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ncurses 5.7 - patch 20101128
[ncurses.git]
/
NEWS
diff --git
a/NEWS
b/NEWS
index 8614a009c98b02bb4602c17dd59ddff116a6e1c9..6a919665159cbdfa4de3e19d16a5d08ecda4ba9e 100644
(file)
--- a/
NEWS
+++ b/
NEWS
@@
-25,7
+25,7
@@
-- sale, use or other dealings in this Software without prior written --
-- authorization. --
-------------------------------------------------------------------------------
--- $Id: NEWS,v 1.1
504 2010/02/13 22:44:31
tom Exp $
+-- $Id: NEWS,v 1.1
615 2010/11/28 16:43:28
tom Exp $
-------------------------------------------------------------------------------
This is a log of changes that ncurses has gone through since Zeyd started
@@
-45,6
+45,338
@@
See the AUTHORS file for the corresponding full names.
Changes through 1.9.9e did not credit all contributions;
it is not possible to add this information.
@@
-221,7
+553,7
@@
it is not possible to add this information.
+ move leak-checking for comp_captab.c into _nc_leaks_tinfo() since
that module since 20090711 is in libtinfo.
+ add configure option --enable-term-driver, to allow compiling with
- terminal-driver. That is used in
mingw
port, and (being somewhat
+ terminal-driver. That is used in
MinGW
port, and (being somewhat
more complicated) is an experimental alternative to the conventional
termlib internals. Currently, it requires the sp-funcs feature to
be enabled.
@@
-638,7
+970,7
@@
it is not possible to add this information.
overlooked til now.
20081011
- +
update
html documentation.
+ +
regenerated
html documentation.
+ add -m and -s options to test/keynames.c and test/key_names.c to test
the meta() function with keyname() or key_name(), respectively.
+ correct return value of key_name() on error; it is null.
@@
-2765,7
+3097,7
@@
it is not possible to add this information.
(request by Mike Aubury).
+ add symbol to curses.h which can be used to suppress include of
stdbool.h, e.g.,
- #define NCURSES_ENABLE_STDBOOL_H 0
+ #define NCURSES_ENABLE_STDBOOL_H 0
#include <curses.h>
(discussion on XFree86 mailing list).
ncurses, with patches starting at ncurses-5.6; new users should use
RSS
Atom | https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff;f=NEWS;h=6a919665159cbdfa4de3e19d16a5d08ecda4ba9e;hp=8614a009c98b02bb4602c17dd59ddff116a6e1c9;hb=82035cb9d3375b8c65b4a5a5d3bd89febdc7e201;hpb=06d92ef542e2ae2f48541e67a02acc50336e981c | CC-MAIN-2021-31 | en | refinedweb |
SSH API Framework
Project description
Korv is an API framework that uses TCP sockets over SSH to exchange JSON data with a REST-like protocol. It's built on top of the
asyncssh module, so it uses
asyncio to manage the sockets and its callbacks. This allows you to build rich APIs with the session security of SSH and without the TCP overhead of HTTP.
Communications over this framework requires SSH keys like logging into a normal SSH server:
- The server itself has a private key and a set of public keys for the authorized clients.
- The client has a private key and a set of public keys for the servers it can connect to.
Verbs
There are 4 main verbs that indicate the intent of your request:
GETfor retrieving information.
STOREfor creating new objects.
UPDATEfor changing existing objects.
DELETEfor removing objects.
Keys
As discussed previously, you establish an SSH session with the server, so it's possible to reuse existing keys or generate them through any standard mechanism like the one below:
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
Server
Getting a server up and running is very simple:
from korv import KorvServer def hello(request): """Callback for the /hello endpoint""" return 200, {'msg': 'Hello World!'} def echo(request): """Callback for the /echo endpoint""" return 200, {'msg': f'{request}'} # Create a server k = KorvServer(host_keys=['PATH_TO_YOUR_SERVER_PRIVATE_KEY'], authorized_client_keys='PATH_TO_YOUR_AUTHORIZED_PUBLIC_KEYS') # Register the callbacks k.add_callback('GET', '/hello', hello) k.add_callback('GET', '/echo', echo) # Start listening for requests k.start()
This will start a new SSH server with the specified private key that listens on port
8022 by default and will accept the clients listed in the authorized keys.
Client
Following is an example on how to communicate with this server.
>>> from korv import KorvClient >>> >>> # Create the client >>> k = KorvClient(client_keys=['PATH_TO_YOUR_CLIENTS_PRIVATE_KEY']) >>> >>> # Issue a GET request and print the output >>> k.get('/hello', callback=lambda response: print(response['body'])) >>> {'msg': 'Hello World!'}
Return Codes
We're using standard HTTP response codes:
200= Success.
400= Malformed request or missing parameters.
404= NotFound
500= Internal error.
Server exceptions map to a
500 return code ans will include a traceback in the response.
Project details
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages. | https://pypi.org/project/korv/ | CC-MAIN-2021-31 | en | refinedweb |
simply baby oil
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Our calming baby oil which works to protect and moisturise the skin, by combining nourishing argan oil with soothing chamomile, this oil is perfect for sensitive. Fantastic for massaging babies, a lovely way to bond with your baby.
ingredients
argania spinosa kernel oil, anthemis nobilis flower extract, citral, geraniol, farnesol, linalool, citronellol, d-limonene
import information
This product may not be suitable if your baby has a nut or skin allergy. Avoid getting into the eyes and wash out thoroughly with water if this occurs.
