SCLK.
To continue our analogy, say our wall clock was being used to keep time
throughout an entire day. Then 10:05:50 is ambiguous, because we don't
know if it falls in the morning or evening ``partition.'' So we append
the indicators ``a.m.''\ or ``p.m.''\ to be clear.
We handle SCLK similarly. Instead of just converting a clock count to
ticks (10:05:50 to 36350), we take into account the partition that the
count falls in, and compute the number of ticks since clock start
(10:05:50 a.m. to 36350; 10:05:50 p.m. to 36350 + 12(60)(60) = 79550).
When you pass a SCLK string to scencd_c, it is normally prefixed with a
number indicating the partition in which the count falls. Sample SCLK
strings for Voyager 2, including partition numbers, are given in an
example program later in this document.
The presence of the partition number is not always required. If it is
missing, scencd_c will assume the partition to be the earliest one
possible that contains the clock string being encoded. It's good
practice to always include the partition number in SCLK strings.
To convert to ticks since clock start, scencd_c processes the partition
number. It has to know how many ticks were in all preceding partitions,
and what the start and stop clock values were for each. This information
is stored in a SCLK kernel file for that spacecraft. The SCLK kernel
file is described in detail in a later section.
New partitions may occur at any time throughout the course of active
missions. The responsible mission operations team must update the SCLK
kernel file to include new partitions as they occur.
In converting encoded SCLK back to an equivalent clock string, scdecd_c
must also use the SCLK kernel file. Note, however, that you only have to
load the SCLK kernel file once in your program, no matter how many calls
to scencd_c and scdecd_c are made afterwards. See the KERNEL required
reading file, kernel.req, for information about ``loading''
miscellaneous kernel files into the kernel pool.
scdecd_c always returns a clock string prefixed by a partition number
and the '/' character, for example
2/2000:83:12
scpart_c ( sc, nparts, pstart, pstop );
In order to correlate data obtained from different components of the
CSPICE system, for example pointing and ephemeris data, it is necessary
to be able to convert between SCLK time and representations of time in
other systems, such as UTC and ephemeris time (also referred to as
``ET,'' ``barycentric dynamical time,'' and ``TDB'').
CSPICE contains the following functions to convert between encoded and
character SCLK, ET and UTC. Note that the names of the functions
involving SCLK are all prefixed with `sc', for Spacecraft Clock.
et2utc_c (et, format, prec, lenout, utc) (Convert ET to a
utc string)
utc2et_c (utc, et) (Convert a utc
string to ET)
scencd_c (sc, sclkch, sclkdp) (Encode SCLK)
scdecd_c (sc, sclkdp, lenout, sclkch) (Decode SCLK)
sct2e_c (sc, sclkdp, et) (Convert encoded
SCLK ticks to ET)
scs2e_c (sc, sclkch, et) (Convert SCLK
string to ET)
sce2c_c (sc, et, sclkdp) (Convert ET to
continuous ticks)
sce2t_c (sc, et, sclkdp) (Convert ET to
encoded SCLK ticks)
sce2s_c (sc, et, lenout, sclkch) (Convert ET to SCLK
string)
It takes at most two function calls to convert between any two of the
four representations.
CSPICE also contains two functions that can encode and decode relative,
or ``delta'' SCLK times. These are SCLK strings without partition
numbers that represent time increments rather than total time since
clock start. Such strings are encoded as tick counts. The functions are:
sctiks_c ( sc, clkstr, ticks ) (Convert delta SCLK to
ticks )
scfmt_c (sc, ticks, lenout, clkstr) (Convert ticks to delta
SCLK)
The algorithms used to encode and decode SCLK, and convert between SCLK
and other time systems are not necessarily the same for each spacecraft.
The differences are handled by the SCLK software at two levels:
High-level differences are managed in the code itself through ``clock
types.'' More detailed spacecraft-specific differences are handled using
parameters in a SCLK kernel.
A clock type is a general clock description that may encompass several
separate spacecraft clocks. Each clock type is identified in the SCLK
functions by an integer code. At the release date of the current
revision of this document, all supported missions use spacecraft clock
type 1.
A spacecraft clock data type has two components: a format defining the
set of acceptable spacecraft clock (SCLK) strings, and a method of
converting SCLK strings to a standard time representation, such as
ephemeris or UTC seconds past J2000.
For example, a type 1 clock consists of some number of cascading integer
counters. An individual counter can increment only when the immediately
preceding counter reaches its maximum expression and ``rolls over.'' Our
wall clock is an example: the counters are hours, minutes and seconds.
One tick for a type 1 clock is defined to be the value of the
least-significant component increment. Clock type 1 uses a
piecewise-linear interpolation process to convert between SCLK and other
time systems.
The chapter ``SLCK01'' describes clock type 1 in detail. It includes the
specific SCLK string formats for each of the type 1 spacecraft clocks
supported by the CSPICE Toolkit.
SCLK functions determine the clock type for a particular spacecraft from
the SCLK kernel file (described in the next section).
Each clock type is supported in the encoding and decoding process by the
function sccc_c, where cc is the number of the clock type. sccc_c
contains two entry points:
sctkcc_ (sc, clkstr, ticks, len_clkstr ) (SCLK string to ticks,
type cc)
scfmcc_ (sc, ticks, clkstr, len_clkstr) (Ticks to SCLK string,
type cc)
sctkcc_ and scfmcc_ do not process any partition information; that work
is handled at a higher level by scencd_c and scdecd_c, and is the same
for all spacecraft clocks.
sctkcc_ and scfmcc_ are called by sctiks_c and scfmt_c, respectively.
Each clock type is supported in the time conversion process by two
functions:
sctecc_ (sc, sclkdp, et) (Encoded SCLK ticks to ET, type cc)
sceccc_ (sc, et, sclkdp) (ET to continuous ticks, type cc)
Once the clock type has been determined, SCLK functions need parameters
that uniquely distinguish each spacecraft within the same SCLK type. For
instance, for type 1, they need to know: How many components make up
this particular clock? What are the modulus values for each of the
components? What are the coefficients defining the mapping from SCLK to
a ``parallel'' time system, such as ET? Spacecraft-specific parameters
such as these are read from the SCLK kernel file at run-time (see
below).
NAIF SCLK kernel files supply CSPICE SCLK conversion functions with
information required to convert between SCLK values and other
representations of time. Typically, a NAIF SCLK kernel will describe the
clock of a single spacecraft.
Before calling any of the functions to encode or decode SCLK, or convert
between SCLK and other time systems, an application program must load
the contents of the SCLK kernel file into the kernel pool, using the
function furnsh_c (load pool):
furnsh_c ( "name_of_SCLK_kernel_file" );
The SCLK kernel file you use should contain values for the particular
spacecraft you are dealing with. The variables expected to be found in
the file are all prefixed with the string
SCLK_
The tick values for the beginning and end of each partition are given
by:
SCLK_PARTITION_START_ss = ( .....
.....
.....
..... )
SCLK_PARTITION_END_ss = ( .....
.....
.....
..... )
SCLK_PARTITITION_END_ss
If --ss is the NAIF ID code of a spacecraft, the associated clock type
for that spacecraft is given by the assignment
SCLK_DATA_TYPE_ss = ( cc )
Note that multiple spacecraft ID codes can be associated with the type 1
SCLK data type at one time. Since the spacecraft codes are included in
the SCLK variable names, there will be no naming conflicts. (We don't
expect this feature to be used much, if at all, but it's there should
you need it.)
Each spacecraft clock type has its own set of parameters that the CSPICE
SCLK functions require in order to convert SCLK values of that type. A
complete list and description of these parameters, and their variable
names for the kernel pool, is given for type 1 in the chapter
``SCLK01.''
Accommodating new spacecraft clocks may involve no code changes to the
SCLK subroutines whatsoever.
If a new clock fits into the framework of clock type 1, then the clock
can be accommodated simply by producing a new kernel file for that
spacecraft clock. For the new clock, a new set of kernel variables
corresponding to those described above, and those in the chapter
``SCLK01,'' could be added to an existing SCLK kernel file.
Alternatively, an entirely new SCLK kernel file containing the new
parameters could be created --- this is the more likely approach. Once
this is done, all existing SCLK functions will function, without
modification, using the spacecraft ID.
If a new clock does not fit into the clock type 1 framework, then NAIF
will design a new clock type. This will involve writing new versions of
the four clock type-specific functions described earlier:
sctkcc_
scfmcc_
sctecc_
sceccc_
New cases will have to be added to the code of the following
higher-level SCxxx conversion functions to call the new, type-specific
functions:
scfmt_c
sctiks_c
sct2e_c
scs2e_c
sce2c_c
sce2t_c
sce2s_c
Adding a new clock type does not change the calling sequence of any of
the high-level conversion functions. Thus, once you've learned how to
use the SCLK conversion functions, you won't have to re-learn just
because a new spacecraft clock has been introduced.
The following example shows how some of the SCLK functions might be used
in a typical application program. This one reads pointing data from a
C-kernel file. In this example, a set of four input clock times are
hard-coded in the program for the purpose of demonstration: A real
application written by you would likely get input times from some
external source, such as a file or through interactive user input.
/*
Request pointing from a C-kernel file for a sequence of
pictures obtained from the Voyager 2 narrow angle camera.
Use an array of character spacecraft clock counts as input.
Decode the output clock counts and print the input and
output clock strings. Also print the equivalent UTC time
for each output clock time.
Note that the SCLK kernel file must contain VGR 2 clock
information.
*/
#include <stdio.h>
#include "SpiceUsr.h"
void main()
{
/*
Local constants:
*/
#define NPICS 4
#define TIMLEN 25
#define LINLEN 80
/*
Names of C kernel and SCLK kernels:
*/
#define CK "VGR2NA.BC"
#define SCLKKER "SCLK.KER"
#define LSK "LSK.KER"
/*
The instrument we want pointing for is the Voyager 2
narrow angle camera. The reference frame we want is
J2000. The spacecraft is Voyager 2.
*/
#define INST -32001
#define REF "J2000"
#define SC -32
/*
Local static variables:
*/
static SpiceChar clktol [ TIMLEN ] = "0:01:001";
static SpiceChar sclkin [ NPICS ] [ TIMLEN ] =
{
"2/20538:39:768",
"2/20543:21:768",
"2/20550:37",
"2/20564:19"
};
/*
Local automatic variables:
*/
SpiceBoolean found;
SpiceChar sclkout [ TIMLEN ];
SpiceChar utc [ TIMLEN ];
SpiceDouble cmat [3][3];
SpiceDouble et;
SpiceDouble timein;
SpiceDouble timeout;
SpiceDouble tol;
SpiceInt i;
SpiceInt sc;
/*
Load the appropriate files. We need
1) A CK file containing pointing data.
2) The SCLK kernel file, for the SCLK conversion functions.
3) A leapseconds kernel, for ET-UTC conversions.
*/
furnsh_c ( CK, );
furnsh_c ( SCLKKER );
furnsh_c ( LSK );
/*
Convert the tolerance string to ticks.
*/
sctiks_c ( SC, clktol, &tol );
for ( i = 0; i < NPICS; i++ )
{
scencd_c ( SC, sclkin[i], &timein );
ckgp_c ( INST, timein, tol, REF, cmat, &timeout,
&found );
scdecd_c ( SC, timeout, TIMLEN, sclkout );
sct2e_c ( SC, timeout, &et );
et2utc_c ( et, "D", 3, TIMLEN, utc );
if ( found )
{
printf ( "\n"
"Input s/c clock count: %s\n"
"Output s/c clock count: %s\n"
"Output UTC: %s\n"
"Output C-Matrix: \n"
"\n"
"%f\t %f\t %f\t\n"
"%f\t %f\t %f\t\n"
"%f\t %f\t %f\t\n"
"\n",
sclkin[i],
sclkout,
utc,
cmat[0][0], cmat[0][1], cmat[0][2],
cmat[1][0], cmat[1][1], cmat[1][2],
cmat[2][0], cmat[2][1], cmat[2][2] );
}
else
{
printf ( "\n"
"Input s/c clock count: %s\n"
"No pointing found.\n",
sclkin[i] );
}
}
}
Input s/c clock count: 2 / 20538:39:768
Output s/c clock count: 2/20538.39.768
Output UTC: 79-186/21:50:23.000
Output C-Matrix: <first C-matrix>
Input s/c clock count: 2 / 20543:21:768
Output s/c clock count: 2/20543.22.768
Output UTC: 79-187/01:35:57.774
Output C-Matrix: <second C-matrix>
Input s/c clock count: 2 / 20550:37
Output s/c clock count: 2/20550.36.768
Output UTC: 79-187/07:23:57.774
Output C-Matrix: <third C-matrix>
Input s/c clock count: 2 / 20564:19
Output s/c clock count: 2/20564.19.768
Output UTC: 79-187/18:22:21.774
Output C-Matrix: <fourth C-matrix>
This chapter describes the type 1 SCLK format and conversion algorithms
in detail. Also, the SCLK formats for supported spacecraft whose clocks
conform to the type 1 specification are described.
The following spacecraft have SCLK formats that conform to the type 1
specification:
The first standard NAIF spacecraft clock data type has two components: a
format defining the set of acceptable spacecraft clock (SCLK) strings,
and a method of converting SCLK strings to any of a set of standard time
systems such as TDT or TDB.
Type 1 SCLK strings have the form
pppp/<time string>
<time string>
An example of a type 1 SCLK string (for Galileo) is
3 / 10110007:09:6:1
A type 1 SCLK time string consists of a series of one or more fields,
each of which contains an integer. All fields but the leftmost are
optional. The fields of a time string represent modular counts of time
units. (A ``mod n'' count increments from zero to n-1, and then cycles
back to zero.) The values for a given field may be offset by some fixed
integer, so that they range from m to m+n, where m is non-negative. The
moduli of the various fields are not necessarily the same. The time unit
associated with a given field, multiplied by the modulus for that field,
gives the time unit for next field to the left.
For each field but the first, values may exceed the modulus for the
field. For example, the modulus of the fourth field of a Galileo SCLK
string is 8, but the digit ``9'' is allowed in that field. So
0:0:0:9
0:0:1:1
- . , : <blank>
Consecutive delimiters containing no intervening digits are treated as
if they delimit zero values.
Note that all fields in time strings represent integers, not decimal
fractions. So, the strings
11000687:9
11000687:90
An example of a valid time string (without a partition number) for the
Galileo spacecraft clock is:
16777214:90:9:7
Field Time unit Modulus
----- --------------------------- --------
1 60 2/3 sec. 16777215
2 2/3 sec. (666 2/3 ms) 91
3 1/15 sec. ( 66 2/3 ms) 10
4 1/120 sec. ( 8 1/3 ms) 8
The maximum time value that the Galileo spacecraft clock can represent
(16777214:90:9:7) is approximately 32 years.
An example of a valid time string (without a partition number) for the
Mars Global Surveyor spacecraft clock is:
4294967295.255
Field Time unit Modulus
----- ---------------------- ----------
1 approximately 1 sec. 4294967296
2 1/256 sec. 256
The maximum time value that the Mars Global Surveyor spacecraft clock
can represent (4294967295.255) is approximately 136 years.
An example of a valid time string (without a partition number) for both
the Voyager 1 and Voyager 2 spacecraft clocks is:
65535.59.800
Field Time unit Modulus
----- ------------------ ---------
1 2880 sec. 65536
2 48 sec. 60
3 0.06 sec. 800
The maximum time value that the Voyager 1 and Voyager 2 spacecraft
clocks can represent (65535:59:800) is approximately six years.
CSPICE contains functions that convert between type 1 clock strings and
the following representations of time:
Since CSPICE also contains functions that convert between any of a
variety of standard time systems, including ET, UTC, Terrestrial
Dynamical Time (TDT), TAI, TDB Julian date, TDT Julian Date, and UTC
Julian Date, conversion between SCLK strings and any other time system
supported by CSPICE requires at most two function calls.
For every type 1 spacecraft clock, encoded SCLK values are converted to
ephemeris time (TDB) as follows: first, encoded SCLK values are mapped
to equivalent time values in a standard time system such as TDB or TDT.
If the standard time system is not TDB, values from this system are
mapped to TDB.
The standard time system used for the conversion is referred to here and
in the CSPICE SCLK functions as the ``parallel'' time system. Normally,
the CSPICE Toolkit will use only one parallel time system for any given
spacecraft clock.
Conversion from TDB to encoded SCLK follows the reverse path: first, TDB
values are converted, if necessary, to equivalent values in the parallel
time system; next, those parallel time values are converted to encoded
SCLK.
For each type 1 spacecraft clock, encoded SCLK is related to the
parallel time system for that clock by a piecewise linear function. The
function is defined by a set of pairs of encoded SCLK values and
corresponding values in the parallel time system, and by a set of
``rate'' values that apply to the intervals between the pairs of time
values. The rate values give the rate at which ``parallel time''
increases with respect to encoded SCLK time during the interval over
which the rate applies. The rates in a type 1 SCLK kernel have units of
parallel time system units
----------------------------
most significant clock count
The specific method by which pairs of time values and rates are used to
map encoded SCLK to parallel time values is explained in detail below.
In the following discussion we'll use the name ``PARSYS'' to refer to
the parallel time system. We'll use the name MSF to indicate the number
of ticks per most significant SCLK field.
We can represent the data that define the SCLK-to-PARSYS mapping as a
set of ordered triples of encoded SCLK values (in units of ticks since
spacecraft clock start), their equivalents in PARSYS time, and the rates
corresponding to each pair of times:
( s/c_clock(1), parsys(1), rate(1) )
.
.
.
( s/c_clock(n), parsys(n), rate(n) )
sclk(i) < clock < sclk(i+1)
-
parsys(i) + ( rate(i)/MSF ) * ( clock - sclk(i) )
clock > clock(n)
-
To convert PARSYS time values to SCLK, we use an analogous method. If
``time'' is the value to be converted, and
parsys(i) < time < parsys(i+1)
_
time - parsys(i)
sclk(i) + ----------------
rate(i)/MSF
time > parsys(n)
-
Note that this method will not handle rate values of 0 parallel time
system units per tick.
When the function described by the pairs of time values and rates is
continuous, then all rates except for the last one are redundant, since
parsys(i+1) - parsys(i)
rate(i)/MSF = ------------------------
sclk(i+1) - sclk(i)
In order for CSPICE SCLK conversion functions to work, the information
represented by the ordered triples described above must be loaded via
the kernel pool. See the section ``The spacecraft clock kernel file''
below for details.
Type 1 SCLK functions are normally called by the higher-level SCLK
functions scencd_c, scdecd_c, scs2e_c, sct2e_c, sce2c_c, sce2t_c,
sce2s_c, sctiks_c, and scfmt_c; you should not need to call these
functions directly, though direct calls to these functions are not
prohibited.
The type 1 SCLK functions are
scfm01_ (sc, ticks, clkstr, len_clkstr) (Convert
ticks to a
type 1 SCLK
string)
sctk01_ (sc, clkstr, ticks, len_clkstr) (Convert a
type 1 SCLK
string to
ticks)
scec01_ (sc, et, sclkdp) (ET to
continuous
ticks, type
1)
scet01_ (sc, et, sclkdp) (Convert ET
to ticks,
type 1)
scte01_ (sc, sclkdp, et) (Convert
ticks to ET,
type 1)
scld01_ (name, sc, maxnv, n, dval) (SCLK look
up of double
precision
data, type
1)
scli01_ (name, sc, maxnv, n, ival) (SCLK look
up of
integer
data, type
1)
sclu01_ (name, sc, maxnv, n, ival, dval) (SCLK
lookup, type
1)
sc01_ (sc, clkstr, ticks, sclkdp, et, len_clkstr) (SCLK
conversion,
type 1)
The last two functions sc01_ and sclu01_ are ``umbrella'' functions
which exist for the purpose of allowing their entry points to share
data. These functions should not be called directly.
Before any CSPICE functions that make use of type 1 SCLK values can be
used, a SCLK kernel file must be loaded into the kernel pool. Regardless
of the clock type, an SCLK kernel assigns values to variables that
define:
SCLK01_
Each SCLK kernel must assign a identifier to the kernel variable
SCLK_KERNEL_ID
@04-SEP-1990
If --ss is the NAIF ID code of a spacecraft, this ID is associated with
a parallel time system by the assignment
SCLK01_TIME_SYSTEM_ss = ( nnn )
If --ss is the NAIF ID code of a spacecraft, this ID is associated with
a SCLK type by the assignment
SCLK_DATA_TYPE_ss = ( 1 )
All of the format constants start with the string
SCLK01
_ss
The format constants that must be assigned are
SCLK01_N_FIELDS_ss
SCLK01_MODULI_ss
SCLK01_OFFSETS_ss
SCLK01_OUTPUT_DELIM_ss
Number of fields:
SCLK01_N_FIELDS_77 = ( 4 )
SCLK01_MODULI_77 = ( 16777215 91 10 8 )
SCLK01_OFFSETS_77 = ( 0 0 0 0 )
Code Delimiter
1 .
2 :
3 -
4 ,
5 <space>
SCLK01_OUTPUT_DELIM_77 = ( 2 )
The data that define the mapping between SCLK and the parallel time
system are called ``time coefficients.'' This name is used because the
data are coefficients of linear polynomials; as a set, they define a
piecewise linear function that maps SCLK to the parallel time system.
The time coefficients are assigned to the variable
SCLK01_COEFFICIENTS_ss
PARALLEL_TIME_UNITS
PARALLEL_TIME_UNITS
----------------------------
most significant clock count
In order to convert between SCLK strings and their encoded form of ticks
since spacecraft clock start, it is necessary to know the initial and
final SCLK readouts for each partition. These values are given by:
PARTITION_START_ss
PARTITION_END_ss
The following is a sample SCLK kernel for Galileo:
KPL/SCLK
\begindata
SCLK_KERNEL_ID = ( @04-SEP-1990//4:23:00 )
SCLK_DATA_TYPE_77 = ( 1 )
SCLK01_N_FIELDS_77 = ( 4 )
SCLK01_MODULI_77 = ( 16777215 91 10 8 )
SCLK01_OFFSETS_77 = ( 0 0 0 0 )
SCLK01_OUTPUT_DELIM_77 = ( 2 )
SCLK_PARTITION_START_77 = ( 0.0000000000000E+00
2.5465440000000E+07
7.2800001000000E+07
1.3176800000000E+08 )
SCLK_PARTITION_END_77 = ( 2.5465440000000E+07
7.2800000000000E+07
1.3176800000000E+08
1.2213812519900E+11 )
SCLK01_COEFFICIENTS_77 = (
0.0000000000000E+00 -3.2287591517365E+08 6.0666283888000E+01
7.2800000000000E+05 -3.2286984854565E+08 6.0666283888000E+01
1.2365520000000E+06 -3.2286561063865E+08 6.0666283888000E+01
1.2365600000000E+06 -3.2286558910065E+08 6.0697000438000E+01
1.2368000000000E+06 -3.2286557090665E+08 6.0666283333000E+01
1.2962400000000E+06 -3.2286507557565E+08 6.0666283333000E+01
2.3296480000000E+07 -3.2286507491065E+08 6.0666300000000E+01
2.3519280000000E+07 -3.2286321825465E+08 5.8238483608000E+02
2.3519760000000E+07 -3.2286317985565E+08 6.0666272281000E+01
2.4024000000000E+07 -3.2285897788265E+08 6.0666271175000E+01
2.5378080000000E+07 -3.2284769395665E+08 6.0808150200000E+01
2.5421760000000E+07 -3.2284732910765E+08 6.0666628073000E+01
2.5465440000000E+07 -3.2284696510765E+08 6.0666628073000E+01
3.6400000000000E+07 -3.2275584383265E+08 6.0666627957000E+01
7.2800000000000E+07 -3.2245251069264E+08 6.0666628004000E+01
1.0919999900000E+08 -3.2214917755262E+08 6.0666628004000E+01
1.2769119900000E+08 -3.2199508431761E+08 6.0665620197000E+01
1.3085799900000E+08 -3.2196869477261E+08 6.0666892494000E+01
1.3176799900000E+08 -3.2196111141061E+08 6.0666722113000E+01
1.3395199900000E+08 -3.2194291139361E+08 6.0666674091000E+01
1.3613599900000E+08 -3.2192471139161E+08 6.0666590261000E+01
1.4341599900000E+08 -3.2186404480160E+08 6.0666611658000E+01
1.5069599900000E+08 -3.2180337818960E+08 6.0666611658000E+01
1.7253599900000E+08 -3.2162137835458E+08 6.0666783566000E+01
1.7515679900000E+08 -3.2159953831258E+08 6.0666629213000E+01
1.7777759900000E+08 -3.2157769832557E+08 6.0666629213000E+01
3.3451599900000E+08 -3.2027154579839E+08 6.0666505193000E+01
3.3713679900000E+08 -3.2024970585638E+08 6.0666627480000E+01
3.3975759900000E+08 -3.2022786587038E+08 6.0666627480000E+01
5.6601999900000E+08 -3.1834234708794E+08 6.0666396876000E+01
5.6733039900000E+08 -3.1833142713693E+08 6.0666626282000E+01
5.6864079900000E+08 -3.1832050714393E+08 6.0666626282000E+01
8.9797999900000E+08 -3.1557601563707E+08 5.9666626282000E+01
8.9798727900000E+08 -3.1557595597007E+08 6.0666626282000E+01
8.9799455900000E+08 -3.1557589430307E+08 6.0666626282000E+01 )
\begintext
\begindata
KPL/SCLK
Status
-----------------------------------------------
This file is a SPICE spacecraft clock (SCLK) kernel containing
information required for Mars Global Surveyor spacecraft
on-board clock to ET conversion.
Production/History of this SCLK files
-----------------------------------------------
This file was generated by the NAIF utility program MAKCLK,
version 3.3, from the most recent Mars Global Surveyor
spacecraft SCLK SCET file.
Usage
-----------------------------------------------
This file must be loaded into the user's program by a call to
the FURNSH subroutine
CALL FURNSH( 'this_file_name' )
in order to use the SPICELIB SCLK family of subroutines to
convert MGS spacecraft on-board clock to ET and vice versa and
to use MGS frames defined below as reference frames for
geometric quantities being returned by high-level SPK and
CK subroutines.
References
-----------------------------------------------
1. SCLK Required Reading file (sclk.req), NAIF document number 222
2. MAKCLK User's Guide, NAIF document number 267
Inquiries
-----------------------------------------------
If you have any questions regarding this file contact
MGS Spacecraft Operations Team (SCOPS)
Lockheed/Martin, Denver
Boris Semenov - NAIF/JPL
(818) 354-8136
bsemenov@spice.jpl.nasa.gov
SCLK DATA
-----------------------------------------------
\begindata
SCLK_KERNEL_ID = ( @1999-02-07/03:51:29.00 )
SCLK_DATA_TYPE_94 = ( 1 )
SCLK01_TIME_SYSTEM_94 = ( 2 )
SCLK01_N_FIELDS_94 = ( 2 )
SCLK01_MODULI_94 = ( 4294967296 256 )
SCLK01_OFFSETS_94 = ( 0 0 )
SCLK01_OUTPUT_DELIM_94 = ( 1 )
SCLK_PARTITION_START_94 = ( 1.3611133440000E+11 )
SCLK_PARTITION_END_94 = ( 1.0995116277750E+12 )
SCLK01_COEFFICIENTS_94 = (
0.0000000000000E+00 -9.9510252675000E+07 9.9999996301748E-01
8.3066265600000E+08 -9.6265476795000E+07 9.9999994844682E-01
1.9330583040000E+09 -9.1959244017000E+07 9.9999994927604E-01
2.7708477440000E+09 -8.8686629183000E+07 9.9999994213351E-01
4.0538009600000E+09 -8.3675093473000E+07 9.9999993609973E-01
4.7829370880000E+09 -8.0826905655000E+07 9.9999993275158E-01
5.2473643520000E+09 -7.9012736777000E+07 9.9999993064539E-01
5.4909818880000E+09 -7.8061105843000E+07 9.9999992770059E-01
6.7515176960000E+09 -7.3137138199000E+07 9.9999992410889E-01
7.9017973760000E+09 -6.8643858540000E+07 9.9999992038548E-01
8.9854187520000E+09 -6.4410962877000E+07 9.9999991689249E-01
9.9588085760000E+09 -6.0608659193000E+07 9.9999991330346E-01
1.1222619136000E+10 -5.5671899621000E+07 9.9999990916047E-01
1.2448517120000E+10 -5.0883236056000E+07 9.9999990447344E-01
1.3831336704000E+10 -4.5481597572000E+07 9.9999990051645E-01
1.5223486464000E+10 -4.0043513113000E+07 9.9999989497162E-01
1.7390367488000E+10 -3.1579135002000E+07 9.9999988993180E-01
1.7567130624000E+10 -3.0888654078000E+07 9.9999989100000E-01 )
\begintext
Minor edit to eliminate typo.
Added a note about the SPICE file identification word for SCLK files.
Updated discussion of type 1 conversion algorithm to clarify role of
parallel time system. Updated discussion of SCLK string formats to
indicate support for 4-digit partition numbers.
Added note regarding detection of non-native text files. Replaced
ldpool_c with furnsh_c.
Performed a spell-check on text.
The document differs from the previous version of April 20, 1992 in that
it documents the new capability of the SCLK software to convert between
ET and continuous ticks. Examples involving Mars Observer have been
updated to refer to Mars Global Surveyor. The quotation style has been
changed from British to American. The program example showing use of the
SCLK system together with the CK reader CKGP has been corrected.
Miscellaneous minor changes of wording have been made throughout the
text. | https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/sclk.html | CC-MAIN-2021-25 | refinedweb | 5,905 | 57.4 |
hline, mvhline, mvvline, mvwhline, mvwvline, vline, whline, wvline - draw lines from single-byte characters and renditions
#include <curses.h> int hline(chtype ch, int n); int mvhline(int y, int x, chtype ch, int n); int mvvline(int y, int x, chtype ch, int n); int mvwhline(WINDOW *win, int y, int x, chtype ch, int n); int mvwvline(WINDOW *win, int y, int x, chtype ch, int n); int vline(chtype ch, int n); int whline(WINDOW *win, chtype ch, int n); int wvline(WINDOW *win, chtype ch, int n);
These functions draw a line in the current or specified window starting at the current or specified position, using ch. The line is at most n positions long, or as many as fit into the window.
These functions do not advance the cursor position. These functions do not perform special character processing. These functions do not perform wrapping.
The hline(), mvhline(), mvwhline() and whline() functions draw a line proceeding toward the last column of the same line.
The vline(), mvvline(), mvwvline() and wvline() functions draw a line proceeding toward the last line of the window.
Upon successful completion, these functions return OK. Otherwise, they return ERR.
No errors are defined.
These functions are only guaranteed to operate reliably on character sets in which each character fits into a single byte, whose attributes can be expressed using only constants with the A_ prefix.
border(), box(), hline_set(), <curses.h>. | http://pubs.opengroup.org/onlinepubs/7990989775/xcurses/hline.html | CC-MAIN-2015-48 | refinedweb | 238 | 70.63 |
Up to [cvs.netbsd.org] / pkgsrc / mail / dovecot
Request diff between arbitrary revisions
Default branch: MAIN
Revision 1.3 / (download) - annotate - [select for diffs], Fri Apr 30 10:43:26 2010 UTC (2 years: +2 -1 lines
Diff to previous 1.2 (colored).
Revision 1.2 / (download) - annotate - [select for diffs], Mon Jan 25 12:31:20 2010 UTC (2 years, 3 months ago) by ghen
Branch: MAIN
CVS Tags: pkgsrc-2010Q1-base, pkgsrc-2010Q1
Changes since 1.1: +39 -1 lines
Diff to previous 1.1 (colored)
Update to Dovecot 1.2.10, Sieve 0.1.15 and ManageSieve 0.11.11. Changelog for Dovecot 1.2.10: + %variables now support %{host}, %{pid} and %{env:ENVIRONMENT_NAME} everywhere. + LIST-STATUS capability is now advertised - maildir: Fixed several assert-crashes. - imap: LIST "" inbox shouldn't crash when using namespace with "INBOX." prefix. - lazy_expunge now ignores non-private namespaces. Changelog for Sieve. Changelog for ManageSieve 0.11.11: *.
Revision 1.1 / (download) - annotate - [select for diffs], Fri Dec 11 20:52:22 2009 UTC (2 years, 5 months ago) by ghen
Branch: MAIN
CVS Tags: pkgsrc-2009Q4-base, pkgsrc-2009Q4. | http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/mail/dovecot/PLIST.sieve | crawl-003 | refinedweb | 188 | 61.73 |
Thursday, January 29, 2015¶
Some tests where not being run¶
I noticed that some test cases in Lino Welfare were not being run
during the test suite. For example
lino_welfare.projects.docs.tests. Fixed.
The
LINO_CACHE_ROOT environment variable¶
Lino now makes use of a
LINO_CACHE_ROOT environment
variable. If this variable is set, then the cached data of demo
databases are no longer written into the file tree of the source code
repository but below the given directory.
On my machine I have now the following line in my
.bashrc file:
export LINO_CACHE_ROOT=/home/luc/tmp/cache
Note that the path should be absolute and without a
~.
This feature was needed because we want to get Lino build on a continuous integratio site such as Travis CI. To enable it for Travis, I modified Lino’s .travis.yml file, changing:
script: fab initdb test
into:
script: export LINO_CACHE_ROOT=$(TRAVIS_BUILD_DIR) ; fab initdb test
(To be honest, I hope that this was the reason. Confirmation will follow.)
This feature caused quite some subtle internal changes. The changes which might cause problems when upgrading are:
The Site attributes
project_dirand
project_namehave slightly different meanings and default values, and they are no longer simple strings but unipath.Path objects.
New Site attribute
cache_dir.
New API for defining demo databases¶
Users of
atelier.fablib who used “demo databases” (which we now
call “Django demo projects”, see
atelier.fablib.env.demo_projects) must adapt their
fabfile.py as follows:
Before:
add_demo_database('lino_welfare.projects.docs.settings.demo')
After:
add_demo_project('lino_welfare/projects/docs')
(I guess that I am the only one who needed to do this…)
About
__all__¶
I removed the
__all__ definitions from all modules.
The first reason is that they caused a problem when Mahmoud tried to build the docs:
Warning, treated as error: /...lino/docs/api/lino.api.ad.rst:4: WARNING: __all__ should be a list of strings, not [u'Site', u'TestSite', u'Plugin', u'configure_plugin', u'_'] (in module lino.api.ad) -- ignoring __all__
Note that this warning is rather a false alert, and thus I’d call it a bug in the latest Sphinx version.
OTOH I am not a friend of
__all__. Anyway it is not
recommended to do
from xxx import *. I never recommend to use it
except for some special situations:
lino/ad.py imports
*from lino/api/ad.py. This module exists only for backwards compatibility.
Another good reason for
import *is when you extend a
lino.core.plugin.Plugin.
Results from travis¶
Here is the first feedback from travis:
$ export LINO_CACHE_ROOT=$(TRAVIS_BUILD_DIR) ; fab initdb test /home/travis/build.sh: line 41: TRAVIS_BUILD_DIR: command not found
The following might work better:
$ export LINO_CACHE_ROOT=$TRAVIS_BUILD_DIR ; fab initdb test | https://luc.lino-framework.org/blog/2015/0129.html | CC-MAIN-2020-24 | refinedweb | 447 | 57.67 |
Hi I followed the tutorial on Swiftless. The last post I worked through was about Keyboard input and it does work. Basically what he covers is how to detect whether a key was pressed or realeased.
So I tried to experiment around. To do so I wanted to make the application to terminate when 'e' is pressed.
#include "glew.h"// Include the GLUT header file #include "glut.h" // Include the GLEW header file bool* keyStates = new bool[256](); // Create an array of boolean values of length 256 (0-255) bool* keySpecialStates = new bool[256](); // Create an array of boolean values of length 256 (0-255) bool* keyPreviousStates = new bool[256](); void renderPrimitive(void) { glBegin(GL_QUADS); // Start drawing a quad primitive glVertex3f(-1.0f,-1.0f,0.0f); //Bottom Left glVertex3f(-1.0f,1.0f,0.0f); //Top Left glVertex3f(1.0f,1.0f,0.0f); //Top Right glVertex3f(1.0f,-1.0f,0.0f); //Bottom Right glEnd(); } void keyOperations(void) { if ((!keyStates['e']) && keyPreviousStates['e']) // If the 'a' key has been pressed { // Perform 'e' key operations exit(0); } } void keySpecialOperations(void) { if (keySpecialStates[GLUT_KEY_LEFT]) // If the left arrow key has been pressed { // Perform left arrow key operations } } void display(void) { keyOperations(); keySpecialOperations(); glClearColor(0.706f, 0.706f, 0.706f, 2.0f); // Clear the background of our window to red glClear(GL_COLOR_BUFFER_BIT); //Clear the colour buffer (more buffers later on) glLoadIdentity(); // Load the Identity Matrix to reset our drawing locations glTranslatef(0.0f,0.0f,-5.0f); // Push eveything 5 units back into the scene, otherwise we won't see the primitive renderPrimitive(); //render the primitive glFlush(); // Flush the OpenGL buffers to the window keyPreviousStates = keyStates; } void reshape(int width, int height) { glViewport(0, 0, (GLsizei)width, (GLsizei)height); // Set our viewport to the size of our window. (0,0) being bottom left in the window. glMatrixMode(GL_PROJECTION); glLoadIdentity(); // Reset the projection matrix to the identity matrix so that we don't get any artifacts (cleaning up) gluPerspective(60,(GLfloat)width/(GLfloat)height,1.0,100.0); // Set the Field of view angle (in degrees), the aspect ratio of our window, and the new and far planes glMatrixMode(GL_MODELVIEW); } void keyPressed(unsigned char key,int x, int y) { keyStates[key] = true; //Set the state of the current key to pressed } void keyUp(unsigned char key,int x, int y) { keyStates[key] = false; //Set the state of the current key to not pressed } void keySpecial(int key, int x,int y) { keySpecialStates[key] = true; } void keySpecialUp(int key,int x,int y) { keySpecialStates[key] = false; } int main(int argc, char **argv) { glutInit(&argc, argv); // Initialize GLUT glutInitDisplayMode(GLUT_SINGLE); // Set up a basic display buffer (only single buffered for now) glutInitWindowSize(500, 500); // Set the width and height of the window glutInitWindowPosition(100, 100); // Set the position of the window glutCreateWindow("Your first OpenGL Window"); // Set the title for the window glutDisplayFunc(display); // Tell GLUT to use the method "display" for rendering glutReshapeFunc(reshape); // Tell GLUT to use the method "reshape" for reshaping glutKeyboardFunc(keyPressed); // Tell GLUT to use the method "keyPressed" for key presses glutKeyboardUpFunc(keyUp); // Tell GLUT to use the method "keyUp" for key up events glutSpecialFunc(keySpecial); // Tell GLUT to use the method "keySpecial" for special key presses glutSpecialUpFunc(keySpecialUp); // Tell GLUT to use the method "keySpecialUp" for special up key events glutMainLoop(); // Enter GLUT's main loop }
So I changed the keyOperations() code a little. I tried to add another bool-array which stores the state of the keys from the previous display()-iteration. Then I try to check if 'e' is currently released and if its previous state was pressed. But nothing happens
I guess this a very basic thing but I am very new to OpenGL and C++ so I could only think of the way I would implement this in XNA. Btw I am assigning the previous key states at the end of the display function.
Thanks in advance.
Edited by Prot, 18 August 2014 - 07:57 AM. | https://www.gamedev.net/topic/660020-how-to-react-on-keypress-release/ | CC-MAIN-2017-04 | refinedweb | 662 | 55.07 |
Lifetime Careers in IT?
Cliff posted more than 11 years ago | from the long-term-predictions dept.
CyPlasm asks: "MSN Careers had this article posted the other day that asked about a "Lifetime Career in IT: Is It Possible?" Does the average Slashdot reader think they will retire (with a pension, benefits, etc) after a long and successful career in IT?"
first post (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177650)
Re:first post (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177670)
Re:first post (0, Offtopic)
frodo from middle ea (602941) | more than 11 years ago | (#5177712)
Not if he keeps replying with these "FP Posts"...
Re:first post (0, Informative)
Anonymous Coward | more than 11 years ago | (#5177744)
RTFA!
Had to be done.
:)
FP (-1, Offtopic)
shivianzealot (621339) | more than 11 years ago | (#5177652)
Re:FP (0)
Anonymous Coward | more than 11 years ago | (#5177692)
Unlikely
ada (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177656)
dejebe tu dejebe
not likely (0)
Anonymous Coward | more than 11 years ago | (#5177657)
quite likely (3, Interesting)
CrudPuppy (33870) | more than 11 years ago | (#5177926).
Maybe... (0)
Anonymous Coward | more than 11 years ago | (#5177659)
Retire? (0)
Anonymous Coward | more than 11 years ago | (#5177662)
Certainly (5, Insightful)
sparkhead (589134) | more than 11 years ago | (#5177667)
Not me though. I'm going to claw my way to middle management and worry about TPS reports.
Re:Certainly (5, Funny)
salemnic (244944) | more than 11 years ago | (#5177803)
And I'll make sure you get another copy of that memo. Okay?
Re:Certainly (4, Informative)
Telastyn (206146) | more than 11 years ago | (#5177828)
Re:Certainly (2, Interesting)
GombuMstr (532073) | more than 11 years ago | (#5177852)
--Travis
Re:Certainly (0, Flamebait)
Anonymous Coward | more than 11 years ago | (#5177875)
Re:Certainly (4, Funny)
FatherOfONe (515801) | more than 11 years ago | (#5177893)
The thing is Bob it's not that I am lazy, its that I just don't care...
No, I don't (1, Funny)
Anonymous Coward | more than 11 years ago | (#5177671)
--
foobar = foo + bar
From hobby it came, and hopefully will soon return (5, Interesting)
boinger (4618) | more than 11 years ago | (#5177672)
Anyone need an overpriced mechanic who specializes in aircooled VWs/Porsches?
BMW Mechanic (2, Interesting)
Anonymous Coward | more than 11 years ago | (#5177785)
Of course. . . . (5, Interesting)
havardi (122062) | more than 11 years ago | (#5177673)
Re:Of course. . . . (5, Insightful)
coyote-san (38515) | more than 11 years ago | (#5177749)
Re:Of course. . . . (3, Insightful)
tshak (173364) | more than 11 years ago | (#5177844).
GOOGLE IS DYING! (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177674)
One more crippling bombshell hit the already beleaguered Google [google.com] community when IDC confirmed that Google [google.com] market share has dropped yet again, now down to less than a fraction of 1 percent of all web searches. Coming on the heels of a recent Netcraft survey which plainly states that Google [google.com] has lost more market share, this news serves to reinforce what we've known all along. Google [google.com] is collapsing in complete disarray, as fittingly exemplified by Yahoo's failure to renew its exclusive deal with Google [com.com] .
You don't need to be a Kreskin [amazingkreskin.com] to predict Google [google.com] 's future. The hand writing is on the wall: Google [google.com] faces a bleak future. In fact there won't be any future at all for Google [google.com] because Google [google.com] is dying. Things are looking very bad for Google [google.com] . As many of us are already aware, Google [google.com] continues to lose market share. Red ink flows like a river of blood.
Google search [google.com] is the most endangered of them all, having lost most of its core affiliates. The sudden and unpleasant departures of Yahoo and AOL only serve to underscore the point more clearly. There can no longer be any doubt: Google [google.com] is dying.
Let's keep to the facts and look at the numbers.
Google.com [google.com] founder Sergey Brin states that there are 7000 users of Google [google.com] . How many users of Verity [verity.com] are there? Let's see. The number of Google [google.com] versus Verity [verity.com] posts on USENET is roughly in ratio of 5 to 1. Therefore there are about 7000/5 = 1400 Verity [verity.com] users. AskJeeves [askjeeves.com] posts on USENET are about half of the volume of Verity [verity.com] posts. Therefore there are about 700 users of Inktomi [inktomi.com] . A recent article put Teoma [teoma.com] at about 80 percent of the search engine market. Therefore there are (7000+1400+700)*4 = 36400 Google [google.com] users. This is consistent with the number of Google [google.com] USENET posts.