Natalja Ziliajeva –
Really good products. Love the smell of baby oil. But the colour or red ruby lip balm is horrendous, its not ruby but ginger rusty. Other than that all good
Jane –
My baby girl was a few weeks prem and had very dry skin. I used the simply baby oil in her bath every night and before long her skin was healthy and peachy! | https://simplyargan.co.uk/product/simply-baby-oil | CC-MAIN-2021-31 | en | refinedweb |
Procedural Terrain With Java – part 1
Every year, around Christmas time I always get a hankering to write some 3D terrain rendering code. Not so much the actual rendering engine, that part has already been done with 3D APIs such as OpenGL and Direct X. Its more about rendering a 3D terrain generated by code, more specifically pseudo-random numbers, enabling a continuous never ending terrain.
This year I’m getting a head start, and to celebrate that, I’m going to blog it as I go. I’m going to be using Java with JMonkeyEngine APIs on top of the LWJGL OpenGL libs. I quite like JMonkeyEngine as it puts more control into your code giving with the power of the Java language. Being Java based means it is flexible enough to use some good design patterns and code structure without too much rigidity and I can unit test my logic too!
So, with that, I’m going to create a Maven project which will pull in the JMonkeyEngine libs and create a very simple, cube lit by a sun. I’m going to be using Java 13 and the latest JMonkeyEngine version (3.2.4 -stable). If you’ve looked at JME before, this probably isn’t going to be anything earth shattering, but serves as a solid ground for part II.
Start by creating a new simple Maven project and add the following content in the
pom.xml file.
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>13</maven.compiler.source> <maven.compiler.target>13</maven.compiler.target> <jme-version>3.2.4-stable</jme-version> </properties> <repositories> <repository> <id>JCenter</id> <url></url> </repository> </repositories> <dependencies> <dependency> <groupId>org.jmonkeyengine</groupId> <artifactId>jme3-core</artifactId> <version>${jme-version}</version> </dependency> <dependency> <groupId>org.jmonkeyengine</groupId> <artifactId>jme3-terrain</artifactId> <version>${jme-version}</version> </dependency> <dependency> <groupId>org.jmonkeyengine</groupId> <artifactId>jme3-plugins</artifactId> <version>${jme-version}</version> </dependency> <dependency> <groupId>org.jmonkeyengine</groupId> <artifactId>jme3-lwjgl</artifactId> <version>${jme-version}</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> <configuration> <source>${maven.compiler.source}</source> <target>${maven.compiler.target}</target> </configuration> </plugin> </plugins> </build> </project>
Now at some point, you will have to download the JMonkeyEngine SDK to get the binary libraries to use with JME. For now, we just need one, which is
liblwjgl64.so. Your filename may be different depending on the platform and 32/64 bit. This is the lib for supporting the LWJGL and for now, can go in the root of the project folder, next to the
pom.xml file.
Our next step it to write a piece of code which will get us displaying some graphics in a page. We’ll create a main class which inherited from the
SimpleApplication class in the JME library.
import com.jme3.app.SimpleApplication; public class Main extends SimpleApplication { public static void main(final String[] args) { final Main app = new Main(); app.start(); } @Override public void simpleInitApp() { } }
Run that and you should get the JMonkeyEngine splash screen where you can pick your settings, and upon clicking OK, you should see a big black screen with some debug information on it:
Not much is going on here, just some debug information including our FPS rate. Of course, we haven’t added anything to the display yet. So we need to add some light and an object. We’ll also position the camera from where we are generating the image so we can get a good view. We’ll do this in the
simpleInitApp method that is used to initialise the content.
@Override public void simpleInitApp() { // move up, to the side and look at the origin getCamera().setLocation(new Vector3f(-4, 5, 10));); // create a simple box final Box b = new Box(1, 1, 1); final Geometry geom = new Geometry("Box", b); // create a very plain lit material final Material mat = new Material(assetManager, "Common/MatDefs/Light/Lighting.j3md"); // assign this material to the box geometry. geom.setMaterial(mat); // add the geometry to the scene and we are good to go rootNode.attachChild(geom); }
This article isn’t meant to be primer on 3D graphics, or JMonkeyEngine in particular, but this is a simple application that will get you up and running with a simple lit scene in JME with Java.
We move the camera and look at the box so we can see all 3 sides and get an idea of how they are shaded. The directional light has no position so its only influence on shading depends solely on the angle between the box face and the direction of the light that was specified in the constructor. The material we have used is a simple lit material using the default parameters.
If you run this, you will see a simple scene with a lit box that you can use the mouse to look around with and the WASD keys to move around in.
This gets us up and running with JME. Next time we’ll look at creating a simple terrain using code, in particular the JME noise functions to create terrain. | https://www.andygibson.net/blog/programming/procedural-terrain-with-java-part-1/ | CC-MAIN-2021-31 | en | refinedweb |
On Fri, Jun 28, 2002 at 05:32:37PM -0700, Richard Henderson wrote: > On Tue, Jun 25, 2002 at 05:32:59AM -0700, Aldy Hernandez wrote: > > + case BUILT_IN_ARGS_INFO: > > + case BUILT_IN_STDARG_START: > > + case BUILT_IN_VA_END: > > + case BUILT_IN_VA_COPY: > > + case BUILT_IN_VARARGS_START: > > Feel free to fix these (plus VA_ARG_EXPR) by changing the backend > hooks to return (unsimplified) trees instead of rtl. In many cases > this can be done simply by not calling expand_expr. woh neato. diego and i had talked about this. this sounds like the most sensible approach. will do this [later]. | https://gcc.gnu.org/pipermail/gcc-patches/2002-June/081123.html | CC-MAIN-2021-31 | en | refinedweb |
SpeechSynthesizer 1.3
When you ask Alexa a question, the SpeechSynthesizer interface returns the appropriate speech response.
For example, if you ask Alexa "What's the weather in Seattle?", your client receives a
Speak directive from the Alexa Voice Service (AVS). This directive contains a binary audio attachment with the appropriate answer, which you must process and play.