Due to the troubles of Google News [google.com] , abysmal sales and so on, Google [google.com] is going out of business and will probably be taken over by idealab! who operate another troubled search engine. Now Inktomi [inktomi.com] is also dead, its corpse turned over to yet another charnel house.
All major surveys show that Google [google.com] has steadily declined in market share. Google [google.com] is very sick and its long term survival prospects are very dim. If Google [google.com] is to survive at all it will be among search engine dilettante dabblers. Google [google.com] continues to decay. Nothing short of a miracle could save it at this point in time. For all practical purposes, Google [google.com] is dead.
Fact: Google [google.com] is dying
lifetime? (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177675)
What's up with all the depressing career stories? (4, Interesting)
Augusto (12068) | more than 11 years ago | (#5177679)???
Between OSS guys destroying code to sell... (-1, Flamebait)
Anonymous Coward | more than 11 years ago | (#5177753)
OSS has to be the biggest culprit. They have this penchant for wanting to destroy markets for products to sell, stuff one can make money off selling and supporting. Eventually there will be an event horizon of such, OSS will have cannibalized IT jobs as you know it. The big winners: your employers. But hey, McDonalds is always hiring.
Re:What's up with all the depressing career storie (1, Funny)
Anonymous Coward | more than 11 years ago | (#5177931)
Mod him down! Show him what _real_ pain is! We'll show him what stress is.
lifetime career indeed (2, Funny)
riqnevala (624343) | more than 11 years ago | (#5177686)
Kevin's on the loose, beware!
no (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177687)
Over 1 million say no.... (5, Insightful)
cylcyl (144755) | more than 11 years ago | (#5177689)
i doubt it (1)
Jarhead83 (532394) | more than 11 years ago | (#5177691)
hahahaah (0)
Anonymous Coward | more than 11 years ago | (#5177693)
Through the military, yes (5, Insightful)
Anonymous Coward | more than 11 years ago | (#5177694)
Re:Through the military, yes (0)
Anonymous Coward | more than 11 years ago | (#5177729)
Yes (1)
pyite69 (463042) | more than 11 years ago | (#5177699)
I expect to be in IT forever, though I doubt I
will spent a whole career at one place. I am
trying to pick an industry that will be around
for awhile, health care, and to get familiar with
it.
Sure (4, Funny)
Anonymous Coward | more than 11 years ago | (#5177700)
Yes. (0)
Anonymous Coward | more than 11 years ago | (#5177702)
Lifetime Career in IT? (1, Interesting)
Anonymous Coward | more than 11 years ago | (#5177708)
Retire? Who's going to retire? (5, Interesting)
ProgressiveCynic (624271) | more than 11 years ago | (#5177709)? (1)
saskboy (600063) | more than 11 years ago | (#5177754)
Re:Retire? Who's going to retire? (2, Interesting)
ProgressiveCynic (624271) | more than 11 years ago | (#5177815)
The odds of finishing an IT career... (3, Insightful)
saskboy (600063) | more than 11 years ago | (#5177711)
Settle into a company, make yourself indispensible, and you are set... If we avoid nuclear war, and stop using SUVs...
3rd Post (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177713)
Woo Hoo!
TP (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177714)
Life long is right! (2, Insightful)
Marqui (512962) | more than 11 years ago | (#5177715)
Third Post (-1, Offtopic)
Anonymous Coward | more than 11 years ago | (#5177716)
of course! (1, Informative)
Anonymous Coward | more than 11 years ago | (#5177717)
Lifetime in IT? Yea, i will be old and grey before i would do anything else.
Retire? (0)
Anonymous Coward | more than 11 years ago | (#5177718)
Hah
WhatMeWorry!
Huh? (5, Insightful)
Otter (3800) | more than 11 years ago | (#5177721).
Rampant Age Discrimination--at Age 35 (1, Interesting)
Anonymous Coward | more than 11 years ago | (#5177897)
Of course!!! (3, Funny)
MrWinkey (454317) | more than 11 years ago | (#5177724)
calm before the storm (5, Interesting)
Rev.LoveJoy (136856) | more than 11 years ago | (#5177730)
hmmm (3, Interesting)
pummer (637413) | more than 11 years ago | (#5177736)
what about those of us that aren't in IT now??
We aren't our parents' generation anymore (1)
Em Emalb (452530) | more than 11 years ago | (#5177738)
No, IMO, IT for the majority won't be a one company career. Hell, I've only been doing this for 10 years and I have already worked for 5 companies. That's an average of (holy cow, math on
I don't see this trend stopping anytime soon. The technology changes too swiftly for people to find their comfort level and sit there doing the same thing for 30 years.
Very Difficult These Days (4, Interesting)
cmacb (547347) | more than 11 years ago | (#5177739)
Difficult, but possible (5, Insightful)
BaronCarlos (34713) | more than 11 years ago | (#5177740)?)
Pension? Benefits? What are they? (2, Insightful)
RetiredMidn (441788) | more than 11 years ago | (#5177752)
I expect to be working or playing at this stuff until retirement age, but I'll probably detach myself from the IT rat-race before then only because it's a rat-race, not because of my ability to contribute.
Writing software is rewarding; writing software for business sucks (after a while; 25+ years in my case).
If it were only a few years ago... (0)
Anonymous Coward | more than 11 years ago | (#5177756)
In order to have a lifelong career in IT... (1, Funny)
MadAnthony02 (626886) | more than 11 years ago | (#5177766)
I would first have to get a job in IT.
(current status: unemployed recent college grad. MIS major).
Re:In order to have a lifelong career in IT... (0)
Anonymous Coward | more than 11 years ago | (#5177886)
Sure, we have lifetime employment. (4, Funny)
Kenja (541830) | more than 11 years ago | (#5177767)
County employee (1, Insightful)
Anonymous Coward | more than 11 years ago | (#5177774)
IT in Government (5, Insightful)
JackL (39506) | more than 11 years ago | (#5177775)
So yes, lifetime IT jobs probably exist and they don't necessarily have to be boring. It really depends on what you are looking for.
Hell no! (4, Funny)
ENOENT (25325) | more than 11 years ago | (#5177777)
A lifelong career IS possible, IF.. (4, Interesting)
sakusha (441986) | more than 11 years ago | (#5177782)
Lifers (2, Interesting)
2Wrongs (627651) | more than 11 years ago | (#5177783)
They tend to have 1 way of doing things because they've never learned other systems. Switching companies is a way to do that.
And to answer the inevitable "Not Me" posts, I know there are always exceptions.
YOU tell me.. (0, Offtopic)
a8f11t18 (614700) | more than 11 years ago | (#5177792)
"FP!"
"Woooooot! FP! Lemchatters envy me!"
"asereje ja deje dejebe tu dejebe"
Of course by the time you retire.... (4, Funny)
Lord_Slepnir (585350) | more than 11 years ago | (#5177800)
Re:Of course by the time you retire.... (1)
Usquebaugh (230216) | more than 11 years ago | (#5177904)
Yes (1)
jwhitener (198343) | more than 11 years ago | (#5177801)
The key to a long IT career is to apply your IT knowledge to something more stable than IT for IT's sake.
Not possible for most (0)
Anonymous Coward | more than 11 years ago | (#5177804)
Not only that, but the ability for most people to learn complexity later in life is greatly diminished so what effectively happens is that in 30 years, the 30 years of that time will have skills that are far more advanced than the typical 60 year old.
So if I can hire a 30 year old with a wider skill set, a faster pace, maybe from a third world country, I'll take that person. The fact is that companies must save money to make more money, insurance for the elderly is more expensive, pensions are expensive, and the time required off from work to tend to illness is an impediment to finishing projects under budget and on time.
Being in the position to hire, the simple truth is I can't afford to allow people to retire under my management. Terminations, down-sizing, restructering, and mergers will continue to be the tools to remove those workers who are getting too old and too expensive.
Re:Not possible for most (0)
Anonymous Coward | more than 11 years ago | (#5177859)
That's why most IT people should migrate to management or some other skill that doesn't take keeping up with technology.
A lifetime in IT will never happen... (0)
Anonymous Coward | more than 11 years ago | (#5177809)
Just being an efficient and capeable IT worker requires continuous learning. For the person that starts out as a sysadmin, he or she will need to move into core programming in order to even begin to ponder staying in IT for a lifetime.
For the individual that starts thier IT career as a core programmer, he or she will need to continuously replenish thier skill set. And even then, they'll need to prove they have fresh skills and ideas in order compete with the younger generation.
A nurse can start out as a nurse and retire as a nurse - not so in IT.
If you're in IT and expect to retire in IT, you'd better re-evaluate. Most will be in for a rude awakening when they reach thier late 50's and no-one will hire them for typical sysadmin or programming jobs.
Really, it sux to think about it, but it's reality.
Sure... (1)
ovapositor (79434) | more than 11 years ago | (#5177812)
Why not? (5, Insightful)
fuzzybunny (112938) | more than 11 years ago | (#5177817).
IT sux (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177819)
Benefits (3, Funny)
fuzzykitty (265256) | more than 11 years ago | (#5177822)
IN CAPITALIST AMERICA (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177824)
I'd like to see a union or guild develop (2, Insightful)
once1er (643921) | more than 11 years ago | (#5177827)
Doubtful (1)
KKin8or (633073) | more than 11 years ago | (#5177830)
If only I'd been able to catch the dot-com wave and retire at 30... Though I suppose that doesn't count for this question, since it would be without pension or benefits (wouldn't need 'em), and after a short successful career in IT.
But that makes me wonder-- do most tech companies (I'm thinking specifically about newer dot-com-type companies) have retirement plans? Many probably haven't been around long enough to have employees with enough longevity at the company to qualify for any kind of retirement benefits. But what about the bigger ones that have been around a while? Anyone know? Can you retire with benefits after a long IT (not management) career? I should hope that if you can't now, by the time most techies are heading for retirement, the system will be in place at most companies.
Longest time in IT with one employer? (1)
TechnoInfidel (569458) | more than 11 years ago | (#5177832)
I'm hoping to retire from the same place, after another 25 years or so.
Oh hell, now I'm depressed...
Overseas Outsourcing Destroying Domestic IT Jobs? (2, Interesting)
panaceaa (205396) | more than 11 years ago | (#5177833).
Lifetime career? HA! (5, Interesting)
MsWillow (17812) | more than 11 years ago | (#5177837).
Gotta Have a Contingency Plan (2, Insightful)
CosmicDreams (23020) | more than 11 years ago | (#5177842)
Work till I'm forty, teach the rest of my life. I know by that time I'll want to pursue what REALLY is important to me, giving back. And besides, I'll be fired due to age discrimination anyway.
Doubtful, running into age discrimination... (1)
meme_police (645420) | more than 11 years ago | (#5177845)
Pension? Never heard of it! (1)
SolitaryMan (538416) | more than 11 years ago | (#5177846)
I can add In Soviet Russia to the subject
Yes. (0)
Anonymous Coward | more than 11 years ago | (#5177850)
No market for it (3, Funny)
Bitmanhome (254112) | more than 11 years ago | (#5177861)
As good as any other field.....STUPID (5, Insightful)
greymond (539980) | more than 11 years ago | (#5177868) (5, Informative)
Anonymous Coward | more than 11 years ago | (#5177872)
Maybe the analysts are wrong, but do you want to bet your career on it?
The warning signs are out there.
Already retired (1)
chrisseaton (573490) | more than 11 years ago | (#5177881)
Sure, why not? (2, Funny)
theGreater (596196) | more than 11 years ago | (#5177883)
Oh yeah, and bribes. Lots of bribes.
Love it or leave it (5, Insightful)
sbillard (568017) | more than 11 years ago | (#5177887) (3, Insightful)
eclectric (528520) | more than 11 years ago | (#5177899).
Would be nice.... (0)
Anonymous Coward | more than 11 years ago | (#5177907)
It's hard to think of staying somewhere for so long when I just hope to be employeed at all.
In the New Economy (2, Funny)
Anonymous Coward +1 (645038) | more than 11 years ago | (#5177911)
2. Bribe government officials for fat military contracts.
3. Retire!!!
Absolutely YES, thanks to OSS (3, Interesting)
nuwayser (168008) | more than 11 years ago | (#5177914)
Of course (1)
bobdehnhardt (18286) | more than 11 years ago | (#5177915)
Will an effing barber shop diploma make millions? (-1, Troll)
Anonymous Coward | more than 11 years ago | (#5177936)
apply for a CLW or MSCBP scrip.
Certified Lindows Wanker
Macro Stiff Certified Button Pusher
It's never ending Bull Shit...
-Will
'wood level' Authorized BSS | http://beta.slashdot.org/story/31989 | CC-MAIN-2014-35 | refinedweb | 3,035 | 72.56 |
Although I myself do not speak Gaeilic, I was proud to be invited by Seanán Ó Coistín to build this app for him after he had read my previous article Creative Writer's Word Processor. (You can't blame him for the bad jokes I may write in this article but you should, however, thank him for conceiving of the plan that resulted in this awesome Irish Language Word Processor.) Since I had written several other similar projects before, I was happy to inform him that I could bring it to life (without promising the moon). We drew up an outline of what he wanted and I had to cut out any ideas he might have had about grammatically correct sentences before they germinated (the fact that my A.I. coding experience is limited to a single Mini-Max Tic-Tac-Toe experiment made my lack of Gaeilic Language Skills moot on that matter). My only condition for agreeing to help promote the Irish Language by writing this app was that it must be made free and available to open-source developers when I'm done.
So, here we are.
When you download Dlús intending to launch the app, you'll have to find the executable file on your hard-drive. Download the files "Dlús Word processor", then extract them onto your hard-drive. Once you have done this, you will have to locate the app's executable file(the one with the Irish flag painted face and the .exe file extension you see highlighted in the image below) and double click on it. I'd encourage you to select this file in your Windows File Manager, then right click your mouse and select 'create shortcut'. This will place an icon on your Desktop which you can then more easily use to launch the app.
The image below should help you find the executable file on your hard-drive. Just remember that in this example, the downloaded files were extracted directly in the C:\ root directory and this may not reflect where you have chosen to extract your files.
style="width: 630px; height: 488px" alt="Image 2" data-src="/KB/Articles/5298566/Launching_the_App.png" class="lazyload" data-sizes="auto" data->
The Dlús word processor was written with the average-to-novice computer user in mind. We did not want to encumber the user with too many options that would clutter the work area. For this reason then, the interface is easy-to-use and fancy free.
All the tools you need to edit your text are available in the Context-Menu (shown below) which you can summon by clicking your right-mouse-button in the main work-area.
In the image below, you can see the tool bar and the ruler located above the working text area. Both are as similar to existing word-processors as imaginable making the transition from MS-Word to Dlús as painless as possible. The ToolBar has all the important commands from Spell-Check and Thesaurus to File Options and Font-Styles right there for you to use. The only difference between Dlús and other writing apps is what makes Dlús such a great application for writing in Irish, the Gaeilge Word List found on the right of the main working area.
style="width: 640px; height: 688px" alt="Image 4" data-src="/KB/Articles/5298566/Main_Screen.png" class="lazyload" data-sizes="auto" data->
The word-list will find the exact word you are looking for as you type in the main work area. Once you find the word you need in the Word-List, you can then insert that word into your text by clicking on the word in this Word-List when your mouse cursor takes the form of the 'word insert' icon. If the word you've typed is a complete word that appears in the word-list, its definition will appear in the top-right corner of the app after you've stopped typing for a brief pause. Alternately, should you wish to read the definition of a word that you scrolled to in the list using the mouse-wheel or the Word-List scroll-bar, just click on that word when your mouse cursor takes this appearance over the word you wish to explore. If there's a word you want to look up that's already written in your text, you can move your mouse cursor over it and click on the mouse-button there to summon that word's definition. These definitions are all taken from the Irish government's Teanglann.ie website, Foclóir Gaeilge-Béarla and can be accessed on your home computer even when you're off-line.
You can type in the accented vowels of the Irish language even if your personal computer's keyboard does not provide you with easy access to these special characters. Although European keyboards are more likely to provide this feature, North-American and many other keyboards around the world do not. For this reason then, since Dlús was intended to be accessible to all users, the application enables you to easily include all Irish accented vowels in your writing projects. To type in an accented vowel into your text you simply precede that vowel with the back-slash character and the word-processor will recognize the two-character combination of the 'back-slash + vowel' and replace both these characters in your text with the single accented vowel you intended to write.
e.g., if you wanted to write the word Tá
you would actually type T\a
and immediately see this text be replaced with the correctly accented word Tá.
The word suggestion option will suggest words as you type. It will only suggest words that are already included in your text and is not limited to those words found in the Irish dictionary. Use the up/down arrow keys to select a word you want to insert, When you have made your selection press the Tab key and the selected word will be inserted into your text. Pressing the Escape key will temporarily hide the Word Suggestion list until the start of the next word.
The Thesaurus also has a quick-access feature. All you need to do is select a word in your text by putting the textbox's cursor on it and then press the Ctrl-T key combination. You can also use the Thesaurus button in the Tool-Bar above the ruler near the top of your workspace . The word's Thesaurus entry may be derived from the root spelling of the word you clicked and will appear in the area at the bottom right corner of the app. Note, however, that some words do not have entries in the thesaurus and will not appear in the Teasáras box. If you've found a word in the Teasáras which you'd like to insert into your text, you can click on it in the Teasáras box and it will appear where the textbox cursor is, right in your work-project where you need it.
Spell checking your work is very important and easy to do when you're working with Dlús. Whenever you're ready to spell-check your work, press F7, click the Spell-Check icon in the ToolBar or use the right-mouse button to call up the Context Menu and select the Spell-Checker option there. You'll have options like Ignore, Ignore All, Add or Replace to help you along. Effort was made to re-create common existing spell-checker products to make it easier for the user to jump right in and be comfortable with the familiarity of this tool's appearance and functionality. Spell-Checker will quit automatically when it has gone through your text, so if you call the Spell-Checker and there are no detected spelling errors in your text, it will simply quit and let you get on with your work.
N.B. Whenever you 'Add' a word to the Spell-Checker, what you're really doing is adding that word to the Word-List that appears on the right of the main working area of your screen. The Spell-Checker only accepts the words that are in its Word-List as correctly spelled words. All these words are derived from the dictionary and have explanatory 'Word-info' tags attached to them explaining the root of the word as well as the type of word it is but when you 'Add' a word using the Spell-Checker, Dlús will not have any word-information for it even though it is accepted as a correctly spelled word and does appear in the Word-List.
As you can see in the example below:
The word 'teaghaisí' is the plural form of the head-word 'teaghais'. You can see that information in both the Dictionary entry above and the light-blue 'Word-Info' tag attached to it in the Word-List below.
Should you find an incorrect entry in Dlús's Word-List you want to change, correct or delete, you simply click the Lexicon Editor icon in the ToolBar above. Whenever you choose to do that, a new form will appear with a green (sometimes red) textbox on the upper-left side of the screen and the word-list below it. You'll have two check boxes asking whether or not you want to see deleted information. This is important because, when you check these boxes words that have been removed from the Word-List will appear in red in their alphabetical ranking with a line struck across them. Each word in the word-list here can be removed from the list of correctly spelled words by selecting it and then un-checking the checkbox beside its spelling in the green text-box above the list. In this way, you can remove words from the Word-List if you feel they are incorrectly spelled or inappropriate entries. You can also use the Lexicon Editor to add words by typing them in the green text box near the top left (note that the color of this textbox will change from green to red depending on whether or not that word is already a correctly spelled word). When you're satisfied that the new word entry you've typed in this textbox is spelled correctly (it will be in red if it has not yet been included in the word list), check the small box beside it (the box will turn to green) and it will then be added to the Word-List and the Spell-Checker.
style="height: 360px; width: 640px" alt="Image 11" data-src="/KB/Articles/5298566/Screenshot_258_.png" class="lazyload" data-sizes="auto" data->
Similarly, in the middle of this form, you will see the list of Word-Info tags associated with this particular spelling of this particular word. The 'New' button to the right of the 'View Deleted Word-Info' check-box will add a new 'un-checked' entry to the Word-Info list for this word. You can use it to add a new 'Word-Info' tag for this word then fill out the information appropriate for that spelling by selecting the FGB file in the app's Dictionary directories. The selected file will be the 'root word' (or 'head word') for this particular spelling and will therefore be the definition that will appear in the top-right Dictionary area of Dlús's main form when you select this word in the Word-List. The combo-box to the right of the Word-Info tag lets you select the kind of word it is and, when you're sure the information is correct, check the box on the right and the word's new info-tag that you just created and it will be added to the Word-List.
Gaelspell hates me. There, I said it. It just hates me. I downloaded a dozen different versions and tried all kinds of files and they all told me to 'Go F!#k' myself. It was really annoying. I don't know why this happened, as I have used HunSpell in several different projects and it has never given me any issues before.
So, I made my own Spell-Checker.
Initially, I wanted to use the popular EXTENDED Version of Extended Rich Text Box (RichTextBoxEx) which has all the features you need to build a word-processor but I couldn't figure out how to change the language files and after I had created my own spell-checker using the on-line dictionary, which I'm going to tell you about in a minute, this Extended Rich Textbox suddenly had systemic heart-failure and consistently rendered the ghost in my app's 'program.cs' file like a reincarnating Brahman doll with cheap Dollarama batteries. This was most disappointing as it made the crash non-debuggable without venturing into the .DLL's Visual Basic source code. Something, I was loathe to do.
So, I made my own Extended RichTextBox.
Then, I was hungry. I hadn't eaten anything for hours except for a dried Wonderbread crust. The local Subway restaurant was closed and the supermarket was far, far away ...
So, I made my own Sandwich.
If you want to create a Spell-Checker what you need is a bunch of words. Like, lots of em. As many as you can get. All of them, really. And then you put them all together and tell your Spell-Checker to pick out words in your text that aren't in that list of 'all the words in the universe' that you've collected.
And that's essentially how a Spell-Checker works.
So... I had to get myself a bunch of words. To do that, I went to the Teanglann.ie website. Conquered it, scraped it and left.
Veni, Vidi, Vici. ~Julius Caesar
If you want to learn more about how to scrape a website, have a look at a previous article I wrote about How I Scraped Merriam Webster's Dictionary.
There are no actual laws prohibiting someone from using electronic means to acquire information on the internet. Laws are only broken when you bypass passcodes, steal login information and post the names of Ashley Madison clients and their spouse-cheating ways. but that's for another day...
I won't be writing a second article on the subject of scraping-websites but if you're interested in seeing the Source Code I wrote to do it for this project, here it is Foclair_Gaeilg_Bearla_ScrapingTool.zip
... and I did send them an email telling them about my scraping ... I even sent them a link to a copy of the RTF files which were derived from their website and are now included in my Creative Writer's Word Processor.
All in the name of Gaeilge.
The source files which I scraped from the FGB website were HTML files. Unless I was planning on incorporating a web-browser into this Word-Processor, they needed to be parsed out and re-written into RichTextFile format. That can be a difficult and daunting process. Take, for example, this website you're looking at now. If you right-mouse-click and call your web-browser's context-menu (mine, anyway) then click on the 'View Page Source' menu item you'll get to see what the page's Mark-Up Language looks like. The generic HTML code is intended to be interpreted by any web-browser on any computer using any operating system. It's essentially comprised of instructions telling the browser you're using how to draw this page. Which fonts to use where and all that. HTML works great because its universal that way. But now, imagine picking through it and trying to figure out how to draw it yourself and then producing RichTextFiles with that information.
That's what I did.
I used a tool that I wrote for the Merriam Webster's files that are now all happily converted and baptised into the RTF hall of prayer. You can have a look at the source code here HTML-ator_20210329_2333.zip
Once I had figured out which HTML tags isolate the different parts of the Dictionary word entry files and knew how to format the text, I wrote the app that converted all the HTML files to RTF. Writing this particular tool took about a week and then processing all the files takes another 10-12 hours (on my slow and emotionally troubled laptop computer, anyway). This had to be done 3 or 4 times as errors in the final output RTF files were discovered and the code needed to be modified to correct the flaws that were appearing in the output files.
It was important for the RTF files to use a specific color of green that was unique for each of the file's 'pop-up tips' (same unique color for all tips) which could later be used to identify a 'tip' when the user's mouse hovers over the dictionary entry in the final word-processor and expects a 'pop-up' explanation for every abbreviation in the word's definition.
Here's the source code that I wrote to convert the HTML files to RTF format Foclair_Gaeilg_Bearla_HTML_to_RTF.zip.
So, here's where the real Gaeilge lives. Or so you'd think, but not really. I didn't need to know anything about the Irish language to interpret the English language definitions. Nor did I have to understand the grammatical usage of any words and their variant spellings to generate these aberrant lexicographic logophilious transmographications. It was relatively easy. Having acquainted myself with the website's source files in those ten days it took me to sift through the HTML in order to produce the long sought out RTF files, I had a better idea of how to pick out the information I needed in order to transform those files into a database of all the variant spellings.
First, I scoured all the files for specific HTML tags that identified the 'word type' information. Found every one of them and stored them in a file for later use TipList.zip. These were all the abbreviations that 'pop-up' on the Teanglann.ie web-site with their complete spellings.
Since variant spellings (in this on-line dictionary) are described inside round brackets, I wrote an app which used each file's 'head-word' as the starting mold, then isolated the round brackets in the definition. Each of these round brackets then tested for 'pop-up' abbreviations. When a 'pop-up' abbreviation was found, the variant spelling's word-type was located. The tilda (~) and the dash (-) symbols on this web-site were interpreted to mean 'replace with head-word' or 'replace end of head-word', respectively.
Because I knew running through all 53,104 word entries was going to result in many 'round-brackets' not being interpreted by this Data-base creating app, I had it ask me what I wanted it to do with text it didn't know how to interpret (All the non-variant spelling round brackets in the dictionary confused this algorithm along with some other mis-formatted file entries). But doing that would mean I would have to tell it what to do with every questionable bracket every time I had to start again, and I knew that that was going to happen ... a lot. and it did. So I had it record whatever text it found confusing along with my instructions on how to handle them into a separate 'data-base building data-base' and so, as I ran through all these files explicitly telling it what to do every time it was confused, it recorded my instructions and never bothered me with those entries again until, by the end, it had it all figured out (or memorized) and left me alone (with few exceptions recurring regardless of my best efforts to train it to leave me alone).
Some Beta-Testers have been using the app and providing me with changes they want to see but none of those changes have been with regards to any of the Word-List entries, so I'm thinking this process worked out pretty good.
Here's the code I wrote to produce the Dictionary's complete Word-List Foclair_Gaeilg_Bearla_-_Alt-Spellings_20210330_0012.zip.
Although the on-line dictionary provides ~all~ the information you need to generate the variant spellings of each word, you have to realize that when we say ~all~ ... the word ~all~ can be open for interpretation. You see, the thing is, the Irish tend to muck things up when it comes time to writing their language. Its really just to keep you honest. I won't make any jokes about slurring drunks or fighting Irish men speaking through bruised, bloody or fattened-lips that distort the sounds of what they're saying because the Real-IRA may come around and ask me whether I'm a Catholic-Atheist or a Protestant-Atheist and I really don't know which way to go on that one.
But, as I was saying, the Irish language is a little blurry about spelling. They have a thing called the 'eclipse' which means that they insert a letter sometimes before and sometimes after the first character of a word depending on how it's used in a sentence. Latin has declensions, French has conjugations and the Irish Eclipse them all with distorted twists in their spelling just to muck you up.
Here's an example, the 'Séimhiú' Eclipse inserts an 'h' after a 'b', 'c' or .. (there's a bunch) to soften the sound because ... why not?
There's a few of them 'Séimhiú', 'Urú' and some mysterious thing I call 'other'.
To manage this and still have a functioning spell-checker, I had to write methods that tested the second and first letters everytime it failed to find the word in the app's Word-List as it is spelled in the user's text.
Here's the method that detects an eclipse which adds one or two characters in front of the word's leading character.
static string RootWord_PeelEclipse_Urú(string strWord)
{
string[] arrEclipses =
{
"n-a",
"mb",
"gc",
"nd",
"n-e",
"bhf",
"ng",
"n-i",
"n-o",
"bp",
"dt",
"n-u"
};
if (strWord.Length > 2)
{
for (int intEclipseCounter = 0;
intEclipseCounter < arrEclipses.Length;
intEclipseCounter++)
{
string strEclipse = arrEclipses[intEclipseCounter];
if (strWord.Length > strEclipse.Length
&&
string.Compare(strWord.Substring(0, strEclipse.Length), strEclipse) == 0)
return strWord.Substring(strEclipse.Length - 1);
}
}
return "";
}
This method peels-off the leading 'eclipse' and returns the word's natural spelling which is then tested against the app's Word-List to see if it is an acceptable spelling. There are three of these methods and they are found in the classDlús_BinaryTree.cs file. They are used whenever a word cannot be found in the Word-List because they may have their spelling-distorted by a similar Irish lexicographer's nightmare. If none of these methods produces a valid spelling, then it quits trying and returns a null 'Not-Found' result indicating that the word is not in the Word-List and is therefore assumed to be misspelled.
null
The code I used to draw the Word-List is a nasty bit of a mess that I've been working on for some time now. It started out with the need to reduce the number of Microsoft objects native to the C# language in my Animation Editor project (which has made giant leaps since the last publishing and will require more attention before I'm ready to show the world what monster I have wrought). I had so many objects on the screen for the User to interface with I was convinced that that was the reason why it was slogging along at such an annoyingly slow pace (I found a few other reasons later and fixed those too). The objective was to draw the Graphical User Interface onto a single MS PictureBox using a Sweep-and-Prune algorithm and thereby wittling away at the unnecessary overhead that resulted from having all those versatile memory burdened and event laden objects I assumed were cluttering my project down to a single PictureBox.
Here's an example of what I mean about a cluttered work area ...
style="width: 575px; height: 465px" alt="Image 12" data-src="/KB/Articles/5298566/Animation_Editor_SPObjects.png" class="lazyload" data-sizes="auto" data->
The image above is a small part of the UI for the Animation Editor which allows the user to sample a rectangle of a source image from a start size and location to an end size and location at given start and end frames and then draw that sampled image on the screen for each frame from a start size/location to an end size/location for any number of animation frames in an animation project (this produces a scrolling effect where the camera pans/zooms across an image or video). There are 87 of these objects that each have events, methods and properties, 95% of which this particular app never uses. The objects native to C# are tried and tested, versatile and bug-free (mostly) but they come with a lot of overhead (or so I figure). My solution to this was intended to reduce this memory overhead and alleviate the processor's work when handling them (Jury is still out on whether this objective was achieved). However, the SPObjects class has grown, changed excessively. I've debugged and tinkered with it so much that all of my projects for the last year have different versions of this same class which keeps getting better (although my SPObjects.TextBox is a crying flop of a disaster which may take much time yet to domesticate properly before it can be brought to the park and play with others without embarrassing me too much).
SPObjects
SPObjects.TextBox
The class is so difficult to use I sometimes take to drink.
I will eventually write an article about it and show the world but for now let me just say ... ouch. It has been one of the most difficult challenges I have set for myself and, although I am pleased with the results, it is far from finished (there really is no hope for that TextBox)...
TextBox
But the SPObjects class does have its advantages.
Without going too deeply into it ... Essentially, there is an imaginary rectangular region which defines the space where objects can be placed. That region can be as big as you like and of any shape you like (as long as its a rectangle) anywhere in the Cartesian plane. The 'Visible Region' can also be placed anywhere in the Cartesian plane and, depending on what is to be shown to the user at any time, scroll-bars will automatically appear if necessary. That means, for this word processor, I can create a space large enough to contain the entire Word-List of the Irish Dictionary, let the user move the scroll bar and then interrupt the SPContainer before it draws itself whenever the Visible Region changes and move the dozen or so SPObjects.Labels I am re-cycling onto the screen into the visible region where they will be displayed with the text & color appropriate for their dance recital in the 'Visible Region'.
SPObjects.Labels
Make sense?
Ok, I'll try again.
I created a tall rectangular region for the SPContainer (the Sweep'n'Prune area) which is much much larger than the rectangular space the user sees on the screen. When this Visible Region needs to be drawn, any labels already in the SPContainer are removed and kept in a side list to be re-cycled and used again. The Visible Region is then compared to the Word-List which has an ascending ranking order of all the words that is used as an index. This indexed list of words is then consulted to figure out what needs to be drawn on the screen, the existing labels are pulled from the side-list (where we just put them a minute ago), they are told what costumes & makeup to wear and when they are dressed and ready for their next performance they run to their intended positions in the SPContainer so that they appear on the screen as they should for the user to see.
This is kind of a convoluted way to draw the Word-List because normally I would just add all the objects into the SPContainer wherever they belong and not worry about re-cycling them as the Visible Region changes, since that's one of the few advantages of using this class but, since we're talking about more than 74 000 unique word spellings in the dictionary, doing it that way would stall the Dlús during load time while it builds the SPContainer's region and then hamper it with unnecessary memory requirements that are best left in Binary-Files on the hard-drive.
SPContainer
The SPObjects.cs classes are included in this project's source-code, it's the latest and greatest and does cut down on all the memory overhead involved in using too many objects with all the versatility Microsoft put into each one but it is still deficient in its ease of use (and lack thereof). You really have to will-it-to-life in order to make it work and despite the advantage of being able to make a scrolling container of any proportion that will automatically add Scroll-Bars for you ... it really still is a major pain if you haven't experienced the masochistic joys of implementing it yourself first.
In order to load RTF files into the dictionary window at the top-right of the screen, what I did was put two RichTextBoxes in the same panel and then alternated between them like an animator might draw on a side plate before putting it on the screen. There are two properties with the names...
RichTextBox
RichTextBox RTX_Next { get { return rtx[(RTXCounter + 1) % 2]; } }
RichTextBox RTX_Current { get { return rtx[RTXCounter]; } }
...which I cycle between using a method that changes the value of the current RichTextBox being referenced in either of them.
void RTX_Cycle()
{
intRtxCounter = (intRtxCounter + 1) % 2;
RTX_Current.BringToFront();
if (formDlús.Debugging)
RTX_Current.ContextMenu = cmnu;
}
Then, when I want to load a new definition, the RTX_Next RichTextBox is the one that actually loads the file before the RTX_Cycle() method is called and puts it in front of the previous one.
RTX_Next
RTX_Cycle()
A timer is set to test whether the user's mouse is hovering over the Dictionary display area. This timer is reset whenever the mouse moves and then quits altogether when the mouse leaves that part of the screen. There's a method in the CK_Objects.cs file which I use to measure the generic 'on-screen' MousePosition relative to any control in my app. It asks Windows where the Mouse is on the screen, then subtracts the Location of each parent control back to the form that contains the app. Have a look:
MousePosition
Location
public class classMouseOnControl
{
public static Point MouseRelTo(Control ctrl)
{
Point ptRetVal = System.Windows.Forms.Control.MousePosition;
while (ctrl != null && ctrl.Parent != null)
{
ptRetVal.X -= ctrl.Location.X;
ptRetVal.Y -= ctrl.Location.Y;
ctrl = ctrl.Parent;
}
return ptRetVal;
}
}
If the user lets the mouse cursor rest anywhere over the Dictionary display long enough, the timer event is triggered. This tells the app to check what word is under the mouse cursor and bring up whatever information is appropriate, then displays that in a PopUp text box near where the mouse cursor is located on the screen.
What gets displayed in the PopUp textbox depends on what is under the mouse cursor. The first thing it asks is 'what color is this text' because if its that 'unique green color' that was used to paint all the abbreviated 'tips' mentioned earlier then it knows that the text under the mouse-cursor is an abbreviation and what it needs to display is the full spelling of that abbreviation. Otherwise, it looks through the Word-List database (being sure to test for the Eclipses I mentioned in the previous section). If it finds a word in the Word-List that matches what appears underneath the mouse-cursor, then it puts that on the screen.
Initially, I had argued to include the same Merriam-Webster's English Dictionary files I added to my Creative Writer's Word-Processor but the intention to "keep it Irish" shillelagh-ed that plan and I took the MW dictionary out.
void PopUpText()
{
string strPopUp = "";
if (intIndex_Start <= intIndex_End && intIndex_Start >= 0)
{
RTX_Current.Select(intIndex_Start, intIndex_End - intIndex_Start+1);
if (RTX_Current.SelectionColor.R == clrTip.R
&& RTX_Current.SelectionColor.G == clrTip.G
&& RTX_Current.SelectionColor.B == clrTip.B)
{
// this is an abbreviation and needs to be matched with its 'tip'
strPopUp = classTip.Search_PopUpKey(_strWordUnderMouse);
panelPopUpDefinition.Abbreviation(strPopUp);
}
else
{
List<classDlús_LLItem> lstLL = classDlús_BinaryTree.Search(WordUnderMouse);
if (lstLL != null && lstLL.Count > 0)
{
panelPopUpDefinition.Definition(lstLL);
}
}
}
}
I went to their web-site and had a look at the XML-ish file they offered.
didn't like it.
Tried to use their Latex_Source file
didn't like it..
GaelSpell ,,,
didn't like it ...
Essentially, I've decided to quit relying on other people and discovering 3rd party whatcha-call'ems that don't do what they're supposed to for me ... so I downloaded the LSG PDF file thinking I could use that to generate the thesaurus database. I went about searching on the internet for a (free) app that would convert the PDF to RTF and wound up giving my credit-card information to two different companies who promised they could do it. I logged into each of my new accounts in turn to discover that Gaeilge is NOT a common language and they had no idea what to do with this file. Thankfully, both accounts were 'Free Trial' accounts and I haven't seen any money come out of my depleted (red-lined) bank statement... yet.
So, there I was with a pretty PDF and no gas in the tank to take her anywhere... hmmm, let me reminisce how often this has happened to me.
Well, we had fun anyway.
Let me introduce you to my date, her name is 'Cut N. Paste'. We had hours of fun. Dropped 21 young'uns and gave them all names from A to Z.
Let me show you a family picture:
style="width: 637px; height: 525px" alt="Image 13" data-src="/KB/Articles/5298566/LSG_Family_Photo.png" class="lazyload" data-sizes="auto" data->
I would have jumped in the photo, but I had to hold the camera.
Next, I set to work on the grand-kids.
Since the kids all look like their mom, I knew that each word-entry started with Bold fonted text. So by scanning each character one at a time looking for Bold fonted letters (and ignoring samples of Bold fonted numerals), I would be able to cut each RTF file up into the separate word-entries and save them individually to generate all the 'grand-kids'. Which is what I did. It took me about an hour to write the code, 9 hours to process all the files and ten minutes to decide to take a nap while the rest of our descendants looked up their history on Ancestry.com to find this proud family picture:
width="505px" alt="Image 14" data-src="/KB/Articles/5298566/LSG_on_Ancestry_dot_Com_II.png" class="lazyload" data-sizes="auto" data->
So, at this point, I had all the RichText files I needed to build the Thesaurus.
RichText
Here is the app I wrote to generate all the RTF Thesaurus files Dl_s_Thesaurus_Build_RTF_Files_20210330_0806.zip
To provide the user with the Thesaurus information of a given word, the spelling of the requested word is used to search for a file name in the appropriate LSG sub-director. If a file with the exact spelling of the word requested is found, then that file's content is drawn to the screen. When a word's variant spelling is requested, then the app needs to scour through a binary-tree for the requested word and then reports back with the word's root spelling which is then used as the file name and the HD is once again searched, the file is found and its content is put to the screen. Skipping the first step in this process would likely simplify the algorithm but why bother fixing what isn't broken. When I decided it was working as I had written it... I just moved on and gave it no further thought.
Here's the code:
public void Thesaurus_Search()
{
RichTextBox rtx = rtxMain.rtx;
string strWordUnderMouse = TextAtCursor(ref rtx);
if (strWordUnderMouse.Length > 0)
{
string strDir = classDlús_BinaryTree.WorkingDirectory + "lsg\\Letter" +
StringLibrary.classStringLibrary.Deaccent(strWordUnderMouse)[0] +
"\\" + strWordUnderMouse + ".rtf";
if (System.IO.File.Exists(strDir))
{
Thesaurus_Show(strDir);
return;
}
bool bolValid = false;
classDlús_BinaryTree.classBTLeaf cBTLeaf =
classDlús_BinaryTree.classBTLeaf.Get(strWordUnderMouse, ref bolValid, true);
strDir = classDlús_BinaryTree.WorkingDirectory + "lsg\\Letter" +
StringLibrary.classStringLibrary.Deaccent(cBTLeaf.key)[0] +
"\\" + cBTLeaf.key + ".rtf";
if (System.IO.File.Exists(strDir))
{
Thesaurus_Show(strDir);
}
}
}
I started working on this project in early January. Since I always have a dozen projects on slow-burners at a time, I've been finding it difficult to actually complete anything without being distracted by something else. My Still has been a distraction. My Animation Editor project often has me spending time actually making animation videos and in the process of doing that, I often discover issues with my Sprite Editor. I play with micro-controllers and now I'm writing my next novel which calls attention to fixes & new features for my Creative Writer's Word Processor. All of these distractions are great fun and a lot of time-consuming work but since Dlús was a project which I was commissioned to write, I put extra diligence in ensuring it was done properly and as user-friendly as I could conceive it. There may still be updates to it in the future ... but for now "tá sé iom. | https://codeproject.freetls.fastly.net/Articles/5298566/Dl-s-Irish-Language-Word-Processor?msg=5805926#xx5805926xx | CC-MAIN-2022-05 | refinedweb | 6,347 | 66.88 |
Opened 11 years ago
Closed 11 years ago
#7274 closed enhancement (duplicate)
graphs: Maximum flow algorithms
Attachments (3)
Change History (11)
Changed 11 years ago by
Changed 11 years ago by
Maximum matching in bipartite graphs
Changed 11 years ago by
Example usage
comment:1 Changed 11 years ago by
- Status changed from new to needs_review
comment:2 Changed 11 years ago by
comment:3 Changed 11 years ago by
- Milestone changed from sage-wishlist to sage-4.3
comment:4 Changed 11 years ago by
- Report Upstream set to N/A
- Reviewers set to Robert Miller
- Status changed from needs_review to needs_work
Patch applies cleanly and passes tests, and I'm ready to approve except for:
def path_iterator(P)This function needs a docstring. The 100% rule applies here too. Just a simple sentence saying what it does and an example or two will do.
comment:5 Changed 11 years ago by
As #7592 and #7593 just got reviewed, this patch can not be directly added to sage : there are now functions Graph.flow and Graph.matching available in Sage ( well, in the next version.. )
The problem with these functions is that they still depend on GLPK or CBC, two optional packages that can not be made standard are their licenses are not compatible, so it would be good to have pure Python equivalent.
Several remarks
- In #7600 and in Graph.coloring, the user can chose which algorithm he would like to use to solve the problem. Maybe the best way is to copy this behaviour in the case of flows and matching to have the two algorithms available.
- It could be very useful to know how these algorithms compare in terms of performances. This will be much easier to test when flow and matching will be natively in Sage
- #7634 may not be ready, but time could come soon : with this update the efficiency of the shortest_path method will be improved, and the speed of this implementation too.
- Somwhere in the code, I saw a call to
path = R.shortest_path(source, sink,by_weight=False, bidirectional=False)I wondered why you chosed not to use the bidirectional version of the algorithm, as it is expected to be faster.. :-)
Thank you for your work !!!
comment:6 Changed 11 years ago by
comment:7 Changed 11 years ago by
comment:8 Changed 11 years ago by
- Milestone changed from sage-4.6 to sage-duplicate/invalid/wontfix
- Resolution set to duplicate
- Status changed from needs_work to closed
Note: See TracTickets for help on using tickets.
Maximum flow algorithms | https://trac.sagemath.org/ticket/7274 | CC-MAIN-2021-17 | refinedweb | 427 | 67.18 |
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Undelete or file recovery software?
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Author
barcher174
Joined: 07 Dec 2012
Posts: 575
Posted: Fri May 08, 2015 5:22 pm
Post subject: Undelete or file recovery software?
Does there exist any kind of undelete software for nextstep?
Thanks,
Brian
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nuss
Joined: 27 Apr 2006
Posts: 40
Location: Germany
Posted: Sat May 09, 2015 12:37 am
Post subject:
Hi Brian,
the saying in comp.sys.next usegroups was that it is not possible in a senseful way to recover files on NeXTstep (UNIX).
Some examples:
Undelete utility needed
UNDELETE? (directory is now lost!)
But in 1991 it was Mike Morton who has posted a recovery program into the public domain:
Recovering deleted files: saga and code
Please read the whole posting and take Mike's warning serious:
"Here's the program. Use it as you see fit, but make sure you know what
you're doing, since this is currently a completely special-purpose,
one-night job. No idea how it will work on any other machines, but
I'm placing it in the public domain in hopes that someone will think
about writing a better scavenger."
Cheers, Nuss
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nuss
Joined: 27 Apr 2006
Posts: 40
Location: Germany
Posted: Sat May 09, 2015 12:40 am
Post subject:
Mike's original code:
Code:
/* Recover unallocated blocks from a file system and store them
in a specified directory, which should not be on the same file
system. We attempt to select only blocks with ASCII; others
might save everything, or have another criterion.
No guarantees at all are made for this code.
Mike Morton, 11 June 91
Based very heavily on code from bp at NeXT
*/
/* If you use the same handleBlock() code, this is the threshhold below
which a block is assumed to be garbage. We don't insist on 100% vanilla
ASCII because some text files may contain non-ASCII stuff (ellipsis,
curly quotes, etc).
*/
#define GOODPCT 0.90 /* assume this %, or more, ASCII means worth saving */
#include <stdio.h>
#include <sys/file.h>
#include <sys/param.h>
#include <ufs/fs.h>
#define FRAGSIZE (MAXBSIZE/8) /* size of one sub-block (better name for this?) */
static char *dirName = 0; /* where to store output */
/* save -- Write some data to a new file "filename" inside the directory
specified in the command line args.
*/
static void save (filename, data, length)
char *filename; /* INPUT: name to save under */
unsigned char *data; /* INPUT: stuff to save */
unsigned long length; /* INPUT: length of stuff to save */
{ char pathname [200];
FILE *f;
/* printf (filename); printf ("\n"); return; */
strcpy (pathname, dirName); /* get dir */
strcat (pathname, "/"); /* get dir/ */
strcat (pathname, filename); /* get dir/file */
#if 0 /* useful for writing out only some stuff during testing */
{ static long counter = 0;
if ((counter++ % 200) != 0) return;
printf ("\nsaving: %s", pathname);
}
#endif
f = fopen (pathname, "w+");
if (! f) { printf ("Couldn't open %s\n", pathname); return; }
if (fwrite (data, 1, length, f) != length)
printf ("Write failed!\n", pathname);
fclose (f);
} /* end of save () */
/* handleBlock -- This is called from findFreeData(). We're passed a partly or completely
free block which has been read in, and write out either the block, fragments of it, or
both.
If you're trying to recover some other kind of data (other than ASCII), you want to
change this function to save different stuff when findFreeData() calls it.
*/
static void handleBlock (block, blkNum, freeInfo)
unsigned char *block; /* INPUT: pointer to MAXBSIZE bytes of data */
unsigned long blkNum; /* INPUT: block number on disk */
unsigned char freeInfo; /* INPUT: bit-coded info for eight fragments of block */
/* one-bits mean the frag is free (hence, interesting) */
{ unsigned int fragNum; /* ranges 0..7, for frags of the block */
register unsigned char *subBlock; /* one frag of data */
register unsigned short count;
register unsigned long goodChars; /* count of apparently-ASCII chars in fragment or block */
unsigned char fragBit; /* bit compared against "freeInfo" */
char filename [200];
/* If the 8-frag block is entirely free, write it out if it looks good. We'll do the
8-frag breakup below as well, if it seems good from that p.o.v. */
if (freeInfo == 0xff)
{ subBlock = block; /* set up a working pointer... */
count = MAXBSIZE; /* ...and a loop counter */
goodChars = 0;
/* My hard disk appears to initialize a lot of stuff with many 0x04s, so use 0x05: */
while (count--)
{ if ((*subBlock > 0x05)
&& ((*subBlock & 0x80) == 0)) /* appears to be ASCII? */
goodChars++;
subBlock++;
}
/* If we beat the quota, save this stuff: */
if (goodChars >= (GOODPCT * MAXBSIZE))
{ sprintf (filename, "Block-%03d-%ld", goodChars*100/MAXBSIZE, blkNum);
save (filename, block, MAXBSIZE);
return; /* HACK -- save space and don't fragment blocks we already write out whole */
}
} /* end of handling all-free block */
/* Do the same thing for each fragment. */
for (fragNum = 0; fragNum <= 7; fragNum++)
{ fragBit = (0x80 >> fragNum); /* bits run left-to-right (lower blocks are lefterly) */
if (freeInfo & fragBit) /* interesting fragment? */
{ subBlock = block + (fragNum * FRAGSIZE); /* point to this frag of the block */
count = FRAGSIZE;
goodChars = 0;
while (count--) /* tally the fragment */
{ if ((*subBlock > 0x05)
&& ((*subBlock & 0x80) == 0)) /* appears to be ASCII? */
goodChars++;
subBlock++;
}
/* If we beat the quota, save this stuff: */
if (goodChars >= (GOODPCT * FRAGSIZE))
{ sprintf (filename, "Frag-%03d-%ld-%d", goodChars*100/FRAGSIZE, blkNum, fragNum);
subBlock = block + (fragNum * FRAGSIZE); /* point (again) to this frag of the block */
save (filename, subBlock, FRAGSIZE);
}
} /* end of handling interesting frag */
} /* end of loop through frags */
} /* end of handleBlock () */
/* bread -- Read a block (specified by 1K-block number, not byte address). */
bread (fd, blk, buf, size)
int fd; /* INPUT: file to read from */
daddr_t blk; /* INPUT: block to start at */
char *buf; /* OUTPUT: where to read to */
int size; /* INPUT: how much to read */
{ if (lseek (fd, (long) dbtob (blk), 0) < 0)
{ fprintf(stderr, "bread: lseek error.\n");
perror("lseek");
return 1;
}
if (read (fd, buf, size) != size)
{ fprintf(stderr, "bread: read error.\n");
perror("read");
return 1;
}
return 0;
} /* end of bread () */
/* findFreeData -- Find all the free or partly-free blocks in a file system, and
pass them to "func".
*/
void findFreeData (filesys, func)
char *filesys; /* INPUT: pathname of file system */
void (* func) (); /* INPUT: function to call with blocks */
{ int rawFd; /* file descriptor for raw device */
char slop[MAXBSIZE]; /* big enough to read a whole block */
struct fs *sblock = (struct fs *) slop; /* superblock, overlaid on buffer */
unsigned int cgNum; /* number of a cylinder group */
char cgSlop[MAXBSIZE]; /* big enough to read a whole block */
struct cg* theCg = (struct cg*) cgSlop; /* cylinder group struct, overlaid on buffer */
unsigned char *freeMapPtr; /* pointer into free-block list */
unsigned long blk; /* index into same */
char blockData [MAXBSIZE]; /* data from one block */
unsigned long totBlksRead = 0;
/* Open the device */
if ((rawFd = open(filesys, O_RDONLY, 0)) < 0)
{ perror("open");
fprintf(stderr, "findFreeData: cannot open %s.\n", filesys);
exit(1);
}
sync (); /* get the disk up to date */
/* Read, check, and chat about the superblock. */
if (bread (rawFd, SBLOCK, sblock, SBSIZE))
{ fprintf(stderr, "Error reading superblock.\n"); exit(1); }
if (sblock->fs_magic != FS_MAGIC)
{ fprintf(stderr, "Bad superblock magic number.\n");
exit(1);
}
printf ("Free blocks %ld\n", sblock->fs_cstotal.cs_nbfree);
printf ("Free frags %ld\n", sblock->fs_cstotal.cs_nffree);
/* Loop through all cylinder groups. */
/* @@@ Why must we use -1 in sblock->fs_ncg-1? We get lots of errors without this... */
for (cgNum = 0; cgNum < sblock->fs_ncg-1; cgNum++)
{ printf ("CYLINDER GROUP #%d\n\n", cgNum); fflush (stdout); /* help impatient humans */
if (bread (rawFd, (daddr_t) cgtod (sblock, cgNum), theCg, MAXBSIZE))
{ printf ("Read of cgtod failed.\n"); return; }
if (theCg->cg_magic != CG_MAGIC)
{ printf ("Magic constant in cylinder group info is wrong!\n"); return; }
if (theCg->cg_cgx != cgNum)
{ printf ("Cylinder number in cylinder group info is wrong!\n"); return; }
/* Walk the array of free blocks at the end of the cylinder block. Each byte in
the array is bit-coded -- any '1' bits at all mean some of the block is free.
*/
freeMapPtr = theCg->cg_free;
for (blk = 0; blk < theCg->cg_ndblk; blk++)
{ if (freeMapPtr [blk]) /* nonzero value means partly or entirely free */
{ daddr_t absBlk; /* absolute block number on disk, suitable for bread() */
absBlk = (8*blk) + cgdmin(sblock, cgNum); /* find start of 8K block */
if (bread (rawFd, absBlk, blockData, MAXBSIZE))
printf ("Read failed for block #%ld.\n", absBlk);
else
{ ++totBlksRead;
(* func) (blockData, absBlk, freeMapPtr [blk]); /* pass block & free-info to whomever */
}
} /* end of handling partly/entirely free block */
} /* end of loop through blocks */
} /* end of loop through cylinders */
printf ("\nTotal blocks read: %ld.\n", totBlksRead);
close(rawFd);
} /* end of findFreeData () */
void main(argc, argv)
int argc;
char *argv[];
{ register int argNum = 0; /* argument number */
char *fileSystemName;
argNum = 1;
while (argNum < argc)
{ if (*argv[argNum] == '-')
{ switch (argv[argNum][1])
{ case 's': /* specify file System */
if (++argNum == argc) usage(argv[0]); /* no more args? */
fileSystemName = argv[argNum];
break;
case 'o': /* specify Output directory */
if (++argNum == argc) usage(argv[0]); /* no more args? */
dirName = argv[argNum];
break;
default:
usage(argv[0]);
} /* end of switch on switch */
} /* end of handling "-" token */
else usage(argv[0]);
++argNum;
} /* end of scanning args */
if (fileSystemName == 0) usage(argv[0]); /* insist on a file system name */
if (dirName == 0) usage(argv[0]); /* insist on an output directory */
/* Pass every unallocated block or fragment to handleBlock() */
findFreeData (fileSystemName, handleBlock);
} /* end of main () */
/* Print a usage message and die. */
usage(s)
char *s;
{ printf("usage: %s -s filesystem -o outputdirectory\n", s);
exit(1);
}
Back to top
nuss
Joined: 27 Apr 2006
Posts: 40
Location: Germany
Posted: Sat May 09, 2015 12:43 am
Post subject:
To compile Mike's code on OpenStep the following change was required:
Code:
131c131
< { if (lseek (fd, (long) dbtob (blk), 0) < 0)
---
> { if (lseek (fd, (long) dbtob (blk, size), 0) < 0)
Of course this is all fully untested and without any warranty!
PS: Sorry for the multi-post, but I could not find any forum feature to upload files or hide long text.
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barcher174
Joined: 07 Dec 2012
Posts: 575
Posted: Sat May 09, 2015 2:46 pm
Post subject:
Sorry if this is a dumb question but is this more effective than just running a 'cat' on the drive and then 'strings' on the output?
Thanks
Brian Archer
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gregwtmtno
Joined: 28 Aug 2011
Posts: 19
Posted: Sun May 10, 2015 7:15 pm
Post subject:
Have you tried something like photorec? It works directly on the data and ignores the filesystem. I don't see why it wouldn't work on a nextstep partition, though you'd probably access the drive from another computer. It does seem pretty portable though so you might even be able to compile it on NeXT.
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barcher174
Joined: 07 Dec 2012
Posts: 575
Posted: Sun May 10, 2015 7:36 pm
Post subject:
The problem is that I'm trying to do this on a MO disk so I have no way to mount it on a linux system.
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mikeboss
Joined: 07 Dec 2011
Posts: 367
Location: berne, switzerland
Posted: Mon May 11, 2015 12:42 am
Post subject:
I still have a canon L10132 (sans optical drive but of course including the SCSI converter board) I'm willing to part with...
_________________
October 12, 1988 Computing Advances To The NeXT Level
Back to top
nuss
Joined: 27 Apr 2006
Posts: 40
Location: Germany
Posted: Mon May 11, 2015 8:23 am
Post subject:
Hi Brian,
I'd try to avoid direct recovery of the "defective" drive, but would make an image of the drive first.
Do you possibly have enough space to dd your MO disk to a harddrive?
Maybe this can remove requirement of a NeXT recovery tool.
As gregwtmtno wrote, when having a drive-image, I'd first try PhotoRec against the image (e.g. on Linux).
If PhotoRec fails on the image, you still can use cat/strings, or the posted recovery tool, without any harm to the MO drive.
Cheers, Nuss
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NEXTSTEP / OPENSTEP | http://www.nextcomputers.org/forums/viewtopic.php?p=20755 | CC-MAIN-2018-09 | refinedweb | 2,014 | 64.34 |
Next Js Router.push is not a function error
you should only use "next/router" inside the client side of your app.
next js client-side routing
next router router push is not a function
next js server side redirect
next js redirect
next/router push not working
next/router history
When I try to redirect using Router.push() I get the following error:
TypeError: next_router__WEBPACK_IMPORTED_MODULE_3__.Router.push is not a function
I am trying to migrate from create-react-app to next js.
const redirectUser = () => { if (true) { Router.push('/'); } };
I had to import like so:
// works import Router from "next/router"; // dont import { Router } from "next/router";
Router.push('/') is not working as expected � Issue #5947 � vercel , Bug report Describe the bug import React, { Component } from 'react'; import Router from 'next/router'; export default class _error extends Component� options: Object - Additional options sent by router.push; If cb returns false, the Next.js router will not handle popstate, and you'll be responsible for handling it in that case. See Disabling file-system routing. Usage
you have to take into account when you use next.js that the redirects should be in
getInitialProps method in order to avoid unnecessary render components.
for example
const MyComponent = ()=>{ return <tag> {/* ... */} </tag> } MyComponent.getInitialProps = ({res}) => { if (res) { /* serve-side */ res.writeHead(302, { Location: '' }) res.end() } else { /* client-side */ Router.push('') } return {} }
Next Js Router.push is not a function error, I had to import like so: // works import Router from "next/router"; // dont import { Router } from "next/router";. This might not be suitable for older versions as v4 had been a rewrite and is not backwards compatible. Due to this issue being the first one to come up in the a google search with the key words: Uncaught TypeError: this.context.router.push is not a function
The Router module is available only client-side
next/router, If you want to access the router object inside any function component in your Handles client-side transitions, this method is useful for cases where next/link is not enough. You don't need to use router.push for external URLs. window. location is when there's an error when changing routes, or a route load is cancelled. I also have a similar issue. <nuxt-link> is working fine, but navigation with router.push() is buggy. Most of the time the route just isn't updated, and I just get a blank page, the loading bar reaches completion but just stays there.
Routing: Shallow Routing, You can use shallow routing to change the URL without triggering a new page change Custom Error Page from 'react' import { useRouter } from 'next/router' // Current URL is '/' function Page() { const router = useRouter() useEffect(() => { // Always do navigations after the first render router.push('/?counter=10', undefined, � This seems a silly question but I'm really struggling right now to accomplish a simple router.go('/') inside store/index.js. Basically I want to change the page after I complete the authentication.
Getting Started, npm install next react react-dom You can even add dynamic route parameters with the filename. function HomePage() { return <div>Welcome to Next.js! Noticing that if I try to redirect inside getInitialProps, it'll still render the component (with no props) Here's an example: export default async function auth (ctx) { const { token } = c
Vue Router this.$router.push not working on , router.push not working next js vue-router push not redirecting vue-router push params not working vue routergo vue router redirect router.push is not a function Next.js is built around the concept of pages. A page is a React Component exported from a .js, .jsx, .ts, or .tsx file in the pages directory. Pages are associated with a route based on their file name. For example pages/about.js is mapped to /about. You can even add dynamic route parameters with the filename. Create a pages directory inside
- Did you try import Router by:
import Router from 'next/router?
- Yes I did import | http://thetopsites.net/article/54968574.shtml | CC-MAIN-2021-04 | refinedweb | 670 | 67.15 |
Hi:
I want to create an sql statment such as the following..
select * from TBALE_A a where a.word like '%time%'
the problem i am facing is that it does not return anything even there is a...
Type: Posts; User: sandy_zeng; Keyword(s):
Hi:
I want to create an sql statment such as the following..
select * from TBALE_A a where a.word like '%time%'
the problem i am facing is that it does not return anything even there is a...
found it...
RDbStoreDatabase.Compact()...
by the way, when I fully close the db in the application and try to reopen it, it generate -21 (KErrAccessDenied) why is that so ??
Hi:
I have created a database in an application, is there any function to compressed the database meanwhile maintain the access efficiency?
is this class in the S60 3rd FP1? if not, is there any 'map' class available? if yes, where I can find the header file?
Regards
Thanks..
I mean is there any tools that I can directly use by just writing the SQL to check the database instead of write another application to check it?
Is there any external tools that i can check whether the database is in the valid states (i.e. what ever the application done has been reflected to the database indeed)?
for example, after the...
Is there any external tools that i can check whether the database is in the valid states (i.e. what ever the application done has been reflected to the database indeed)?
Regards
User::LeaveIfError(lex_temp.Val(value))
the above is the problem since i define value as TInt...which only has limited range...but it reads the data, it exceed its limits!
there many times of looping here and i don;t know which statement hits the panic...and when it hits the panic, the application exist automatically...is there any way to see what is on the stack when...
by the way, there may be potential a lot of tuples need to be inserted..that is why I need to use the database..is there any limit on the size of the database? I just run on the emulator..but it...
Hi:
I have the following code to read the file and insert the data in to the database
do
{
while((pos=temp.Find(kconstant))!=KErrNotFound)//still found
{
//get a...
Thx..
but the problem still exist...may be the file format is not correct..
the above txt file is written by java, so I think it is in ascii, but when the application try to read in, it...
hi:
I have the following txt file and I want to load into the application..
3456 //<- this is the number of records
leave 456 //<- records
come 234
....
hi:
when i query one webpage, it returns "'" , which stands for " ' " in unicode. so i need to code such that it will display " ' " instead of "'"...is there any class that can...
thanks for the quick reply..
it is '...it is the unicode of " ' ", since it is in the string, I want to replace the "'" to character in the string? how can i do that?
Hi guys:
I have a string that is "Je t #&39 aime", how do i make it as "Je t'aime" .. that is to ask how to automatically detect the unicode and translate to standard character?
Thanks..it do help..
So in this case, no matter what I specify it as TUint8, it will store as 4 bytes any way, but when it interpret the number, it generate exception?
in this situation, what...
the reason why I want to use TUint8 is that I want to save memory for subsequence operation..\
But anyway, I will try to see whether this works..thanks
Hi:
I have the following code
RArray<TUint8>yConv;//reset and close
RArray<TUint8>xConv;//reset and close
User::LeaveIfError(xConv.Reserve(this->picsize));
...
but it appears in the libc math.h file
actually none of the following can get compiled ..
#define gaussian(x, sigma) (expf(-(x * x)) / (2 * sigma * sigma))
...
TInt low =...
the issue has been solved...
btw, how to use the function in math.h?
I have the folloing code, where hypotf is from math.h from libc
#include <math.h> // i also try #include <libc\math.h>...
I have following in the h file
#include <e32base.h>
#include <e32cmn.h>
#include <e32std.h>
class CCanny
{
//method
public:
CCanny();
Dear All:
I am trying to display strings using CEikGlobalTextEditor::iEditor->SetTextL(&display_content);
but this seems can not display the escape character such as new line...what other...
I have the following code:
TInt code=content.Find(target); //find some pattern from a long string
HBufC* temp_name=HBufC::NewL(code+5);
TPtr pointer=temp_name->Des();
TPtr8...
I have already found that it is in the ImageReady call back function that has the error=KErrInUse..can someone help to explain why is the case? | http://developer.nokia.com/Community/Discussion/search.php?s=a8d89959c469e9988a7e224f2cd9c920&searchid=1843551 | CC-MAIN-2013-48 | refinedweb | 817 | 76.42 |
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Hot questions for Using Neural networks in imagenet
Question:
I'm using the pretrained imagenet model provided along the caffe (CNN) library (
'bvlc_reference_caffenet.caffemodel'). I can output a 1000 dim vector of object scores for any images using this model.
However I don't know what the actual object categories are. Did someone find a file, where the corresponding object categories are listed?
Answer:
You should look for the file
'synset_words.txt' it has 1000 line each line provides a description of a different class.
For more information on how to get this file (and some others you might need) you can read this.
If you want all the labels to be ready-for-use in Matlab, you can read the txt file into a cell array (a cell per class):
C = textread('/path/to/synset_words.txt','%s','delimiter','\n');
Question:
After several month working with caffe, I've been able to train my own models successfully. For example further than my own models, I've been able to train ImageNet with 1000 classes.
In my project now, I'm trying to extract the region of my interest class. After that I've compiled and run the demo of Fast R-CNN and it works ok, but the sample models contains only 20 classes and I'd like to have more classes, for example all of them.
I've already downloaded the bounding boxes of ImageNet, with the real images.
Now, I've gone blank, I can't figure out the next steps and there's not a documentation of how to do it. The only thing I've found is how to train the INRIA person model, and they provide dataset + annotations + python script.
My questions are:
- Is there maybe any tutorial or guide that I've missed?
- Is there already a model trained with 1000 classes able to classify images and extract the bounding boxes?
Thank you very much in advance.
Regards.
Rafael.
Answer:
Dr Ross Girshik has done a lot of work on object detection. You can learn a lot from his detailed git on fast RCNN: you should be able to find a caffe branch there, with a demo. I did not use it myself, but it seems very comprehensible.
Another direction you might find interesting is LSDA: using weak supervision to train object detection for many classes.
BTW, have you looked into faster-rcnn?
Question:
ImageNet images are all different sizes, but neural networks need a fixed size input.
One solution is to take a crop size that is as large as will fit in the image, centered around the center point of the image. This works but has some drawbacks. Often times important parts of the object of interest in the image are cut out, and there are even cases where the correct object is completely missing while another object that belongs to a different class is visible, meaning your model will be trained wrong for that image.
Another solution would be to use the entire image and zero pad it to where each image has the same dimensions. This seems like it would interfere with the training process though, and the model would learn to look for vertical/horizontal patches of black near the edge of images.
What is commonly done?
Answer:
There are several approaches:
- Multiple crops. For example AlexNet was originally trained on 5 different crops: center, top-left, top-right, bottom-left, bottom-right.
- Random crops. Just take a number of random crops from the image and hope that the Neural Network will not be biased.
- Resize and deform. Resize the image to a fixed size without considering the aspect ratio. This witll deform the image contents but preserves but now you are sure that no content is cut.
- Variable-sized Inputs. Do not crop and train the network on variable sized images, using something like Spatial Pyramid Pooling to extract a fixed size feature vector that can be used with fully connected layers.
You could take a look how the latest ImageNet networks are trained, like VGG and ResNet. They usually describe this step in detail.
Question:
def preprocess_input(x): x /= 255. x -= 0.5 x *= 2. return x
I am using keras inception_v3 imagenet pretrained model(inception_v3.py) to finetune on my own dataset. When I want to subtract the imagenet mean value [123.68, 116.779, 103.939] and reverse axis RGB to BGR as we often do, I find that the author provided a _preprocess_input()_ function at the end.I am confused about this.
Should I use the provided function preprocess_input() or subtract mean value and reverse axis as usual? Thanks lot.
Answer:
Actually in a original Inception paper the autors mention as a data preprocessor the function you provided (one which is zero-centering all channels and resizes it to
[-1, 1] interval). As in InceptionV3 paper no new data transformation is provided I think that you may assume that you should use the following function:
def preprocess_input(x): x /= 255. x -= 0.5 x *= 2. return x
Will YOLO anyhow perform differently from VGG-16. Will using it for image classification instead of VGG make sense?
Question:
I have already implemented image captioning using VGG as the image classification model. I have read about YOLO being a fast image classification and detection model and it is primarily used for multiple object detection. However for image captioning i just want the classes not the bounding boxes.
Answer:
I completely agree with what Parag S. Chandakkar mentioned in his answer. YOLO and RCNN the two most used object detection models are slow if used just for classification compared to VGG-16 and other object classification networks. However in support of YOLO, I would mention that , you can create a single model for image captioning and image object detection.
YOLO generates a vector of length 1470.
Tune YOLO to generate number of classes as supported by your dataset i.e make YOLO generate a vector of 49*(number of classes in your dataset) + 98 + 392.
Use this vector to generate the Bounding boxes.
- Further tune this vector to generate a vector of size equal to the number of classes. You can use a dense layer for the same.
- Pass this vector to your language model for generating captions.
Thus to sum up, you can generate the bounding boxes first and then further tune that vector to generate captions.
Question:
I understand that bigger batch size gives more accurate results from here. But I'm not sure which batch size is "good enough". I guess bigger batch sizes will always be better but it seems like at a certain point you will only get a slight improvement in accuracy for every increase in batch size. Is there a heuristic or a rule of thumb on finding the optimal batch size?
Currently, I have 40000 training data and 10000 test data. My batch size is the default which is 256 for training and 50 for the test. I am using NVIDIA GTX 1080 which has 8Gigs of memory.
Answer:
Test-time batch size does not affect accuracy, you should set it to be the largest you can fit into memory so that validation step will take shorter time.
As for train-time batch size, you are right that larger batches yield more stable training. However, having larger batches will slow training significantly. Moreover, you will have less backprop updates per epoch. So you do not want to have batch size too large. Using default values is usually a good strategy.
Question:
When I try to run Google's Inception model in a loop over a list of images, I get the issue below after about 100 or so images. It seems to be running out of memory. I'm running on a CPU. Has anyone else encountered this issue?
Traceback (most recent call last): File "clean_dataset.py", line 33, in <module> description, score = inception.run_inference_on_image(f.read()) File "/Volumes/EXPANSION/research/dcgan-transfer/data/classify_image.py", line 178, in run_inference_on_image node_lookup = NodeLookup() File "/Volumes/EXPANSION/research/dcgan-transfer/data/classify_image.py", line 83, in __init__ self.node_lookup = self.load(label_lookup_path, uid_lookup_path) File "/Volumes/EXPANSION/research/dcgan-transfer/data/classify_image.py", line 112, in load proto_as_ascii = tf.gfile.GFile(label_lookup_path).readlines() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/lib/io/file_io.py", line 110, in readlines self._prereadline_check() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/lib/io/file_io.py", line 72, in _prereadline_check compat.as_bytes(self.__name), 1024 * 512, status) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/contextlib.py", line 24, in __exit__ self.gen.next() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tensorflow/python/framework/errors.py", line 463, in raise_exception_on_not_ok_status pywrap_tensorflow.TF_GetCode(status)) tensorflow.python.framework.errors.ResourceExhaustedError: /tmp/imagenet/imagenet_2012_challenge_label_map_proto.pbtxt real 6m32.403s user 7m8.210s sys 1m36.114s
Answer:
The issue is you cannot simply import the original 'classify_image.py'() in your own code, especially when you put it into a huge loop to classify thousands of images 'in batch mode'.
Look at the original code here:
with tf.Session() as sess: # Some useful tensors: # 'softmax:0': A tensor containing the normalized prediction across # 1000 labels. # 'pool_3:0': A tensor containing the next-to-last layer containing 2048 # float description of the image. # 'DecodeJpeg/contents:0': A tensor containing a string providing JPEG # encoding of the image. # Runs the softmax tensor by feeding the image_data as input to the graph. softmax_tensor = sess.graph.get_tensor_by_name('softmax:0') predictions = sess.run(softmax_tensor, {'DecodeJpeg/contents:0': image_data}) predictions = np.squeeze(predictions) # Creates node ID --> English string lookup. node_lookup = NodeLookup() top_k = predictions.argsort()[-FLAGS.num_top_predictions:][::-1] for node_id in top_k: human_string = node_lookup.id_to_string(node_id) score = predictions[node_id] print('%s (score = %.5f)' % (human_string, score))
From above you can see that for each classification task it generate a new instance of Class 'NodeLookup', which loads below from files:
- label_lookup="imagenet_2012_challenge_label_map_proto.pbtxt"
- uid_lookup_path="imagenet_synset_to_human_label_map.txt"
So the instance would be really huge, and then in your codes' loop it will generate over hundreds of instances of this class, which results in 'tensorflow.python.framework.errors.ResourceExhaustedError'.
What I am suggesting to get ride of this is to write a new script and modify those classes and functions from 'classify_image.py', and avoid to instantiate the NodeLookup class for each loop, just instantiate it for once and use it in the loop. Something like this:
with tf.Session() as sess: softmax_tensor = sess.graph.get_tensor_by_name('softmax:0') print 'Making classifications:' # Creates node ID --> English string lookup. node_lookup = NodeLookup(label_lookup_path=self.Model_Save_Path + self.label_lookup, uid_lookup_path=self.Model_Save_Path + self.uid_lookup_path) current_counter = 1 for (tensor_image, image) in self.tensor_files: print 'On ' + str(current_counter) predictions = sess.run(softmax_tensor, {'DecodeJpeg/contents:0': tensor_image}) predictions = np.squeeze(predictions) top_k = predictions.argsort()[-int(self.filter_level):][::-1] for node_id in top_k: human_string = node_lookup.id_to_string(node_id) score = predictions[node_id] | https://thetopsites.net/projects/neural-network/imagenet.shtml | CC-MAIN-2021-31 | refinedweb | 1,833 | 58.79 |
.
(Sorry if this is a double-post. The first attempt to post seemed to do nothing at all.)
Resharper does member reordering. I learned this the hard way.
At a previous company we had a moderate-to-large size of code-base with maybe 20 to 30 developers. We were building a game, but we had lots of associated command-line programs too. At some point the command-line programs
all
started
writing
their
output
like
this.
It seems that nobody noticed or cared for a while, because they rarely invoked the help. I only noticed when I was adding a new command-line tool. It turned out that the help tool, for reasons best known to the original author, used P/Invoke to determine the dimensions of the console (rather than, say, Console.BufferWidth) in order to do word-wrapping. It called GetConsoleScreenBufferInfo, for which it needed to define the structs CONSOLE_SCREEN_BUFFER_INFO, SMALL_RECT and COORD. More recently, somebody had applied what was *supposed* to be a global clean-up using Resharper in order to bring things like spacing, identifiers and comments in-line with our newly agreed coding style. Unfortunately this clean-up also alphabetically sorted the members of every class, and somehow this wasn't noticed when it was checked in. Since in C# structs default to LayoutKind.Sequential, the original code was correct, but alphabetically sorted it became gibberish.
I removed all the P/Invoke and replaced them with Console.BufferWidth, grumbled at the people who had re-ordered everything, and wondered why anyone would even *want* to sort their members alphabetically. It makes about as much sense to me as ordering a music collection by the colour of the album art.
Reordering: if that happens to you, you're doing it wrong.
That said, if you do have a method to reorder a class automatically to an order that doesn't make sense, it still wouldn't help you...
Perhaps, still it could be a starting point, I stopped to use resharper because of the useless comments of the type "make a method static" or "don't use the "this" keyword" and moreover it had some bugs which make it worst than the built in functions of visual studio, like the find all references, it was replaced with a resharper method which for some reason didn't find all references.
But at this point I would suggest to remove also the "sort and remove the using" option from VS because it could order or remove them in an way that somebody doesn't like, so because somebody doesn't like it nobody should use it, correct?
And for me make more sense a class ordered like a in the class diagram than a spaghetti class:
public class MySpaghettiClass
{
public void OnSpathettiAreUsed(){TheSpaghettiAreUsed(this,EventArgs.Empty);}
public void GetSomeSause() {....}
public event EventHandler TheSpaghettiAreThere;
private int howManySpaghetti=0;
public string TheName {get; set;}
pubclic void IsSomeSpaghettiThere(){ ...}
public MySpaghettiClass() : this(11) {}
public int HowManySpaghettiAreLeft(){return _spaghetti;}
public event EventHandler TheSpaghettiAreUsed;
public int HowManySpaghetti{ger{return howManySpaghetti;} set{ howManySpaghetti=value;}}
public MySpaghettiClass(istring name) {TheName=name;}
public void UseSpaghetti(int spaghetti){howManySpaghetti-=spaghetti; OnSpaghettiAreUsed();}
....
}
@Reordering: How would a class get that way anyway? Unless you just drop code off at the end of the class when you need to add anything, which is a very bad practice, the class should be organized according to whatever order it is that you like them to be, which would normally not be alphabetic or according to accessibility.
Classes get in this state because after x years y people have worked on them and they have added code somewhere.
You get committed to extend an existing application with new features, the application is already 4 years old, you receive the code and it looks like this one, what do you do? Do you think to refactor it? No, absolutely not! It's not your duty, nobody asked you to do it and you won't lose your time doing it, you are paid to add new feature not to reordering a class, moreover, as already said, it's really dangerous reordering a class by hand, the risk of a copy paste error is very high.
At the end you add your code at the end or at the top of the class, and so will do the next one who has to add some new code. At this point have a function to reorder classes could be really useful, at least you get a better structure than a tasty spaghetti class.
@Reordering.
Ugh that's awful. Either work through it to understand what was the connections are and understand it/split it up/ sort it or leave it as is (low risk, no nasty to merge/annotate changes) | http://blogs.msdn.com/b/ericlippert/archive/2011/01/17/not-as-easy-as-it-looks-part-two.aspx?PageIndex=2 | CC-MAIN-2014-23 | refinedweb | 794 | 59.94 |
Wiki.
The Trac wiki support the following font styles: bold, italic,
underline and strike-through.
The Trac wiki support the following font styles: '''bold''', ''italic'',
__underline__ and ~~strike-through~~..
= Heading =
== Subheading ==
A new text paragraph is created whenever two blocks of text are separated
by one or more empty lines.
A forced line break can also be inserted, using:
Line 1[[BR]]Line 2
Display:
Line 1Line 2
Text paragraphs can be indented by starting the lines with two or more spaces.
Text paragraphs can be indented by starting the lines with two or more spaces.
The wiki supports both ordered/numbered and unordered lists.
Example:
* Item 1
* Item 1.1
* Item 2
1. Item 1
1. Item 1.1
1. Item 2
Block quotes, preformatted text, are suitable for source code snippets, notes and examples. Use three curly braces wrapped around the text to define a block quote:
Example:
{{{
def HelloWorld()
print "Hello World"
}}}
def HelloWorld()
print "Hello World"
Simple tables can be created like this:
||Cell 1||Cell 2||Cell 3||
||Cell 4||Cell 5||Cell 6||
!Hyperlinks are automatically created for WikiPageNames and urls. WikiPageLinks can be disabled by
prepending an exclamation mark (!) character, such as !WikiPageLink.
Examples:
TitleIndex,.
TitleIndex,.
Links can be given a more descriptive title by writing the link followed by
a space and a title and all this inside two square brackets. Like this:
* [ Edgewall Software]
* [wiki:TitleIndex Title Index]
Wiki pages can link directly to other parts of the Trac system.
Pages can refer to tickets, reports, changesets, milestones, source files and
other Wiki pages using the following notation: automatically interpreted as image links, and converted to IMG tags.
Macros are custom functions to insert dynamic content in a page. See WikiMacros for usage.
[[Timestamp]]
Timestamp
Timestamp>
}}}
Example 2:
{{{
#!python
class Test:
def __init__(self):
print "Hello World"
if __name__ == '__main__':
Test()
}}}
class Test:
def __init__(self):
print "Hello World"
if __name__ == '__main__':
Test()
Four or more dashes will be replaced by a horizontal line (<HR>)
----
See also: TracLinks, TracGuide, WikiHtml, WikiMacros, WikiProcessors, TracSyntaxColoring. | https://www.tribler.org/WikiFormatting/ | CC-MAIN-2019-43 | refinedweb | 342 | 64.1 |
Ok so lets begin, first we will create our Game class, this will contain some of the functions for our game.
Game.h
#ifndef _GAME_H_ #define _GAME_H_ #include <SDL.h> class Game { public: Game(); void Init(); private: bool m_bRunning }; #endif
Quite basic to start with, we create our constructor and the Initialize function, this will be the first call for the program.
Next lets write our Game.cpp file
#include "Game.h" // constructor Game::Game() { } void Game::Init() { m_bRunning = true; }
This will be the class that most of our game will run through, so lets write our main.cpp and test it out
#include "Game.h" int main(int argc, char* argv[]) { Game game; game.Init(); }
Ok that should compile now, it won't do anything at the moment but should compile with no errors.
So that the hub of our game where we will call all of the functions needed to keep the game running, if you recall from the last tutorial I covered the functions needed for a main game loop these were:
Initialize // while the game is running Handle Events Update Draw // once the game is done Clean
we will incorporate the basic framework of these functions now, open up the Game.h file and add the functions.
#ifndef _GAME_H_ #define _GAME_H_ #include <SDL.h> class Game { public: Game(); bool Init(); void HandleEvents(); void Update(); void Draw(); void Clean(); private: bool m_bRunning; }; #endif
Ok now lets go to our Game.cpp file and create the function body's
#include "Game.h" // constructor Game::Game() { } void Game::Init() { m_bRunning = true; } void Game::HandleEvents() { } void Game::Update() { } void Game::Draw() { } void Game::Clean() { }
That is the main framework of our game created, Init will load anything we need such as NPC's, player files, map files or sound files. Handle Events will check for key-presses and handle them accordingly. Update will do any movement and time based features and Draw will draw everything to the screen. These functions will be called in a constant loop when the game is running.
Lets write our main.cpp to incorporate these functions
#include "Game.h" int main(int argc, char* argv[]) { Game game; game.Init(); while(game.Running()) { game.HandleEvents(); game.Update(); game.Draw(); } // cleanup the engine game.Clean(); return 0; }
Ok so now we have the framework down, we can now add some SDL code to create a window once we initialize our game. First we have to think about what we need to do when creating an SDL window, we need to know the height and width of the screen, bpp and whether the window is fullscreen or not.
Re-open the Game.h file and we will incorporate this code, I won't paste the entire file again only the part's we are working on.
// change our init function to incorporate the parameters we will need public: void Init(const char* title, int width, int height, int bpp, bool fullscreen); // add a pointer to an SDL surface for our screen and also a bool for fullscreen private: SDL_Surface* screen; bool m_bFullscreen;
now open up the Game.cpp file so we can write the body of this function screen = SDL_SetVideoMode(width, height, bpp, flags); m_bFullscreen = fullscreen; m_bRunning = true; // print our success printf("Game Initialised Succesfully\n"); }
Now the program creates a window using SDL according to our parameters so lets update our main.cpp to incorporate this revised function
#include "Game.h" int main(int argc, char* argv[]) { Game game; game.Init("test",640,480,32,false); while(game.Running()) { game.HandleEvents(); game.Update(); game.Draw(); } // cleanup the engine game.Clean(); return 0; }
That should compile fine but there is one problem we have no way to exit the program, you will most likely have to force it to close using CTRL+ALT+DELETE or ForceQuit. Lets write a way to close this window using SDL so that we can quit it easier.
Open up the Game.h file and we need to update our handle events function, we need to pass in a pointer to our current game.
void HandleEvents(Game* game);
now open up the Game.cpp file and we will add some way of handling events so we can use the SDL_QUIT event. An SDL_QUIT event is when you click the cross button on an SDL window, we earlier wrote a quit function that simply sets our m_bRunning bool to false, this in turn stops the game loop and our Clean function is called. So lets write a way to handle this event
void Game::HandleEvents(Game* game) { SDL_Event event; if (SDL_PollEvent(&event)) { switch (event.type) { case SDL_QUIT: game->Quit(); break; case SDL_KEYDOWN: switch (event.key.keysym.sym) { case SDLK_ESCAPE: game->Quit(); } break; } } }
There we go, I also added a way to quit using the escape key, this is useful while building and debugging but make sure to remove it once you are finished.
Ok then back to the main.cpp file for a small update.
#include "Game.h" int main(int argc, char* argv[]) { Game game; game.Init("test",640,480,32,false); while(game.Running()) { game.HandleEvents(&game); game.Update(); game.Draw(); } // cleanup the engine game.Clean(); return 0; }
We update the handle events function and pass in our game.
To recap we create a basic framework for our games incorporating the main game loop, we created a way to create a window according to our needs by passing in values needed to our init function and we created a way for SDL to handle events, one of which is our quit function which is called via escape key or by clicking the cross on and SDL window.
Thanks for reading, in part 3 I am hoping to incorporate a state manager or a sprite class any requests?
Happy coding and of course any questions will be answered
| https://www.dreamincode.net/forums/topic/110460-beginning-sdl-part-2-the-basic-framework/ | CC-MAIN-2018-51 | refinedweb | 975 | 78.48 |
To help with the deployment of a database project, I have chosen to embed a blank Access database into the setup program. The tables will then be added by calling SQL statements on the database. I chose this course for two reasons:
I still find it easier to use Access to design my database. I searched the internet for a tool that could automate the transformation of the database to SQL statements. When I couldn't find anything suitable, I decided to write my own.
I chose to write the module in C# (I am trying to learn it at the moment). It uses the OleDbConnection.GetOleDbSchemaTable command to extract schema information from the database, then parses the information to give a collection of 'Tables'. These Tables are then written out in SQL commands.
OleDbConnection.GetOleDbSchemaTable
The only major problem that I have found is that I could not identify whether a column was AutoNumber or not from the schema information returned. I have assumed that any Primary Key with an Integer data type is an AutoNumber.
Since the module was written primarily for my own use, I have really only checked that it works with my database. I also have successfully read and written the Northwind database. If other information is required, have a look at the information returned by the various OleDbSchemaGuid values.
OleDbSchemaGuid
The code still requires a lot of work on the error/exception handling side of things. It shouldn't effect the database you are running it against, but use it at your own risk!
The class SQLWriter contains a single public method, GetSQLString(). To use the library, simply instantiate the class by passing the filename of the Access database, then call GetSQLString(). This function returns a string of the SQL commands needed to create the database tables.
SQLWriter
GetSQLString()
For example:
// An example of using GetSQLString()
using JetDBReader;
class ConsoleApp {
public static void Main(string[] args)
{
SQLWriter cl = new SQLWriter (@"c:\databases\northwind.mdb");
Console.WriteLine(cl.GetSQLString());
}
}
The class also uses a separate library, AlgorithmLib, that I have started. At the moment it only contains a single function, TopologicalSort (probably highly unoptimised), but I hope to add any generic algorithms as I need them.
AlgorithmLib
TopologicalSort
The example project includes a very simple WinForms project that basically allows you to choose an input file and output file. No verification or exception handling is included.
Coming from a total non-CS background (I am a Civil Engineer by trade), there are likely to be a lot of stylistic and syntactic problems with the code. I am really interested in people's comments as to how I can improve my coding and design skills, hopefully so, by the time the next dot-com boom comes around, I might be up to a reasonable standard. Designing code beats designing sewer systems any day!
This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.
A list of licenses authors might use can be found here
OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM [" +
tableName + "] WHERE 1=0", openConnection);
DataTable tableSchema = adapter.FillSchema(new DataTable(),
SchemaType.Source);
for (int j = 0; j < tableSchema.Columns.Count; j++)
{
if(tableSchema.Columns[j].AutoIncrement)
{
// is identity
}
}
General News Suggestion Question Bug Answer Joke Rant Admin
Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.