Version changes
- Support for user interruption of Text-To-Speech (TTS) output.
- ADDED
SpeechInterruptedevent.
- Support for cloud-initiated interruption of TTS output.
- Support for captions for TTS.
States
SpeechSynthesizer has the following states:
- PLAYING – When Alexa speaks, SpeechSynthesizer is in the
PLAYINGstate. SpeechSynthesizer transitions to the
FINISHEDstate when speech playback completes.
- FINISHED – When Alexa finishes speaking, SpeechSynthesizer transitions to the
FINISHEDstate with a
SpeechFinishedevent.
- INTERRUPTED – When Alexa speaks and gets interrupted, SpeechSynthesizer transitions to the
INTERRUPTEDstate. Interrupted events occur through use of voice, physical Tap-to-Talk or a
Speakdirective with a
REPLACE_ALL
playBehavior.
INTERRUPTEDis temporary until the next
Speakdirective starts.
Capability assertion
A device can implement SpeechSynthesizer 1.3 on its own behalf, but not on behalf of any connected endpoints.
New AVS integrations must assert support through Alexa.Discovery. Alexa continues to support existing integrations using the Capabilities API.
Sample object
{ "type": "AlexaInterface", "interface": "SpeechSynthesizer", "version": "1.3" }
Context
For each playing TTS that requires context, your client must report
playerActivity and
offsetInMilliseconds.
To learn more about reporting Context, see Context Overview.
Example message
{ "header": { "namespace": "SpeechSynthesizer", "name": "SpeechState" }, "payload": { "token": "{{STRING}}", "offsetInMilliseconds": {{LONG}}, "playerActivity": "{{STRING}}" } }
Payload parameters
Directives
Speak
AVS sends a
Speak directive to your client every time Alexa delivers a speech response. Alexa can receive a
Speak directive in two different ways, including:
- When a user makes a voice request, such as asking Alexa a question. AVS sends a
Speakdirective to your client after it receives a Recognize event.
- When a user performs an action, such as setting a timer. First, the timer starts with the
SetAlertdirective. Second, AVS sends a
Speakdirective to your client, notifying you that the timer started.
Example message
The
Speak directive is a multipart message containing two different formats – one JSON-formatted directive and one binary audio attachment.
JSON
{ "directive": { "header": { "namespace": "SpeechSynthesizer", "name": "Speak", "messageId": "{{STRING}}", "dialogRequestId": "{{STRING}}" }, "payload": { "url": "{{STRING}}", "format": "{{STRING}}", "token": "{{STRING}}", "playBehavior": "{{STRING}}", "caption": { "content": "{{STRING}}", "type": "{{STRING}}" } } } }
Binary audio attachment
The following multipart headers precede the binary audio attachment.
Content-Type: application/octet-stream Content-ID: {{Audio Item CID}} {{BINARY AUDIO ATTACHMENT}}
Header parameters
Payload parameters
Events
SpeechStarted
Send the
SpeechStarted event to AVS after your client processes the
Speak directive and begins playback of synthesized speech.
Example message
{ "event": { "header": { "namespace": "SpeechSynthesizer", "name": "SpeechStarted", "messageId": "{{STRING}}" }, "payload": { "token": "{{STRING}}" } } }
Header parameters
Payload parameters
SpeechFinished
When Alexa finishes speaking, send the
SpeechFinished event.
Send this event only after Alexa fully processes the
Speak directive and finishes rendering the TTS.
If a user cancels TTS playback, don't send the
SpeechFinished event. For example, if a user interrupts the Alexa TTS with "Alexa, stop" don't send a
SpeechFinished event, but instead send the
SpeechInterrupted event.
Example message
{ "event": { "header": { "namespace": "SpeechSynthesizer", "name": "SpeechFinished", "messageId": "{{STRING}}" }, "payload": { "token": "{{STRING}}" } } }
Header parameters
Payload parameters
SpeechInterrupted
When Alexa is interrupted, send the
SpeechInterrupted event.
When Alexa is in a
PLAYING state and a user barges in to make a new voice request, the device must do the following:
- Transition the playback state to
INTERRUPTED.
- Send the
SpeechInterruptedevent to AVS.
A new voice request can come from a wake word detection, a physical button press on Tap-to-Talk device, or a
Speak directive with a
REPLACE_ALL
playBehavior. The
INTERRUPTED playback state is temporary until the next
Speak directive starts.
Example message
{ "event": { "header": { "namespace": "SpeechSynthesizer", "name": "SpeechInterrupted", "messageId": "{{STRING}}", }, "payload": { "token": "{{STRING}}", "offsetInMilliseconds": {{LONG}} } } }
Header parameters
Payload parameters | https://developer.amazon.com/es-ES/docs/alexa/alexa-voice-service/speechsynthesizer.html | CC-MAIN-2021-31 | en | refinedweb |
SciChart® the market leader in Fast WPF Charts, WPF 3D Charts, and iOS Chart & Android Chart Components
Hi,
I have a question concerning multithreaded access to the DataSeries:
We implemented an overview for our chart as described here. This works fine when we load data, add it to the series and then display it.
Now, for a certain use case we need to display live data. We implemented this in a background thread. We noticed that after some time the application freezes when the update frequency rises. In the documentation I found this:
NOTE: Considerations when a DataSeries is shared across multiple chart surfaces. Currently only a single parent chart is tracked, so DataSeries.SuspendUpdates() where the DataSeries is shared may have unexpected results.
I guess this is what is happening here…so what is the recommended approach to achieve something like this? Do we have to add the data on the UI thread if we want to have the Overview? Here it says:
When appending Data in a background thread, you cannot share a DataSeries between more than one SciChartSurface. You can still share a DataSeries between more than one RenderableSeries.