News on the future of C# as a language | http://www.codeproject.com/Articles/4893/JET-to-SQL-Converter | CC-MAIN-2014-10 | refinedweb | 596 | 55.13 |
A Dummy's Guide To Writing Articles
Written by TAD
(or how to upset and confuse people by talking rubbish)
This contains my own thoughts about writing articles and how easy it is to get started and being famous, or ignored (like me). I hope to motivate some newbie writers into spending a hour or two in front of their keyboards and write a short article.
Warning: This is my own way of writing articles. I am sure that there will be millions other ways which will be better or worse for different people.
This formula was found by accident and isn't a "written-in-stone" set of rules, just write the way you want and see what you get.
But I can't write!
Yes you can. Don't think of it as writing a boring 'what I did in my summer holiday' essay (like you did/still do in school) but as literal graffity in digital form which will be seen by thousand, if not millions of people.
I'm not a writer!
Well no-one is until they begin to write. It's like riding a bike. You get covered in oil and your chain falls off while in busy traffic. Then while you are at the shops some skuzz-bag steals it.
Sorry, only joking (grin).
Don't worry about your first article not being a masterpiece. You don't need to agonize over each and every word (like you see most actors doing in film or on the television). Just make it interesting. If a subject is interesting to yourself then it will be interesting to others too.
My English (or German) isn't great.
Well, most people on the net post messages which are full of spell mistakes, incorrect grammar and badly formatted text. But enough about me (grin). Some purists can't stand this 'corruption of English' and look down on the smallest of errors. But a number of centuries ago English had no proper spelling for words. Look at some of the old parchments and manuscripts and you will see different spellings of the same word on the same page. This is something which the purists seem to overlook.
My philosophy is that if people understand what you are saying then screw the spelling, grammar and the rest. It's just a form of snobbery. A cave painting isn't the Mona Lisa, but it still communicates ideas, anyway most English words are spelt completely differently to how they sound. To me "creative writing" is finding new ways to spell old words (heh heh).
Okay, how do I start my first article?
First decide on a topic. This can be a subject which you are an expert in or just beginning to learn about. I think some of the best articles are the ones were the author learns and develops ideas while writing it.
All the usual areas in computing like compression, graphics, sound and algorithms are always worth reading and writing about. From the recent issues of Hugi there seems to be a lack of articles about sound and music, so if you have coded some nice new tricks or have just learnt about the principles of programming sound and music code then why not write a short article. You may find that this helps to clarify your own understanding of a subject.
The way I got into writing articles was by reading an article by Dario Phong (hi Dario) and thought that there were a few areas which could use a little more explanation, or improvement. Now I've written close to 30 articles (and they haven't got any better, hee hee).
Here is the basic format I use:
1. Introduction.
Give a quick, easy to read outline which describes what the article is about. It makes it so much quicker to find articles you want to read and makes finding them again later on much easier.
For example: "How to fake your own break-in and get lots of money from your insurance company without going to jail".
2. Warning.
I use this to give the restrictions or problems which a article has. Also any reference or previous knowledge which is required to understand an article.
For Example: "This assumes that you already what NURBS and B-SPLINES are."
3. An overview or Aim.
Give a short description (and perhaps code) about why you thought the article needed to be written. What you want to accomplish in the remaining text.
For Example: "The problem with the X algorithm is this..."
4. Terminology.
Sometimes, especially if you are a newbie coder, there will be unfamilar jargon which you don't understand, or you may use incorrect naming of methods which might confuse others. I admit to being very guilty of this.
For Example: "Phraze = a collection of sequential symbols."
(Is this right, Dario?)
5. Your main text section(s).
All your groovy new stuff with psuedo and C++, Pascal, Basic, 80x86 code snippets. This is just the main body of the article. If it is very long then perhaps you might consider breaking it up into small sections.
6. Improvements.
Most coding articles have this section. It just explains your own thoughts about how to improve the previously presented code or algorithm. The most common subject is optimization, in the size of code, memory required or speed of operation.
For Example: "A binary search or small software cache would help to speed up this algorithm. You may also want to try buying a new CPU too (grin)."
7. Credits/References.
Give credits to any reference papers, or existing algorithms on which your article is based. Not only does this make the original author happy but it helps the reader to find more information if they wish. Let's face it, you probably have missed a few tricks or a vital definition which prevents the reader from understanding your article.
For Example: "Check out the X newsgroup, or the Y website..."
8. Closing words.
Give a quick summing up, a working e-mail and your home page address. The e-mail is vital because it allows the readers to post their suggestions, comments and bug reports. Without this feedback articles will not get any better.
What document format?
I suggest using a plain 80-column ASCII text format such as .TXT or .DOC which can be created using the NOTEPAD, WORDPAD or similar application that came with your Operating-System.
I personally use my trusty old BRIEF editor in MS-DOS mode as it's nice and easy to use and never crashes.
The Editor(s).
Once you are happy with your article simply e-mail it to Adok/Hugi. He will be happy to scan through your article, reformat it for the Hugi magazine and send the edited version back to you.
Closing words.
See, it's really easy writing an article. Go on, you will be surprised how much fun it is to spread your words across the world and cause arguments by simply saying:
For Example: "Linux really sucks..."
Then wait for all those Penguin freaks to hurl verbal abuse in your direction (grin). But seriously, if you do intend to slag off someone else's code or ideas just remember to give reasons for doing so, explain WHY you think X sucks or Y is better. And prepare to recieve some abusive criticism in return (i.e. When you throw a grenade...... remember to duck!!).
All you need to write a short article is an idea, a working keyboard and a free hour or two to type the words in.
The scene needs new ideas and new people to make it more dynamic and ground-breaking than it currently is and a good way to do this is to exchange ideas and algorithms with others. Every coder, musican and artist has different ways of producing their own form of art. There will always be people who know a trick which you don't and vice-versa. Who knows, your article might be the start of a ground-breaking technique or the road to fame, fortune and lots of bare flesh (grin).
Happy writing.
Regards
TAD #:o) | http://hugi.scene.org/online/hugi16/dmtadart.htm | CC-MAIN-2017-13 | refinedweb | 1,371 | 73.07 |
bzr 1.4rc1)
- Reconfigure can convert a branch to be standalone or to use a shared repository. (Aaron Bentley))
- VersionedFileStore no longer uses the transaction parameter given to most methods; amongst other things this means that the get_weave_or_empty method no longer guarantees errors on a missing weave in a readonly transaction, and no longer caches versioned file instances which reduces memory pressure (but requires more careful management by callers to preserve performance). (Robert Collins)
Testing
New -Dselftest_debug flag disables clearing of the debug flags during tests. This is useful if you want to use e.g. -Dhpss to help debug a failing test. Be aware that using this feature is likely to cause spurious test failures if used with the full suite. (Andrew Bennetts)
selftest –load-list now uses a new more agressive test loader that will avoid loading unneeded modules and building their tests. Plugins can use this new loader by defining a load_tests function instead of a test_suite function. (a forthcoming patch will provide many examples on how to implement this). (Vincent Ladeuil)
selftest –load-list now does some sanity checks regarding duplicate test IDs and tests present in the list but not found in the actual test suite. (Vincent Ladeuil)
Slightly more concise format for the selftest progress bar, so there’s more space to show the test name. (Martin Pool)
[2500/10884, 1fail, 3miss in 1m29s] test_revisionnamespaces.TestRev
The test suite takes much less memory to run, and is a bit faster. This is done by clearing most attributes of TestCases after running them, if they succeeded. (Andrew Bennetts)) | https://documentation.help/Bazaar-help/bzr-1.4rc1.html | CC-MAIN-2020-10 | refinedweb | 263 | 61.36 |
XML Pipeline Contracts
XML Pipeline Contracts
The XMLProducer contract is part of how Cocoon assembles the actual SAX pipeline to handle a particular request. It is a little different from the Sitemap related interfaces in that the focus is on the assembled pipeline instead of the decisions of which elements to use in the pipeline. If you think of the pipeline in a strict engineering mindset, an XMLProducer is a source of SAX events and an XMLConsumer is a sink for SAX events. An XMLPipe is both a source and a sink of SAX Events.
The XMLProducer is a very simple beast, comprised of only one method to give the component the next element of the pipeline. Cocoon calls the setConsumer() method with the reference to the next XMLConsumer in the pipeline. The approach allows the XMLProducer to call the different SAX related methods on the XMLConsumer without knowing ahead of time what that consumer will be. The design is very simple and very powerful in that it allows Cocoon to daisy chain several components in any order and then execute the pipeline.
Any producer can be paired with any consumer and we have a pipeline. The core design is very powerful and allows the end user to mix and match sitemap components as they see fit. Cocoon will always call setConsumer() on every XMLProducer in a pipeline or it will throw an exception saying that the pipeline is invalid (i.e. there is no serializer for the pipeline). The only contract that the XMLProducer has to worry about is that it must always make calls to the XMLConsumer passed in through the setConsumer() method.
An XMLConsumer is much more complex due to the interfaces it implements. An XMLConsumer is also a SAX ContentHandler and a SAX LexicalHandler. That means the XMLConsumer has to respect all the contracts with the SAX interfaces. SAX stands for Serialized API for XML. A document start, and each element start must be matched by the corresponding element end or document end. So why does Cocoon use SAX instead of manipulating a DOM? For two main reasons: performance and scalability. A DOM tree is much more heavy on system memory than successive calls to an API. SAX events can be sent as soon as they are read from the originating XML, the parsing and processing can happen essentially at the same time.
Most people's needs will be handled just fine with the ContentHandler interface, as that declares your namespaces. However if you need lexical support to resolve entity names and such, you need the LexicalHandler interface. The AbstractXMLConsumer base class can make implementing this interface easier so that you only need to override the events you intend to do anything with.
The XMLPipe is both an XMLProducer and an XMLConsumer. All the Transformers implement this interface for example. By having an XMLPipe interface, we can chain more than one pipeline component together. What this means is that Cocoon will honor all the XMLProducer contracts in a pipeline first. The SAX pipeline will be completely assembled before any SAX calls are issued. Cocoon does not want any stray calls to get lost. There can be zero or more XMLPipes in a pipeline, but there must always be at least one XMLProducer and XMLConsumer pair.
Because an XMLPipe is both a source and a sink for SAX events, the basic contract that you need to worry about is that you must forward any SAX events on that you are not intercepting and transforming. As you receive your startDocument event, pass it on to the XMLConsumer you received as part of the XMLProducer side of the contract. An example ASCII art will help make it a bit more clear:
XMLProducer -> (XMLConsumer)XMLPipe(XMLProducer) -> XMLConsumer
A typical example would be using the FileGenerator (an XMLProducer), sending events to an XSLTTransformer (an XMLPipe), which then sends events to an HTMLSerializer (an XMLConsumer). The XSLTTransformer acts as an XMLConsumer to the FileGenerator, and also acts as an XMLProducer to the HTMLSerializer. It is still the responsibility of the XMLPipe component to ensure that the XML passed on to the next component is valid--provided the XML received from the previous component is valid. In layman's terms it means if you don't intend to alter the input, just pass it on. In most cases we just want to transform a small snippet of XML. For example, inserting a snippet of XML based on an embedded element in a certain namespace. Anything that doesn't belong to the namespace you are worried about should be passed on as is. | http://cocoon.apache.org/2.2/core-modules/core/2.2/689_1_1.html | CC-MAIN-2016-50 | refinedweb | 769 | 61.06 |
Hello Folks,
I tear my hair out over this. I have a STM32F0 Discovery board here and
i would like to get all 16 bits of PORTC high. Most of the pins do what
i expect them to do, but PC1 and PC2 dont. They stay low out of what
ever reason. I am a bloody newbie in this , so please dear gurus, give
me some code that will get pin1 and pin 2 in the high state. I am not
sure what is wrong here.
In some data sheet of the board is found that these 2 pins are also used
for external interrupts but i am not sure if that is the reason and how
to disable that alternative function to get these 2 pins into a usable
state.
Any help would be deeply appreciated, I am chewing on this problem
already since a week and ready to give up on it.
#include "stm32f0xx.h"
#include "stm32f0xx_rcc.h"
#include <stm32f0xx_conf.h>
#include "stm32f0xx_gpio.h"
#include "diag/Trace.h"
//#include <stdio.h>
int main()
{
GPIO_InitTypeDef GPIO_InitDef;
RCC->AHBENR |= RCC_AHBENR_GPIOCEN;
GPIO_InitDef.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5\
| GPIO_Pin_6 | GPIO_Pin_7| GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12 \
| GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15 ;
GPIO_InitDef.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
GPIO_InitDef.GPIO_PuPd = 0x01;
GPIO_InitDef.GPIO_Speed = GPIO_Speed_2MHz;
//Initialize pins
GPIO_Init(GPIOC, &GPIO_InitDef);
GPIOC->ODR =0xFFFF; | https://embdev.net/topic/363456 | CC-MAIN-2018-13 | refinedweb | 218 | 60.61 |
Throughout the recent years during browsing, I have encountered several examples
of Applets with what I would consider a magnificent feat of architectureal
design. One of the examples most relevent to my situation is Burning Metal,
a car racing game.
I look at the Applet and see the extremely intricate loading functions ...
after that it transfers to a mode select (single player, multiplayer), and
from there the game, victory animations, and high score entry.
My problem is that while I can easily write an Applet to do any given stage
of the above game, I am having trouble combining them to form the game as
a whole.
The Applet (not application) that I am writing will consist of a loading
stage, a map selection stage, the game stage, and the victory/defeat stage,
where it will promptly loop back to the map selection stage. It is to be
a VERY complex game with professional-quality user interface and graphics.
On the side, I plan to release the complete and well-documented source code
for other people who have encountered the countless problems I have as well
as the ones I am sure to face in the future.
Previously, for something like this, I would have an INTEGER value called
Mode (private int mode) that utilizes several FINAL INTEGERS to determine
which stage of the game I am on. An example for the simplified structure
I listed above would be:
private int mode;
private static final int GAME_LOADING = 1;
private static final int GAME_MAPSELECTION = 2;
private static final int GAME_PLAYING = 3;
private static final int GAME_OVER = 4;
And I would proceed to have a Paint function that used a case statement to
run specific paint routines as follows:
public void paint(Graphics g) {
switch(mode) {
case GAME_LOADING:
paintLoading(g); break;
case GAME_MAPSELECTION:
paintMapSelection(g); break;
etc. ... if you don't get the point by now, you can't help me =] (j/k!)
The problem is that while that worked, I encountered several programming
complexities when I implemented user interaction...
public void KeyTyped(KeyEvent e) {
switch(mode) {
case GAME_LOADING:
handleKeyLoading(e);
etc.
The same occured for MouseDown (or whatever the MouseListener function is
called)...
Keep in mind that I will NOT use any of the AWT or Swing classes for graphics
and implementation reasons.
Looking back at previous programs I have written using the above method,
I see a very poorly-coded mess that would be extremely difficult for any
programmer but me to quickly sort out. In other words, I am unsatisfied
with this method AND I don't think it will apply to a complex game like I
am planning.
And so I am lost as to how to structure the program. The two methods I can
think of either use the "Mode-Case" method listed above, or rely solely on
user input on buttons to change the modes by adding different components
to the frame whose "mode" I would have changed...
Other game source codes I have seen use the "Mode-Case" method as well, and
that is a shame because I find it insufficient for the complexity if my game.
Then I see professional games like "Starcraft" and "Halflife" and KNOW that
they didn't use Modes! I'm not trying to make something up to their level,
but certainly it would be nice to know exactly how they implemented their
initial menu and game interface using the "public static void main" or, in
my case, the "public class <game> extends java.applet.Applet"...
Thank you in advance for any help or light you can shine on my situation...
I have even considered e-mailing some of the lesser game companies (the
more friendly ones) to ask how something like this can be implenented...
but I don't expect much success there.
Forum Rules
Development Centers
-- Android Development Center
-- Cloud Development Project Center
-- HTML5 Development Center
-- Windows Mobile Development Center | http://forums.devx.com/showthread.php?29311-AWT-vs.-Swing&goto=nextnewest | CC-MAIN-2016-26 | refinedweb | 652 | 55.37 |
Hide Forgot
On my frech install of the RH6.1, the file beginning of the file
/usr/include/rpm/rpmlib.h is :
...
#include <rpmio.h>
#include <dbindex.h>
#include <header.h>
#include <popt.h>
and it should be
...
#include <rpm/rpmio.h>
#include <rpm/dbindex.h>
#include <rpm/header.h>
#include <popt.h>
because gcc said said that it could not find rpmio.h, dbindex.h and
header.h
Add -I/usr/include/rpm to your CFLAGS.
I believe that this is still a bug. The maximum rpm book says to write
#include <rpm/rpmlib.h>
but then the header files don't work unless I write -I/usr/include/rpm in which
case I could have written
#include <rpmlib.h>
And what if I am writing something that wants to use another package that has a
header.h file in its include path somewhere. (E.g. /usr/include/pci/header.h)
In that case I could end up with a collision. | https://partner-bugzilla.redhat.com/show_bug.cgi?id=7423 | CC-MAIN-2020-29 | refinedweb | 162 | 81.19 |
Please Help, Need to add several namespaces to Envelope using Perl
Expand Messages
- View SourceI've taken over some code for my company and need some help. We have a soap lite script which is called from another module. The calling module contains the following:
$self->{path} = '/TktServices/services/TicketSoapHttpPort';
$self->{method_name} = 'getTicketRequest';
$self->{method_attr} = {
"xmlns"=> '' }
This in turns calls the underlying module containing the soap calls.
There is an entry in the module that issues this:
my $data = SOAP::Data->name($self->{method_name})->attr($self->{method_attr});
And then he enters the data and parameters in this way:
$self->{request} = $soap->serializer->envelope(method => $data, @params);
I need to add several namespaces to the envelope in order to get this to work. However am I using the correct command. Is there a way to add it to the serializer->envelope above.
$soap->serializer->namespaces({
""=>"xmlns:m2",
""=>"xmlns:q0",
""=>"xmlns:q1",
""=>"xmlns:q2",
});
Cause when I run the script I don't see these namespaces in the envelope.
Also there is this entry in the header:
<soapenv:Header>
<m2:Security xmlns:
Questions:
1) Can I add this namespace to the header?
2) Is there a difference between adding the namespace to the envelope versus the header?
3) If I were to be successful on adding the namespaces do i need to add the attr to this header name or does the namespace take care of it:
("m2:Security")->attr({'xmlns:m2'=>''})
Please help.
Your message has been successfully submitted and would be delivered to recipients shortly. | https://groups.yahoo.com/neo/groups/soaplite/conversations/topics/6621?var=0&l=1 | CC-MAIN-2014-15 | refinedweb | 255 | 50.77 |
Hi
I'm working on storage discovery. For that I want SMI-s provider document for the below storage, IBM DS 8000 IBM DS Raid Storage IBM Storwize v7000 For the above what is the CIM namespace and CreationClassName. Thanks in advance
Regards KabirAkamlKhan
Answer by JorgeHdez (88) | Dec 01, 2017 at 02:38 PM
@KabirAkmalKhan , as you move forward with your project consider that REST API is where to the standard is moving so in the future you might want to be ready for that change. Storage solutions like the ones you ask about are also looking into that direction.
Answer by Gino Lv (16) | Dec 01, 2017 at 01:28 AM
Hi Kabir, for IBM storage, all the CIM namespace is root/ibm. You can retrieve it by enumerating the instances of CIM_Namespace. For SVC, the creatationClass is IBMTSSVC_Namespace; For DS/XIV, the creationClass is IBMTSDS_Namespace.
Answer by JorgeHdez (88) | Nov 30, 2017 at 02:45 PM
Hi KabirAkmalKhan,
You can find information related to CIM in the Architecture and Implementation Guide >
It'll help if you could elaborate further what the ultimate purpose of this question will be. Are you trying to integrate these products into a software monitoring tool? If so what tools is this?
128 people are following this question. | https://developer.ibm.com/answers/questions/416070/ibm-storage-smis-provider.html?sort=newest | CC-MAIN-2019-39 | refinedweb | 215 | 60.85 |
If coding tutorials with math examples are the bane of your existence, keep reading. This series uses relatable examples like dogs and cats.
File Handling
File handling allows you to create, read, update and delete files. I assume this is where CRUD comes from.
Opening a File
Using the open() function, you can create, read, and update files
#syntax open('filename', mode)
Mode
Reading a File
This first examples let's us look at the WHOLE file
file = open('./dogs.txt','r') text = file.read(). # put a number as a parameter & get that many characters print(text) #output allllllllllllllllllllllllllllllllllllllllllllllll the words of the file print here and blah blah blah...
you may also
readlines() and
read().splitlines()
Writing to a File
If you write a file that doesn't exist, it will create one. Here's an example.
with open('./dogs.txt','w') as f: f.write('text about dogs')
Append to a File
To append = add to the end
If I want to make my file include cats, here's what I'd do
with open('./dogs.txt','a') as f: f.write('and cats')
Now the file reads: "text about dogs and cats"
Deleting a File
import os os.remove('./dogs.txt')
If the file doesn't exist, it can't remove it and will give an error. For this case, it may be good to use an if-else condition.
import os if os.path.exist('./dogs.txt’): os.remove('./dogs.txt') else: os.remove("file doesn't exist")
Series loosely based on
Discussion (6)
Hi Vicki, nice notes!
I'm going to suggest the builtin module pathlib as well, which has an object oriented interface on path navigation and manipulation. You might find it helpful!
Thanks! This looks pretty helpful. :)
This is awesome Vicki! I just started learning Python again and I plan on incorporating your series into my learning process.
Awesome! I'm happy to help and clear up anything that might not be so clear. If you have questions just ask.
😱 Thanks for letting me know. I’ll get that fixed | https://practicaldev-herokuapp-com.global.ssl.fastly.net/vickilanger/charming-the-python-file-handling-41om | CC-MAIN-2021-10 | refinedweb | 347 | 60.41 |
Search: Search took 0.02 seconds.
- 29 Jul 2013 7:21 AM
I see. Well, thank you very much! ^^
- 29 Jul 2013 6:46 AM
..my code killed you all, am i right? :))
- 25 Jul 2013 8:01 AM
This is MyInfo
public class MyInfo extends Info {
private native Stack<Info> getSlots() /*-{
return @com.sencha.gxt.widget.core.client.info.Info::slots;
}-*/;
...
- 25 Jul 2013 7:48 AM
Thank you very much, both of you have been very kind and crystal clear. While this solved my problem about the private attribute, I'm afraid I still cannot achieve what I had in mind.
That's what...
- 25 Jul 2013 1:55 AM
That's a good news, for the future :D for now, is there a way you could help me doing what you suggested..?
- 24 Jul 2013 9:13 AM
Thanks for the answer! That's exactly what I tried to do, but ( and I assume this is my fault, that's pure Java ) I cannot access the private attribute slots of the method
How can I achieve that?...
- 24 Jul 2013 8:46 AM
Hello
I need to change the position of the Info.display popup: I need it on the bottom right, instead of on top. Can you please show me how to? Thanks in advance!
- 5 Mar 2013 11:55 AM
- Replies
- 5
- Views
- 1,169
Hello folks
I have a problem when I try to add a new window on my desktop
When I proceed to add it, no matter wether I do set height and width or not, the window has a fixed, small resolution and...
Results 1 to 8 of 8 | https://www.sencha.com/forum/search.php?s=c5dfeb93739e311fe67ac5b65880e809&searchid=13305920 | CC-MAIN-2015-48 | refinedweb | 278 | 90.19 |
Request for Comments: 8323
Updates: 7641, 7959
Category: Standards Track
ISSN: 2070-1721
Universitaet Bremen TZI
S. Lemay
Zebra Technologies
H. Tschofenig
ARM Ltd.
K. Hartke
Universitaet Bremen TZI
B. Silverajan
Tampere University of Technology
B. Raymor, Ed.
February 2018
CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets
Abstract .....................................6 3. CoAP over TCP ...................................................7 3.1. Messaging Model ............................................7 3.2. Message Format .............................................9 3.3. Message Transmission ......................................11 3.4. Connection Health .........................................12 4. CoAP over WebSockets ...........................................13 4.1. Opening Handshake .........................................15 4.2. Message Format ............................................15 4.3. Message Transmission ......................................16 4.4. Connection Health .........................................17 5. Signaling ......................................................17 5.1. Signaling Codes ...........................................17 5.2. Signaling Option Numbers ..................................18 5.3. Capabilities and Settings Messages (CSMs) .................18 5.4. Ping and Pong Messages ....................................20 5.5. Release Messages ..........................................21 5.6. Abort Messages ............................................23 5.7. Signaling Examples ........................................24 6. Block-Wise Transfer and Reliable Transports ....................25 6.1. Example: GET with BERT Blocks .............................27 6.2. Example: PUT with BERT Blocks .............................27 7. Observing Resources over Reliable Transports ...................28 7.1. Notifications and Reordering ..............................28 7.2. Transmission and Acknowledgments ..........................28 7.3. Freshness .................................................28 7.4. Cancellation ..............................................29 8. CoAP over Reliable Transport URIs ..............................29 8.1. coap+tcp URI Scheme .......................................30 8.2. coaps+tcp URI Scheme ......................................31 8.3. coap+ws URI Scheme ........................................32 8.4. coaps+ws URI Scheme .......................................33 8.5. Uri-Host and Uri-Port Options .............................33 8.6. Decomposing URIs into Options .............................34 8.7. Composing URIs from Options ...............................35 9. Securing CoAP ..................................................35 9.1. TLS Binding for CoAP over TCP .............................36 9.2. TLS Usage for CoAP over WebSockets ........................37 10. Security Considerations .......................................37 10.1. Signaling Messages .......................................37 11. IANA Considerations ...........................................38 11.1. Signaling Codes ..........................................38 11.2. CoAP Signaling Option Numbers Registry ...................38 11.3. Service Name and Port Number Registration ................40 11.4. Secure Service Name and Port Number Registration .........40 11.5. URI Scheme Registration ..................................41 11.6. Well-Known URI Suffix Registration .......................43 11.7. ALPN Protocol Identifier .................................44 11.8. WebSocket Subprotocol Registration .......................44 11.9. CoAP Option Numbers Registry .............................44 12. References ....................................................45 12.1. Normative References .....................................45 12.2. Informative References ...................................47 Appendix A. Examples of CoAP over WebSockets ......................49 Acknowledgments ...................................................52 Contributors ......................................................52 Authors' Addresses ................................................53
1. Introduction
The Constrained Application Protocol (CoAP) [RFC7252] was designed for Internet of Things (IoT) deployments, assuming that UDP [RFC768] can be used unimpeded as can the Datagram Transport Layer Security (DTLS) protocol [RFC6347] over UDP. The use of CoAP over UDP is focused on simplicity, has a low code footprint, and has a small over-the-wire message size.
The primary reason for introducing CoAP over TCP [RFC793] and TLS [RFC5246] is that some networks do not forward UDP packets. Complete blocking of UDP happens in between about 2% and 4% of terrestrial access networks, according to [EK2016]. UDP impairment is especially concentrated in enterprise networks and networks in geographic regions with otherwise challenged connectivity. Some networks also rate-limit UDP traffic, as reported in [BK2015], and deployment investigations related to the standardization of Quick UDP Internet Connections (QUIC) revealed numbers around 0.3% [SW2016].
The introduction of CoAP over TCP also leads to some additional effects that may be desirable in a specific deployment:
- Where NATs are present along the communication path, CoAP over TCP leads to different NAT traversal behavior than CoAP over UDP. NATs often calculate expiration timers based on the transport-layer protocol being used by application protocols. Many NATs maintain TCP-based NAT bindings for longer periods based on the assumption that a transport-layer protocol, such as TCP, offers additional information about the session lifecycle. UDP, on the other hand, does not provide such information to a NAT and timeouts tend to be much shorter [HomeGateway]. According to [HomeGateway], the mean for TCP and UDP NAT binding timeouts is 386 minutes (TCP) and 160 seconds (UDP). Shorter timeout values require keepalive messages to be sent more frequently. Hence, the use of CoAP over TCP requires less-frequent transmission of keepalive messages.
- TCP utilizes mechanisms for congestion control and flow control that are more sophisticated than the default mechanisms provided by CoAP over UDP; these TCP mechanisms are useful for the transfer of larger payloads. (However, work is ongoing to add advanced congestion control to CoAP over UDP as well; see [CoCoA].)
Note that the use of CoAP over UDP (and CoAP over DTLS over UDP) is still the recommended transport for use in constrained node networks, particularly when used in concert with block-wise transfer. CoAP over TCP is applicable for those cases where the networking infrastructure leaves no other choice. The use of CoAP over TCP leads to a larger code size, more round trips, increased RAM requirements, and larger packet sizes. Developers implementing CoAP over TCP are encouraged to consult [TCP-in-IoT] for guidance on low-footprint TCP implementations for IoT devices.
Standards based on CoAP, such as Lightweight Machine to Machine [LWM2M], currently use CoAP over UDP as a transport; adding support for CoAP over TCP enables them to address the issues above for specific deployments and to protect investments in existing CoAP implementations and deployments.
Although HTTP/2 could also potentially address the need for enterprise firewall traversal, there would be additional costs and delays introduced by such a transition from CoAP to HTTP/2. Currently, there are also fewer HTTP/2 implementations available for constrained devices in comparison to CoAP. Since CoAP also supports group communication using IP-layer multicast and unreliable communication, IoT devices would have to support HTTP/2 in addition to CoAP.
Furthermore, CoAP may be integrated into a web environment where the front end uses CoAP over UDP from IoT devices to a cloud infrastructure and then CoAP over TCP between the back-end services. A TCP-to-UDP gateway can be used at the cloud boundary to communicate with the UDP-based IoT device.
Finally, CoAP applications running inside a web browser may be without access to connectivity other than HTTP. In this case, the WebSocket Protocol [RFC6455] may be used to transport CoAP requests and responses, as opposed to cross-proxying them via HTTP to an HTTP-to-CoAP cross-proxy. This preserves the functionality of CoAP without translation -- in particular, the Observe Option [RFC7641].
To address the above-mentioned deployment requirements, this document defines how to transport CoAP over TCP, CoAP over TLS, and CoAP over WebSockets. For these cases, the reliability offered by the transport protocol subsumes the reliability functions of the message layer used for CoAP over UDP. (Note that for both a reliable transport and the message layer for CoAP over UDP, the reliability offered is per transport hop: where proxies -- see Sections 5.7 and 10 of [RFC7252] -- are involved, that layer's reliability function does not extend end to end.) Figure 1 illustrates the layering:
+--------------------------------+ | Application | +--------------------------------+ +--------------------------------+ | Requests/Responses/Signaling | CoAP (RFC 7252) / This Document |--------------------------------| | Message Framing | This Document +--------------------------------+ | Reliable Transport | +--------------------------------+
Figure 1: Layering of CoAP over Reliable Transports
This document specifies how to access resources using CoAP requests and responses over the TCP, TLS, and WebSocket protocols. This allows connectivity-limited applications to obtain end-to-end CoAP connectivity either (1) by communicating CoAP directly with a CoAP server accessible over a TCP, TLS, or WebSocket connection or (2) via a CoAP intermediary that proxies CoAP requests and responses between different transports, such as between WebSockets and UDP.
Section 7 updates [RFC7641] ("Observing Resources in the Constrained Application Protocol (CoAP)") for use with CoAP over reliable transports. [RFC7641] is an extension to CoAP that enables CoAP clients to "observe" a resource on a CoAP server. (The CoAP client retrieves a representation of a resource and registers to be notified by the CoAP server when the representation is updated.) that readers are familiar with the terms and concepts that are used in [RFC6455], [RFC7252], [RFC7641], and [RFC7959].
The term "reliable transport" is used only to refer to transport protocols, such as TCP, that provide reliable and ordered delivery of a byte stream.
Block-wise Extension for Reliable Transport (BERT):
Extends [RFC7959] to enable the use of larger messages over a reliable transport.
BERT Option:
A Block1 or Block2 option that includes an SZX (block size) value of 7.
BERT Block:
The payload of a CoAP message that is affected by a BERT Option in descriptive usage (see Section 2.1 of [RFC7959]).
Transport Connection:
Underlying reliable byte-stream connection, as directly provided by TCP or indirectly provided via TLS or WebSockets.
Connection:
Transport Connection, unless explicitly qualified otherwise.
Connection Initiator:
The peer that opens a Transport Connection, i.e., the TCP active opener, TLS client, or WebSocket client.
Connection Acceptor:
The peer that accepts the Transport Connection opened by the other peer, i.e., the TCP passive opener, TLS server, or WebSocket server.
3. CoAP over TCP
The request/response interaction model of CoAP over TCP is the same as CoAP over UDP. The primary differences are in the message layer. The message layer of CoAP over UDP supports optional reliability by defining four types of messages: Confirmable, Non-confirmable, Acknowledgment, and Reset. In addition, messages include a Message ID to relate Acknowledgments to Confirmable messages and to detect duplicate messages.
Management of the transport connections is left to the application, i.e., the present specification does not describe how an application decides to open a connection or to reopen another one in the presence of failures (or what it would deem to be a failure; see also Section 5.4). In particular, the Connection Initiator need not be the client of the first request placed on the connection. Some implementations will want to implement dynamic connection management similar to the technique described in Section 6 of [RFC7230] for HTTP: opening a connection when the first client request is ready to be sent, reusing that connection for subsequent messages until no more messages are sent for a certain time period and no requests are outstanding (possibly with a configurable idle time), and then starting a release process (orderly shutdown) (see Section 5.5). In implementations of this kind, connection releases or aborts may not be indicated as errors to the application but may simply be handled by automatic reconnection once the need arises again. Other implementations may be based on configured connections that are kept open continuously and lead to management system notifications on release or abort. The protocol defined in the present specification is intended to work with either model (or other, application-specific connection management models).
3.1. Messaging Model
Conceptually, CoAP over TCP replaces most of the message layer of CoAP over UDP with a framing mechanism on top of the byte stream provided by TCP/TLS, conveying the length information for each message that, on datagram transports, is provided by the UDP/DTLS datagram layer.
TCP ensures reliable message transmission, so the message layer of CoAP over TCP is not required to support Acknowledgment messages or to detect duplicate messages. As a result, both the Type and Message ID fields are no longer required and are removed from the message format for CoAP over TCP.
Figure 2 illustrates the difference between CoAP over UDP and CoAP over reliable transports. The removed Type and Message ID fields are indicated by dashes.
CoAP Client CoAP Server CoAP Client CoAP Server | | | | | CON [0xbc90] | | (-------) [------] | | GET /temperature | | GET /temperature | | (Token 0x71) | | (Token 0x71) | +------------------->| +------------------->| | | | | | ACK [0xbc90] | | (-------) [------] | | 2.05 Content | | 2.05 Content | | (Token 0x71) | | (Token 0x71) | | "22.5 C" | | "22.5 C" | |<-------------------+ |<-------------------+ | | | | CoAP over UDP CoAP over reliable transports
Figure 2: Comparison between CoAP over Unreliable Transports and
-
CoAP over Reliable Transports
3.2. Message Format
The CoAP message format defined in [RFC7252], as shown in Figure 3, relies on the datagram transport (UDP, or DTLS over UDP) for keeping the individual messages separate and for providing length information. 3: CoAP Message Format as Defined in RFC 7252
The message format for CoAP over TCP is very similar to the format specified for CoAP over UDP. The differences are as follows:
- Since the underlying TCP connection provides retransmissions and deduplication, there is no need for the reliability mechanisms provided by CoAP over UDP. The Type (T) and Message ID fields in the CoAP message header are elided.
- The Version (Vers) field is elided as well. In contrast to the message format of CoAP over UDP, the message format for CoAP over TCP does not include a version number. CoAP is defined in [RFC7252] with a version number of 1. At this time, there is no known reason to support version numbers different from 1. If version negotiation needs to be addressed in the future, Capabilities and Settings Messages (CSMs) (see Section 5.3) have been specifically designed to enable such a potential feature.
- In a stream-oriented transport protocol such as TCP, a form of message delimitation is needed. For this purpose, CoAP over TCP introduces a length field with variable size. Figure 4 shows the adjusted CoAP message format with a modified structure for the fixed header (first 4 bytes of the header for CoAP over UDP), which includes the length information of variable size.
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Len | TKL | Extended Length (if any, as chosen by Len) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Code | Token (if any, TKL bytes) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options (if any) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1 1 1 1 1 1 1 1| Payload (if any) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: CoAP Frame for Reliable Transports
Length (Len): 4-bit unsigned integer. A value between 0 and 12 inclusive indicates the length of the message in bytes, starting with the first bit of the Options field. Three values are reserved for special constructs: 13: An 8-bit unsigned integer (Extended Length) follows the initial byte and indicates the length of options/payload minus 13. 14: A 16-bit unsigned integer (Extended Length) in network byte order follows the initial byte and indicates the length of options/payload minus 269. 15: A 32-bit unsigned integer (Extended Length) in network byte order follows the initial byte and indicates the length of options/payload minus 65805.
The encoding of the Length field is modeled after the Option Length field of the CoAP Options (see Section 3.1 of [RFC7252]).
For simplicity, a Payload Marker (0xFF) is shown in Figure 4; the Payload Marker indicates the start of the optional payload and is absent for zero-length payloads (see Section 3 of [RFC7252]). (If present, the Payload Marker is included in the message length, which counts from the start of the Options field to the end of the Payload field.)
For example, a CoAP message just containing a 2.03 code with the Token 7f and no options or payload is encoded as shown in Figure 5.
0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x01 | 0x43 | 0x7f | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Len = 0 ------> 0x01 TKL = 1 ___/ Code = 2.03 --> 0x43 Token = 0x7f
Figure 5: CoAP Message with No Options or Payload
The semantics of the other CoAP header fields are left unchanged.
3.3. Message Transmission
Once a Transport Connection is established, each endpoint MUST send a CSM (see Section 5.3) as its first message on the connection. This message establishes the initial settings and capabilities for the endpoint, such as maximum message size or support for block-wise transfers. The absence of options in the CSM indicates that base values are assumed.
To avoid a deadlock, the Connection Initiator MUST NOT wait for the Connection Acceptor to send its initial CSM before sending its own initial CSM. Conversely, the Connection Acceptor MAY wait for the Connection Initiator to send its initial CSM before sending its own initial CSM.
To avoid unnecessary latency, a Connection Initiator MAY send additional messages after its initial CSM without waiting to receive the Connection Acceptor's CSM; however, it is important to note that the Connection Acceptor's CSM might indicate capabilities that impact how the Connection Initiator is expected to communicate with the Connection Acceptor. For example, the Connection Acceptor's CSM could indicate a Max-Message-Size Option (see Section 5.3.1) that is smaller than the base value (1152) in order to limit both buffering requirements and head-of-line blocking.
Endpoints MUST treat a missing or invalid CSM as a connection error and abort the connection (see Section 5.6).
CoAP requests and responses are exchanged asynchronously over the Transport Transport Connection is bidirectional, so requests can be sent by both the entity that established the connection (Connection Initiator) and the remote host (Connection Acceptor). If one side does not implement a CoAP server, an error response MUST be returned for all CoAP requests from the other side. The simplest approach is to always return 5.01 (Not Implemented). A more elaborate mock server could also return 4.xx responses such as 4.04 (Not Found) or 4.02 (Bad Option) where appropriate.
Retransmission and deduplication of messages are provided by TCP.
3.4. Connection Health
Empty messages (Code 0.00) can always be sent and MUST be ignored by the recipient. This provides a basic keepalive function that can refresh NAT bindings.
If a CoAP client does not receive any response for some time after sending a CoAP request (or, similarly, when a client observes a resource and it does not receive any notification for some time), it can send a CoAP Ping Signaling message (see Section 5.4) to test the Transport Connection and verify that the CoAP server is responsive.
When the underlying Transport Connection is closed or reset, the signaling state and any observation state (see Section 7.4) associated with the connection are removed. Messages that are in flight may or may not be lost.
4. CoAP over WebSockets
CoAP over WebSockets is intentionally similar to CoAP over TCP; therefore, this section only specifies the differences between the transports.
CoAP over WebSockets can be used in a number of configurations. The most basic configuration is a CoAP client retrieving or updating a CoAP resource located on a CoAP server that exposes a WebSocket endpoint (see Figure 6). The CoAP client acts as the WebSocket client, establishes a WebSocket connection, and sends a CoAP request, to which the CoAP server returns a CoAP response. The WebSocket connection can be used for any number of requests.
___________ ___________ | | | | | _|___ requests ___|_ | | CoAP / \ \ -------------> / / \ CoAP | | Client \__/__/ <------------- \__\__/ Server | | | responses | | |___________| |___________| WebSocket =============> WebSocket Client Connection Server
Figure 6: CoAP Client (WebSocket Client) Accesses CoAP Server
-
(WebSocket Server)
The challenge with this configuration is how to identify a resource in the namespace of the CoAP server. When the WebSocket Protocol is used by a dedicated client directly (i.e., not from a web page through a web browser), the client can connect to any WebSocket endpoint. Sections 8.3 and 8.4 define new URI schemes that enable the client to identify both a WebSocket endpoint and the path and query of the CoAP resource within that endpoint.
Another possible configuration is to set up a CoAP forward proxy at the WebSocket endpoint. Depending on what transports are available to the proxy, it could forward the request to a CoAP server with a CoAP UDP endpoint (Figure 7), an SMS endpoint (a.k.a. mobile phone), or even another WebSocket endpoint. The CoAP client specifies the resource to be updated or retrieved in the Proxy-Uri Option.
___________ ___________ ___________ | | | | | | | _|___ ___|_ _|___ ___|_ | | CoAP / \ \ ---> / / \ CoAP / \ \ ---> / / \ CoAP | | Client \__/__/ <--- \__\__/ Proxy \__/__/ <--- \__\__/ Server | | | | | | | |___________| |___________| |___________| WebSocket ===> WebSocket UDP UDP Client Server Client Server
Figure 7: CoAP Client (WebSocket Client) Accesses CoAP Server (UDP Server) via a CoAP Proxy (WebSocket Server / UDP Client)
A third possible configuration is a CoAP server running inside a web browser (Figure 8). The web browser initially connects to a WebSocket endpoint and is then reachable through the WebSocket server. When no connection exists, the CoAP server is unreachable. Because the WebSocket server is the only way to reach the CoAP server, the CoAP proxy should be a reverse-proxy.
___________ ___________ ___________ | | | | | | | _|___ ___|_ _|___ ___|_ | | CoAP / \ \ ---> / / \ CoAP / / \ ---> / \ \ CoAP | | Client \__/__/ <--- \__\__/ Proxy \__\__/ <--- \__/__/ Server | | | | | | | |___________| |___________| |___________| UDP UDP WebSocket <=== WebSocket Client Server Server Client
Figure 8: CoAP Client (UDP Client) Accesses CoAP Server (WebSocket
-
Client) via a CoAP Proxy (UDP Server / WebSocket Server)
Further configurations are possible, including those where a WebSocket connection is established through an HTTP proxy.
4.1. Opening Handshake
Before CoAP requests and responses are exchanged, a WebSocket connection is established as defined in Section 4 of [RFC6455]. Figure 9 shows an example.
The WebSocket client MUST include the subprotocol name "coap" in the list of protocols; this indicates support for the protocol defined in this document.
The WebSocket client includes the hostname of the WebSocket server in the Host header field of its handshake as per [RFC6455]. The Host header field also indicates the default value of the Uri-Host Option in requests from the WebSocket client to the WebS
Figure 9: Example of an Opening Handshake
4.2. Message Format
Once a WebSocket connection is established, CoAP requests and responses can be exchanged as WebSocket messages. Since CoAP uses a binary message format, the messages are transmitted in binary data frames as specified in Sections 5 and 6 of [RFC6455].
The message format shown in Figure 10 is the same as the message format for CoAP over TCP (see Section 3.2), with one change: the Length (Len) field MUST be set to zero, because the WebSocket frame contains the length.
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Len=0 | TKL | Code | Token (TKL bytes) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options (if any) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1 1 1 1 1 1 1 1| Payload (if any) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: CoAP Message Format over WebSockets
As with CoAP over TCP, the message format for CoAP over WebSockets eliminates the Version field defined in CoAP over UDP. If CoAP version negotiation is required in the future, CoAP over WebSockets can address the requirement by defining a new subprotocol identifier that is negotiated during the opening handshake.
Requests and responses can be fragmented as specified in Section 5.4 of [RFC6455], though typically they are sent unfragmented, as they tend to be small and fully buffered before transmission. The WebSocket Protocol does not provide means for multiplexing. If it is not desirable for a large message to monopolize the connection, requests and responses can be transferred in a block-wise fashion as defined in [RFC7959].
4.3. Message Transmission
As with CoAP over TCP, each endpoint MUST send a CSM (see Section 5.3) as its first message on the WebSocket connection.
CoAP requests and responses are exchanged asynchronously over the WebSocket connection is bidirectional, so requests can be sent by both the entity that established the connection and the remote host.
As with CoAP over TCP, retransmission and deduplication of messages are provided by the WebSocket Protocol. CoAP over WebSockets therefore does not make a distinction between Confirmable messages and Non-confirmable messages and does not provide Acknowledgment or Reset messages.
4.4. Connection Health
As with CoAP over TCP, a CoAP client can test the health of the connection for CoAP over WebSockets by sending a CoAP Ping Signaling message (Section 5.4). To ensure that redundant maintenance traffic is not transmitted, WebSocket Ping and unsolicited Pong frames (Section 5.5 of [RFC6455]) SHOULD NOT be used.
5. Signaling
Signaling messages are specifically introduced only for CoAP over reliable transports to allow peers to:
- Learn related characteristics, such as maximum message size for the connection.
- Shut down the connection in an orderly fashion.
- Provide diagnostic information when terminating a connection in response to a serious error condition.
Signaling is a third basic kind of message in CoAP, after requests and responses. Signaling messages share a common structure with the existing CoAP messages. There are a code, a Token, options, and an optional payload.
(See Section 3 of [RFC7252] for the overall structure of the message format, option format, and option value formats.)
5.1. Signaling Codes
A code in the 7.00-7.31 range indicates a Signaling message. Values in this range are assigned by the "CoAP Signaling Codes" subregistry (see Section 11.1).
For each message, there are a sender and a peer receiving the message.
Payloads in Signaling messages are diagnostic payloads as defined in Section 5.5.2 of [RFC7252], unless otherwise defined by a Signaling message option.
5.2. Signaling Option Numbers
Option Numbers for Signaling messages are specific to the message code. They do not share the number space with CoAP options for request/response messages or with Signaling messages using other codes.
Option Numbers are assigned by the "CoAP Signaling Option Numbers" subregistry (see Section 11.2).
Signaling Options are elective or critical as defined in Section 5.4.1 of [RFC7252]. If a Signaling Option is critical and not understood by the receiver, it MUST abort the connection (see Section 5.6). If the option is understood but cannot be processed, the option documents the behavior.
5.3. Capabilities and Settings Messages (CSMs)
CSMs are used for two purposes:
- Each capability option indicates one capability of the sender to the recipient.
- Each setting option indicates a setting that will be applied by the sender.
One CSM MUST be sent by each endpoint at the start of the Transport Connection. Additional CSMs MAY be sent at any other time by either endpoint over the lifetime of the connection.
Both capability options and setting options are cumulative. A CSM does not invalidate a previously sent capability indication or setting even if it is not repeated. A capability message without any option is a no-operation (and can be used as such). An option that is sent might override a previous value for the same option. The option defines how to handle this case if needed.
Base values are listed below for CSM options. These are the values for the capability and settings before any CSMs send a modified value.
These are not default values (as defined in Section 5.4.4 in [RFC7252]) for the option. Default values apply on a per-message basis and are thus reset when the value is not present in a given CSM.
CSMs are indicated by the 7.01 (CSM) code; see Table 1 (Section 11.1).
5.3.1. Max-Message-Size Capability Option
The sender can use the elective Max-Message-Size Option to indicate the maximum size of a message in bytes that it can receive. The message size indicated includes the entire message, starting from the first byte of the message header and ending at the end of the message payload.
(Note that there is no relationship of the message size to the overall request or response body size that may be achievable in block-wise transfer. For example, the exchange depicted in Figure 13 (Section 6.1) can be performed if the CoAP client indicates a value of around 6000 bytes for the Max-Message-Size Option, even though the total body size transferred to the client is 3072 + 5120 + 4711 = 12903 bytes.)
+---+---+---+---------+------------------+--------+--------+--------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+---------+------------------+--------+--------+--------+ | 2 | | | CSM | Max-Message-Size | uint | 0-4 | 1152 | +---+---+---+---------+------------------+--------+--------+--------+
C=Critical, R=Repeatable
As per Section 4.6 of [RFC7252], the base value (and the value used when this option is not implemented) is 1152.
The active value of the Max-Message-Size Option is replaced each time the option is sent with a modified value. Its starting value is its base value.
5.3.2. Block-Wise-Transfer Capability Option
+---+---+---+---------+------------------+--------+--------+--------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+---------+------------------+--------+--------+--------+ | 4 | | | CSM | Block-Wise- | empty | 0 | (none) | | | | | | Transfer | | | | +---+---+---+---------+------------------+--------+--------+--------+
C=Critical, R=Repeatable
A sender can use the elective Block-Wise-Transfer Option to indicate that it supports the block-wise transfer protocol [RFC7959].
If the option is not given, the peer has no information about whether block-wise transfers are supported by the sender or not. An implementation wishing to offer block-wise transfers to its peer therefore needs to indicate so via the Block-Wise-Transfer Option.
If a Max-Message-Size Option is indicated with a value that is greater than 1152 (in the same CSM or a different CSM), the Block-Wise-Transfer Option also indicates support for BERT (see Section 6). Subsequently, if the Max-Message-Size Option is indicated with a value equal to or less than 1152, BERT support is no longer indicated. (Note that the indication of BERT support does not oblige either peer to actually choose to make use of BERT.)
Implementation note: When indicating a value of the Max-Message-Size Option with an intention to enable BERT, the indicating implementation may want to (1) choose a particular BERT block size it wants to encourage and (2) add a delta for the header and any options that may also need to be included in the message with a BERT block of that size. Section 4.6 of [RFC7252] adds 128 bytes to a maximum block size of 1024 to arrive at a default message size of 1152. A BERT-enabled implementation may want to indicate a BERT block size of 2048 or a higher multiple of 1024 and at the same time be more generous with the size of the header and options added (say, 256 or 512). However, adding 1024 or more to the base BERT block size may encourage the peer implementation to vary the BERT block size based on the size of the options included; this type of scenario might make it harder to establish interoperability.
5.4. Ping and Pong Messages
In CoAP over reliable transports, Empty messages (Code 0.00) can always be sent and MUST be ignored by the recipient. This provides a basic keepalive function. In contrast, Ping and Pong messages are a bidirectional exchange.
Upon receipt of a Ping message, the receiver MUST return a Pong message with an identical Token in response. Unless the Ping carries an option with delaying semantics such as the Custody Option, it SHOULD respond as soon as practical. As with all Signaling messages, the recipient of a Ping or Pong message MUST ignore elective options it does not understand.
Ping and Pong messages are indicated by the 7.02 code (Ping) and the 7.03 code (Pong).
Note that, as with similar mechanisms defined in [RFC6455] and [RFC7540], the present specification does not define any specific maximum time that the sender of a Ping message has to allow when waiting for a Pong reply. Any limitations on patience for this reply are a matter of the application making use of these messages, as is any approach to recover from a failure to respond in time.
5.4.1. Custody Option
+---+---+---+----------+----------------+--------+--------+---------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+----------+----------------+--------+--------+---------+ | 2 | | | Ping, | Custody | empty | 0 | (none) | | | | | Pong | | | | | +---+---+---+----------+----------------+--------+--------+---------+
C=Critical, R=Repeatable
When responding to a Ping message, the receiver can include an elective Custody Option in the Pong message. This option indicates that the application has processed all the request/response messages received prior to the Ping message on the current connection. (Note that there is no definition of specific application semantics for "processed", but there is an expectation that the receiver of a Pong message with a Custody Option should be able to free buffers based on this indication.)
A sender can also include an elective Custody Option in a Ping message to explicitly request the inclusion of an elective Custody Option in the corresponding Pong message. In that case, the receiver SHOULD delay its Pong message until it finishes processing all the request/response messages received prior to the Ping message on the current connection.
5.5. Release Messages
A Release message indicates that the sender does not want to continue maintaining the Transport Connection and opts for an orderly shutdown, but wants to leave it to the peer to actually start closing the connection. The details are in the options. A diagnostic payload (see Section 5.5.2 of [RFC7252]) MAY be included.
A peer will normally respond to a Release message by closing the Transport Connection. (In case that does not happen, the sender of the release may want to implement a timeout mechanism if getting rid of the connection is actually important to it.)
Messages may be in flight or responses outstanding when the sender decides to send a Release message (which is one reason the sender had decided to wait before closing the connection). The peer responding to the Release message SHOULD delay the closing of the connection until it has responded to all requests received by it before the Release message. It also MAY wait for the responses to its own requests.
It is NOT RECOMMENDED for the sender of a Release message to continue sending requests on the connection it already indicated to be released: the peer might close the connection at any time and miss those requests. The peer is not obligated to check for this condition, though.
Release messages are indicated by the 7.04 code (Release).
Release messages can indicate one or more reasons using elective options. The following options are defined:
+---+---+---+---------+------------------+--------+--------+--------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+---------+------------------+--------+--------+--------+ | 2 | | x | Release | Alternative- | string | 1-255 | (none) | | | | | | Address | | | | +---+---+---+---------+------------------+--------+--------+--------+
C=Critical, R=Repeatable
The elective Alternative-Address Option requests the peer to instead open a connection of the same scheme as the present connection to the alternative transport address given. Its value is in the form "authority" as defined in Section 3.2 of [RFC3986]. (Existing state related to the connection is not transferred from the present connection to the new connection.)
The Alternative-Address Option is a repeatable option as defined in Section 5.4.5 of [RFC7252]. When multiple occurrences of the option are included, the peer can choose any of the alternative transport addresses.
+---+---+---+---------+-----------------+--------+--------+---------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+---------+-----------------+--------+--------+---------+ | 4 | | | Release | Hold-Off | uint | 0-3 | (none) | +---+---+---+---------+-----------------+--------+--------+---------+
C=Critical, R=Repeatable
The elective Hold-Off Option indicates that the server is requesting that the peer not reconnect to it for the number of seconds given in the value.
5.6. Abort Messages
An Abort message indicates that the sender is unable to continue maintaining the Transport Connection and cannot even wait for an orderly release. The sender shuts down the connection immediately after the Abort message (and may or may not wait for a Release message, Abort message, or connection shutdown in the inverse direction). A diagnostic payload (see Section 5.5.2 of [RFC7252]) SHOULD be included in the Abort message. Messages may be in flight or responses outstanding when the sender decides to send an Abort message. The general expectation is that these will NOT be processed.
Abort messages are indicated by the 7.05 code (Abort).
Abort messages can indicate one or more reasons using elective options. The following option is defined:
+---+---+---+---------+-----------------+--------+--------+---------+ | # | C | R | Applies | Name | Format | Length | Base | | | | | to | | | | Value | +---+---+---+---------+-----------------+--------+--------+---------+ | 2 | | | Abort | Bad-CSM-Option | uint | 0-2 | (none) | +---+---+---+---------+-----------------+--------+--------+---------+
C=Critical, R=Repeatable
Bad-CSM-Option, which is elective, indicates that the sender is unable to process the CSM option identified by its Option Number, e.g., when it is critical and the Option Number is unknown by the sender, or when there is a parameter problem with the value of an elective option. More detailed information SHOULD be included as a diagnostic payload.
For CoAP over UDP, messages that contain syntax violations are processed as message format errors. As described in Sections 4.2 and 4.3 of [RFC7252], such messages are rejected by sending a matching Reset message and otherwise ignoring the message.
For CoAP over reliable transports, the recipient rejects such messages by sending an Abort message and otherwise ignoring (not processing) the message. No specific Option has been defined for the Abort message in this case, as the details are best left to a diagnostic payload.
5.7. Signaling Examples
An encoded example of a Ping message with a non-empty Token is shown in Figure 11.
0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x01 | 0xe2 | 0x42 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Len = 0 -------> 0x01 TKL = 1 ___/ Code = 7.02 Ping --> 0xe2 Token = 0x42
Figure 11: Ping Message Example
An encoded example of the corresponding Pong message is shown in Figure 12.
0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x01 | 0xe3 | 0x42 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Len = 0 -------> 0x01 TKL = 1 ___/ Code = 7.03 Pong --> 0xe3 Token = 0x42
Figure 12: Pong Message Example
6. Block-Wise Transfer and Reliable Transports
The message size restrictions defined in Section 4.6 of [RFC7252] to avoid IP fragmentation are not necessary when CoAP is used over a reliable transport. While this suggests that the block-wise transfer protocol [RFC7959] is also no longer needed, it remains applicable for a number of cases:
- Large messages, such as firmware downloads, may cause undesired head-of-line blocking when a single transport connection is used.
- A UDP-to-TCP gateway may simply not have the context to convert a message with a Block Option into the equivalent exchange without any use of a Block Option (it would need to convert the entire block-wise exchange from start to end into a single exchange).
BERT extends the block-wise transfer protocol to enable the use of larger messages over a reliable transport.
The use of this new extension is signaled by sending Block1 or Block2 Options with SZX == 7 (a "BERT Option"). SZX == 7 is a reserved value in [RFC7959].
In control usage, a BERT Option is interpreted in the same way as the equivalent Option with SZX == 6, except that it also indicates the capability to process BERT blocks. As with the basic block-wise transfer protocol, the recipient of a CoAP request with a BERT Option in control usage is allowed to respond with a different SZX value, e.g., to send a non-BERT block instead.
In descriptive usage, a BERT Option is interpreted in the same way as the equivalent Option with SZX == 6, except that the payload is also allowed to contain multiple blocks. For non-final BERT blocks, the payload is always a multiple of 1024 bytes. For final BERT blocks, the payload is a multiple (possibly 0) of 1024 bytes plus a partial block of less than 1024 bytes.
The recipient of a non-final BERT block (M=1) conceptually partitions the payload into a sequence of 1024-byte blocks and acts exactly as if it had received this sequence in conjunction with block numbers starting at, and sequentially increasing from, the block number given in the Block Option. In other words, the entire BERT block is positioned at the byte position that results from multiplying the block number by 1024. The position of further blocks to be transferred is indicated by incrementing the block number by the number of elements in this sequence (i.e., the size of the payload divided by 1024 bytes).
As with SZX == 6, the recipient of a final BERT block (M=0) simply appends the payload at the byte position that is indicated by the block number multiplied by 1024.
The following examples illustrate BERT Options. A value of SZX == 7 is labeled as "BERT" or as "BERT(nnn)" to indicate a payload of size nnn.
In all these examples, a Block Option is decomposed to indicate the kind of Block Option (1 or 2) followed by a colon, the block number (NUM), the more bit (M), and the block size (2**(SZX + 4)) separated by slashes. For example, a Block2 Option value of 33 would be shown as 2:2/0/32), or a Block1 Option value of 59 would be shown as 1:3/1/128.
6.1. Example: GET with BERT Blocks
Figure 13 shows a GET request with a response that is split into three BERT blocks. The first response contains 3072 bytes of payload; the second, 5120; and the third, 4711. Note how the block number increments to move the position inside the response body forward.
CoAP Client CoAP Server | | | GET, /status ------> | | | | <------ 2.05 Content, 2:0/1/BERT(3072) | | | | GET, /status, 2:3/0/BERT ------> | | | | <------ 2.05 Content, 2:3/1/BERT(5120) | | | | GET, /status, 2:8/0/BERT ------> | | | | <------ 2.05 Content, 2:8/0/BERT(4711) |
Figure 13: GET with BERT Blocks
6.2. Example: PUT with BERT Blocks
Figure 14 demonstrates a PUT exchange with BERT blocks.
CoAP Client CoAP Server | | | PUT, /options, 1:0/1/BERT(8192) ------> | | | | <------ 2.31 Continue, 1:0/1/BERT | | | | PUT, /options, 1:8/1/BERT(16384) ------> | | | | <------ 2.31 Continue, 1:8/1/BERT | | | | PUT, /options, 1:24/0/BERT(5683) ------> | | | | <------ 2.04 Changed, 1:24/0/BERT | | |
Figure 14: PUT with BERT Blocks
7. Observing Resources over Reliable Transports
This section describes how the procedures defined in [RFC7641] for observing resources over CoAP are applied (and modified, as needed) for reliable transports. In this section, "client" and "server" refer to the CoAP client and CoAP server.
7.1. Notifications and Reordering
When using the Observe Option [RFC7641] with CoAP over UDP, notifications from the server set the option value to an increasing sequence number for reordering detection on the client, since messages can arrive in a different order than they were sent. This sequence number is not required for CoAP over reliable transports, since TCP ensures reliable and ordered delivery of messages. The value of the Observe Option in 2.xx notifications MAY be empty on transmission and MUST be ignored on reception.
Implementation note: This means that a proxy from a reordering transport to a reliable (in-order) transport (such as a UDP-to-TCP proxy) needs to process the Observe Option in notifications according to the rules in Section 3.4 of [RFC7641].
7.2. Transmission and Acknowledgments
For CoAP over UDP, server notifications to the client can be Confirmable or Non-confirmable. A Confirmable message requires the client to respond with either an Acknowledgment message or a Reset message. An Acknowledgment message indicates that the client is alive and wishes to receive further notifications. A Reset message indicates that the client does not recognize the Token; this causes the server to remove the associated entry from the list of observers.
Since TCP eliminates the need for the message layer to support reliability, CoAP over reliable transports does not support Confirmable or Non-confirmable message types. All notifications are delivered reliably to the client with positive acknowledgment of receipt occurring at the TCP level. If the client does not recognize the Token in a notification, it MAY immediately abort the connection (see Section 5.6).
7.3. Freshness
For CoAP over UDP, if a client does not receive a notification for some time, it can send a new GET request with the same Token as the original request to re-register its interest in a resource and verify that the server is still responsive. For CoAP over reliable transports, it is more efficient to check the health of the connection (and all its active observations) by sending a single CoAP Ping Signaling message (Section 5.4) rather than individual requests to confirm each active observation. (Note that such a Ping/Pong only confirms a single hop: a proxy is not obligated or expected to react to a Ping by checking all its own registered interests or all the connections, if any, underlying them. A proxy MAY maintain its own schedule for confirming the interests that it relies on being registered toward the origin server; however, it is generally inadvisable for a proxy to generate a large number of outgoing checks based on a single incoming check.)
7.4. Cancellation
For CoAP over UDP, a client that is no longer interested in receiving notifications can "forget" the observation and respond to the next notification from the server with a Reset message to cancel the observation.
For CoAP over reliable transports, a client MUST explicitly deregister by issuing a GET request that has the Token field set to the Token of the observation to be canceled and includes an Observe Option with the value set to 1 (deregister).
If the client observes one or more resources over a reliable transport, then the CoAP server (or intermediary in the role of the CoAP server) MUST remove all entries associated with the client endpoint from the lists of observers when the connection either times out or is closed.
8. CoAP over Reliable Transport URIs
CoAP over UDP [RFC7252] defines the "coap" and "coaps" URI schemes. This document introduces four additional URI schemes for identifying CoAP resources and providing a means of locating the resource:
- The "coap+tcp" URI scheme for CoAP over TCP.
- The "coaps+tcp" URI scheme for CoAP over TCP secured by TLS.
- The "coap+ws" URI scheme for CoAP over WebSockets.
- The "coaps+ws" URI scheme for CoAP over WebSockets secured by TLS.
Resources made available via these schemes have no shared identity even if their resource identifiers indicate the same authority (the same host listening to the same TCP port). They are hosted in distinct namespaces because each URI scheme implies a distinct origin server.
In this section, the syntax for the URI schemes is specified using the Augmented Backus-Naur Form (ABNF) [RFC5234]. The definitions of "host", "port", "path-abempty", and "query" are adopted from [RFC3986].
Section 8 ("Multicast CoAP") in [RFC7252] is not applicable to these schemes.
As with the "coap" and "coaps" schemes defined in [RFC7252], all URI schemes defined in this section also support the path prefix "/.well-known/" as defined by [RFC5785] for "well-known locations" in the namespace of a host. This enables discovery as per Section 7 of [RFC7252].
8.1. coap+tcp URI Scheme
The "coap+tcp" URI scheme identifies CoAP resources that are intended to be accessible using CoAP over TCP.
coap-tcp-URI = "coap+tcp:" "//" host [ ":" port ] path-abempty [ "?" query ]
The syntax defined in Section 6.1 of [RFC7252] applies to this URI scheme, with the following change:
- The port subcomponent indicates the TCP port at which the CoAP Connection Acceptor is located. (If it is empty or not given, then the default port 5683 is assumed, as with UDP.)
Encoding considerations: The scheme encoding conforms to the encoding rules established for URIs in [RFC3986]. Interoperability considerations: None. Security considerations: See Section 11.1 of [RFC7252].
8.2. coaps+tcp URI Scheme
The "coaps+tcp" URI scheme identifies CoAP resources that are intended to be accessible using CoAP over TCP secured with TLS.
coaps-tcp-URI = "coaps+tcp:" "//" host [ ":" port ] path-abempty [ "?" query ]
The syntax defined in Section 6.2 of [RFC7252] applies to this URI scheme, with the following changes:
- The port subcomponent indicates the TCP port at which the TLS server for the CoAP Connection Acceptor is located. If it is empty or not given, then the default port 5684 is assumed.
- If a TLS server does not support the Application-Layer Protocol Negotiation (ALPN) extension [RFC7301] or wishes to accommodate TLS clients that do not support ALPN, it MAY offer a coaps+tcp endpoint on TCP port 5684. This endpoint MAY also be ALPN enabled. A TLS server MAY offer coaps+tcp endpoints on ports other than TCP port 5684, which MUST be ALPN enabled.
- For TCP ports other than port 5684, the TLS client MUST use the ALPN extension to advertise the "coap" protocol identifier (see Section 11.7) in the list of protocols in its ClientHello. If the TCP server selects and returns the "coap" protocol identifier using the ALPN extension in its ServerHello, then the connection succeeds. If the TLS server either does not negotiate the ALPN extension or returns a no_application_protocol alert, the TLS client MUST close the connection.
- For TCP port 5684, a TLS client MAY use the ALPN extension to advertise the "coap" protocol identifier in the list of protocols in its ClientHello. If the TLS server selects and returns the "coap" protocol identifier using the ALPN extension in its ServerHello, then the connection succeeds. If the TLS server returns a no_application_protocol alert, then the TLS client MUST close the connection. If the TLS server does not negotiate the ALPN extension, then coaps+tcp is implicitly selected.
- For TCP port 5684, if the TLS client does not use the ALPN extension to negotiate the protocol, then coaps+tcp is implicitly selected.
Encoding considerations: The scheme encoding conforms to the encoding rules established for URIs in [RFC3986]. Interoperability considerations: None. Security considerations: See Section 11.1 of [RFC7252].
8.3. coap+ws URI Scheme
The "coap+ws" URI scheme identifies CoAP resources that are intended to be accessible using CoAP over WebSockets.
coap-ws-URI = "coap+ws:" "//" host [ ":" port ] path-abempty [ "?" query ]
The port subcomponent is OPTIONAL. The default is port 80.
The WebSocket endpoint is identified by a "ws" URI that is composed of the authority part of the "coap+ws" URI and the well-known path "/.well-known/coap" [RFC5785] [RFC8307]. Within the endpoint specified in a "coap+ws" URI, the path and query parts of the URI identify a resource that can be operated on by the methods defined by CoAP:
coap+ws://example.org/sensors/temperature?u=Cel \______ ______/\___________ ___________/ \/ \/ Uri-Path: "sensors" ws://example.org/.well-known/coap Uri-Path: "temperature" Uri-Query: "u=Cel"
Figure 15: The "coap+ws" URI Scheme
Encoding considerations: The scheme encoding conforms to the encoding rules established for URIs in [RFC3986]. Interoperability considerations: None. Security considerations: See Section 11.1 of [RFC7252].
8.4. coaps+ws URI Scheme
The "coaps+ws" URI scheme identifies CoAP resources that are intended to be accessible using CoAP over WebSockets secured by TLS.
coaps-ws-URI = "coaps+ws:" "//" host [ ":" port ] path-abempty [ "?" query ]
The port subcomponent is OPTIONAL. The default is port 443.
The WebSocket endpoint is identified by a "wss" URI that is composed of the authority part of the "coaps+ws" URI and the well-known path "/.well-known/coap" [RFC5785] [RFC8307]. Within the endpoint specified in a "coaps+ws" URI, the path and query parts of the URI identify a resource that can be operated on by the methods defined by CoAP:
coaps+ws://example.org/sensors/temperature?u=Cel \______ ______/\___________ ___________/ \/ \/ Uri-Path: "sensors" wss://example.org/.well-known/coap Uri-Path: "temperature" Uri-Query: "u=Cel"
Figure 16: The "coaps+ws" URI Scheme
Encoding considerations: The scheme encoding conforms to the encoding rules established for URIs in [RFC3986]. Interoperability considerations: None. Security considerations: See Section 11.1 of [RFC7252].
8.5. Uri-Host and Uri-Port Options
CoAP over reliable transports maintains the property from Section 5.10.1 of [RFC7252]:
The default values for the Uri-Host and Uri-Port Options are sufficient for requests to most servers.
Unless otherwise noted, the default value of the Uri-Host Option is the IP literal representing the destination IP address of the request message. The default value of the Uri-Port Option is the destination TCP port.
For CoAP over TLS, these default values are the same, unless Server Name Indication (SNI) [RFC6066] is negotiated. In this case, the default value of the Uri-Host Option in requests from the TLS client to the TLS server is the SNI host.
For CoAP over WebSockets, the default value of the Uri-Host Option in requests from the WebSocket client to the WebSocket server is indicated by the Host header field from the WebSocket handshake.
8.6. Decomposing URIs into Options
The steps are the same as those specified in Section 6.4 of [RFC7252], with minor changes:
This step from [RFC7252]:
- If |url| does not have a <scheme> component whose value, when converted to ASCII lowercase, is "coap" or "coaps", then fail this algorithm.
is updated to:
- If |url| does not have a <scheme> component whose value, when converted to ASCII lowercase, is "coap+tcp", "coaps+tcp", "coap+ws", or "coaps+ws", then fail this algorithm.
This step from [RFC7252]:
- If |port| does not equal the request's destination UDP port, include a Uri-Port Option and let that option's value be |port|.
is updated to:
- If |port| does not equal the request's destination TCP port, include a Uri-Port Option and let that option's value be |port|.
8.7. Composing URIs from Options
The steps are the same as those specified in Section 6.5 of [RFC7252], with minor changes:
This step from [RFC7252]:
- If the request is secured using DTLS, let |url| be the string "coaps://". Otherwise, let |url| be the string "coap://".
is updated to:
- For CoAP over TCP, if the request is secured using TLS, let |url| be the string "coaps+tcp://". Otherwise, let |url| be the string "coap+tcp://". For CoAP over WebSockets, if the request is secured using TLS, let |url| be the string "coaps+ws://". Otherwise, let |url| be the string "coap+ws://".
This step from [RFC7252]:
- If the request includes a Uri-Port Option, let |port| be that option's value. Otherwise, let |port| be the request's destination UDP port.
is updated to:
- If the request includes a Uri-Port Option, let |port| be that option's value. Otherwise, let |port| be the request's destination TCP port.
9. Securing CoAP
"Security Challenges For the Internet Of Things" [SecurityChallenges] recommends the following:
... it is essential that IoT protocol suites specify a mandatory to implement but optional to use security solution. This will ensure security is available in all implementations, but configurable to use when not necessary (e.g., in closed environment). ... even if those features stretch the capabilities of such devices.
A security solution MUST be implemented to protect CoAP over reliable transports and MUST be enabled by default. This document defines the TLS binding, but alternative solutions at different layers in the protocol stack MAY be used to protect CoAP over reliable transports when appropriate. Note that there is ongoing work to support a data- object-based security model for CoAP that is independent of transport (see [OSCORE]).
9.1. TLS Binding for CoAP over TCP
The TLS usage guidance in [RFC7925] applies, including the guidance about cipher suites in that document that are derived from the mandatory-to-implement cipher suites defined in [RFC7252].
This guidance assumes implementation in a constrained device or for communication with a constrained device. However, CoAP over TCP/TLS has a wider applicability. It may, for example, be implemented on a gateway or on a device that is less constrained (such as a smart phone or a tablet), for communication with a peer that is likewise less constrained, or within a back-end environment that only communicates with constrained devices via proxies. As an exception to the previous paragraph, in this case, the recommendations in [RFC7525] are more appropriate.
Since the guidance offered in [RFC7925] differs from the guidance offered in [RFC7525] in terms of algorithms and credential types, it is assumed that an implementation of CoAP over TCP/TLS that needs to support both cases implements the recommendations offered by both specifications.
During the provisioning phase, a CoAP device is provided with the security information that it needs, including keying materials, access control lists, and authorization servers. At the end of the provisioning phase, the device will be in one of four security modes:
NoSec: TLS is disabled. PreSharedKey: TLS is enabled. The guidance in Section 4.2 of [RFC7925] applies. RawPublicKey: TLS is enabled. The guidance in Section 4.3 of [RFC7925] applies. Certificate: TLS is enabled. The guidance in Section 4.4 of [RFC7925] applies.
The "NoSec" mode is optional to implement. The system simply sends the packets over normal TCP; this is indicated by the "coap+tcp" scheme and the TCP CoAP default port. The system is secured only by keeping attackers from being able to send or receive packets from the network with the CoAP nodes.
"PreSharedKey", "RawPublicKey", or "Certificate" is mandatory to implement for the TLS binding, depending on the credential type used with the device. These security modes are achieved using TLS and are indicated by the "coaps+tcp" scheme and TLS-secured CoAP default port.
9.2. TLS Usage for CoAP over WebSockets
A CoAP client requesting a resource identified by a "coaps+ws" URI negotiates a secure WebSocket connection to a WebSocket server endpoint with a "wss" URI. This is described in Section 8.4.
The client MUST perform a TLS handshake after opening the connection to the server. The guidance in Section 4.1 of [RFC6455] applies. When a CoAP server exposes resources identified by a "coaps+ws" URI, the guidance in Section 4.4 of [RFC7925] applies towards mandatory- to-implement TLS functionality for certificates. For the server-side requirements for accepting incoming connections over an HTTPS (HTTP over TLS) port, the guidance in Section 4.2 of [RFC6455] applies.
Note that the guidance above formally inherits the mandatory-to- implement cipher suites defined in [RFC5246]. However, modern browsers usually implement cipher suites that are more recent; these cipher suites are then automatically picked up via the JavaScript WebSocket API. WebSocket servers that provide secure CoAP over WebSockets for the browser use case will need to follow the browser preferences and MUST follow [RFC7525].
10. Security Considerations
The security considerations of [RFC7252] apply. For CoAP over WebSockets and CoAP over TLS-secured WebSockets, the security considerations of [RFC6455] also apply.
10.1. Signaling Messages
The guidance given by an Alternative-Address Option cannot be followed blindly. In particular, a peer MUST NOT assume that a successful connection to the Alternative-Address inherits all the security properties of the current connection.
11. IANA Considerations
11.1. Signaling Codes
IANA has created a third subregistry for values of the Code field in the CoAP header (Section 12.1 of [RFC7252]). The name of this subregistry is "CoAP Signaling Codes".
Each entry in the subregistry must include the Signaling Code in the range 7.00-7.31, its name, and a reference to its documentation.
Initial entries in this subregistry are as follows:
+------+---------+-----------+ | Code | Name | Reference | +------+---------+-----------+ | 7.01 | CSM | RFC 8323 | | | | | | 7.02 | Ping | RFC 8323 | | | | | | 7.03 | Pong | RFC 8323 | | | | | | 7.04 | Release | RFC 8323 | | | | | | 7.05 | Abort | RFC 8323 | +------+---------+-----------+
Table 1: CoAP Signaling Codes
All other Signaling Codes are Unassigned.
The IANA policy for future additions to this subregistry is "IETF Review" or "IESG Approval" as described in [RFC8126].
11.2. CoAP Signaling Option Numbers Registry
IANA has created a subregistry for Option Numbers used in CoAP Signaling Options within the "Constrained RESTful Environments (CoRE) Parameters" registry. The name of this subregistry is "CoAP Signaling Option Numbers".
Each entry in the subregistry must include one or more of the codes in the "CoAP Signaling Codes" subregistry (Section 11.1), the number for the Option, the name of the Option, and a reference to the Option's documentation.
Initial entries in this subregistry are as follows:
+------------+--------+---------------------+-----------+ | Applies to | Number | Name | Reference | +------------+--------+---------------------+-----------+ | 7.01 | 2 | Max-Message-Size | RFC 8323 | | | | | | | 7.01 | 4 | Block-Wise-Transfer | RFC 8323 | | | | | | | 7.02, 7.03 | 2 | Custody | RFC 8323 | | | | | | | 7.04 | 2 | Alternative-Address | RFC 8323 | | | | | | | 7.04 | 4 | Hold-Off | RFC 8323 | | | | | | | 7.05 | 2 | Bad-CSM-Option | RFC 8323 | +------------+--------+---------------------+-----------+
Table 2: CoAP Signaling Option Codes
The IANA policy for future additions to this subregistry is based on number ranges for the option numbers, analogous to the policy defined in Section 12.2 of [RFC7252]. (The policy is analogous rather than identical because the structure of this subregistry includes an additional column ("Applies to"); however, the value of this column has no influence on the policy.)
The documentation for a Signaling Option Number should specify the semantics of an option with that number, including the following properties:
- Whether the option is critical or elective, as determined by the Option Number.
- Whether the option is repeatable.
- The format and length of the option's value.
- The base value for the option, if any.
11.3. Service Name and Port Number Registration
IANA has assigned the port number 5683 and the service name "coap", in accordance with [RFC6335].
Service Name:
-
coap
Transport Protocol:
-
tcp
Assignee:
-
IESG <iesg@ietf.org>
-
IETF Chair <chair@ietf.org>
Description:
Constrained Application Protocol (CoAP)
Reference:
-
RFC 8323
Port Number:
11.4. Secure Service Name and Port Number Registration
IANA has assigned the port number 5684 and the service name "coaps", in accordance with [RFC6335]. The port number is to address the exceptional case of TLS implementations that do not support the ALPN extension [RFC7301].
Service Name:
-
coaps
Transport Protocol:
-
tcp
Assignee:
-
IESG <iesg@ietf.org>
-
IETF Chair <chair@ietf.org>
Description:
Constrained Application Protocol (CoAP)
Reference:
-
[RFC7301], RFC 8323
Port Number:
11.5. URI Scheme Registration
URI schemes are registered within the "Uniform Resource Identifier (URI) Schemes" registry maintained at [IANA.uri-schemes].
Note: The following has been added as a note for each of the URI schemes defined in this document:
CoAP registers different URI schemes for accessing CoAP resources via different protocols. This approach runs counter to the WWW principle that a URI identifies a resource and that multiple URIs for identifying the same resource should be avoided <>.
This is not a problem for many of the usage scenarios envisioned for CoAP over reliable transports; additional URI schemes can be introduced to address additional usage scenarios (as being prepared, for example, in [Multi-Transport-URIs] and [CoAP-Alt-Transports]).
11.5.1. coap+tcp
IANA has registered the URI scheme "coap+tcp". This registration request complies with [RFC7595].
Scheme name:
-
coap+tcp
Status:
-
Permanent
Applications/protocols that use this scheme name:
The scheme is used by CoAP endpoints to access CoAP resources using TCP.
-
IETF Chair <chair@ietf.org>
Change controller:
-
IESG <iesg@ietf.org>
Reference:
-
11.5.2. coaps+tcp
IANA has registered the URI scheme "coaps+tcp". This registration request complies with [RFC7595].
Scheme name:
-
coaps+tcp
Status:
-
Permanent
Applications/protocols that use this scheme name:
The scheme is used by CoAP endpoints to access CoAP resources using TLS.
-
IETF Chair <chair@ietf.org>
Change controller:
-
IESG <iesg@ietf.org>
Reference:
-
11.5.3. coap+ws
IANA has registered the URI scheme "coap+ws". This registration request complies with [RFC7595].
Scheme name:
-
coap+ws
Status:
-
Permanent
Applications/protocols that use this scheme name:
The scheme is used by CoAP endpoints to access CoAP resources using the WebSocket Protocol.
-
IETF Chair <chair@ietf.org>
Change controller:
-
IESG <iesg@ietf.org>
Reference:
-
11.5.4. coaps+ws
IANA has registered the URI scheme "coaps+ws". This registration request complies with [RFC7595].
Scheme name:
-
coaps+ws
Status:
-
Permanent
Applications/protocols that use this scheme name:
The scheme is used by CoAP endpoints to access CoAP resources using the WebSocket Protocol secured with TLS.
-
IETF Chair <chair@ietf.org>
Change controller:
-
IESG <iesg@ietf.org>
References:
-
11.6. Well-Known URI Suffix Registration
IANA has registered "coap" in the "Well-Known URIs" registry. This registration request complies with [RFC5785].
URI suffix:
-
coap
Change controller:
-
IETF
Specification document(s):
-
RFC 8323
Related information:
None.
11.7. ALPN Protocol Identifier
IANA has assigned the following value in the "Application-Layer Protocol Negotiation (ALPN) Protocol IDs" registry created by [RFC7301]. The "coap" string identifies CoAP when used over TLS.
Protocol:
-
CoAP
Identification Sequence:
0x63 0x6f 0x61 0x70 ("coap")
Reference:
-
RFC 8323
11.8. WebSocket Subprotocol Registration
IANA has registered the WebSocket CoAP subprotocol in the "WebSocket Subprotocol Name Registry":
Subprotocol Identifier:
-
coap
Subprotocol Common Name:
Constrained Application Protocol (CoAP)
Subprotocol Definition:
-
RFC 8323
11.9. CoAP Option Numbers Registry
IANA has added this document as a reference for the following entries registered by [RFC7959] in the "CoAP Option Numbers" subregistry defined by [RFC7252]:
+--------+--------+--------------------+ | Number | Name | Reference | +--------+--------+--------------------+ | 23 | Block2 | RFC 7959, RFC 8323 | | | | | | 27 | Block1 | RFC 7959, RFC 8323 | +--------+--------+--------------------+
Table 3: CoAP Option Numbers
12. References
12455] Fette, I. and A. Melnikov, "The WebSocket Protocol", RFC 6455, DOI 10.17487/RFC6455, December 2011, <>. [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, June 2014, <>. 95] Thaler, D., Ed., Hansen, T., and T. Hardie, "Guidelines and Registration Procedures for URI Schemes", BCP 35, RFC 7595, DOI 10.17487/RFC7595, June 2015, <>. [RFC7641] Hartke, K., "Observing Resources in the Constrained Application Protocol (CoAP)", RFC 7641, DOI 10.17487/RFC7641, September7959] Bormann, C. and Z. Shelby, Ed., "Block-Wise Transfers in the Constrained Application Protocol (CoAP)", RFC 7959, DOI 10.17487/RFC7959,307] Bormann, C., "Well-Known URIs for the WebSocket Protocol", RFC 8307, DOI 10.17487/RFC8307, January 2018, <>.
12.2. Informative References
[BK2015] Byrne, C. and J. Kleberg, "Advisory Guidelines for UDP Deployment", Work in Progress, draft-byrne-opsec-udp- advisory-00, July 2015.
[CoAP-Alt-Transports]
-
Silverajan, B. and T. Savolainen, "CoAP Communication with Alternative Transports", Work in Progress, draft-silverajan-core-coap-alternative-transports-10, July 2017. [CoCoA] Bormann, C., Betzler, A., Gomez, C., and I. Demirkol, "CoAP Simple Congestion Control/Advanced", Work in Progress, draft-ietf-core-cocoa-02, October 2017. [EK2016] Edeline, K., Kuehlewind, M., Trammell, B., Aben, E., and B. Donnet, "Using UDP for Internet Transport Evolution", arXiv preprint 1612.07816, December 2016, <>.
[HomeGateway]
-
Haetoenen, S., Nyrhinen, A., Eggert, L., Strowes, S., Sarolahti, P., and N. Kojo, "An experimental study of home gateway characteristics", Proceedings of the 10th ACM SIGCOMM conference on Internet measurement, DOI 10.1145/1879141.1879174, November 2010.
[IANA.uri-schemes]
-
IANA, "Uniform Resource Identifier (URI) Schemes", <>. [LWM2M] Open Mobile Alliance, "Lightweight Machine to Machine Technical Specification Version 1.0", February 2017, < V1_0-20170208-A/ OMA-TS-LightweightM2M-V1_0-20170208-A.pdf>.
[Multi-Transport-URIs]
-
Thaler, D., "Using URIs With Multiple Transport Stacks", Work in Progress, draft-thaler-appsawg-multi-transport- uris-01, July 2017. [OSCORE] Selander, G., Mattsson, J., Palombini, F., and L. Seitz, "Object Security for Constrained RESTful Environments (OSCORE)", Work in Progress, draft-ietf-core-object- security-08, January 2018. [RFC768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, <>. , <>.
[SecurityChallenges]
-
Polk, T. and S. Turner, "Security Challenges For the Internet Of Things", Interconnecting Smart Objects with the Internet / IAB Workshop, February 2011, < Turner.pdf>. [SW2016] Swett, I., "QUIC Deployment Experience @Google", IETF 96 Proceedings, Berlin, Germany, July 2016, < slides-96-quic-3.pdf>.
[TCP-in-IoT]
-
Gomez, C., Crowcroft, J., and M. Scharf, "TCP Usage Guidance in the Internet of Things (IoT)", Work in Progress, draft-ietf-lwig-tcp-constrained-node- networks-01, October 2017.
Appendix A. Examples of CoAP over WebSockets
This appendix gives examples for the first two configurations discussed in Section 4.
An example of the process followed by a CoAP client to retrieve the representation of a resource identified by a "coap+ws" URI might be as follows. Figure 17 below illustrates the WebSocket and CoAP messages exchanged in detail.
- The CoAP client obtains the URI <coap+ws://example.org/sensors/temperature?u=Cel>, for example, from a resource representation that it retrieved previously.
- The CoAP client establishes a WebSocket connection to the endpoint URI composed of the authority "example.org" and the well-known path "/.well-known/coap", <ws://example.org/.well-known/coap>.
- CSMs (Section 5.3) are exchanged (not shown).
- The CoAP client sends a single-frame, masked, binary message containing a CoAP request. The request indicates the target resource with the Uri-Path ("sensors", "temperature") and Uri-Query ("u=Cel") Options.
- The CoAP client waits for the server to return a response.
- The CoAP client uses the connection for further requests, or the connection is closed.
CoAP CoAP Client Server (WebSocket (WebSocket : : :<-------->: Exchange of CSMs (not shown) | | +--------->| Binary frame (opcode=%x2, FIN=1, MASK=1) | | +-------------------------+ | | | GET | | | | Token: 0x53 | | | | Uri-Path: "sensors" | | | | Uri-Path: "temperature" | | | | Uri-Query: "u=Cel" | | | +-------------------------+ | | |<---------+ Binary frame (opcode=%x2, FIN=1, MASK=0) | | +-------------------------+ | | | 2.05 Content | | | | Token: 0x53 | | | | Payload: "22.3 Cel" | | | +-------------------------+ : : : : +--------->| Close frame (opcode=%x8, FIN=1, MASK=1) | | |<---------+ Close frame (opcode=%x8, FIN=1, MASK=0) | |
Figure 17: A CoAP Client Retrieves the Representation of a Resource
-
Identified by a "coap+ws" URI
Figure 18 shows how a CoAP client uses a CoAP forward proxy with a WebSocket endpoint to retrieve the representation of the resource "coap://[2001:db8::1]/". The use of the forward proxy and the address of the WebSocket endpoint are determined by the client from local configuration rules. The request URI is specified in the Proxy-Uri Option. Since the request URI uses the "coap" URI scheme, the proxy fulfills the request by issuing a Confirmable GET request over UDP to the CoAP server and returning the response over the WebSocket connection to the client.