Does that mean we should create more different RenderableSeries for the main chart surface and the overview surface that are based on the same DataSeries? Any help would be appreciated!
I am trying to implement the Custom Overview control but the above namespace cannot be resolved.
I tried adding the required classes to my project but cannot find a way to reference them from Xaml. The required classes are the following –
DoubleToGridLengthConverter
ActualSizePropertyProxy
Without these classes the Overview scrollbar cannot be resized and stays fully expanded.
Any help please?
In your custom overview example the width of the grid column used as padding is linked to the width of the y axis.
<Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <!-- Hosts overview control --> <ColumnDefinition Width="{Binding ActualWidthValue, ElementName=proxy, Mode=OneWay, Converter={StaticResource DoubleToGridLengthConverter}}" /> <!-- Used to bind to parent surface YAxis --> </Grid.ColumnDefinitions> <!-- This class is in the Examples Source Code, under your install directory --> <helpers:ActualSizePropertyProxy x:
What do you use for the Path if you have multiple y axes. I have tried objects like AxisAreaLeft with no success. | https://www.scichart.com/questions/tags/overview | CC-MAIN-2019-09 | en | refinedweb |
Failamp is a simple audio & video mediaplayer implemented in Python, using the built-in Qt playlist and media handling features. It is modelled, very loosely on the original Winamp, although nowhere near as complete (hence the fail).
The main window
The main window UI was built using Qt Designer. The screenshot below shows the constructed layout, with the default colour scheme as visible within Designer.
The layout is constructed in a
QVBoxLayout which in turn contains the playlist
view (
QListView) and two
QHBoxLayout horizontal layouts which contain the
time slider and time indicators and the control buttons respectively.
Player
First we need to setup the Qt media player controller
QMediaPlayer. This
controller handles load and playback of media files automatically, we just
need to provide it with the appropriate signals.
We create a persistent player which we'll use globally. We setup an error
handler by connecting our custom
erroralert slot to the error signal.
class MainWindow(QMainWindow, Ui_MainWindow): def __init__(self, *args, **kwargs): super(MainWindow, self).__init__(*args, **kwargs) self.setupUi(self) self.player = QMediaPlayer() self.player.error.connect(self.erroralert)
The generic media player controls can all be connected to the player directly,
using the appropriate slots on
self.player.
# Connect control buttons/slides for media player. self.playButton.pressed.connect(self.player.play) self.pauseButton.pressed.connect(self.player.pause) self.stopButton.pressed.connect(self.player.stop)
We also have two slots for volume control and time slider position. Updating either of these will alter the playback automatically, without any handling on by us.
self.volumeSlider.valueChanged.connect(self.player.setVolume) self.timeSlider.valueChanged.connect(self.player.setPosition)
Finally we connect up our timer display methods to the player position signals, allowing us to automatically update the display as the play position changes.
self.player.durationChanged.connect(self.update_duration) self.player.positionChanged.connect(self.update_position)
When you drag the slider, this sends a signal to update the play position, which in turn sends a signal to update the time display. Chaining operations off each other allows you to keep your app components independent, one of the great things about signals.
Qt Multimedia also provides a simple playlist controller. This does not provide the widget itself,
just a simple interface for queuing up tracks (we handle the display using our own
QListView).
Playlist
Helpfully, the playlist can be passed to the player, which wil then use it to automatically select the track to play once the current one is complete.
self.playlist = QMediaPlaylist() self.player.setPlaylist(self.playlist)
The previous and next control buttons are connected to the playlist and will perform skip/restart/back
as expected (all handled by
QMediaPlaylist). Because the playlist is connected to the player, this
will automatically trigger the player to play the appropriate track.
self.previousButton.pressed.connect(self.playlist.previous) self.nextButton.pressed.connect(self.playlist.next)
The display of the playlist is handled by a
QListView object. This is a view
component from Qt's model/view architecture, which is used to efficiently display data held
in data models. In our case, we are storing the data in a playlist object
QMediaPlaylist
from the Qt Multimedia module.
The
PlaylistModel is our custom model for taking data from the
QMediaPlaylist and mapping
it to the view. We instantiate the model and pass it into our view.
self.model = PlaylistModel(self.playlist) self.playlistView.setModel(self.model) self.playlist.currentIndexChanged.connect(self.playlist_position_changed) selection_model = self.playlistView.selectionModel() selection_model.selectionChanged.connect(self.playlist_selection_changed)
Opening and dropping
We have a single file operation — open a file — which adds the file to the playlist. We also accept drag and drop, which is covered later.
self.open_file_action.triggered.connect(self.open_file) self.setAcceptDrops(True)
Video
Finally, we add the viewer for video playback. If we don't add this the player will still play
videos, but just play the audio component. Video playback is handled by a specific
QVideoWidget.
To enable playback we just pass this widget to the players
.setVideoOutput method.
self.viewer = ViewerWindow(self) self.viewer.setWindowFlags(self.viewer.windowFlags() | Qt.WindowStaysOnTopHint) self.viewer.setMinimumSize(QSize(480,360)) videoWidget = QVideoWidget() self.viewer.setCentralWidget(videoWidget) self.player.setVideoOutput(videoWidget)
Finally we just enable the toggles for the viewer to show/hide on demand.
self.viewButton.toggled.connect(self.toggle_viewer) self.viewer.state.connect(self.viewButton.setChecked)
Playlist Model
As mentioned we're using a
QListView object from Qt's model/view architecture for playlist display,
with data held in the
QMediaPlaylist. Since the data store is already handled for us, all we need to
handle is the mapping from the playlist to the view.