CoAP CoAP CoAP Client Proxy Server (WebSocket (WebSocket (UDP Client) Server) Endpoint) | | | +--------->| | Binary frame (opcode=%x2, FIN=1, MASK=1) | | | +------------------------------------+ | | | | GET | | | | | Token: 0x7d | | | | | Proxy-Uri: "coap://[2001:db8::1]/" | | | | +------------------------------------+ | | | | +--------->| CoAP message (Ver=1, T=Con, MID=0x8f54) | | | +------------------------------------+ | | | | GET | | | | | Token: 0x0a15 | | | | +------------------------------------+ | | | | |<---------+ CoAP message (Ver=1, T=Ack, MID=0x8f54) | | | +------------------------------------+ | | | | 2.05 Content | | | | | Token: 0x0a15 | | | | | Payload: "ready" | | | | +------------------------------------+ | | | |<---------+ | Binary frame (opcode=%x2, FIN=1, MASK=0) | | | +------------------------------------+ | | | | 2.05 Content | | | | | Token: 0x7d | | | | | Payload: "ready" | | | | +------------------------------------+ | | |
Figure 18: A CoAP Client Retrieves the Representation of a Resource
Identified by a "coap" URI via a WebSocket-Enabled CoAP Proxy
Acknowledgments
We would like to thank Stephen Berard, Geoffrey Cristallo, Olivier Delaby, Esko Dijk, Christian Groves, Nadir Javed, Michael Koster, Achim Kraus, David Navarro, Szymon Sasin, Goeran Selander, Zach Shelby, Andrew Summers, Julien Vermillard, and Gengyu Wei for their feedback.
Last Call reviews from Yoshifumi Nishida, Mark Nottingham, and Meral Shirazipour as well as several IESG reviewers provided extensive comments; from the IESG, we would like to specifically call out Ben Campbell, Mirja Kuehlewind, Eric Rescorla, Adam Roach, and the responsible AD Alexey Melnikov.
Contributors
Matthias Kovatsch Siemens AG Otto-Hahn-Ring 6 Munich D-81739 Germany Phone: +49-173-5288856 Email: matthias.kovatsch@siemens.com Teemu Savolainen Nokia Technologies Hatanpaan valtatie 30 Tampere FI-33100 Finland Email: teemu.savolainen@nokia.com Valik Solorzano Barboza Zebra Technologies 820 W. Jackson Blvd. Suite 700 Chicago, IL 60607 United States of America Phone: +1-847-634-6700 Email: vsolorzanobarboza@zebra.com
Authors' Addresses
Carsten Bormann Universitaet Bremen TZI Postfach 330440 Bremen D-28359 Germany Phone: +49-421-218-63921 Email: cabo@tzi.org Simon Lemay Zebra Technologies 820 W. Jackson Blvd. Suite 700 Chicago, IL 60607 United States of America Phone: +1-847-634-6700 Email: slemay@zebra.com Hannes Tschofenig ARM Ltd. 110 Fulbourn Road Cambridge CB1 9NJ United Kingdom Email: Hannes.tschofenig@gmx.net URI: Klaus Hartke Universitaet Bremen TZI Postfach 330440 Bremen D-28359 Germany Phone: +49-421-218-63905 Email: hartke@tzi.org Bilhanan Silverajan Tampere University of Technology Korkeakoulunkatu 10 Tampere FI-33720 Finland Email: bilhanan.silverajan@tut.fi Brian Raymor (editor)
-
brianraymor@hotmail.com | http://pike.lysator.liu.se/docs/ietf/rfc/83/rfc8323.xml | CC-MAIN-2020-05 | refinedweb | 11,918 | 54.73 |
In this article, which is part of a series on Windows SharePoint Services (WSS) 3.0, I am going to show you how to create a component called an event receiver. An event receiver is essentially a piece of code which can be attached to a specific SharePoint object; it will be executed whenever a specified event occurs within that object. An example might be something that executes whenever an item is created in a specific list.
In many cases a project that might at first seem to be a workflow is actually better suited to being implemented with an event receiver. This is because simple actions such as validation of input data, verification and data processing can be performed quickly and smoothly with an event receiver. Event receivers are also typically used for initiating additional external business processes.
At this point you are probably already realising that event receivers provide a developer with a good way to add extra functionality at a specific point (or variety of points) within the SharePoint environment and therefore ‘extend’ the functionality of the native SharePoint environment in a way which is supported by Microsoft.
Event receivers can, for example, be attached to instances of the
SPSite,
SPList and
SPListItem classes. An event receiver will execute either before or after the specified event occurs. ‘Before events’ are synchronous and can be used to cancel the event entirely whereas ‘After events’ are asynchronous and therefore cannot have any impact on the event because it has already occurred by then.
In order to create an event receiver you have to create a specific class: In truth you have to inherit a very specific base class. Each of the base classes contains an overridable method for each event. If you override this method with your custom code then this is what will be executed when that event is raised. The four base classes are:
- SPWebEventReceiver
- SPListEventReceiver
- SPItemEventReceiver
- SPEmailEventReceiver
The first three are the main base classes for working with site, list and item events. The email event receiver is specifically for use on email enabled lists. The method-overrides that are available to you within these main event receiver base classes are outlined in the table below. You must override the appropriate base class for the methods which you wish to implement.
SPWebEventReceiver
SPListEventReceiver
SPItemEventReceiver
Creating an event receiver
To show how to create an event receiver, I am going to implement a piece of code that renames any document uploaded to a document library to its ID, and the original filename is then used as the title of the document. This can be useful as it keeps the URL length for your documents nice and short.
We need to override the
ItemAdded method of the
SPItemEventReceiver. This will allow the code to execute asynchronously so that the code execution will not block the UI whilst it takes place.
Note: I am using Visual Studio 2008 with the WSPBuilder extensions installed.
- Open Visual Studio 2008, and select File > New > Project.
- Select a Class Library, and select an appropriate name and location.
Please ensure that your assembly is signed, your project references the WSS 3.0 dll and that you have a 12 folder set-up with a single feature folder as shown below (you will only need the 12, TEMPLATE and FEATURES folders not the others)
- Right-click on your project and select Add > New Item.
- Select Class and then choose an appropriate name for your event receiver. Click Add.
- Open up your event receiver code file.
- Import the
Microsoft.SharePointnamespace and set the class to inherit from
SPItemEventReceiver
- Add a new method to override the
ItemAdded method of the base class. Add the following code to this method to allow documents to be renamed when they are uploaded.
Essentially this code is saving the name of the original file (minus its file extension) and then using this information as the Title of the document. The name of the document (which is stored internally as
FileLeafRef by SharePoint) is then saved as the ID of the relevant item in the document library using the same file extension as the original.
The benefit of this is that if I upload a document called ‘Product Specification 1.pdf’, the URL to this could then become as short as. Anyone who has had to deal with the 255 character limit for URLs will see the point. .Right-click on the feature folder and rename this to something sensible, as this will be the name of your SharePoint feature. I used ‘DocumentRenamer’ Right-click on your feature folder and select Add > New Item. Select XML file and call this feature.xml The feature.xml file contained in the feature folder will now need to be changed to reflect your feature requirements.
You will need to ensure that the [GUID] is replaced with a valid GUID without the braces { }.
Right-click on your feature folder and select Add > New Item. Select XML file and call this elements.xml The elements.xml file contained in the feature folder will also need to be changed to reflect your feature requirements. Essentially you want to bind your event receiver to a list or library, or to many lists and libraries. In our case we are going to bind to all document libraries within our site (SPWeb.)
It may be that, in your application, you wish to bind your event receiver to a specific list instance. In this case you can write an SPFeatureReceiver in order to bind your event receiver to the appropriate list instance when the feature is activated.
The
Assembly element of the receiver will need to be a fully qualified reference to the assembly which contains your event receiver, and the
Class element will need to include the root namespace of your project.
The
ListTemplateId attribute specifically refers to the ID for document libraries which is 101. Other
ListTemplateId values can be found by browsing the SharePoint documentation on MSDN.
The infrastructure required for your feature is now complete. It is at this point that the benefits of using WSPBuilder for your packaging and deployment will become obvious. To build and package your WSP file, simply right-click the project and select WSPBuilder > Build WSP.
You will now have a compiled and packaged WSP file at the root of your project. To deploy this solution to your development farm simply right-click the project file and select WSPBuilder > Deploy. Once this operation is complete you can then visit a site on your development SharePoint installation and activate the feature:If you upload a document to any document library on this site then you will notice that the event receiver has executed the code and made the required changes. Although this is an asynchronous action so you will not notice it straight away.
This example has demonstrated the power of an event receiver. Essentially the code that you execute can perform any action that you can think of by implementing the WSS 3.0 object model or any other 3rd party programming interface.
Workflow or Event Receiver?
If you need some action to happen in response to an action undertaken in SharePoint, then you have two choices: you could develop a workflow (as detailed in my previous two articles) or you could create an event receiver. If there is no cause for any kind of human interaction in the process required then you should probably looking to the event receiver model to implement this. However if the action is going to involve a human decision or interaction then you should be looking to implement it as a workflow.
It is worth bearing in mind that workflows are handled by the SharePoint workflow engine built on top of Windows Workflow Foundation and that there is a lot of core code and functionality which is kicked off in support of a running workflow instance which is not required in order to implement an event receiver. If you don’t need all those bells and whistles then steer clear of workflow as it may be an unnecessary performance drain!
Hopefully this article has helped you to see the benefits of implementing a solution via an event receiver. As I have mentioned before it all too easy for a project to end up as a workflow when actually what was required was an event receiver.
Next time I plan to take a deeper dive into writing custom SharePoint code by looking at the feature framework and how you can use it to leverage custom code in SharePoint.
For previous articles in this series on using SharePoint Services see
How to Create Custom Lists in Windows SharePoint Services 3.0
How to Create Custom Workflows in Windows SharePoint Services 3.0
How to Create Custom SharePoint Workflows in Visual Studio 2008
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A class that reads data from a delimited data set.
A class that writes data as a delimited data set.
A static class that reads GML data.
A static class that writes GML data.
A simple and fast xml reader that converts an XML string into a JSON object.
Ignores tags that start with "<!" or "<?" as these are usually comments, XML schema, or doctype tags.
Supports CData tag: <![[CData ]]>
Can extract all namespaces in the document.
A simple and fast XML writing class that makes it easy to efficiently build an XML string.
An add operator filter.
Represents an AND logic operator filter.
Abstract class for binary comparison operator filters.
Represents a custom defined XML Filter string component. Do not wrap with the tag.
A divide operator filter.
Abstract filter class in which all other filters inherit from.
Represents a filter on the GML id of a shape.
Uses ogc:GmlObjectId for version 1.1.0 and fes:ResourceId for all other versions.
Version 1.0.0 typically does not support this filter.
Checks to see if a value is between two other specified values.
Compares two values to see if they are equal.
Checks to see if one value is greater than another.
Checks to see if one value is greater than or equal to another.
Checks to see if one value is less than another.
Checks to see if one value is less than or equal to another.
Checks to see if a value is like another using a wild card search.
Checks to see if a value is nil.
Compares two values to see if they are not equal.
Checks to see if a value is null.
Represents a logic operator filter.
An abstract class in which all math operator filters inherit from.
A multiply operator filter.
Represents an NOT logic operator filter.
Represents an OR logic operator filter.
Property name value.
A subtract operator filter.
A class that manages connections to an OGC Web Mapping Feature Service (WFS)
A static class for reading/writing Well Known Text (WKT) strings as GeoJSON geometries.
Renders raster tiled images on top of the map tiles from an OGC Web Mapping Service (WMS or WMTS).
A layer that simplifies the rendering of geospatial data on the map.
Note: Because this layer wraps other layers which will be added/removed with this
some layer ordering operations are not supported.
Adding this layer before another, adding another layer before this, and moving this layer are not supported.
These restrictions only apply to this layer and not the layers wrapped by this.
A data object that contains a set of features and/or kml ground overlays.
This is an extension of the FeatureCollection class thus allowing it to easily be added to a data source.
Options used for reading spatial data files.
Options that customize how XML files are read and parsed.
Column header definition for a delimited file.
Defines a custom XML namespace.
A Feature Collection that has properties for the collection.
Options that customize how GML files are read and parsed.
Options that are used to customize how to write GML.
Options that customize how GPX files are read and parsed.
Represents an XML Document object.
Represents an XML Node object.
Options for a binary comparison filter.
Options for an IsNil filter.
Options for a Like filter.
Options that customize how KML files are read and parsed.
A custom OGC dimension.
An object that describes the capabilities of an OGC WMS and WMTS service.
Options for an OGC layer.
OGC WMS and WMTS layer style information.
Sublayer information for OGC WMS and WMTS services.
A collection of sub layers used by the SimpleDataLayer class for rendering shapes.
Options used to customize how the SimpleDataLayer renders.
A set of common properties that may be included in feature properties
capture style information and common content when reading or writing a spatial data.
The SimpleDataLayer uses these properties to dynamically style the data it renders.
Most of these are the property values used in the geometries respective layer options.
Options used for reading delimited files.
Options for writing delimited files.
Statistics about the content and processing time of a XML feed.
Base options for writing spatial data.
Options that are used to customize how to write XML.
The capabilities of a WFS service.
Options for requesting features from a WFS service.
Information about a feature type in a WFS service.
Details about a feature type.
Options for connecting to a WFS service.
A literal value type. string, number, boolean, or Date
Options that customize how spatial files are read and parsed.
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score:8
The reason why you did not get updated state is because you called it inside useEffect(() => {}, []) which is only called just once.
useEffect(() => {}, []) works just like componentDidMount().
When gameStart function is called, gamePlaytime is 100, and inside gameStart, it uses the same value however the timer works and the actual gamePlayTime is changed. In this case, you should monitor the change of gamePlayTime using useEffect.
... useEffect(() => { if (gamePlay); } }, [gamePlayTime]); const gameStart = () => { gameStartInternal = setInterval(() => { setGamePlayTime(t => t-1); }, 1000); }; ...
score:4
You shouldn't use setInterval with hooks. Take a look at what Dan Abramov, one of the maintainers of React.js, said regarding an alternative on his blog:
score:5
Dan Abramov article explain well how to works with hooks, state, and the setInterval() type of api!
Dan Abramov! Is one of the React maintaning team! So known and i pesonally love him!
Quick explanation
The problem is the problem of how to access state with a useEffect() that execute only once (first render)!
The short answer is: by the use of refs (useRef)! And another useEffect() that run again when update is necessary! Or at each render!
Let me explain! And check the Dan Abramov solution! And you'll get better the statement above at the end! With a second example that is not about setInterval()!
=>
useEffect() either run once only, or run in each render! or when the dependency update (when provided)!
Accessing state can be possible only through a useEffect() that run and render each relevant time!
Or through
setState((state/*here the state*/) => <newStateExpression>)
But if you want to access the state inside useEffect() => rerun is necessary! meaning passing and executing the new callback!
That doesn't work well with setInterval! If you set it each time! the counter get reset! Leading to no execution if the component is re-rendering fast!
If you render only once! The state is not updated! As the first run, run a one callback! And make a closure! The state is fixed!
useEffect(() => { <run once, state will stay the same> setInterval(() => { <state fixed> }) }, []).
For all such kind of situation! We need to use useRef! (refs)!
Save to it a callback that hold the state! From a useEffect() that rerender each time! Or by saving the state value itself in the ref! Depending on the usage!
Dan abramov solution for setInterval (simple and clean)
That's what you are looking for!
useInteval hook (by Dan Abramov)
import React, { useState, useEffect, useRef } from 'react'; function useInterval(callback, delay) { const savedCallback = useRef(); // Remember the latest callback. useEffect(() => { savedCallback.current = callback; }, [callback]); // Set up the interval. useEffect(() => { function tick() { savedCallback.current(); } if (delay !== null) { let id = setInterval(tick, delay); return () => clearInterval(id); } }, [delay]); }
Usage
import React, { useState, useEffect, useRef } from 'react'; function Counter() { let [count, setCount] = useState(0); useInterval(() => { // Your custom logic here setCount(count + 1); }, 1000); return <h1>{count}</h1>; }
We can see how he kept saving the new callback at each re-render! A callback that contain the new state!
To use ! it's a clean simple hook! That's a beauty!
Make sure to read Dan article! As he explained and tackled a lot of things!
setState()
Dan Abramov mentioned this in his article!
If we need to set the state! Within a setInteral! One can use simply setState() with the callback version!
useState(() => { setInterval(() => { setState((state/*we have the latest state*/) => { // read and use state return <newStateExpression>; }) }, 1000); }, []) // run only once
we can even use that! Even when we are not setting state! Possible! Not good though! We just return the same state value!
setState((state) => { // Run right away! // access latest state return state; // same value (state didn't change) });
However this will make different react internal code part to run (1,2,3), And checks! Which end by bailing out from re-rendering! Just fun to know!
We use this only for when we are updating the state! If not ! Then we need to use refs!
Another example: useState() with getter version
To show case the how to work with refs and state access! Let's go for another example! Here another pattern! Passing state in callbacks!
import React from 'react'; function useState(defaultVal) { // getting the state const [state, setState] = React.useState(defaultValue); // state holding ref const stateRef = React.useRef(); stateRef.current = state; // setting directly here! // Because we need to return things at the end of the hook execution // not an effect // getter function getState() { // returning the ref (not the state directly) // So getter can be used any where! return stateRef.current; } return [state, setState, getState]; }
The example is of the same category! But here no effect!
However we can use the above hook to access state in the hook simply as bellow!
const [state, useState, getState] = useState(); // Our version! not react // ref is already uptated by this call React.useEffect(() => { setInteval(() => { const state = getState(); // do what you want with the state! // it works because of the ref! Get State return a value to the same ref! // which is already updated }, 1000) }, []); // running only once
For setInterval()! The good solution is Dan Abramov hook! Making a strong custom hook for a thing is the cool thing to do! This second example is more to showcase the usage and importance of refs, in such state access need or problem!
It's simple! We can always make a custom hook! Use refs! And update the state in ref! Or a callback that hold the new state! Depending on usage! We set the ref on the render (directly in the custom hook [the block execute in render()])! Or in a useEffect()! That re-run at each render or depending on the dependencies!
Note about useEffect() and refs setting
To note about useEffect()
useEffect => useEffect runs asynchronously and after a render is painted to the screen.
- You cause a render somehow (change state, or the parent re-renders)
- React renders your component (calls it)
- The screen is visually updated
- THEN useEffect runs
Very important of a thing! useEffect() run after render() finish and the screen is visually updated! It run last! You should be aware!
Generally however! Effects should be run on useEffect()! And so any custom hook will be ok! As it's useEffect() will run after painting and before any other in render useEffect()! If not! As like needing to run something in the render directly! Then you should just pass the state directly! Some people may pass a callback! Imagine some Logic component! And a getState callback passed to it! Not a good practice!
And if you do something somewhere of some of such sense! And talking about ref! Make sure the refs are updated right! And before!
But generally you'll never have a problem! If you do then it's a smell! the way you are trying to go with is high probably not the right good way!
In the whole i hope that gave you a good sense!
score:7
You're creating a closure because
gameStart() "captures" the value of
gamePlayTime once when the useEffect hook runs and never updates after that.
To get around this, you must use the functional update pattern of React hook state updating. Instead of passing a new value directly to
setGamePlayTime(), you pass it a function and that function receives the old state value when it executes and returns a new value to update with. e.g.:
setGamePlayTime((oldValue) => { const someNewValue = oldValue + 1; return someNewValue; });
Try this (essentially just wrapping the contents of your setInterval function with a functional state update):
const [gamePlayTime, setGamePlayTime] = React.useState(100); let targetShowTime = 3; // call function React.useEffect(() => { gameStart(); }, []); const gameStart = () => { gameStartInternal = setInterval(() => { setGamePlayTime((oldGamePlayTime) => { console.log(oldGamePlayTime); // will print previous gamePlayTime value if (oldGamePlay); } return oldGamePlayTime - 1; }); }, 1000); };
Source: stackoverflow.com
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- ReactJS - Construct html from mapping | https://www.appsloveworld.com/reactjs/100/12/can-not-update-state-inside-setinterval-in-react-hook | CC-MAIN-2022-40 | refinedweb | 1,963 | 57.37 |
Recursion is a programming method, in which a function calls itself one or more times in its body. Usually, it is returning the return value of this function call. If a function definition follows recursion, we call this function a recursive function.
A recursive function has to terminate to be used in a program. It terminates, if with every recursive call the solution of the problem is becomes smaller and moves towards a base case, where the problem can be solved without further recursion. A recursion can lead to an infinite loop, if the base case is not met in the calls.
The following code returns the sum of first n natural numbers using a recursive python function.
def sum_n(n): if n== 0: return 0 else: return n + sum_n(n-1)
This prints the sum of first 100 natural numbers and first 500 natural numbers
print(sum_n(100)) print(sum_n(500))
C:/Users/TutorialsPoint1/~.py 5050 125250 | https://www.tutorialspoint.com/How-can-we-create-recursive-functions-in-Python | CC-MAIN-2021-25 | refinedweb | 158 | 63.29 |
Ever since I found out about the E-paper technology I was fascinated by it. I always wondered if there something I can build using it. Couple months ago I bought a Kindle e-reader and I found out that despite having a black and white screen, the images looked stunning. Almost as if they had some Instagram filter. So I decided to make a digital picture frame with an E-ink display.
The great thing about these displays is that they don't need any power to retain an image. You only need to power it in order to change the screen. Even if you completely unplug one of these displays it will retain the last image indefinitely. This is why using it as a picture frame is actually viable.
Most people can't even tell they are looking at a screen since it looks just like a printed photo. The image is updated every 24 hours. Unlike a regular picture frame where you stop noticing it after a couple of days, this one always catches your attention.
It's running on 3 button cell batteries which should last about 9-12 months. Using AAA batteries would extend that to a couple of years. The nice thing is that if the battery does run out the last image will stay loaded on the screen. The images are saved on a microSD card and the software just cycles through them. There is also a button to skip a current picture.
Step 1: Tools and Materials
Tools:
- Soldering iron
- 3D printer (optional)
- Hand saw
- Hot glue gun
Materials:
- 4.3 inch E-ink display module
- microSD card
- Button cell battery holder / 3x AAA battery holder
- arduino mini pro + USB to serial converter
- BC548 transistor
- Momentary push button
- 1k resistor
- 100k resistor
- Pref board
- picture frame 9x13cm (or similar size)
Step 2: Wiring
First of all, it's a good idea to just test if your components are working. Fortunately, that's quite easy to do. Simply connect the screen to your Arduino the same way as on my schematic, except for the transistor and button which you don't have to use. Simply connect the power pins directly to 5V. You can use the example sketch from epd.h library.
The schematic is quite simple as there is just a couple of components. However, the resistors, transistor and the button can't be just floating in mid-air. The simplest solution is to just solder them on a tiny pref-board. With this board ready they can all be laid out and wired permanently.
Of course, in order to lay the parts out, you need to have the picture frame ready. I chose 9x13cm picture frame which can comfortably house the display and the other electronics. Similarly sized picture frames will do the job. It's just a matter of making a cutout for the screen. If you have the same sized frame you can 3D print the back side like I did since I'm not capable of cutting a hole in a piece of hardened cardboard...
You may notice I'm using Arduino nano yet I suggest using an Arduino mini pro. You can use either one but you need to remove the power regulator and the LEDs. If you're using nano you'll also have to remove the USB to serial chip and any other unnecessary components. This is necessary otherwise your battery will be drained in a couple of days. The Arduino mini pro just doesn't have as many unnecessary components.
Once you wire everything together, tape the wires down to keep it low profile. I have also placed paper cutout between the glass the back side of the frame to hide everything except for the screen.
Step 3: Software
The software was written in Arduino 1.8.5. It requires two libraries, epd, and Arduino low power. Both of these should be in the library manager. With these two libraries installed you should be able to compile and upload the code to your Arduino. If you want to configure it there is really just one variable, refreshRate. This is the time it takes between loading pictures. By default, it's set to 10800 which is 24h. That means one unit is 8 seconds. So setting it to one, pictures will update every 8 seconds. Setting it to 2 will be 16 seconds and setting it to 10800 is 24h.
<p>#include <lowpower.h><br>#include <epd.h></epd.h></lowpower.h></p><p>const int wake_up = 6; const int reset = 5; const int lcd_on = 4; const int button = 3;</p><p>int refreshRate = 10800; //time between loading images. number you enter * 8 = seconds between refresh (10800 = 24h) int counter = 1; int refreshCounter = 0; int ByteReceived; bool errorFlag = false; bool picSend = false; bool picLoaded = false;</p><p>void(* resetFunc) (void) = 0;</p><p>void setup(void) { pinMode(lcd_on,OUTPUT); pinMode(13,OUTPUT); digitalWrite(13,LOW); //LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF); }</p><p>void loop(void){ DrawPic(counter); counter++; }</p><p>void wakeUp(){ refreshCounter++; if(refreshCounter < refreshRate) enterSleep(); }</p><p>void DrawPic(int index){ pinMode(lcd_on,OUTPUT); pinMode(13,OUTPUT); digitalWrite(13,LOW); //delay(2000); digitalWrite(lcd_on,HIGH); delay(300); epd_init(wake_up, reset); epd_wakeup(wake_up); epd_set_memory(MEM_TF); epd_clear(); digitalWrite(13,HIGH);</p><p> /(); }</p><p>void noSDcard(){ epd_wakeup(wake_up); //delay(5000); epd_clear(); epd_set_ch_font(GBK32); epd_set_en_font(ASCII32); epd_disp_string("Can't find SD card", 0, 300); epd_udpate(); delay(10000); }</p><p>void noPic(){ epd_wakeup(wake_up); //delay(5000); epd_clear(); epd_set_ch_font(GBK32); epd_set_en_font(ASCII32); epd_disp_string("Can't find this picture", 0, 300); epd_udpate(); delay(10000); }</p><p>void enterSleep(){ attachInterrupt(1, wakeUp, RISING); LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF); wakeUp(); detachInterrupt(1); }</p>
Step 4: Preparing Photos
The screen has a resolution of 800x600 and 4 colors, black, white, and two shades of grey. The screen also has a card reader which we'll be using. Simply uploading pictures on the card won't do the job however. The display only supports BMP files and the smaller the file size the faster it'll be loaded which will save a lot of battery.
Fortunately, all of these problems can be solved with just a single program. Adobe Photoshop. I understand that not everyone has the program but you can always use GIMP or paint. But I'll be showing you how to do all of this in photoshop only.
I would suggest watching the video for this one as it's a lot more descriptive. Basically, start by dragging the image to PS. Go to Image -> image size. Make sure units are pixels and set the height to 600. Width will be changed automatically. If the width is not 800 you'll need to remove the sides of the image to get the correct resolution. Go to Image -> canvas size. Set units to pixels again and set the width to 800. Press OK and then Proceed. Your Image should now be the correct size.
The images usually look a bit darker on the E-ink screen so it's a good idea to turn the brightness up a bit. Click on the moon icon (circle with black and white halves) in the bottom right-hand corner and choose Brightness/Contrast. I usually set the brightness to 30 but you can play with it of course. Next, we'll change it to the 4 colors so that we can preview what it'll look like. Go to Image -> Mode -> Indexed Color... . If it asks you to flatten layers click OK. In the palette choose Local(adaptive). In Colors put 4 and click OK. Next go to Image -> Mode -> Color Table. You should see your 4 colors. Set the one on the left on to black and the one on the right to white. The two between should be shades of gray. Select OK. Next go to File -> Save as. Select BMP as type.
The name of the file should be iX.BMP where X is a number of the picture. if it's the first one you'll name it i1 and hit save .BMP will be added automatically. twenty-sixth picture would be i26.BMP etc. Once you hit save you'll be presented with BMP options. Change depth to 4 Bit and hit OK.
Make sure your microSD card is formatted to FAT32 format. The card should be empty and you can just copy your pictures in. As mentioned they should be named from i1 to i150 or whatever number is your last image. If you'll be missing a number, for example, you'll have i21.BMP and then i23.BMP the i23 and beyond will never be loaded as it will go back to 1 after 21.
Step 5: Done
With the images loaded, you can just insert the memory card and put the batteries in. The first image should be loaded after a couple of seconds and will be updated every 24 hours. Despite only four colors, the images look truly spectacular. The resolution is really high for such a small screen and the adaptive color diffusion makes it look like there are at least 50 shades of gray.
Needless to say, I'm very pleased with the result. This is something I'm keeping on my desk. Please check out the video as well for more info and huge thanks to dfrobot.com for providing the parts for free. If you have any questions just leave them here or tweet @Gyro_youtube
11 Discussions
Question 4 months ago on Step 1
Great job putting this together and its awesome! I'm an arduino noob so I tried building one and it works well with timing however the issue is that the button push does not advance the image properly.
If the refresh rate is 1 or 2 I can get it to advance on 1 push, but if it is higher, like 10 - 20 I have to push it many times. I'm guessing its only decreasing the time to refresh rather than advancing the image. On the full 24 hours it doesn't advance no matter how many times I push it. Please help!
Answer 3 months ago
I reached out for help on Reddit and after some tweaking I got the following code to work for both the timing and the button. Some of the code was re-written as it was unnecessary. Hope this helps anyone else struggling with this.
Updates:
1) Added de-bounce
2) Button press moves the refresh counter to match the refresh rate which then advances the picture.
Code:
#include "LowPower.h"
#include "epd.h"
const int wake_up = 6;
const int reset = 5;
const int lcd_on = 4;
const int button = 3;
int refreshRate = 10800; //time between loading images. number you enter * 8 = seconds between refresh (10800 = 24h)
int counter = 1;
int refreshCounter = 0;
int ByteReceived;
bool errorFlag = false;
bool picSend = false;
bool picLoaded = false;
bool buttonP() {
if (digitalRead(button) == HIGH) {
delay(500);
return true;
} else {
return false;
}
}
void setup(void)
{
pinMode(lcd_on, OUTPUT);
pinMode(13, OUTPUT);
pinMode (buttonP,INPUT);
digitalWrite(13, LOW);
attachInterrupt(1, buttonPr, RISING);
}
void loop(void) {
DrawPic();
counter++;
}
void buttonPr(){
refreshCounter = refreshRate;
wakeUp();
}
void wakeUp() {
refreshCounter++;
if (refreshCounter < refreshRate ) enterSleep();
}
void DrawPic() {
digitalWrite(13, LOW);
//delay(2000);
digitalWrite(lcd_on, HIGH);
delay(300);
epd_init(wake_up, reset);
epd_wakeup(wake_up);
epd_set_memory(MEM_TF);
epd_clear();
digitalWrite(13, HIGH);
/();
}
void enterSleep() {
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
wakeUp();
}
Reply 3 months ago
Sorry I didn't reply sooner. But thank you very much for fixing it :)
4 months ago
This is so awesome I decided to make one! Worked great while testing, I had set to refresh rate to 1 so I could test out all the images but after changing back to full 24 hours it doesn't want to refresh the display :( Have tried different refresh rates to test the math at lowe numbers and this works fine. Not sure what would cause this?
6 months ago
Nice work
8 months ago on Step 5
Very nice project. Especially because you managed to get the power consumption extremely low something I appreciate a lot. Jan.
Reply 8 months ago
thanks :)
Reply 8 months ago
And I do like this project !
8 months ago
I really like this project. I think I might take a stab at building one myself. I think it would be a really cool gift. It is unfortunate that the process of putting pictures on it is a bit tedious. But that is where opportunity is.
Also, it would be fun to try to take this project to the next step: make it wireless. It would almost certainly need a bigger battery for that. But that would be an interesting project.
Thanks for sharing!
Reply 8 months ago
Thanks :) I agree that making it wireless would be a lot more interesting. Good luck if you decide to build one :)
8 months ago
Yeah, I agree, certain types of photos do look really good on e-ink displays. This is such a cool project!
Thanks for sharing! | https://www.instructables.com/id/E-Paper-Picture-Frame/ | CC-MAIN-2019-04 | refinedweb | 2,177 | 73.47 |
[Roaming] Changes 1
VERIFIED FIXED in mozilla1.8alpha2
Status
▸
Profile: Roaming
People
(Reporter: BenB, Assigned: BenB)
Tracking
Firefox Tracking Flags
(Not tracked)
Details
Attachments
(3 attachments, 3 obsolete attachments)
I'll attach a bunch of changes to the roaming code. Some of them shuffle code around, others fix bugs in the same code, so I can't attach them as simple patches to the relevant bugs. This contains a few changes I did while using much of the same code for another application (Mozilla updater). List of changes: - Some code refactoring: Creating file filesList.js, which contains generic functions for using file lists (arrays whose entries keep file names and statistics) and corresponding listing files. They can be (and are) used in another application, and previously were in file conflictCheck.js. conflictCheck.js is now even more focussed on the 2-way-sync logic of roaming. - Added some safe-exception-catches, and showing the error in the UI. Currently, the code just malfunctions (broken dialog buttons?) in that case. This should help with bug 244589 and bug 244720, if the fix below fails, and other future unexpected problems. - Making the status message actually show something. - Renaming dumbObject() to ddumpObject() to match ddump() for easier replace In filesList.js: - Changing listing file to actually use Unixtime as claimed (breaks existing files, but should only cause conflicts once) - Using indexed file lists, should be faster, probably not significant for roaming - Allow last modified time to differ 1 sec, because of FAT inaccuracy, not needed for roaming - Option to allow newer files, not needed for roaming - Fixing bug 244589 and probably bug 244720 by moving dom creation after the empty filename check. - Please ignore the |XXX|es for now. To allow you to more easily see the changes I made to the functions which now moved to filesList, I'll add a diff between the old conflictCheck.js and the new filesList.js. Because I splitted the old conflictCheck.js into conflictCheck and filesList.js, you'll see lots of removal in the diffs. Pete Zha, please review.
Created attachment 150751 [details] [diff] [review] Patch, v1, diff -uw extensions/sroaming/
Created attachment 150752 [details] [diff] [review] Changes to filesList.js, v1 (for convience)
Created attachment 150753 [details] [diff] [review] Patch, v1, diff -uwN Forgot the -N to include filesList.js
Target Milestone: --- → mozilla1.8alpha2
Created attachment 150896 [details] [diff] [review] Patch, v2, diff -uwN More changes: - fixed bug 246201 - infinite conflicts - less conflicts, if files non-existant - transfer less (if we know we have the file already) - minimal API change for extractFiles() - code doc improved - pref API usage
Attachment #150753 - Attachment is obsolete: true
Created attachment 150897 [details] [diff] [review] Patch, v2, diff -uN (includes whitespace changes, for applying) See the other bugs (e.g. bug 246201) for further fix description.
Created attachment 150899 [details] [diff] [review] Changes to filesList.js, v2 (for review) The patches here fix a number of serious roaming bugs and should go in before alpha2 closes.
Attachment #150752 - Attachment is obsolete: true
Comment on attachment 150896 [details] [diff] [review] Patch, v2, diff -uwN >+ setTimeout(loaded, 0); >+ /* using timeout, so that we first return (to deliver |result| to the >+ caller) before we invoke loadedCallback, so that loadedCallback >+ can use |result|. */ Probably you can just pass the result to the "loaded" function? >+function printtree(domnode, indent) >+{ >+ return; >+ if (!indent) >+ indent = 1; >+ for (var i = 0; i < indent; i++) >+ ddumpCont(" "); >+ ddumpCont(domnode.nodeName); >+ if (domnode.nodeType == Node.ELEMENT_NODE) >+ ddump(" (Tag)"); >+ else >+ ddump(""); >+ >+ var root = domnode.childNodes; >+ for (var i = 0, l = root.length; i < l; i++) >+ printtree(root.item(i), indent + 1); >+} Do we need to comment out the ddump? > //ddump(" finished callbacks: " + this.finishedCallbacks.length); > //ddump(" progress callbacks: " + this.progressCallbacks.length); >- for (var i = 0, l = this.finishedCallbacks.length; i < l; i++) >- ddump(this.finishedCallbacks[i]); >+ //for (var i = 0, l = this.finishedCallbacks.length; i < l; i++) >+ //dump(this.finishedCallbacks[i]); We really need to think about the debug code style. not just comment out. There is a feature that we can use the compiling switch in js. Probably we can use this feature to write debug code in the furture. Besides these issues, it looks ok for me.
Attachment #150896 - Flags: review?(pete.zha) → review+
Thanks for the review, Pete! > Probably you can just pass the result to the "loaded" function? No, this would cause a different execution flow, it would execute the loaded function before the readAndLoad... function returns, so anything that potentially comes after the call would not be executed at the right time. This code is just moved anyways, IIRC, I didn't change this code itself in the patch. > Do we need to comment out the ddump? No, there's a |return;| at the very beginning. > We really need to think about the debug code style. Yes! It's a terrible hack. I have a constant in ddump() to suppress the output, but the ddump call and its parameters would still be evaluated, which IIRC causes a somewhat notable slowdown. Let's talk about that in another bug, if necessary.
Status: NEW → ASSIGNED
Comment on attachment 150896 [details] [diff] [review] Patch, v2, diff -uwN +//XXX! what's that for? should we worry? there are several of these. how about adding some comments? rs=darin
Attachment #150896 - Flags: superreview?(darin) → superreview+
Nothing to worry (see above "- Please ignore the |XXX|es for now"), not relevant for Mozilla, will remove them before checkin.
Checked in. Thanks for the fast reviews!
Status: ASSIGNED → RESOLVED
Last Resolved: 14 years ago
Resolution: --- → FIXED
Component: Profile: BackEnd → Profile: Roaming
QA Contact: core.profile-manager-backend → core.profile-roaming
Status: RESOLVED → VERIFIED
Product: Core → Core Graveyard | https://bugzilla.mozilla.org/show_bug.cgi?id=246710 | CC-MAIN-2018-17 | refinedweb | 944 | 58.89 |
Jamstack is a modern web development architecture based on client-side JavaScript, reusable APIs, and prebuilt Markup. It is not yet a full technology stack like MEAN, MERN or LAMP. Rather, it is an architectural concept built using JavaScript, API and Markup.
Before we look at how to use Jamstack in more detail, let’s examine its component parts and what they represent:
Jamstack applications are hosted, in their entirety, on a Content Delivery Network (CDN) or an Application Delivery Network (ADN). Everything is stored in GIT, and automated builds are provided with a workflow when developers push the code. The pre-built markup is automatically deployed to the CDN/ADN.
These characteristics provide a bunch of significant benefits:
- The whole process is practically serverless , removing a lot of failure points and potential security exploits.
- The pre-built content served via CDN provides super-fast user experiences.
- The reduced complexity of development lowers costs.
- The Develop => Build => Test => Deploy Cycle is very well-managed.
How to Build Jamstack Apps
Today, there are myriad tools, frameworks, library and services available to build and manage Jamstack applications. Among the most popular are static site generators (SSGs) which facilitate the construction of pre-built markups, as well as CDNs/ADNs. These SSGs come with generous price plans to deploy and host the applications, and offer both services and APIs.
One of the most popular members of the current generation of SSGs is Gatsby, a React-based framework specifically designed to create prebuilt markups. As well as offering a plethora of plug-in ecosystems, Gatsby is also hooked up to a vibrant community support network.
In this post, we’re going to show you how to build Gatsby with Bugfender, our remote logging service which allows users to collect logs for everything that happens in their application. It’s easy to integrate Bugfender with web apps and there are lots of SDKs available to integrate with mobile apps, too.
Ok, enough of the pitch. Let’s get moving!
What are we building today?
We’re going to build a basic blogging site called
The Purple Blog. In doing so, we will see that Gatsby can build such sites in double-quick time with the help of GraphQL and markdown files. During the build process, we will integrate
Bugfender to collect application logs, create automatic user feedback, issues and crash reports, and analyze them.
When we’re done, the Gatsby and Bugfender-powered blog site may look like this:
TL;DR
If at any point of time you want to look into the source code or play around with the blog site, here are the links:
GitHub Repository:
and
Demo Link:
Create the Project Structure with Gatsby
We will use a Gatsby starter to create the initial project structure. To do this, you need to install Gatsby CLI globally, and the best way to do this is by opening a command prompt and running this command:
npm install -g gatsby-cli
Now, use the following command to create a Gatsby project structure.
gatsby new purple-blog
We are using the
gatsby-starter-default starter project template to create our blogging tool, as this will initiate the project with all required libraries and dependencies.
Once done, you will see a project folder called purple-blog has been created. Go to that folder and open a command prompt there. Type the following command to run the app in the development mode:
gatsby develop
Now, you should be able to access the interface using.
Set Up Bugfender
To kick things off, simply create an account with Bugfender. Once logged in, create a Bugfender application for web apps using the Web SDK option. You can follow this step-by-step guide to create a Bugfender application, and you will find an API key ready for you. Keep it safe.
Once you have created your app, the Bugfender dashboard will enable you to keep track of logs, issues, feedback and crashes. This is how my dashboard looks:
Gatsby and Bugfender
A
gatsby-based application can run in two different environments.
gatsby develop: A development environment with hot reloading enabled. In this environment, all browser-specific APIs like
localstorage, and objects like
windowwork well.
gatsby buildwith
gatsby serve: This is the environment to build the app to produce deployable artifacts; once you have created them, you can run the app from the built artifacts. In this environment, the browser-specific APIs and objects will not work as the environment is based on
nodejs. For example, the
windowobject is not available in the
nodejsand we may end up getting an error like:
On the other hand, Bugfender is a client-specific tool and it depends on browser-specific objects like window. Hence there is a chance that a Bugfender API that works well in the gatsby develop environment may fail in the gatsby build. We need to provide some configurations along with code changes to allow the Bugfender APIs to work with both the Gatsby environments.
Install Bugfender SDK
Open a command prompt and the root of the project folder and use this command to install the Bugfender SDK:
yarn add @bugfender/sdk # Or, npm i @bugfender/sdk
Configure gatsby-node for Bugfender
Open the file named gatsby-node.js and add the following content:
exports.onCreateWebpackConfig = ({ stage, loaders, actions }) => { if (stage === "build-html") { /* * During the build step, @bugfender will break because it relies on * browser-specific APIs. Fortunately, we don’t need it during the build. * Using Webpack’s null loader, we’re able to effectively ignore @bugfender * during the build. (See src/utils/bugfender.js to see how we prevent this * from breaking the app.) */ actions.setWebpackConfig({ module: { rules: [ { test: /@bugfender/, use: loaders.null(), }, ], }, }) } }
A few things are going on here. We are telling gatsby that Bugfender is a client-specific thing and it is not required at the build stage. Using Webpack’s null loader, we’re able to effectively ignore Bugfender during the build. The loader checks for an npm package that starts with the name @bugfender, then ignores it. Simple!
Create a Utility for Bugfender APIs
Next, we will create a utility file to wrap the Bugfender APIs so that they can be ignored at the build stage. You can do this by creating a folder called
utils under
src, then creating a file called
bugfender.js under
src\\utils with the following content:
import { Bugfender } from '@bugfender/sdk' const isBrowser = typeof window !== "undefined" const GatsbyBugfender = { init: () => { if (!isBrowser) { return } Bugfender.init({ appKey: '', }) }, log: (...messages) => { if (!isBrowser) { return } Bugfender.log(messages.join( )) }, error: (...messages) => { if (!isBrowser) { return } Bugfender.error(messages.join( )) }, sendUserFeedback: (key, value) => { if (!isBrowser) { return } Bugfender.sendUserFeedback(key, value) }, sendIssue: (key, value) => { if (!isBrowser) { return } Bugfender.sendIssue(key, value) }, sendCrash: (key, value) => { if (!isBrowser) { return } Bugfender.sendCrash(key, value) } } export default GatsbyBugfender;
We are actually taking care of a few things here:
- First, we’re checking that the app is running in the browser mode or nodejs mode.