In this case the requirements are pretty basic — we need:
- a method
rowCountto return the total number of rows in the playlist, via
.mediaCount()
- a method
datawhich returns data for a specific row, in this case we're only displaying the filename
You could extend this to access media file metadata and show the track name instead.
class PlaylistModel(QAbstractListModel): def __init__(self, playlist, *args, **kwargs): super(PlaylistModel, self).__init__(*args, **kwargs) self.playlist = playlist def data(self, index, role): if role == Qt.DisplayRole: media = self.playlist.media(index.row()) return media.canonicalUrl().fileName() def rowCount(self, index): return self.playlist.mediaCount()
By storing a reference to the playlist in
__init__ the can get the other data easily at any time. Changes to the playlist in the application will be automatically reflected in the view.
The playlist and the player can handle track changes automatically, and we have the controls for skipping. However, we also want users to be able to select a track to play in the playlist, and we want the selection in the playlist view to update automatically as the tracks progress.
For both of these we need to define our own custom handlers. The first is for updating the playlist position in response to playlist selection by the user —
def playlist_selection_changed(self, ix): # We receive a QItemSelection from selectionChanged. i = ix.indexes()[0].row() self.playlist.setCurrentIndex(i)
The next is to update the selection in the playlist as the track progresses. We specifically check for
-1 since this value is sent by the playlist when there are not more tracks to play — either we're at
the end of the playlist, or the playlist is empty.
def playlist_position_changed(self, i): if i > -1: ix = self.model.index(i) self.playlistView.setCurrentIndex(ix)
Drag, drop, and file operations
We enabled drag and drop on the main window by setting
self.setAcceptDrops(True). With this enabled,
the main window will raise the
dragEnterEvent and
dropEvent events when we perform drag-drop
operations.
This enter/drop duo is the standard approach to drag-drop in desktop UIs. The enter event recognises what is being dropped and either accepts or rejects. Only if accepted can a drop occur.
The
dragEnterEvent checks whether the dragged object is droppable on our application. In this
implementation we're very lax — we only check that the drop is file (by path). By default
QMimeData has checks built in for html, image, text and path/URL types, but not audio or video.
If we want these we would have to implement them ourselves.
We could add a check here for specific file extension based on what we support.
def dragEnterEvent(self, e): if e.mimeData().hasUrls(): e.acceptProposedAction()
The
dropEvent iterates over the URLs in the provided data, and adds them to the playlist.
If we're not playing, dropping the file triggers autoplay from the newly added file.
def dropEvent(self, e): for url in e.mimeData().urls(): self.playlist.addMedia( QMediaContent(url) ) self.model.layoutChanged.emit() # If not playing, seeking to first of newly added + play. if self.player.state() != QMediaPlayer.PlayingState: i = self.playlist.mediaCount() - len(e.mimeData().urls()) self.playlist.setCurrentIndex(i) self.player.play()
The single operation defined is to open a file, which adds it to the current playlist. We predefine a
number of standard audio and video file types — you can easily add more, as long as they are supported
by the
QMediaPlayer controller, they will work fine.
def open_file(self): path, _ = QFileDialog.getOpenFileName(self, "Open file", "", "mp3 Audio (*.mp3);mp4 Video (*.mp4);Movie files (*.mov);All files (*.*)") if path: self.playlist.addMedia( QMediaContent( QUrl.fromLocalFile(path) ) ) self.model.layoutChanged.emit()
Position & duration
The
QMediaPlayer controller emits signals when the current playback duration and position are updated.
The former is changed when the current media being played changes, e.g. when we progress to the next track.
The second is emitted repeatedly as the play position updates during playback.
Both receive an
int64 (64 bit integer) which represents the time in milliseconds. This same scale
is used by all signals so there is no conversion between them, and we can simply pass the value to our
slider to update.
def update_duration(self, duration): self.timeSlider.setMaximum(duration) if duration >= 0: self.totalTimeLabel.setText(hhmmss(duration))
One slightly tricky thing occurs where we update the slider position. We want to update the slider as the track progresses, however updating the slider triggers the update of the position (so the user can drag to a position in the track). This can trigger weird behaviour and a possible endless loop.
To work around it we just block the signals while we make the update, and re-enable the after.
def update_position(self, position): if position >= 0: self.currentTimeLabel.setText(hhmmss(position)) # Disable the events to prevent updating triggering a setPosition event (can cause stuttering). self.timeSlider.blockSignals(True) self.timeSlider.setValue(position) self.timeSlider.blockSignals(False)
Video viewer
The video viewer is a simple
QMainWindow with the addition of a toggle handler to show/display the
window. We also add a hook into the
closeEvent to update the toggle button, while overriding the
default behaviour — closing the window will not actually close it, just hide it.
class ViewerWindow(QMainWindow): state = pyqtSignal(bool) def closeEvent(self, e): # Emit the window state, to update the viewer toggle button. self.state.emit(False) def toggle_viewer(self, state): if state: self.viewer.show() else: self.viewer.hide()
Style
To mimic the style of Winamp (badly) we're using the Fusion application style as a base, then applying a dark theme. The Fusion style is nice Qt cross-platform application style. The dark theme has been borrowed from this Gist from user QuantumCD.
app.setStyle("Fusion") palette = QPalette() # Get a copy of the standard palette. palette.setColor(QPalette.Window, QColor(53, 53, 53)) palette.setColor(QPalette.WindowText, Qt.white) palette.setColor(QPalette.Base, QColor(25, 25, 25)) palette.setColor(QPalette.AlternateBase, QColor(53, 53, 53)) palette.setColor(QPalette.ToolTipBase, Qt.white) palette.setColor(QPalette.ToolTipText, Qt.white) palette.setColor(QPalette.Text, Qt.white) palette.setColor(QPalette.Button, QColor(53, 53, 53)) palette.setColor(QPalette.ButtonText, Qt.white) palette.setColor(QPalette.BrightText, Qt.red) palette.setColor(QPalette.Link, QColor(42, 130, 218)) palette.setColor(QPalette.Highlight, QColor(42, 130, 218)) palette.setColor(QPalette.HighlightedText, Qt.black) app.setPalette(palette) # Additional CSS styling for tooltip elements. app.setStyleSheet("QToolTip { color: #ffffff; background-color: #2a82da; border: 1px solid white; }")
This covers all the elements used in this Failamp. If you want to use this is another app you may need to add additional CSS tweaks, like that added for
QToolTip.
Timer
Finally, we need a method to convert a time in milliseconds in to an
h:m:s or
m:s display. For this we
can use a series of
divmod calls with the milliseconds for each time division. This returns the number
of complete divisions (
div) and the remainder (
mod). The slight tweak is to only show the hour part
when the time is longer than an hour.
def hhmmss(ms): # s = 1000 # m = 60000 # h = 360000 h, r = divmod(ms, 36000) m, r = divmod(r, 60000) s, _ = divmod(r, 1000) return ("%d:%02d:%02d" % (h,m,s)) if h else ("%d:%02d" % (m,s))
Want to build your own apps?
Then you might enjoy this book! Create Simple GUI Applications with Python & Qt is my guide to building cross-platform GUI applications with Python. Work step by step from displaying your first window to building fully functional desktop software.
Further ideas
A few nice improvements for this would be —
- Auto-displaying the video viewer when viewing video (and auto-hiding when not)
- Docking of windows so they can be snapped together — like the original Winamp.
- Graphic equalizer/display —
QMediaPlayerdoes provide a stream of the audio data which is playing. With
numpyfor FFT we should be able to create a nice nice visual. | https://www.twobitarcade.net/article/media-player-python-qt/ | CC-MAIN-2019-09 | en | refinedweb |
Thread: The makers of Programs
On a previous post, we talked about Processes. In this post, we will talk about ‘their offspring’, the Thread!
What are threads?
Threads are squiggly lines:
But to be more realistic we can interpret the name Threads coming from:
- an analogy to the Thread of fabrics: they work together to span a piece of a bigger thing, i.e. the fabric
- or as the dictionary puts it:
- something continuous or drawn out
- a line of reasoning or train of thought that connects the parts in a sequence (as ideas or events)
What is the difference between Threads and Processes?
Actually, we can think of a process as one big thread. A process has an address space and one thread of execution (hence the “big thread” idea). If you create another process, you would have it with its own address space and execution thread.
Threads on the other hand, as mentioned before, share the address space among themselves. Although we might think of threads as separate processes, one has to be aware that they are sharing memory which if not planned correctly can lead to some undesirable side effects.
What can you use them for?
Why would we want a “smaller process” inside a process? Well, there are actually several reasons, so let’s check upon a few:
You can use Threads to parallelize tasks
If you have a task that can run in parallel, i.e. to perform the task, its parts don’t depend on each other, you can benefit from running them in different threads.
Take for instance a list of items that have to be worked. Let’s say there is a huge amount of cans, that you have to work through. You have to take each can and copy down the text which it is labeled on the surface of the can to a paper and put that into a pile. Some of the cans have really long texts and others have short ones which can take more or less time to copy.
This is an example of a task that can be parallelized. If there are more people all reading from the same list, copying down the text and putting the paper to the pile, than the number of cans will go down faster than if you are doing it alone!
Don’t Always have to be cans though
You can now substitute the people for threads and the cans for something like a text parser which is copying some relevant info into a file. You can even add another thread that will be saving the file every minute or so so that you don’t lose your work.
If this process was single threaded than every time the user triggered the save operation, no info would be parsed and the whole process would take much longer.
Now the image above is mostly true: if we have a multi-core CPU running these than we see a scenario like that. On the other hand, if the machine has 1 core, there is a subtle switching that happens and this would not turn out to happen exactly like the image.
Threads really shine on systems where there are multiple CPUs available. But more on that later!
Wouldn’t Processes work just as well?
Because threads all share the same memory space, it is possible to achieve something like the situation described above, i.e. they all can save into a shared file and they all can read from the same stream of incoming data (some problems may arise on this… we will talk about that soon).
Since processes don’t share memory space, this would be impossible (or very complicated) to implement as described with processes.
Threads are also lightweight when we compare them to processes. This makes it easier and faster to create and switch the context of these threads. In many systems, creating a thread goes 10–100 times faster than creating a process.[1]
The Classical Model
There are other models, with attention to the one used in UNIX systems. However, in this post, I will focus on the classical one. This one is the theoretical one and the base for the other models so it will suit you just fine to learn it!
Processes and Threads – A Symbiotic relation
So let us start with the big picture: You can imagine processes as ways of grouping related resources together: files, other processes, alarms, handles, data, etc. Because these resources are all bundled in together as a process, they can all be managed and accessed more easily.
A process has itself a Thread of Execution (often just shortened to Thread) which is where the execution of tasks runs. The thread has:
- Program counter – keeps track of instructions to execute
- Registers – where the current variables are stored
- Stack – contains the execution history which has frames for each procedure called and not yet returned.
this Thread, as well as any other need to run inside the context of a process. However, they are different concepts and can be treated separately: Processes are used for grouping of resources and threads are the ones that get scheduled for execution on the CPU.
What Threads bring to the Model
With threads, we extend the process model to allow multiple executions in the same environment. This is called multi-threading. This is a situation analogous to the one of having multiple processes running in parallel on one computer. But there is one difference: the threads are sharing resources which can ease the communication and sharing that happens among threads and reduce the total communication overhead in an application.