- We’re allowing the calling of a Bugfender API if we’re sure it is running in the browser mode.
- The
initfunction uses the
API_KEYyou noted down while setting up
Bugfendera while ago.
- You can add all the Bugfender APIs or just the ones you need.
Use the API function from the Utility
Now we will be able to initialize and use Bugfender in the Gatsby code without any issues.
Let’s start by taking a look at a single usage. Open the file,
src/pages/index.js and import the
GatsbyBugfender utility we have created:
import GatsbyBugfender from '../utils/bugfender'
Call the
init method after all the imports:
// all imports .... GatsbyBugfender.init(); const IndexPage = ({data}) => ( ....
Now you can call the Bugfender APIs in the Gatsby app from any of the pages, components or templates. Here is an example:
if (posts.length > 0) { GatsbyBugfender.log(`${posts.length} posts found in the repository`) GatsbyBugfender.sendUserFeedback('Posts created', 'Default Posts created Successfully!') } else { GatsbyBugfender.sendIssue('No Posts Found') }
The Blogging App
Now we will focus on building
The Purple Blog.
To do so, we can take advantage of Gatsbyjs’s well-established ecosystem, provided by an amazing community is constantly writing plug-ins and making them available to install.
We need two specific plug-ins for our app.
gatsby-source-filesystem: This helps us source data from a local file system. Our blogging app is going to source the data from local markdown (*.md) files, and this plug-in turns them into
Filenodes – which can then be converted into different data types using transformer plug-ins.
gatsby-transformer-remark: As we will be using the markdown files as the data source, we need to convert the File node into a
MarkdownRemarknode so that we can query the HTML representation of the markdown. We will use the
gatsby-transformer-remarkplug-in for that purpose.
Install Dependencies
You will most probably have installed the
gatsby-source-filesystem plug-in when creating the basic project structure. Let us now install the rest of the dependencies:
yarn add gatsby-transformer-remark lodash react-feather # Or npm i ...
We have created our project from the starter project
gatsby-starter-default. It should have installed
gatsby-source-filesystem already. You can check it by finding it in the
package.json file. If you don’t find it installed, please install it manually using the yarn or npm command as shown above.
Also note that we are installing the
lodash and
react-feather libraries for the JavaScript object, using array operations and free icons respectively.
Gatsby Configuration File
Open the
gatsby.config.js file and perform the following changes:
- Declare the source and transform plug-in configurations so that the build process knows where to load the source files from and transform them. Add these to the
pluginsarray. Here we are telling Gatsby to expect the data source files from the
_datafolder.
plugins: [ // ... omitted other things unchanged { resolve: `gatsby-source-filesystem`, options: { name: `markdown-pages`, path: `${__dirname}/_data`, }, }, `gatsby-transformer-remark`, // ... omitted other things unchanged ]
- Change the value of the
titleproperty of the
siteMetadataobject to something meaningful. We will provide the name of our app here, i.e.
The Purple Blog.
module.exports = { siteMetadata: { title: `The Purple Blog`, // ... omitted other things unchanged
Gatsby, Markdown and GraphQL
Now, we will create the data source files and query them so that we can use the result on the React components.
Create a folder called
_data at the root of the project folder, and create a markdown file with the following format:
-------- date: 2020-05-18 title: What is Life? tags: - soft-skill - spirituality - life - science author: Matt Demonic -------- > Taken from [Wikipedia]() to dmonstrate an example. Life is a characteristic that distinguishes physical entities that have biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased, or because they never had such functions and are classified as inanimate. In the past, there have been many attempts to define what is meant by "life" through obsolete concepts such as odic force, hylomorphism, spontaneous generation and vitalism, that have now been disproved by biological discoveries. Aristotle is considered to human-made reconstruction of any aspect of life, which is often used to examine systems related to natural life. Death is the permanent termination of all biological processes which sustain an organism, and as such, is the end of its life. Extinction is the term describing the dying out of a group or taxon, usually a species. Fossils are the preserved remains or traces of organisms.
If you are new to markdown file structure, you can learn it here. As the purpose of our app is to create blog articles, we have defined the structure of an article here. Notice that we have the publication date, title, author, tags and finally the content of the article. You can create as many such files as you wish.
At this stage, start the Gatsby development server using the
gatsby develop command if it is not running already. If it is running, please restart it. Open a browser tab and try the URL. It will open an editor for you to create the desired queries to query data from the source files.
The image below shows three panels. The first is to select the attributes to form a query. The second shows the query formed and allows you to change things manually. The last panel is to show the results.
The query formed here is a GraphQL query. We will use queries like this in the reactjs components using Gatsby GraphQL support, which is provided out-of-the-box.
Gatsby Template and Dynamic Page Creation
You may recall that we have included
tags among the properties for the blog article. This means that we can show tags for an article and allow blog readers to use them to filter articles.
For example, when we click on the tag
javascript, we want to list all the articles that have the same tag.. The same applies for any other tags we add.
Also, notice that the URL changes when we click on a tag to filter the articles.
With Gatsbyjs you can also create pages, and each of them will create a route (a unique URL) for you automatically.
A page can be created statically simply by creating a file under the
src/pages directory. The name of the file then becomes the unique URL name. You can also create a page dynamically using templates: this is an extremely powerful concept very apt for the tag use-case we have seen just now.
We have to create a page dynamically for each of the tags, so that it also creates a unique URL, and when an article title is clicked. We have to show the full article content to the user and the unique part of the URL is called
slug.
To create pages dynamically, open
gatsby-node.js and add these lines at the top of the file:
const path = require(`path`); const _ = require("lodash"); const { createFilePath } = require(`gatsby-source-filesystem`);
Here we are importing required libraries to create the setup for the dynamic page creation.
Next, we will override two Gatsby methods,
onCreateNode and
createPages.
Override
onCreateNode
We will override this method to create a new node field called
slug, so that we can use this node in our query later. To create
slug, add this code snippet after the require statements:
//... all require statements exports.onCreateNode = ({ node, getNode, actions }) => { const { createNodeField } = actions if (node.internal.type === `MarkdownRemark`) { const slug = createFilePath({ node, getNode, basePath: `pages` }) createNodeField({ node, name: `slug`, value: slug, }) } }
Override
createPages
Add this code snippet after the onCreateNode method:
exports.createPages = async ({ graphql, actions }) => { const { createPage } = actions // 1 - Query to all markdown files const result = await graphql(` query { allMarkdownRemark { edges { node { fields { slug } frontmatter { title tags date } } } } } `); const tagSet = new Set(); // 2 - Iterate through the nodes and create pages result.data.allMarkdownRemark.edges.forEach((edge) => { // 3 Create page for each of the node createPage({ path: edge.node.fields.slug, component: path.resolve(`./src/templates/blog-post.js`), context: { // Data passed to context is available // in page queries as GraphQL variables. slug: edge.node.fields.slug, }, }); // 4- Generate a list of tags if (edge.node.frontmatter.tags) { edge.node.frontmatter.tags.forEach(tag => { tagSet.add(tag); }); } // 5- Generate pages for each of the tags tagSet.forEach(tag => { createPage({ path: `/tags/${_.kebabCase(tag)}/`, component: path.resolve(`./src/templates/tagged-post.js`), context: { tag } }); }); }) }
A few things are going on here:
- First, we need to create a query that results out in listing all the markdown files. Here we are interested in the
title,
dateand the newly created field,
slug.
- The query returns an array of transformed file nodes, each of which contains the information we intended to make queries for. We loop through the array to create the required pages.
- Create pages for each of the nodes. Here, we are telling the Gatsby build process to use the
blog-post.jsfile under the
src/templatesfolder to create pages. These pages will be used when our users click on the article title to get to article details.
- Next, we loop through the tags of all the articles and create a set (which is the unique collection in JavaScript) of unique tags.
- Create a page for each of the tags. Here, we are telling the Gatsby build process to use the
tagged-post.jsfile under the
src/templatesfolder to create pages. These pages will be used when our users click on the tag of an article to filter out the articles with the same tag.
We will create both the template files shortly.
Create Templates and Components
Now we will create a reactjs component to render the article list. Simply create a file called
PostList.js under the folder
src/components with the following content. This is a simple react component which loops through each of the post articles and renders them.
import React from "react" import TagCapsules from "./TagCapsules" import { Link } from "gatsby" import { User } from 'react-feather' import GatsbyBugfender from '../utils/bugfender' const Post = props => ( {props.details.frontmatter.title} {' '} {props.details.frontmatter.author} {", "} on {props.details.frontmatter.date} {props.details.excerpt} ) export default (props) => { let posts = props.data.allMarkdownRemark.edges if (posts.length > 0) { GatsbyBugfender.log(${posts.length} posts found in the repository) GatsbyBugfender.sendUserFeedback('Posts created', 'Default Posts created Successfully!') } else { GatsbyBugfender.sendIssue('No Posts Found') } return ( {posts.map((post, index) => ( ))} ) }
Next, create a file called
TagCapsules.js under the same folder. This is a component to create representation for the tags in the article list page.
import React from "react" import _ from "lodash" import { Link } from "gatsby" import GatsbyBugfender from '../utils/bugfender' import styles from "./TagCapsules.module.css" const Tag = props => { const tag = props.tag GatsbyBugfender.log(`Recieved Tag ${tag}`) return ( {tag} ) } const Tagcapsules = props => { const tags = props.tags GatsbyBugfender.log(`Recieved ${tags.length} tags`) return ( {tags && tags.map(tag => )} ) } export default Tagcapsules
We will be using some styling to make the tags look better. To do this, create a file called
TagCapsules.module.css under the same folder, with the following content:
.tags { list-style: none; margin: 0 0 5px 0px; overflow: hidden; padding: 0; } .tags li { float: left; } .tag { background: rgb(230, 92, 230); border-radius: 3px 0 0 3px; color: rgb(255, 255, 255); display: inline-block; height: 26px; line-height: 26px; padding: 0 20px 0 23px; position: relative; margin: 0 10px 10px 0; text-decoration: none; } .tag::before { background: #fff; border-radius: 10px; box-shadow: inset 0 1px rgba(0, 0, 0, 0.25); content: ''; height: 6px; left: 10px; position: absolute; width: 6px; top: 10px; } .tag::after { background: #fff; border-bottom: 13px solid transparent; border-left: 10px solid rgb(230, 92, 230); border-top: 13px solid transparent; content: ''; position: absolute; right: 0; top: 0; } .tag:hover { background-color: rgb(143, 4, 224); color: white; } .tag:hover::after { border-left-color: rgb(143, 4, 224); }
Now we will create both the template files. Create a folder called
templates under the
src folder and create the file
blog-post.js, using the content below. Please note the query at the end of the file: it queries the title and the content for a post article, and renders that. This is the page to show when a user clicks on the title of an article to see the details.
import React from "react"; import { graphql } from "gatsby"; import SEO from "../components/seo" import Layout from "../components/layout"; export default ({ data }) => { const post = data.markdownRemark return ( {post.frontmatter.title} ) } export const query = graphql` query($slug: String!) { markdownRemark(fields: { slug: { eq: $slug } }) { html frontmatter { title } } }
Now it’s time to create another template. Create a file called
tagged-post.js under
src/template folder, using the following content. Here we make a query for all the posts that match a particular tag. Then we pass the matched post array to the
PostList component we have already created.
import React from "react"; import { graphql } from "gatsby"; import Layout from "../components/layout"; import PostList from '../components/PostList'; export default ({data}) => { console.log(data); return ( ) }; export const query = graphql` query($tag: String!) { allMarkdownRemark( sort: { fields: [frontmatter___date], order: DESC } filter: { frontmatter: { tags: { in: [$tag] } } } ) { totalCount edges { node { id frontmatter { title date(formatString: "DD MMMM, YYYY") tags } fields { slug } excerpt } } } } `
Now, the last thing is to change the
index.js page so that our home page shows all the articles. Open the index.js file and replace the content with the following. Here, we are querying all the post articles and passing the array as a props to the
PostList component.
import React from "react" import Layout from "../components/layout" import SEO from "../components/seo" import { graphql } from "gatsby" import GatsbyBugfender from '../utils/bugfender' import PostList from '../components/PostList' GatsbyBugfender.init({ appKey: 'YOUR_BUGFENDER_APP_KEY', }); const IndexPage = ({data}) => ( ) export default IndexPage export const GET_ALL_POSTS = graphql` { allMarkdownRemark ( sort: { fields: [frontmatter___date], order: DESC } ){ edges { node { id frontmatter { title tags date(formatString: "DD MMMM, YYYY") author } html excerpt fields { slug } } } } } `
All you need to do is replace the
YOUR_BUGFENDER_APP_KEY in the above code with the app key you created while setting up the Bugfender app. Cool, right?
Now, restart
gatsby develop if it is running already. You can access the app with the URL to see it running successfully.
Deploy it on Netlify
The app is running successfully on localhost. Let’s make it accessible to users by hosting it on a CDN. While doing that, we will also set up a continuous integration and deployment (CI/CD) so that a build-and-deploy kicks off with the code changes pushed to the Git repository.
The Netlify platform enables us to do this easily. Create an account with Netlify and log in to the application using the web interface. Now follow the steps mentioned below to deploy the app on Netlify with the CI/CD enabled by default.
Make sure to commit and push all the source code to the GitHub repository. You can create a new site with Netlify simply by selecting your GitHub repository.
In the next step, provide the build settings as shown in the image below.
A build will be initiated automatically once the steps are completed. Please wait for the build to finish successfully. In case of an issue, you can consult the build logs for more details.
Netlify creates a site for you with a random name. However, you can change it as per your choice based on availability.
That’s it! Now the app will be available using the URL that appears below the site name field. In my case, it is
Inspecting with Bugfender
You can inspect the logs from the Bugfender web console. As it starts collecting the logs, you can find them for each of your devices. In our case, it is a web application. Hence the device is the browser you have used to access the app.
You can drill into and see the logs collected for a specific timeframe. In the image below, it shows the logs along with the user feedback created when a post is successfully published in our app.
It is also easy to spot the errors.
You can find issues, crashes, etc. under the respective tabs. In the screenshot below, we see an issue has been created as no article posts are found.
You can drill-down to the issue and send it to the GitHub for further triaging.
Please explore the Bugfender app further for all the other options.
Before we go…
Bugfender is a tool that helps you finding errors in your production apps. We strongly believe in sharing knowledge and that’s why we create articles like this one. If you liked it, help us to continue creating content by sharing this article or signing up in Bugfender.
Top comments (0) | https://practicaldev-herokuapp-com.global.ssl.fastly.net/bugfenderapp/jamstack-application-with-gatsby-and-bugfender-1lgi | CC-MAIN-2022-40 | refinedweb | 3,969 | 57.37 |
For some reason my quaternions and vector3s for my picking up and holding items script aern't working. Would you guys please be so kind as to help me with fixing this?
My declarations:
private Vector3 CharVec;
private Vector3 KnifeVec;
private Vector3 CleaverVec;
private Vector3 BreadKnifeVec;
private Quaternion CharQua;
private Quaternion KnifeQua;
private Quaternion CleaverQua;
private Quaternion BreadKnifeQua;
My values:
CharVec = Character.transform.position;
KnifeVec = new Vector3(1.68f, 3.05f, 2.12f);
CleaverVec = new Vector3(1.68f, 2.61f, 1.95f);
BreadKnifeVec = new Vector3(1.59f, 2.62f, 1.90f);
CharQua = Character.transform.rotation;
KnifeQua = new Quaternion(13.80f, -23.77f, -81.62f, 1f);
CleaverQua = new Quaternion(17.86f, -42.52f, -92.53f, 1f);
BreadKnifeQua = new Quaternion(-17.16f, 167.89f, 90.24f, 1f);
And my usages:
if(CarryableObject.name == "knife"){
CarryableObject.transform.rotation = CharQua * KnifeQua;
CarryableObject.transform.position = CharVec + KnifeVec;
}
if(CarryableObject.name == "cleaver"){
CarryableObject.transform.rotation = CharQua * CleaverQua;
CarryableObject.transform.position = CharVec + CleaverVec;
}
if(CarryableObject.name == "bread knife"){
CarryableObject.transform.rotation = CharQua * BreadKnifeQua;
CarryableObject.transform.position = CharVec + BreadKnifeVec;
}
Why aren't you just using some sort of universal hand slot?
You basically place an empty GameObject childed to the players hand, then set the equipped weapons to the objects position and rotation.
You may also need to place your weapons inside empty GameObjects so that their standard 0,0,0 position is actually where the Hand;e would be sitting in the proper position of the hand slot.
Also if you are childing these objects to anything at all, then position and rotation no longer work as intended, you must use localPosition and localRotation so that they are only altered to their new world space and not independently.
Yeah - my gut feeling is that this could all be completely replaced with:
CarryableObject.transform.SetParent(Character.transform);
Answer by leech54
·
May 18, 2017 at 11:03 AM
Quaternions are values between -1.0 and 1.0 it looks like you are trying to give it euler angles. I think the fix might be Quaternion.Euler(...).
Answer by FireStone720
·
May 15, 2017 at 05:22 PM
From what I understand your trying to make a script that places an item in your hand and you want to pick it up from the ground? I assume here is a simple script that does that. I have not tested if this works there may be some syntax errors I did this completly without auto completion and on notepad++ I will test it and edit it when I am home if it doesn't work. I did this in 10 minutes so its not perfect but should give you an idea at least.
My script should picks up any item when you left click while looking at it and overrides what it in your hand if you try picking up a new item;
public class PickupItem : MonoBehaviour
{
public Transform hand; //The location of the hand, could use Vector3 instead of Transform but I like doing it this way.
public GameObject itemInHand; //A nice reference to the item you picked up.
void Update()
{
//What I'm gonna do is draw a raycast from the middle of the screen aka when you look at an object. and if you click while looking it will pick up the object.
RaycastHit hit;
Ray ray = Camera.main.ViewportPointToRay (Vector3(0.5f, 0.5f, 0));
if(Physics.Raycast(ray, out hit)
{
if(Input.GetMouseButtonDown(0))
{
Debug.Log(hit.collider.transform.name);
if(hit.collider.tag == "Item"); //MAKE SURE TO NOW TAG any items you want to pickup with a new tag called Item <---- I forgot to do this a lot.
{
if(itemInHand == null) //if no item is in hand pickup what your looking at.
{
hit.collider.transform.SetParent(hand);
itemInHand = hit.collider.transform.gameObject;
itemInHand.position = Vector3.zero;
}
else //if an item is in the hand
{
hand.DetachChildren();
hit.collider.transform.SetParent(hand);
itemInHand = hit.collider.transform.gameObject;
itemInHand.position = Vector3.zero;
}
}
}
}
}
You probably want to set the localPosition to zero and not the world position of the object. At the moment you move the item to the world
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*WD TV Live Plus HD media player only. Blockbuster online membership or Netflix unlimited membership required. US only.
See your personal media and Internet content on your HDTV.
Play almost any type of media file The media players support. Works with USB keyboards Use the on-screen keyboard, an alphanumeric keypad, or attach your wired or wireless USB keyboard for easy text input. Perfect for searching videos on YouTube or updating your status on Facebook. WiFi ready Supports a wireless connection to your home network with an optional USB wireless adapter. Or, get the speed you need to stream HD with a WD Livewire powerline AV network kit - it extends the Internet to any room in your home using your electrical outlets. Supports DVD Navigation View all the content included on your DVDs, including complete menu navigation, chapter listings, special features, and subtitles. Play media seamlessly from multiple USB drives Two USB ports on the player let you connect multiple USB storage devices and access them simultaneously. Our media library feature collects the content on all the drives into one list sorted by
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3. Select Playlists, then press ENTER.
4. Select OK, then press ENTER. 5. Type in the name of your playlist using the on-screen keyboard, select Submit, then press ENTER. Favorite Radios Accessing a favorite radio station in My Music: 1. In the Deezer main screen, press / to select My Music, then press ENTER. 2. Sign in to your Deezer account if not already logged in. 3. Select Favorite Radios, then press ENTER.
Note: If you have not added any stations, the screen displays "no favorite available."
4. Press / to select a station from the list, then press listening to the radio station.
or ENTER to begin
Add to Playlist
You can add songs to a playlist using the OPTION button on the remote. 1. With a song selected in a Radio or Top Charts screen, press OPTION to display Add to a playlist. Press ENTER. 2. Press / to select a playlist you have created in My Music, then press ENTER to add the song the selected playlist.
Delete a Playlist
You can delete a playlist using the OPTION button on the remote. 1. With a playlist selected in My Music > Playlists screen, press OPTION. 2. Press / to select Delete this playlist , then press ENTER. 3. Select OK, then press ENTER.
Delete a Radio Station
You can delete a radio station using the OPTION button on the remote. 1. With a radio station selected in My Music > Favorite Radios screen, press OPTION.
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2. Press / to select Delete from Favorite 3. Select OK, then press ENTER.
Top Charts
These are songs deemed most popular by Deezer users by country. 1. In the Deezer main screen, press / to select Top Charts, then press ENTER. 2. Press / to filter channel results (French, BE, UK, US), then press / select a song from the display. 3. Press or ENTER to start listening to the selected song.
Search
1. In the Deezer main screen, press / to select Search, then press ENTER. 2. Press / to filter results (All, Title, Artist, or Album), then press ENTER.
3. Use the navigation buttons to type a search using the on-screen keyboard. Select Submit, then press ENTER.
Note: You can also press on the remote control to toggle to the results list after entering several characters in the search field.
4. Press / listening.
to select a song from the display, then press
or ENTER to start
Deleting a Deezer Account from the Media Player
1. 2. 3. 4. On the Deezer main screen, press / to select Sign in, then press ENTER. Press / to select Delete Account, then press ENTER. Press / to select the account you want to delete, then press ENTER. Press / to select OK on the confirmation prompt, then press ENTER.
Share your status, photos, videos, and your favorite links on Facebook. Find out the latest news from your social network or the world and so much more. Access it all on your big screen TV.
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You must have have a valid Facebook account to use this service. You can create a Facebook account at.
1. Navigate to the Home | Internet media menu bar and press ENTER. 2. The list of Internet services display in alphabetical order. Press / to select Facebook, then press ENTER. 3. Press ENTER, then use the navigation buttons to type in your Facebook user name using the on-screen keyboard. Select Submit, then press ENTER. 4. Press ENTER, then use the navigation buttons to type in your Facebook password using the on-screen keyboard. Select Submit, then press OK. 5. Press ENTER to complete the sign-in process. The Facebook home screen displays.
Newsfeed
The Facebook news feed displays all of your friends comments and allows you to Like or comment. The number of people who like or have commented on each entry displays inside the corresponding icons to the right of the news feed entry. 1. In the Facebook main menu, press / to select News Feed, then press ENTER. 2. Press / to view your friends comments and posts. in the news feed screen.
The Facebook Wall displays all of your entries and your friends comments and allows you to Like or comment. The number of people who like or have commented on each entry displays inside the corresponding icons to the right of the Wall entry. 1. In the Facebook main menu, press / to select Wall, then press ENTER. 2. Press / to view your friends comments and posts.
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Photos
You can view the photos or photo albums you and others users have posted to Facebook either individually or as a slideshow. 1. In the Facebook main menu, select Photos then press ENTER. 2. Navigate to a photo album, then press ENTER. 3. Navigate to a photo then press ENTER, or press (PAUSE/PLAY) to start a photo slideshow (see Slideshow Playback Controls on page 63). Photos Options With an individual photo selected or a slideshow running, press OPTION. See Photo Display Options on page 59 for details on using these options.
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Flickr Photostream
The Flickr photostream layout is the same as that of a Photos directory in thumbnail mode.
You can use the navigation buttons to select content. To view content in fullscreen mode, select the file and press ENTER. To view a slideshow using all the current photostreams content, press or ENTER. Contents display in the Flickr Player screen. Go to next section for information. To return to the photostream from fullscreen mode, press. To return to the photostream from Player mode, press. To view all photos in full screen, go to Photo Settings and select Fit to screen (see Photo Scaling on page 133).
Flickr Player
The Flickr Player layout is the same as that of a photo slideshow. Press to view the next content in the photostream. Press to view the previous content in the photostream. To return to the photostream, press.
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Player Options As with a regular photo slideshow, you can customize the way content is displayed in the Flickr Player. To do this, press OPTION to bring up the Player toolbar.
Note: To view photos enlarged in fit to screen or full screen mode, access the Settings menu and follow the instructions under Photo Scaling on page 133.
To change the displays viewing scale, press / and select to zoom in or to zoom out, then press ENTER repeatedly until the preferred viewing scale is achieved. Press OPTION or to revert to the default viewing scale. To rotate the image display, press / and select or , then press ENTER repeatedly until the preferred display angle is achieved. The display is rotated clockwise or counter-clockwise in 90 increments. Press OPTION or to revert to the default display angle. To view the profile page of the contents author, press / and select. If the user has other public photostreams, you can explore them as well. Use the navigation buttons to select a content selection, then press ENTER to explore it. To view the info bar at the bottom of the screen, press / and select. The info bar shows the slideshows progress both visually and numerically. Press OPTION to resume the slideshow. To pan the image, press / and select (see Panning Around the Picture on page 59 for further details). To change the slideshow play mode, press / and select (see Repeating and/or Shuffling a Slideshow on page 64 for further details).
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Flingo
Flingo offers free Internet Television from leading studios, TV networks, and video websites. It also allows you to turn the Web into your remote control. You can simply "fling" your favorite videos to the Queue in the Flingo application on your media player. For more information go to. To access Flingo: 1. Navigate to the Home | Internet Media menu bar and press ENTER. 2. The list of Internet services display in alphabetical order. Press / to select , then press ENTER. 3. Press , then press / to choose a category (Channels, Popular, Favorites, Queue, and Search) from the Flingo interface. Press ENTER. 4. Use the navigation buttons to select a channel, then a video within the channel. Press or ENTER to begin playing the video.
Live365 Preferences
When browsing or searching for radio stations, you can: Specify that only radio stations of a specific audio quality display. Choose to sort radio stations alphabetically or by popularity (based on user recomendations). To specify the audio quality of accessible stations: 1. On the Live365 main screen, press / to select Preferences, then press ENTER. 2. Press / to select Audio, then press ENTER. 3. Press / to select an audio quality option, then press ENTER.
To set how radio stations are sorted: 1. On the Live365 main screen, press ENTER. / to select Preferences, then press
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to select Sorting, then press ENTER. to select a sort option, then press ENTER.
Sign out of Live365 after a listening session to ensure that nobody can make changes to your Live365 settings and stations without your permission. To sign out from Live365: 1. On the Live365 main screen, press ENTER. / to select Sign In/Sign Out, then press ,
Tip: You can also press OPTION to show the toolbar, press / to select then press ENTER. 2. Press / to select OK on the confirmation prompt, then press ENTER.
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Mediafly
Mediafly conveniently brings your favorite Internet content and podcasts to your media player from favorite sources like CNN, BBC, NBC, ESPN, WSJ, Fox, NPR, and more. Set up once with Mediafly and enjoy the same content on TVs, smartphones, computers, and beyond. Mediafly is available worldwide; features may vary based on country. To access Mediafly: 1. Navigate to the Home | Internet Media menu bar and press ENTER. 2. The list of Internet services display in alphabetical order. Press / to select Mediafly , then press ENTER. The Mediafly dashboard displays.
3. Press / to choose an option, then press ENTER. Options include: My Channels Popular Channels Browse content plug-ins Search
Note: If you do not have a Mediafly account and want to create one, go to.
1. Navigate to the Home | Internet Media menu bar. , then press ENTER. 2. Press / to select Mediafly 3. On the Mediafly dashboard, press / to select My Channels ENTER.
, then press
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4. Select Sign in, then press ENTER.
4. Press to move the selection down to the prompt buttons. 5. Press / to select Yes, then press ENTER to confirm your rating. 6. Your video rating is confirmed. Press ENTER to go back to the Player screen. The average number of stars users give to the video are used to determined the overall video rating. Tip: You can also rate videos after playback. On the Related Videos screen, press / to select Rate Video, then press ENTER.
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Adding Videos to Favorites
If you enjoyed a particular video or simply want to refer to it later, you can tag it as a favorite to add it to your My Favorites list. Once added, you can keep track of this video. To add a video to My Favorites from the Related Videos screen: 1. On the Related Videos screen of the video you want to add as a favorite, press to move the selection to the links on the left side of the screen. 2. Press / to select Add to Favorites, then press ENTER.
3. Press ENTER at the confirmation prompt.
Sign out from YouTube after a viewing session to prevent other users from accessing your YouTube account without your permission. To sign out from YouTube: 1. On your Account page, press OPTION. 2. Press / to select Logout , then press ENTER. 3. Press / to select Yes on the confirmation prompt, then press ENTER.
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Deleting a YouTube Account from the Media Player
To delete a YouTube account from the media player: 1. Press / ENTER. 2. Press / in the YouTube main screen to select Account to select Delete account, then press ENTER. , then press
to select the account you want to delete, then press ENTER.
4. Press
to select Yes on the confirmation prompt, then press ENTER.
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Restricted Video Content
Some videos on YouTube are restricted by the content owner from playback via TV-connected devices. If you attempt to play one of these videos, the following screen displays:
Press ENTER to return to the previous screen.
Encoding Support for YouTube Worldwide
Many YouTube videos are encoded in a language other than the one you set as your media players system language. In some cases, this results in garbled characters in the video ID or even playback failure. If this is the case, you need to enable the encoding support for the language that is causing the error. To set the media players additional encoding setting: 1. 2. 3. 4. Navigate to Home | Settings menu bar. Press / to select System settings , then press ENTER. Press / to select Additional encoding support, then press ENTER. Press / to select the encoding support you require, then press ENTER.
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Settings and Advanced Features
The Settings menu lets you customize the way you use the media player and set preferences for media playback. To select a Settings category: 1. Press HOME, then select the Settings icon.
Share WD TV on Your Network
See Transferring Files on page 67 for information and instructions.
Workgroup Name
Allows you to join a specific workgroup on your network. Microsoft operating systems in the same workgroup may allow each other access to their files, printers, or Internet connection. Members of different workgroups on the same local area network and TCP/IP network can only access resources in workgroups to which they are joined. To create a new workgroup, select Workgroup Name, then press OK. Enter a new workgroup name using the on-screen keyboard.
SETTINGS AND ADVANCED FEATURES 137
Auto Login to Network Share
Use this menu to select a login procedure. When set to On, the media player logs into the network share anonymously. When set to Off, the media player prompts you to enter the account name and password to access the network share.
Clear Login Info for Network Share
Use this menu to clear login information (preset password) for the network share.
SETTINGS AND ADVANCED FEATURES 138
System
Use the menus in this category to configure the media players general functions. Press / to make a selection from the list of options, then press ENTER.
Set Time Zone
Use this menu to select your local time zone and turn Daylight Savings Time Off or On so that the media player displays the current time.
Language
Press / to select the display language, then press ENTER.
Media Library
Use this menu to enable or disable (turn Off or On) the Media Library, which refers to the process of consolidating the contents of a USB drive into one database so you can locate media files based on metadata information. See Media Library on page 142 for more information.
Screensaver Delay
Use this menu to set the time of system inactivity before the screensaver display is enabled. The default setting is 5 minutes.
SETTINGS AND ADVANCED FEATURES 139
Display File Size
Set this menu to On to display the file size information in the media browser screen.
User Interface Transition Effect
Use this menu to set the visual transition between screens in the media players user interface (None or Fade in and fade out).
Additional Encoding Support
Press / to select an encoding support for a secondary language, then press ENTER. This prevents garbled characters in file names and subtitles defined in the selected language.
Solution
The TV screen is blank and the media player power LED is on.
Make sure that the Composite option is selected as the video output. Make sure the TV system setting matches the system used in your region.
If you are using an LCD TV, navigate to the Home | Settings | System screen and:
The video display is cut off or appears in a sidebar. The slideshow pictures are distorted.
Make sure that the HDMI option is selected as the video output. Make sure that the video resolution option is set as Auto.
Navigate to the Home | Settings | Audio/Video screen and make sure that aspect ratio is set as Normal. Navigate to the Home | Settings | Photo screen and select Keep as original or Fit to screen in the Photo Scaling field.
SYSTEM MAINTENANCE 147
FILES File does not play.
Verify compatibility. Refer to Supported Formats on page 153. Use a media converter program to convert the file to a usable format.
AUDIO There is no sound. Make sure the volume on the entertainment unit is not muted. Navigate to the Home | Settings | System screen and make sure the correct audio output setting is enabled.
If you are using the composite audio cable, the Stereo setting should be enabled. If you are using an S/PDIF (optical) or HDMI connection, the Digital setting should be enabled.
If you are watching a video that supports multiple audio channels, make sure that the Audio Off option is disabled. Press Options | <icon>, and then press ENTER repeatedly until the intended audio channel is displayed. USB DEVICE The Media Library process failed. Make sure that: the USB device has no read-only protection. the USB device is not using the HFS+ Journaling file system. there is enough storage space on the USB device. The attached USB device is not visible on the Home screen. The media player only supports mass USB storage mode. Make sure that the USB device is configured as a "mass storage device." Make sure the USB devices file system is supported (NTFS, FAT/FAT32, or HFS+). REMOTE CONTROL The media player remote control does not work. Press only one button at a time. Make sure the batteries are properly inserted. The batteries may already be drained out. Replace batteries with new ones. Make sure that the path between the remote control and the media player is not blocked.
SYSTEM MAINTENANCE 148
FIRMWARE UPGRADE The firmware upgrade recovery splash screen is shown after you turned on the media player or the media player keeps rebooting to the splash screen.
The previous or current firmware upgrade process failed. Repeat the firmware upgrade process. Go to page 145 for instructions. If you are still unable to update the system firmware, perform a system reset. Go to page 140 for instructions.
SYSTEM MAINTENANCE 149
Common Error Messages
If this message appears HOME Hard drive cannot aggregate. There are different conditions under which this error message may appear. The message will specify the issue. For example, not enough space is used on the storage or a journaled file system. Attach the USB device that contains your media files. 1. Eject and disconnect the USB device from the media player. 2. Connect the USB device to your computer and delete unnecessary files to meet the required storage space. 3. Attach the USB device to the media player again. 1. Eject and disconnect the USB device from the media player. 2. Connect the USB device to your Apple computer and disable the journaling function. Refer to the Apple Help for information. 3. Attach the USB device to the media player again. 1. Eject and disconnect the USB device from the media player. 2. Connect the USB device to your computer and make sure the read-only protection is disabled. 3. Attach the USB device to the media player again. There are two different conditions under which this error message may appear: 1. Insufficient storage space on the drive(s). 2. Drive is configured as read-only. Free up drive storage space or adjust the drive settings to resolve this error. The USB device model is not supported. Use another USB device. This indicates a system diagnostic failure. Contact WD Technical Support for assistance. Perform this action
No storage present. Media Library requires more storage space: [XXXMB]
Please turn off journaling on the attached storage's file system for the media player to compile the media library.
Unable to compile media library on read-only storage.
Unable to compile media library. Please check your storage setting.
Unrecognized storage. Question XX: WD USB HDD Trouble Shooting CONTENT PLAYBACK This folder is empty.
There are no supported media files in the selected folder. Select another folder that contains media files of the correct format.
SYSTEM MAINTENANCE 150
If this message appears Unable to play the selected file. Please recreate the file by using the included media editing software.
Perform this action 1. Eject and disconnect the USB device from the media player. 2. Connect the USB device to your computer and make sure the file format is correct. You can use the media editing software included in the WD Documentation CD. (See How do I find media files and create playlists? on page 151) 3. Attach the USB device to the media player again.
How do I find media files and create playlists? Several media player applications are currently available, such as Winamp and iTunes, that let you play, arrange, and edit media files. These media players also let you create playlists and edit the metadata information for media files. You can search the Internet with your browser to locate where these applications are available for download. How do I copy the files from my music CD to my computer? Digital audio extraction, or Ripping, is the process of copying audio (or video) content to a hard drive, typically from removable media, such as CDs or DVDs, or from media streams. To rip music from CDs to a computer: 1. Insert the CD into the optical drive of your computer. 2. Open the program that you use to rip the music to your computer, such as iTunes or Windows Media Player. 3. Press the Import button (using iTunes), - OR Press the Rip button (using Windows Media Player). 4. Click the music you want to copy (Windows Media Player) and note where the music files are saved after they are copied. iTunes imports the entire CD into your iTunes music library. 5. Click the Start Rip button (Windows Media Player). 6. When ripping is complete, remove the CD. The music is now on your computer.
Some music may be covered by copyright laws which prevent its copying or distribution.
Can I use a universal remote control with the media player? You can use most popular universal remote control devices such as the Logitech Harmony models.
SYSTEM MAINTENANCE 151
Appendix
APPENDIX 157
Le symbole CE indique que ce systme est conforme aux directives du Conseil de l'Union Europenne, notamment la Directive CEM (2004/108/CE) et la Directive Basse tension (2006/95/CE). Une " dclaration de conformit " aux directives applicables a t dpose auprs de Western Digital Europe. I marchi con il simbolo CE denotano la conformit di questo sistema alle direttive del Consiglio dell'Unione europea, ivi compresa la Direttiva EMC (2004/108/CE) e la Direttiva Bassa Tensione (2006/95/CE). In adempimento con le vigenti direttive stata rilasciata una "Dichiarazione di conformit", depositata presso Western Digital Europe. La marca con el smbolo CE indica el cumplimiento de este sistema con las correspondientes directivas del Consejo de la Unin Europea, que incluye la Directiva CEM (2004/108/CE) y la Directiva de bajo voltaje (2006/95/CE). Se ha realizado una "Declaracin de conformidad" de acuerdo con las directivas correspondientes y se encuentra documentada en las instalaciones de Western Digital en Europa. Mrkning av CE-symbolen anger att detta systemet uppfyller kraven enligt det Europeiska Parlamentet och Rdets direktiv, inklusive EMC-direktivet (2004/108/EC) och Direktivet om Lgspnning (2006/95/EC). En "Frskran om verensstmmelse" har gjorts enligt de gllande direktiven och har registrerats hos Western Digital Europa. Merking med CE-symbolet indikerer dette systemets overholdelse av gjeldende direktiver for EU, inkludert EMC-direktivet (2004/108/EC) og lavspenningsdirektivet (2006/95/EC). En "samsvarserklring" i henhold til gjeldende direktiver har blitt skrevet og finnes arkivert hos Western Digital Europe. CE-merkint osoittaa tmn jrjestelmn yhdenmukaisuuden sovellettavissa olevien Euroopan unionin neuvoston direktiivien kanssa, mukaan lukien EMC-direktiivi (2004/108/EC), sek alijnnitedirektiivi (2006/95/EC). "Yhdenmukaisuusvakuutus" sovellettavien direktiivien kanssa on tehty ja se on arkistoituna Western Digital Europe:ssa. CE , (2004/108/EC) (2006/95/EC). , Western Digital,
APPENDIX 158
KCC Notice (Republic of Korea only)
B ( ) .
Class B Device 1 Please note that this device has been approved for nonbusiness purposes and may be used in any environment, including residential areas.
Environmental Compliance (China)
Warranty Information
Obtaining Service
WD values your business and always attempts to provide you the very best of service. If this Product requires maintenance, either contact the dealer from whom you originally purchased the Product or visit our product support Web site at for information on how to obtain service or a Return Material Authorization (RMA). If it is determined that the Product may be defective, you will be given an RMA number and instructions for Product return. An unauthorized return (i.e., one for which an RMA number has not been issued) will be returned to you at your expense. Authorized returns must be shipped in an approved shipping container, prepaid and insured, to the address provided on your return paperwork. Your original box and packaging materials should be kept for storing or shipping your WD product. To conclusively establish the period of warranty, check the warranty expiration (serial number required) via. WD shall have no liability for lost data regardless of the cause, recovery of lost data, or data contained in any Product placed in its possession.
GNU general public license 158 GPL software 158
HD media player error messages 148 features 6 firmware upgrade 143 home screen 33 I/O connectors 7 installation procedures 11 installation requirements 10 language setting 137 LED indicators 8 operating 30 overview 4 package contents 10 preferences 124 regulatory compliance notices 155 remote control 9 screensaver delay 137 troubleshooting 145 warranty 157 HDMI connection 15 connectors 7 Home button 30, 31 error messages 148 Music directory 51 overview 33 Photo directory 55 screen navigation 34 Settings screen 124 Video directory 40 Home Theater connection 18
slideshow 61, 62 videos 44 installation composite AV connection 17 HDMI connection 15, 18 power connection 13, 16, 17 requirements 10 USB connection 19 Internet services Live365 64, 70
LED indicators power 8 status 8 list mode 129, 130, 132 Liveadding a station to your preset list 93 getting track information 94 listening 90 preferences 94 providing song feedback 93 removing a station from your preset list 93 searching 92 sign in 88 signing out 95 locating media content manual search 36 Search function 37
maintenance system 143 media content accessing from network share 64 media library exemptions 140 media library compilation categories 35 enable 34 error messages 148 exemptions 34 LED indicator 8 overview 34, 140 media servers 64 Mediafly 96 browse content plug-ins 98 deleting an account 99 my channels 97 player 97
INDEX 161
I/O connectors composite AV 7 HDMI 7 Toslink 7 USB ports 7 information panel music 52 photos 60
player options 97 popular channels 98 search 99 signing in 96 moving files 133 music album art 51 audio track display 131 auto play 138 MLB categories 35 playback controls 53 playback procedures 51 playback screen 52 sequence setting 131 shuffle mode 54 supported formats 150 use in slideshow 60 music playback options 53
navigation buttons 30, 31 Netflix 100 activate the media player 100 existing membership 100 navigation 100 new membership 100 network services transferring files 65 network setting auto login 136 check connection 135 clear login info for network share 136 device name 135 network setup 135 samba server 135 wireless favorites 135 workgroup 135 network setup Ethernet 22 wireless 25 network share 135 enable file sharing 65 network shares 64 NTSC 126
operating precautions 1 operating system requirements 10
package contents 10
PAL 126 Pandora 101 bookmarking a song or artist 106 providing song feedback 105 QuickMix 105 signing in 102 signing out 106 sorting stations 106 stations 103 why a song is in my stations playlist 106 panning photos 58 videos 47 photo menus interval time 131 photo scaling 131 slideshow sequence 131 transition effect 131 photos digital camera support 56 display options 58 information panel 59 menu options 57 MLB categories 35 panning 58 rotating 59 scaling settings 131 supported formats 150 upload to Facebook 57 view 55 zoom options 59 Play To 5 playlist supported formats 150 videos, playback 41, 52 power AC connector 7 cable connection 13 global AC adapter configurations 13 LED indicator 8 power button 30, 31 turn on 13, 16, 17 product accessories 3 obtaining service 157 overview 4 recording information 3 registration 3 regulatory compliance 155 safety information 1
INDEX 162
warranty 157
regulatory compliance environmental compliance (China) 157 remote control 9 layout 9 transmission range 30 troubleshooting 146 repeat mode music 53 slideshow 63 videos 48 reset switch 7 reset to factory defaults 138 RoHS 157
Search function button 30, 31 procedure 37 settings apply new values 125 Audio/Video menu 125 Movie menu 128 network 135 Photo menu 130 Settings menu bar 124 Settings screen navigation 125 System menu 135, 137 Setup select time zone 137 share WD TV on your network 135 shuffle mode music 54 slideshow interval time 131 music background 60 playback controls 62 repeat mode 63 sequence setting 131 shuffle mode 36 transition effect 131 troubleshooting 145 view 60 slideshow options 62 Software, GPL 158 subtitle border setting 128 default setting 128 enable 46
font size setting 128 supported formats 150 system compatibility 10 system preferences audio/video quality 125 general functions 137 music sequence 131 navigation buttons 125 photo function 130 Settings menu bar 124 video sequence 128 system reset 138 procedures 138 System Setting menus About screen 140 additional encoding support 138 auto play 138 browser display 129, 130, 132 display file size 138 language 137 media library 137 reset to factory defaults 138 screensaver delay 137 system information screen 139 update device 139 user interface transition effect 138
WD TV Live Plus
HD Media Player Stream movies and Internet video to your HDTV
Full-HD video playback and navigation Stream Netflix and other online media Play a wide variety of file formats
Play media from your home network and the Internet on your big screen TV. Plus, enjoy access to your Netflix unlimited membership and other premium content. Experience your movies, music, and photos as big as life on your TV in Full-HD 1080p with WD TV Live Plus HD media player.