Because of this property of the threads that can be compared to the processes, Threads very often are called lightweight processes.
On the right: 1 process with 3 threads
Who has what
Just to make it clear, let’s write it down what belongs to processes and what belongs to threads:
As one can see: the threads have their own “stuff” that only they know about and take care of. However due to the fact that threads are all inside a process, they have access to the process “stuff” too, and there is where the problem lies…
Problems of thread misuse
Although threads may offer a variety of benefits, one should also be aware of the problems that may arise with their usage.
I am not saying you should never make use of them, but by being aware of the problems you can start to watch out for them in your implementations and even test the behavior in order to catch them before they get in production.
Many Threads
If a few threads offer some benefits, then adding more can only be even better right??? Right???
Wrooooooooong!
Of course, if you have many threads they might start to incur a problem for the system memory. There are ways around that too, by pooling them together for example. This, however, is not within the scope of this article!
There are problems that can arise when we use several threads together with each other, these usually involve some kind of situation where one thread expects something and another also does or some situation such as where a thread is faster than the other. To go around this Here are the problems which you are most likely to see:
Deadlocks
In this case, what happens is pretty simple: Someone is “hogging” someone else’s stuff and both can’t play on without each other!
But let’s explain this better. Suppose we have 2 Threads: Thread_A and Thread_B. The deadlock situation occurs when none of the threads can finish their work because they are both dependent on one another.
- To finish its task Thread_A needs the results that Thread_B is going to deliver so it (Thread_A) can write to a file, let’s call it, file_out.txt
- Thread_A has acquired the file_out.txt and it is waiting on Thread_B to finish its computations
- Thread_B is doing its stuff, BUT it needs to access file_out.txt … but it can’t since Thread_A is using it
- Now Thread_B is waiting to use the file and Thread_A is not going to release it until he receives the values from Thread_B
Can you see the problem here?
There are different strategies to solve these situations: Locks, Semaphores, etc. But we will cover these topics in another post.
A famous thought experiment/problem in computer science is called the Dining Philosophers. Here is the Wikipedia explanation of the problem:
Five silent philosophers sit at a table around a bowl of spaghetti. A fork is placed between each pair of adjacent philosophers. (An alternative problem formulation uses rice and chopsticks instead of spaghetti and forks.)
Each philosopher must alternately think and eat. However, a philosopher can only eat spaghetti when he has both left and right forks. Each fork can be held by only one philosopher and so a philosopher can use the fork only if it.
If you’d like a nice little post about it, check out Austin Walter’s blog about it!
Starvation
Now this one is all about never getting a chance to do what you want!
This case happens when a Thread never gets access to a resource it needs in order to finish its work. This might happen because another thread never releases the resource or even because of some unfortunate timing, there is always another thread taking the resource needed before the thread has a chance.
Livelock
This case is somewhat similar to the other two above, but it does involve some different nuances. In this case, differently, from the Deadlock case, the threads don’t keep waiting without doing anything. The threads usually keep doing something but are involved in some kind of loop which they can’t get out of due to other factors. Here is an example:
We have 1 Thread again: T_A and T_B. And both can communicate with each other. Now suppose they both share one resource with other threads and that they are both so programmed that they have to give up the resource on request, this happens for example because they should be secondary threads and there are other more important tasks.
Now the problem of a Livelock happens when T_A is using the resource and the T_B thread asks for the resource. T_A will than stop using the resource and give them access to T_B. T_A, however, will want to poll for usage of the resource again, and by doing this T_B will get the request of another thread wanting to use the resource and will forgo it. This will happen again and again and both threads won’t get any work done.
Race Conditions
This is a tricky one. A race condition is what usually gets us, developers, scratching our head trying to understand what is happening. It is also a “mean one” since it is hard to debug it because adding a debugger will affect the timing of the program. If you need another reason to wish this never happens, then here you go: This issue might only happen sometimes! Maybe it runs 2, 3 or even 1000 times but it will fail at the 1004th time.
This case happens when 2 or more threads access a critical section of the code at the same time. What might happen is that a value changes unexpectedly and thus you get a value different from what you would’ve expected.
Let’s see a very easy example to illustrate this:
public class VeryBrittleClass { private int counter; public int increaseAndReturnCounter() { return value+1; } }
Now if you the counter was let’s say “99” and you call the class method above, you would expect it to return you 100 right? Yes. But what happens if several threads ask for the value at the same time? Well then, since the value+1 is not an atomic operation, i.e. it does not happen in one step in the processor, this could lead to some problems that are best explained with such an image showing the steps on each thread:
So we end up with two threads that have the same count although this should not be the case.
Final thoughts on Thread
We saw quite a bit with this post, but there is way more to find out.
I definitely recommend Deadlock Empire for you to get a feeling of the problems with multithreading. This is a simple role that puts you in charge of the CPU processor. Your job is to make the program fail by giving the threads CPU time. It is quite easy to get a hold on the control and will give a nice feel for these problems.
Please share with me anything that you liked or disliked about this post so I can improve. Hope to see you next 🙂
[1](modern Operating Systems – A.S.Tanenbaum (P.98)) | http://fdiez.org/thread-program-makers/ | CC-MAIN-2019-09 | en | refinedweb |
import org.slf4j.LoggerFactory; import ch.qos.logback.classic.Level; import ch.qos.logback.classic.Logger; Logger root = (Logger)LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME); root.setLevel(Level.DEBUG); //change to debug
Saturday, October 16, 2010
Logback: Change root logger level programmatically
A couple of years ago, I wrote about how it is possible to change log4j logging levels using JMX. I'm now using logback, which is intended to be the successor of log4j and provides several advantages over it. The following code snippet can be used to change the root logger's logging level in logback:
Labels: Java, logback, programming
If i do something like this
val funch(packageName : String)
{
Logger root = (Logger)LoggerFactory.getLogger(packageName);
root.setLevel(Level.DEBUG); //change to debug
}
Will this add a logger if the logger has not been defined inside logback.xml and make the changes ? Because i have no logger defined but still this works . Dont know y . Any clue ? | http://fahdshariff.blogspot.com/2010/10/logback-change-root-logger-level.html | CC-MAIN-2019-09 | en | refinedweb |
Urho.Application Class
Base class for creating applications which initialize the Urho3D engine and run a main loop until exited.