HD Media Player
Product Features
Full-HD video playback
Experience Full-HD video picture quality and crystal-clear digital audio.
DVD Navigation
Netflix instant streaming ready
View all the content included on your DVDs, including complete menu navigation, chapter listings, special features, and subtitles.
Media formats JPEG, GIF, TIFF, BMP, PNG MP3, WAV/PCM/LPCM, WMA, AAC, FLAC, MKA, AIF/AIFF, OGG, Dolby Digital, DTS
Access your Netflix unlimited membership and watch TV episodes and movies on your big screen TV.*
Control your media from your computer
Your personal media and Internet content on your HDTV
Stream YouTube, Flickr, Pandora, daily video podcasts from CNN, NBC, MTV, ESPN, and other online content.**
This media player is Windows 7 compatible, so you can use the Play To feature to easily stream your computers files to your TV through your WD TV Live Plus HD media player.
*Netflix unlimited membership required. US only. **Availability varies by country. Pandora available in US only. These streaming services may be changed, terminated or interrupted at any time.
Playlist Subtitle
PLS, M3U, WPL SRT, ASS, SSA, SUB, SMI
Play almost any type of media file
Supports a wide variety of the most popular file formats.
Access media anywhere on your home network
The Ethernet port lets you connect to your home network through a wired connection or wirelessly with an optional USB wireless adapter.. An audio receiver is required for multi-channel surround sound digital output. Compressed RGB JPEG formats only and progressive JPEG up to 2048x2048. Single layer TIFF files only. Uncompressed BMP only. Specific details, please refer to the user manual.
Product Specifications
interface USB 2.0 (input) HDMI (output) Composite A/V (output) Ethernet Component video (output) Optical audio (output) Contents HD media player Compact remote with batteries Composite AV cable Component cable AC adapter Quick Install Guide IInstallation CD Dimensions Height: 1.57 in (40 mm) Depth: 3.94 in (100 mm) Width: 4.94 in (125 mm) Weight: 0.73 lb (0.33 kg) requirements Standard or high definition television with HDMI, component, or composite video connection. Model Number Americas WDBABX0000NBK-NESN
Operating Specifications Operating temperature: 5C to 35C Non-op. temperature: 40C to 65C
Limited Warranty 1 year Americas
Western Digital, WD, the WD logo, WD TV, and Put Your Life On It are registered trademarks in the U.S. and other countries; LIve is a trademark support.wdc.com/warranty for the detailed terms and conditions of our limited warranty. 2010 Western Digital Technologies, Inc. All rights reserved. TV required for multimedia viewing (not included). Manufactured under license from Dolby Laboratories. Dolby and the double-D symbol are trademarks of Dolby Laboratories. This product features Adobe Flash technology. For further information, visit 4178-705112-A00 June 2010
Technical specifications
HTS3152 93 Versatis 155 INA-N333R Firmware FW-M355 AW2092F-1 F1246 Wireless SA-AK77 Module Voice Server LE40F86BD Sbcru545-00U FM620X 740NW 50-2007 RDR-VD6 RT-50PZ45V 42PFL7403H 10 DCR-TRV250E Review CPX 2600 Nomad Iii-morrowind XM-444 SF-300-48 HTS3011 HX2000 C5300 All-IN-ONE R1245AV DCS 520 40 KVA Destiny Energy DX7400 RMB383 Media Player STR-DA3400ES 42PC56 Avaya RFG297aabp XAA Vivicam 3715 Speedtouch 530 Syncmaster 510S RH7800H Hulu GT110 WTL5410UC KX-TCD210PD Forum D-copia 1600 RQ 745 GC1720 CD6002 Photosmart 3310 SC-33 GC2510 02 RP-29FA30A Kawai MP8 CA64-TC MHC-S7AV NP-N220P DCP-185C BT-03I DVP5990K Kodak C875 Wii FIT HP6515 S2700HD IC-T7E 35xx 45XX PRE Plus 3G3JV SA-WM20 360PX E3300 Desktop 60P8341 Dcs-525 Hd Media Player Review P4S333 VSX-415-K ERG47800 8101P624-60 DSM415PF EMM2015S DSC-2100 Enduro R Doro 520 - 1997 AX4GER Hotkeys NS-DXA1 32WS23U ND-BC20PA EW705F Manual DVG-2001S URC22D-8 ME103 Master 100 AT3720 Series Tuner 8350I Innov | http://www.ps2netdrivers.net/hd.media.player/western.digital.tv.live.plus/ | crawl-003 | refinedweb | 6,438 | 63.49 |
Details
- Type:
Bug
- Status:
Closed
- Priority:
Minor
- Resolution: Not A Bug
- Affects Version/s: 1.6-beta-2
- Fix Version/s: None
- Component/s: command line processing
- Labels:None
- Environment:Windows vista 64 bit.
- Testcase included:
- Number of attachments :
Description
When i pass garbage arguments as part of my command line i get no indication that anything is amiss...
I think it would be better to have a mode in which command line processing is 'strict' and anything that is not specified as a valid option triggers some kind of informative err msg or exception...
If you agree that this suggestion is worthwhile and you want help implementing the feature pls drop you a line and i can work on a patch...
it seems like it should be pretty straight forward.
thanks...
/chris
Here is a test case that demonstrates the issue >>
//
// Generated from archetype; please customize.
//
package com.lackey
import groovy.util.GroovyTestCase
/**
- Tests for the {@link Example}
class.{ def cli = new CliBuilder([writer: print_writer]); cli.r( argName: 'dir', longOpt: 'rootDirectory', args: 1, required: false, 'root directory from which to start the scan ' + '- Default: root (/) if not specified', ); return cli; }
*/
class NewTest extends GroovyTestCase
{
protected static CliBuilder getOptionParser(PrintWriter print_writer)
protected static OptionAccessor getParsedCommandLineOptions(
String[] args,
PrintWriter pw= new PrintWriter(System.out)) {
// try/catch so we can gracefully handle NPEs in commons command line parsing library
try
catch (Exception e){ return null; }
;
}
void testBadArgHandling(){ ByteArrayOutputStream baos = new ByteArrayOutputStream(); PrintWriter pwriter = new PrintWriter(baos); String[] bad_args1 = ["blah", "foo"] as String[] //String[] bad_args1 = ["-r", "-u"] as String[] OptionAccessor opts = FindFile.getParsedCommandLineOptions( bad_args1, pwriter); println "Note that no errors are printed.. no exceptions are thrown" println "there is nothing to inform the user that he/she is using invalid arguments " print "opts are = " + opts.toString() print "parse result = " + baos.toString() }
}
Activity
Now I realize that this is actually not a bug...
It seems you can call the OptionAccessor.arguments() after you finish parsing, and if there is anything left over you know that there are (possibly, depending on your case) some garbage args.. .and you can take action at that point.
This wasn't clear from my reading of the groovy in action book or any of the docs.. maybe it warrants a mention ?
thanks
-chris
woops .. i meant pls drop me a line...(not you)...
cb | http://jira.codehaus.org/browse/GROOVY-3272 | CC-MAIN-2014-35 | refinedweb | 385 | 55.54 |
Active Directory® Federation Services (AD FS) 3.0 includes built-in attribute stores that you can use to query for claim information from external data stores, such as Enterprise Active Directory, Lightweight Directory Access Protocol (LDAP) directories, and Microsoft SQL Server. You can also define custom attribute stores to query for claim information from other external data stores.
This article shows you how to create a custom attribute store for AD FS 3.0. The process for AD FS 2.x is the same, but the target .NET Framework will be different, as well as the location of the AD FS binaries.
Please keep in mind that the code that we will write, and the DLL that we will create will by NO MEANS be production-ready code. This document and its contents are provided AS IS without warranty of any kind, and should not be interpreted as an offer or commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED, OR STATUTORY, AS TO THE INFORMATION IN THIS DOCUMENT.
Prerequisites
.NET Framework 4.5 () This is installed by default on Windows 8.1
Visual Studio 2013 ()
Windows Server 2012 R2 with the Active Directory Federation Services role installed and configured.
We will assume you use Windows 8.1 and Visual Studio 2013, and have a Relying Party configured in AD FS that can be used to test the custom attribute store. In this example a custom attribute store will be created using Visual C#.
Copy down the file “Microsoft.IdentityServer.ClaimsPolicy.dll” from the AD FS Server to your PC. The default location of this DLL in Windows Server 2012 R2 is “C:\Windows\ADFS”.
Building the Custom Attribute Store
Start Visual Studio, and create a new Project by clicking “File”, “New” and then “Project”, or by hitting Ctrl+Shift+N.
Create a Project of type “Class Library” (located in the branch “Installed”, “Templates”, “Visual C#”, and “Windows”) and make sure the target framework is the .NET Framework 4.5 (for AD FS 3.0). Give the Project a proper name, in my example “My Custom Attribute Store” and click “OK”.
In Visual Studio, the Project should now have been created and a new Class file (called Class1.cs) should be opened. On the right side of the page, locate the “References” branch under your Project and your Solution in the Solution Explorer and right-click it. Click on “Add Reference…” to add a reference to the DLL you copied from the AD FS Server.
Select “Browse” on the left side, and click the “Browse…” button.
Now, locate the DLL you copied down from the AD FS Server, and click it.
Click “Add” to select the DLL to be referenced in you project.
Make sure the checkbox in front of the name has been checked, and click OK.
A new reference to the DLL should now have been created in your Solution. The reference shows up as “Microsoft.IdentityServer.ClaimsPolicy”.
After adding this reference, we can implement a custom attribute store in our code. Yet, this custom attribute will require access to some classes not referenced by default. We need to create a reference to the proper component in order to be able to use these classes.
Again, right-click the same References branch and select “Add Reference…”.
We will now add a reference to the System.IdentityModel namespace.
In the dialog box, on the right top, type “identity”. On the search results pane, in the center of the screen, check the checkbox in front of “System.IdentityModel” to select the namespace and click “OK”.
Now, in our project, we can see a reference to “Microsoft.IdentityServer.ClaimsPolicy”, which we added before by browsing to the AD FS DLL, as well as a reference to “System.IdentityModel”, that we added just now.
Now that all the proper references are in place, we can start building our custom attribute store in code. In the code page of the Class1.cs file that has been opened by default, we need to make sure we can easily access the namespaces we added before. Locate the “using” statements at the top of the Class1.cs file. (If the Class1.cs file was not opened by default, double-click it in the Solution Explorer.)
Underneath the existing “using” statements, type two new “using” statements;
using Microsoft.IdentityServer.ClaimsPolicy.Engine.AttributeStore;
using System.IdentityModel;
Directly after the declaration of the class, which should show like this;
public class Class1
on the same line, type:
: IAttributeStore
This way, we inform Visual Studio that this Class, called Class1, will implement the Interface “IAttributeStore” (which comes from the “Microsoft.IdentityServer.ClaimsPolicy.Engine.AttributeStore” namespace). The line should look like this:
public class Class1 : IAttributeStore
Your Class1.cs code page should now look like this:
Now, right-click on “IAttributeStore” that you typed in the last step, and select “Implement Interface” and “Implement Interface”.
Now, Visual Studio will create all the methods you need to properly implement the Attribute Store. Your code should resemble this;
The AD FS runtime calls Initialize to initialize the attribute store with configuration parameters. These parameters are name-value pairs that are specific to the attribute store definition.
The policy engine calls the BeginExecuteQuery method to start a query request on the attribute store. The callback parameter is a reference to the callback method that the attribute store invokes at the end of the query. The state parameter is made available in the AsyncState property of the IAsyncResult reference returned by this method. It is also made available in the IAsyncResult reference that is passed to the AsyncCallback method that is specified in the callback parameter. The IAsyncResult reference that is returned by this method is passed as the result parameter of the EndExecuteQuery method.
The policy engine calls the EndExecuteQuery method to get the result of the query. This method should block until the query is over and then return the results of the query in the two-dimensional string array. The columns in the array represent claim types, and the rows represent claim values. The result parameter is the IAsyncResult reference that is returned by the BeginExecuteQuery method.
We now need to actually implement the code for the three methods.
In this example we will implement two different methods (or “queries”) in the Attribute Store’s code. These queries are “ToUpper” and “ToLower” to convert any incoming value to upper- or lowercase equivalents.
Please modify the body of the BeginExecuteQuery method to match this screenshot:
Since we do not use the asynchronous nature of the call, we can directly calculate the values and return the result. Please modify to body of the EndExecuteQuery and Initialize methods to match this screenshot:
As you can see, the Initialize method is empty, because our sample Attribute Store does not require initialization, but make sure you remove the single line that was in there by default.
At this point, we are ready to compile our Solution!
Compiling the Custom Attribute Store
Click “Build” and then “Build Solution” (or simply hit F6) to build the solution:
Check the Output window, at the bottom of the screen, to see if any errors occurred:
If no errors occurred, we just compiled our AD FS Attribute Store (in Debug mode) and the resulting DLL should be created under you project’s directory. In this example, the DLL is called “My Custom Attribute Store.dll” and is present in the “My Custom Attribute Store\bin\Debug” folder under your project folder.
Please note that Visual Studio also copied the AD FS dll to the output directory. This is default behavior, and can be modified, but for now we can safely ignore this DLL. Visual Studio also created a PDB file. A program database (PDB) file holds debugging and project state information that allows incremental linking of a Debug configuration of your program. We do not need this file, and we can ignore it.
Creating the Custom Attribute Store in AD FS
The projects main output DLL, in my case “My Custom Attribute Store.dll” has to be copied from your development PC to all the AD FS servers in the farm. Not to the AD FS Proxy Servers (if you have any); only to all the AD FS servers in the farm.
In AD FS 3.0, you have to copy the DLL to the “C:\Windows\ADFS” folder:
Now that the Custom Attribute Store is in place, we can configure AD FS to actually use the store. Start AD FS Management by clicking “Tools” and “AD FS Management” in Server Manager.
In the AD FS Management Console, expand “AD FS” and expand “Trust Relationships”. Right click the “Attribute Stores” branch and click “Add Custom Attribute Store…” or, after selecting the Attribute Stores branch, click “Add Custom Attribute Store…” on the right side of the console.
We now need to identify our Attribute Store. The display name used, in this case “MyCustomAttributeStore”, is how we will reference this attribute store later on, when we create claim rules that actually utilize the custom attribute store.
In the “Custom attribute store class name” box, we need to identify the exact namespace, class and file that we created in this way; [namespace].[classname],[filename_without_.dll]
Our namespace was “My_Custom_Attribute_Store”, as we can see in the Class1.cs code file:
namespace My_Custom_Attribute_Store
Our class name was Class1, as we can see in the same file:
public class Class1 : IAttributeStore
And the resulting DLL is called “My Custom Attribute Store.dll” (the file we copied over to the AD FS server. We could have changed this name in Visual Studio, by right-clicking the project name on the right side of the screen, in the Solution Explorer). Please for now, don’t do that, but in case you want to know how to change the resulting DLL’s filename, we will show you how to do this.
There, click Properties;
In the “Assembly name” we see how the DLL will be named, and the “Default namespace” is the indication of the default namespace new classes in our project get.
But back to the AD FS server and the Attribute Store configuration.
Since our DLL is called “My Custom Attribute Store.dll”, our namespace is “My_Custom_Attribute_Store” and our class is called “Class1”, the proper identification to AD FS that we need to type into the “Custom attribute store class name” box is:
My_Custom_Attribute_Store.Class1, My Custom Attribute Store
Click “OK” and the custom attribute store will be added to AD FS.
We can directly check the AD FS Event log to see if the attribute store loaded successfully. Start the Event Viewer, again through the Server Manager, and expand “Applications and Services Logs” and “AD FS” and click the “Admin” log.
Locate the latest AD FS event with Event ID 251 and read the text in the event log;
Attribute store 'MyCustomAttributeStore' is loaded successfully.
This indicates that the DLL has been loaded properly, and that the Attribute Store can be used using it’s display name (“MyCustomAttributeStore”).
If you see any errors in the event log, most likely with Event ID 159, the attribute store could not be loaded. Here is an example;
During processing of the Federation Service configuration, the attribute store 'MyCustomAttributeStore' could not be loaded.
Attribute store type: My_Custom_Attribute_Store.Class1, My Custom Attribute Store
User Action
If you are using a custom attribute store, verify that the custom attribute store is configured using AD FS Management snap-in.
Additional Data
Could not load file or assembly 'My Custom Attribute Store' or one of its dependencies. The system cannot find the file specified.
This is an indication that either the DLL could be found, or the namespace or class name is incorrect.
Please make sure you copy the file to all AD FS servers in the farm, and check on all AD FS servers in the farm that the attribute has been successfully initialized.
Now that the custom attribute store is successfully added to AD FS, we can start using the attribute store in our claim rules.
Issuing claims using the Custom Attribute Store
In our example, we will configure a single web application called “Claimsweb” with claims issued by the custom attribute store. In order to do that, we need to add a claim rule to the Relying Party Trust.
Click on “Relying Party Trusts” in the “Trust Relationships” branch on the left of the screen. Right-click the relying party trust you want to modify, in this case it’s called “claimsweb.gbslab.com”, and click “Edit Claim Rules…”. You can also click on the relying party trust, and click on “Edit Claim Rules…” on the right of the management console.
This relying party currently has a single claim rule defined, that passes through a UPN claim.
We will use the UPN value to calculate the upper-case equivalent of this UPN and issue it as a “Common Name”. In order to do so, click “Add Rule…” to add a new claim rule.
Select “Send Claims using a Custom Rule” from the “Claim rule template” drop-down and click “Next”.
In the “Add Transform Claim Rule Wizard” type a friendly name for the rule in the “Claim rule name” text box (for example “UPN To UpperCase”), and type this text in the “Custom rule” text box:
c:[Type == ""]
=> issue(store = "MyCustomAttributeStore", types = (""), query = "ToUpper", param = c.Value);
This claim rule will get the UPN claim from the previous claim rule, and issue a new claim of type by passing the UPN-claim value to the custom attribute store (MyCustomAttributeStore). It will call the ToUpper query in the attribute store and issue the resulting value as the claim.
Please keep in mind that if no UPN claim exists in the claim set, this claim rule will not execute.
Click “Finish” when finished. The new claim rule is now part of the claim rule set for the relying party.
Click “OK” to close the dialog. We are now ready to test the new claim rule!
Testing the Custom Attribute Store
In my case, the sample application called “claimsweb.gbslab.com” will show me exactly what claims were issued, as well as the raw SAML 2.0 token:
Note: This sample web application uses the Saml2TokenVisualizer from the Identity Developer Training Kit which can be downloaded from
Please note that there is a new claim of type in the claim set, and it contains the exact same value as the UPN claim, only now in upper-case.
The SAML 2.0 token contains this attribute statement:
<saml:Attribute
<saml:AttributeValue>TINO@GBSLAB.COM</saml:AttributeValue>
</saml:Attribute>
Exactly what we were looking for!
Hope this helps you create your own Custom Attribute Store in AD FS 3.0!
@Aeon: The custom attribute will be used whenever a claim rule asks for it. If you use the attribute store in the claims provider trust rules as well as in the relying party trust rules, the attribute store will be queried twice, even though it might yield
the same results. (AD FS will filter duplicates.) This is of course if you do not specifically create a claim rule in the claims provider trust that, for example, takes use of the NOT EXISTS clause. That way you could first create a pass through rule and then
use the NOT EXISTS clause in another rule to access the attribute store when a claim you expect does not exist. Just an option… Whether you should put the rule on the CPT or on the RPT depends to the time and processing power it costs to use the attribute
store and how often you need the specific claims from the attribute store.
@Banchio: Thanks for your great tip! Much appreciated!
@Thomas: Not sure. Perhaps will give a great start.
@Isidro: I’m not sure if I can share that application. But the most important part of the application is the Security Token Visualizer. That component comes with the Windows Identity Foundation SDK. If you create a new Web Application in Visual Studio
2013, and select Claims Based Authentication as the authentication method, simply add the control to a page. Make sure you save the bootstrap tokens (web.config) and you’re good to go!
How to create a Custom Attribute Store for Active Directory Federation Services 3.0
thank you
Pingback from How to create a Custom Attribute Store for Active Directory Federation Services 3.0 | MS Tech BLOG
Thanks for creating this – very helpful!
How can I set up this to enable debugging in Visual Studio? Can the dll be installed in GAC as an alternative?
More and more of our customers are unleashing the power of Windows Azure Active Directory . This Enterprise
if you copy the dll and the relative pdb in the adfs folder you then should be able to debug by simply attaching to the adfs executable (directly on the adfs server or using the remote debugger). The Adfs process should be the one listed in the services console
Can you share the sample application called “claimsweb.gbslab.com” ?
Hi I would like to know when the processing of the custom attribute store happens. EG We have a custom attribute store defined, we have a claim rule on the claims provider trust Active Directory that uses this custom attribute store and we also have a
claim rule on the relying party that uses it. If we remove the claim rule from the relying party, will it bypass the custom attribute store processing then? Or will it still process (query) it because there’s a claim rule on the claims provider trust? The
reason I’m asking is that we’re experiencing some delays and some relying parties don’t have to use this custom attribute store anyway. I can’t seem to find an article explaining in which order ADFS processes this.
Thank you for the article! I found it to be well written, easy to follow and accurate; each step is nicely explained. There is a dearth of articles on the latest release of ADFS (people can’t even agree on the name/version) so this article is very welcome.
what do Schema XML I need to use if I want to UpperCase the sAMAccountName?
e.g.
=> issue(store = "ADFSCaseConv", types = (""), query = "ToUpper", param = c.Value);
for the Type I changed it to c:[Type == ""]
I am not 100% sure what I need to do for Uppercase to sAMAccountName.
the DLL was loaded fine into the ADFS.
Tino, this is a truly amazing article! Thank you very much!!! Usually these articles always omit some step(s) which makes it impossible for us that aren’t hard core .NET developer to out how things work and actually use the example but yours is really
well written and explanatory!
I am looking at the following solution, I have multiple web applications with SSO configured with ADFS 3.0. I have custom claim attributes which needs to be shared with all the application , does custom attribute store approach works out
Naren, custom or not, attribute stores are available for use by any CP or RP defined in ADFS.
Any idea how can I get raw SAML token in RP? I am interested in getting encrypted SAML assertion which was posted on ADFS during SSO signin. I am using dit net based Web app as RP.
Thanks
The following post is provided as-is with no warranty nor support of any sort. This is to illustrate
In my case I have a “Send LDAP Attributes as Claims” rule as #1, which maps SAM Account to Given Name. In rule #2, I have a Transform an Incoming Claim rule which transforms Given Name to Name ID. Then in # 3, I have my code that takes the Name ID and runs it through “MyCustomAttributeStore”, which makes it UPPER case. The only problem I have is when I check Event Viewer, it doesn’t like multiple claims using the same claim rule. Event ID 186. Can I take care of the transform in # 2 and run the claim through the upper case query in the same custom rule? If so, what would that look like?
Great article.
I’m getting an error that the “Attribute store ‘StringProcessing’ is not configured.” I have a primary ADFS server, a secondary ADFS server and an app proxy. I’ve copied the .dll to the primary and secondary servers and added via the MMC on the primary ADFS server. I can’t do the same on the secondary server as it’s not the primary. Any tips to why it’s failing?
Thanks.
Nevermind, just needed to restart the service on the secondary server. | https://blogs.technet.microsoft.com/cloudpfe/2013/12/27/how-to-create-a-custom-attribute-store-for-active-directory-federation-services-3-0/?replytocom=333 | CC-MAIN-2018-47 | refinedweb | 3,469 | 62.98 |
I know there are A LOT of similar or the same questions, but i still cannot understand / find the right way for me to work with modules. Python is my favorite language, and i like everything in it except working with imports: recursive imports (when you try to reference a name that is not yet there), import paths, etc.
So, I have this kind of a project structure:
my_project/
package1/
__init__.py
module1
module2
package2/
__init__.py
module1
module2
Package1
package2
package1.module1
from package1 import module2
import module2
package2
from . import module2
module1
from package1 import module2
package1.module1
package1.module1
package2
package1.module1
import os, sys
currDir = os.path.dirname(os.path.realpath(__file__))
rootDir = os.path.abspath(os.path.join(currDir, '..'))
if rootDir not in sys.path: # add parent dir to paths
sys.path.append(rootDir)
package1.module1
root.pth
package1
..
import package1.module1
This PEP is to change theidiom toidiom to
if __name__ == "__main__": ...
so that you at least have a chanceso that you at least have a chance
if __name__ == sys.main: ....
__main__
What is the entry point for your program? Usually the entry point for a program will be at the root of the project. Since it is at the root, all the modules within the root will be importable, provided there is an
__init__.py file in them.
So, using your example:
my_project/ main.py package1/ __init__.py module1 module2 package2/ __init__.py module1 module2
main.py would be the entry point for your program. Because the file that is executed as main is automatically put on the PYTHONPATH, both
package1 and
package2 are available from the top level import.
# in main.py from package1.module1 import * from package1.module2 import * # in package1.module1 import module2 from package2.module1 import * # in package2.module1 import * import module2 from package1.module1 import *
Note that in the above, package1 and package2 depend on each other. That should never be the case. But this is just an example of being able to import from anywhere.
main.py doesn't have to be anything fancy either. It can be very simple:
# main.py if __name__ == '__main__': from package1.module1 import SomeClass SomeClass().start()
The point I'm trying to make, is that if a module needs to be accessible by other modules, that module should be available as a top level import. A module should not attempt to put itself as a top level import (directly on the PYTHONPATH).
It should be the responsibility of the project for ensuring that all imports can be satisfied if the module is included directly in the project. There are two ways to do this. The first is by creating a bootstrapper file such as
main.py in the project folder. The other, is by creating a file that adds all relevant paths to PYTHONPATH, that is loaded by any entry points that may exist.
For example:
# setup.py import sys def load(): paths = ['/path1/','/path2/','/path3/'] for p in path: sys.path.insert(0, p) # entrypoint.py from setup import load load() # continue with program
The main thing to take away, is that a module is not supposed to put itself on the path. The path should be determined automatically by the entry point into the program, or defined explicitly by a setup script that knows where all the relevant modules are. | https://codedump.io/share/bs3t0kigpx6e/1/import-paths---the-right-way | CC-MAIN-2016-50 | refinedweb | 561 | 69.38 |
*
Pausing and restarting other threads at arbitrary times
Will Bramble
Greenhorn
Joined: Jan 21, 2006
Posts: 10
posted
Jan 21, 2006 20:02:00
0
Hi,
This will sound like a rehash of the old 'why can't I use suspend/resume', and in a way it is, but after doing some net searching I'm wondering if there really is a way to pause and restart
other
threads from, say, a master controlling thread, at arbitrary times. This would be incredibly useful.
And the 'arbitrary times' requirement implies that the threads to be paused should not be using any state checking logic of their own to decide when to pause. eg. if (shouldIPausedNow) wait(); .
I noticed a snippet of text in the new concurrency utils doco for the Condition class which was interesting, and maybe implied that it could do what I was after:
"A Condition implementation can provide behavior and semantics that is different from that of the Object monitor methods, such as guaranteed ordering for notifications, or
not requiring a lock to be held when performing notifications
. If an implementation provides such specialized semantics then the implementation must document those semantics."
But it doesn't elaborate on that, and the rest of the documentation indicates that (as we're already accustomed to) an
IllegalMonitorStateException
would be thrown if a wait call is made by a thread other than the one holding the lock..?
I understand that it's a big ask to pause a thread when it could really be doing anything, in an unstable state, etc.. but it would be nice if this were supported, perhaps at the VM level.
Any ideas, or is this a lost cause?
Jim Yingst
Wanderer
Sheriff
Joined: Jan 30, 2000
Posts: 18671
posted
Jan 21, 2006 20:35:00
0
"not requiring a lock to be held when performing notifications" - they aren't necessarily talking about notify() or notifyAll() here. This is a more general sense of the word. With a Condition, you use await() and signal()/signalAll() rather than wait() and notify()/notifyAll(). The Condition methods don't require synchronization, but the traditional wait/notify methods still do.
"I'm not back." - Bill Harding,
Twister
Will Bramble
Greenhorn
Joined: Jan 21, 2006
Posts: 10
posted
Jan 21, 2006 20:50:00
0
Yep, understand that Condition uses different calls in await() and signal()/signalAll() rather than wait() and notify()/notifyAll().
So can I legitimately call await(), signal()/signallAll() for a lock from a different thread which does not hold the lock?
Jim Yingst
Wanderer
Sheriff
Joined: Jan 30, 2000
Posts: 18671
posted
Jan 21, 2006 21:44:00
0
I see - I read your question too quickly.
It's theoretically possible to have a Condition which allows you to do this, yes. Condition is an interface, and this behavior is allowed. The interface also allows implementations to throw
IllegalStateException
if the lock is not held (or for other reasons), and stipulates that it's the responsibility of the implementation (or subinterface) to document what behavior is to be expected. This means you have to look at the particular Lock which you got the Condition from. As far as I know, the only Lock implementations available in JDK 5 are
ReentrantLock
ReentrantReadWriteLock.WriteLock
ReentrantReadWriteLock.ReadLock
ConcurrentHashMap.Segment
The first two specifically document that their newCondition() method returns a Condition which throws IllegalStateException if wait/notify methods are called without holding the lock. The third doesn't even allow you to create a Condition, and the fourth is a non-public class which inherits newCondition() from
ReentrantLock
anyway.
So, for existing JDK 5 classes, no. You can't call wait/notify methods without holding the lock. Unless you provide your own Lock/Condition implementations, or find some from a third party. Then, it's possible.
AbstractQueuedSynchronizer
may have some building blocks that would be useful in such an endeavor. Don't know much else about it, myself - guess you just have to read the specs carefully. Enjoy.
Will Bramble
Greenhorn
Joined: Jan 21, 2006
Posts: 10
posted
Jan 21, 2006 22:23:00
0
Hi Jim, thanks for your excellent responses.
I guess I'll have to keep looking for now, but I have a feeling that what I'm after may not be possible because it's inherently unsafe at the JVM level ie. pausing of threads when they could be in an indeterminate state.
It would be really handy to have though. Imagine you have a game interface, where there are many threads each dealing with different game elements on screen, and then the user may wish to momentarily pause everything (or at least the game threads) while they change settings, etc.
If this can't be done in Java then it's a serious shortcoming.
One possible, yet very long-winded way would be to create a nested VM and scripting language of sorts within Java so that even if you don't have control of pausing the JVM itself, you can pause the execution of your own scripting language. A very roundabout solution, but one that's been used before (see UnrealScript) to great effect..
Jim Yingst
Wanderer
Sheriff
Joined: Jan 30, 2000
Posts: 18671
posted
Jan 22, 2006 01:02:00
0
Well, I suppose you
could
try using suspend() and resume() even though they're deprecated. It seems risky, but possible. The challenge then becomes trying to figure out what the "critical system resources" are, and make sure the threads you want to pause are never locking those resources. Dunno if that's possible, but it might be worth a try.
However, I'd be more inclined to just implement a static checkForPause() utility method somewhere that checks to see if a boolean has been set to true, and if so, blocks until it's set to false. Once you get that working, just sprinkle that method liberally through all your thread code. Anywhere you're not holding a lock on some critical system resource.
I'm thinking that in a game, most of these threads are probably in loops that repeat many times a second (e.g. once per screen refresh) - it should be sufficient to call checkForPause() just once at the beginning of the loop. I don't think this is as difficult as you seem to imply - the API is just set up to encourage you to
think
about where pauses may be appropriate. I think it's a good thing that they don't make this
too
easy (as they had with suspend/resume), because that makes it too easy to get in deadlock or other troubles. Maybe that means I'm just blindly following the company line here - but I think you should give it a shot. Unless you've already been down this road and found problems with this approach?
[ January 22, 2006: Message edited by: Jim Yingst ]
Will Bramble
Greenhorn
Joined: Jan 21, 2006
Posts: 10
posted
Jan 22, 2006 03:21:00
0
Hmm I think I'll be steering clear of the suspend() and resume() calls, even if they do still work for now.. it's living dangerously.
It's unfortunate, especially with those methods defined on
ThreadGroup
as well which may have been perfectly suited for this sort of purpose.
The liberal sprinkling of 'flag watch' code is really what I'm trying to avoid, but I take your point about this encouraging the developer to think more about the control of their threads, and therefore the careful design of the code that utilise them. It does make sense from that end.
As it is though I'm starting to think that it might be a little crazy trying to use concurrent Java threads for my particular project, where many threads would be active within an engine, each doing their own task.. or at least a portion of it within a discrete universal time
unit
, which is where the problem would come in: some threads would naturally sneak in more time than others within that time unit, leading to some inconsistent results. There's not enough control.. and yes I'm talking to myself now..
Thanks for the insightful responses anyway.
Tanu Kumar
Greenhorn
Joined: Dec 07, 2005
Posts: 10
posted
Feb 02, 2006 23:47:00
0
I have query, I want to have a deoman thread running, and it shoudl run after every 20sec/min ( configurable) how do i achieve this?
I agree. Here's the link:
subject: Pausing and restarting other threads at arbitrary times
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In Java, a method is just like a function in C.
The method that we are creating here will simply print out a text message. To invoke (call) it from the main method an instance of the MyApp class must first be created.
The dot operator is then used after the instance’s name in order to access its members, which includes the PrintOut method.
package javaapplication15; public class JavaApplication15 { static class MyApp { void PrintOut() { System.out.println("Hello"); } } public static void main(String[] args) { MyApp m = new MyApp(); m.PrintOut(); } }
With the declaration
MyApp m = new MyApp();
m is now an instance of the class MyApp. We can now use m to access a method of the class PrintOut as in
m.PrintOut(); | https://codecrawl.com/2014/11/17/java-calling-methods/ | CC-MAIN-2018-47 | refinedweb | 124 | 73.58 |
Memory Types¶
ESP32-S2 chip has multiple memory types and flexible memory mapping features. This section describes how ESP-IDF uses these features by default.
ESP-IDF distinguishes between instruction memory bus (IRAM, IROM, RTC FAST memory) and data memory bus (DRAM, DROM). Instruction memory is executable, and can only be read or written via 4-byte aligned words. Data memory is not executable and can be accessed via individual byte operations. For more information about the different memory buses consult the ESP32-S2 Technical Reference Manual* > System and Memory [PDF].
DRAM (Data RAM)¶
Non-constant static data (.data) and zero-initialized data (.bss) is placed by the linker into Internal SRAM as data memory. Remaining space in this region is used for the runtime heap.
Note
The maximum statically allocated DRAM size is reduced by the IRAM (Instruction RAM) size of the compiled application. The available heap memory at runtime is reduced by the total static IRAM and DRAM usage of the application.
Constant data may also be placed into DRAM, for example if it is used in an non-flash-safe ISR (see explanation under How to place code in IRAM).
IRAM (Instruction RAM)¶
ESP-IDF allocates part of Internal SRAM region for instruction RAM. The region is defined in ESP32-S2 Technical Reference Manual > System and Memory > Internal Memory [PDF]. Except for the first block (up to 32 kB) which is used for MMU cache, the rest of this memory range is used to store parts of application which need to run from RAM.
Note
Any internal SRAM which is not used for Instruction RAM will be made available as DRAM (Data RAM) for static data and dynamic allocation (heap).
Why place code in IRAM¶
Cases when parts of application should be placed into IRAM:
Interrupt handlers must be placed into IRAM if
ESP_INTR_FLAG_IRAMis used when registering the interrupt handler. For more information, see IRAM-Safe Interrupt Handlers.
Some timing critical code may be placed into IRAM to reduce the penalty associated with loading the code from flash. ESP32-S2 reads code and data from flash via the MMU cache. In some cases, placing a function into IRAM may reduce delays caused by a cache miss and significantly improve that function’s performance.
How to place code in IRAM¶
Some code is automatically placed into the IRAM region using the linker script.
If some specific application code needs to be placed into IRAM, it can be done by using the Linker Script Generation feature and adding a linker script fragment file to your component that targets entire source files or functions with the
noflash placement. See the Linker Script Generation docs for more information.
Alternatively, it’s possible to specify IRAM placement in the source code using the
IRAM_ATTR macro:
#include "esp_attr.h" void IRAM_ATTR gpio_isr_handler(void* arg) { // ... }
There are some possible issues with placement in IRAM, that may cause problems with IRAM-safe interrupt handlers:
Strings or constants inside an
IRAM_ATTRfunction may not be placed in RAM automatically. It’s possible to use
DRAM_ATTRattributes to mark these, or using the linker script method will cause these to be automatically placed correctly.can be hard, the compiler will sometimes recognize that a variable or expression is constant (even if it is not marked
const) and optimize it into flash, unless it is marked with
DRAM_ATTR.
GCC optimizations that automatically generate jump tables or switch/case lookup tables place these tables in flash. There are two possible ways to resolve this issue:
Use a linker script fragment to mark the entire source file as
noflash
Pass specific flags to the compiler to disable these optimizations in the relevant source files. For CMake, place the following in the component CMakeLists.txt file:
set_source_files_properties("${CMAKE_CURRENT_LIST_DIR}/relative/path/to/file" PROPERTIES COMPILE_FLAGS "-fno-jump-tables -fno-tree-switch-conversion")
IROM (code executed from Flash)¶
If a function is not explicitly placed into IRAM (Instruction RAM) or RTC memory, it is placed into flash. The mechanism by which Flash MMU is used to allow code execution from flash is described in ESP32-S2 Technical Reference Manual > Memory Management and Protection Units (MMU, MPU) [PDF]. As IRAM is limited, most of an application’s binary code must be placed into IROM instead.
During Application Startup Flow, the bootloader (which runs from IRAM) configures the MMU flash cache to map the app’s instruction code region to the instruction space. Flash accessed via the MMU is cached using some internal SRAM and accessing cached flash data is as fast as accessing other types of internal memory.
RTC fast memory¶
The same region of RTC fast memory can be accessed as both instruction and data memory. Code which has to run after wake-up from deep sleep mode has to be placed into RTC memory. Please check detailed description in deep sleep documentation.
Remaining RTC fast memory is added to the heap unless the option CONFIG_ESP_SYSTEM_ALLOW_RTC_FAST_MEM_AS_HEAP is disabled. This memory can be used interchangeably with DRAM (Data RAM), but is slightly slower to access.
DROM (data stored in Flash)¶
By default, constant data is placed by the linker into a region mapped to the MMU flash cache. This is the same as the IROM (code executed from Flash) section, but is for read-only data not executable code.
The only constant data not placed into into this memory type by default are literal constants which are embedded by the compiler into application code. These are placed as the surrounding function’s executable instructions.
The
DRAM_ATTR attribute can be used to force constants from DROM into the DRAM (Data RAM) section (see above).
RTC slow memory¶
Global and static variables used by code which runs from RTC memory must be placed into RTC slow memory. For example deep sleep variables can be placed here instead of RTC fast memory, or code and variables accessed by the ULP Coprocessor programming. peripheral }
It is also possible to allocate DMA-capable memory buffers dynamically by using the MALLOC_CAP_DMA capabilities flag.
DMA Buffer in the stack¶
Placing DMA buffers in the stack is possible but discouraged. If doing so, pay attention to the following:
Placing DRAM buffers on the stack is not recommended if if the stack may be in PSRAM. If the stack of a task is placed in the PSRAM, several steps have to be taken as described in Support for external RAM. } | https://docs.espressif.com/projects/esp-idf/en/stable/esp32s2/api-guides/memory-types.html | CC-MAIN-2021-31 | refinedweb | 1,065 | 52.19 |
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Find that pretty interesting stuff!
I don't quite understand why switching to Dalvik made you drop the distributed nature of the view hierarchy though.
Looked into OpenBinder before. As one part of my PhD project I look into how the behaviour of an application can be changed at runtime (basically by rewiring components). For the prototype I used many ideas from OpenBinder and especially pidgen to generate the base object binder code. However, I mixed in a bit of qt's thread safe signal/ slot semantic to make it easier to make stuff thread safe ().
Is there actually something you miss from the Cobalt platform (binder related) that is not in Android?
Part of this is that a lot of those features in OpenBinder were based on creating a dynamic nature as part of the core binder design. When we went back and started on a new platform based on Dalvik, we already had a language with its own dynamic nature. Just taking what had been done for OpenBinder would leave us with these two conflicting dynamic environments. We even ended up dropping the basic ability to have multiple binder interfaces on an object because that didn't map well to the Java language. (In theory you can still implement such a thing on Android based on the native binder framework, but not in Dalvik where most of the interesting stuff happens.)
There was also just a practical issue that we couldn't take the OpenBinder code as-is for licensing reasons, so we needed to re-write it for what we shipped in Android. The development schedule for Android was pretty tight, so we needed to be really efficient in building the system, and reproducing all of OpenBinder and the sophisticated frameworks on top of it that weren't open-sourced would have been a lot of work that was hard to justify vs. what we would get by going back and doing something slightly different that leveraged a lot more of Dalvik.
And ultimately it was a different team that built Android -- yes some key people were from PalmSource with the experience with Cobalt, but there was a lot of influence as well from people coming from Danger, Microsoft, and other places. Ultimately ideas from all those places were mixed together by picking and choosing those that seemed best for the project.
I also think that from a development perspective building most of our system services on top of Dalvik has been a good thing for Android. The Dalvik environment is just a much more efficient development environment than C++; with all of our very core system services like the window manager and package manager written in it, we can move much more quickly in evolving our platform and more easily triage and fix bugs. (Given a crash report from someone's device, you are very often going to be able to identify and fix the problem when it happens in Dalvik far more quickly issues than in native code.)
Member since:
2006-02-15
Yep, it allowed you to have process boundaries at any points in the hierarchy, and one of the significant motivations was indeed for dealing with things like flash content. Basically the entire UI was one single distributed view hierarchy, rooted at the display, with the window manager sitting at the top owning the display and the top-level children there. If you know about OpenBinder, a short description is that in the design every View was an IBinder object, so it had binder interfaces for accessing the view allowing these to go across processes. In particular there were three interfaces:
- IView: the main interface for a child in the view hierarchy.
- IViewParent: the interface for a view that will be the parent of other views.
- IViewManager: the interface for managing children of a view.
These interfaces also allowed for strong security between the different aspects of a view. For example, a child view would only get an IViewParent for its parent, giving it only a very limited set of APIs on it, only those needed to interact with it as a child.
You can look at the documentation on the binder storage model at... to get a real-life flavor for a similar way to deal with objects that have multiple distinct interfaces with security constraints between them. In fact... the view hierarchy was *also* part of the storage namespace, so if you had the capability to get to it you could traverse down through it and examine it, such as from the shell!
Many of the fundamentals of this design were carried over to Android. Android dropped the distributed nature of the view hierarchy (switching to Dalvik as our core programming abstraction with Binder relegated to only on dealing with IPC lead to some different design trade-offs), but still we have our version of IViewParent in and the basic model for how operations flow down and up the hierarchy came from solving how to implement that behavior in the Cobalt distributed view hierarchy. | http://www.osnews.com/thread?555486 | CC-MAIN-2018-13 | refinedweb | 860 | 55.37 |
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