See Also: Application
Syntax
[Preserve(AllMembers=true)]
public class Application : UrhoObject
public class Application : UrhoObject
Remarks
This is the base class that your application should subclass and provide at implementations for the Application.Setup and Application.Start methods. You can use await asynchronous methods from the Application.Start methods.
Access to various subsystems in Urho is available through the various properties in this class:
- Application.Audio
- Application.Console
- Application.FileSystem
- Application.Graphics
- Application.Input
- Application.Log
- Application.Network
- Application.Profiler
- Application.Renderer
- Application.ResourceCache
- Application.Time
- Application.UI
An application is tied to a Context which should be passed on the initial constructor.
This shows a minimal application:
C# Example
public class HelloWorld : Application { public HelloWorld(Context c) : base(c) { } public override void Start() { var cache = ResourceCache; var helloText = new Text(Context) { Value = "Hello World from UrhoSharp", HorizontalAlignment = HorizontalAlignment.Center, VerticalAlignment = VerticalAlignment.Center }; helloText.SetColor (new Color(0f, 1f, 0f)); helloText.SetFont (font: cache.GetFont("Fonts/Anonymous Pro.ttf"), size: 30); UI.Root.AddChild (helloText); Graphics.SetWindowIcon(cache.GetImage("Textures/UrhoIcon.png")); Graphics.WindowTitle = "UrhoSharp Sample"; // Subscribe to Esc key: SubscribeToKeyDown(args => { if (args.Key == Key.Esc) Engine.Exit(); }); } }
Requirements
Namespace: Urho
Assembly: Urho (in Urho.dll)
Assembly Versions: 1.0.0.0
Assembly: Urho (in Urho.dll)
Assembly Versions: 1.0.0.0
The members of Urho.Application are listed below.
See Also: UrhoObject | https://developer.xamarin.com/api/type/Urho.Application/ | CC-MAIN-2019-09 | en | refinedweb |
The wrapper itself is autogenerated by a tool i wrote, and so i hope to be able to keep up with updates extremely quickly.
Not every part of the wrapper is covered by unit tests yet, but what i have used works flawlessly (mainly loading, playing rewinding etc.).
Usage is straight forward, e.g:
Code: Select all
PM> Install-Package Sunvox.Net
Have fun
Code: Select all
using Sunvox.Net; namespace SunvoxPackageTest { class Program { static void Main(string[] args) { var i = Vox.Init("", 44100, 2, 0); Vox.OpenSlot(0); Vox.Load(0, "test.sunvox"); Vox.Play(0); System.Threading.Thread.Sleep(2000); Vox.Stop(0); Vox.CloseSlot(0); Vox.Deinit(); } } }
(P.s. i hope im not breaking any licensing issues by publishing this, as far as i could tell it seemed a.okay
| http://www.warmplace.ru/forum/viewtopic.php?f=3&t=4297 | CC-MAIN-2019-09 | en | refinedweb |
iGenMeshAnimationControlState Struct Reference
[Mesh plugins]
This interface describes the API for setting up the animation control as implemented by the 'gmeshanim' plugin. More...
#include <imesh/gmeshanim.h>
Inheritance diagram for iGenMeshAnimationControlState:
Detailed Description
This interface describes the API for setting up the animation control as implemented by the 'gmeshanim' plugin.
The objects that implement iGenMeshAnimationControl also implement this interface.
Definition at line 36 of file gmeshanim.h.
Member Function Documentation
Execute the given animation script.
This will be done in addition to the scripts that are already running. Returns false in case of failure (usually a script that doesn't exist).
Stop execution of the given script.
Stop execution of all animation scripts.
The documentation for this struct was generated from the following file:
- imesh/gmeshanim.h
Generated for Crystal Space 2.1 by doxygen 1.6.1 | http://crystalspace3d.org/docs/online/api/structiGenMeshAnimationControlState.html | CC-MAIN-2016-50 | en | refinedweb |
I have a activity A in which I have a fragment.
In this activity Fragment changes to fragment A(default when activity A is called) or fragment B based on user input in activity A.
In both fragments A & B I have a button with on click listener. but this button works only for the first time when activity A is started.
when user changes fragment the button in those fragments stop responding to on click.
Please suggest what I need to do in order to make buttons in fragment A & B work when fragments are changed by user.
I am replacing fragments based on user input by this code:
fr = new FragmentOneDice();
FragmentManager fm = getFragmentManager();
FragmentTransaction fragmentTransaction = fm.beginTransaction();
fragmentTransaction.replace(R.id.fragment_place, fr);
fragmentTransaction.commit();
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import java.util.ArrayList;
import java.util.Collections;
public class FragmentOneDice extends Fragment implements View.OnClickListener {
Button button1;
View view;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
//Inflate the layout for this fragment
view = inflater.inflate(R.layout.activity_fragment_one, container, false);
button1 = (Button) view.findViewById(R.id.button_one);
button1.setOnClickListener(this);
return view;
}
@Override
public void onClick(View v) {
//MY CODE HERE
}
The problem was in my activity_main.XML, where I had defined
<Fragment> as a placeholder for all fragments and had set one fragment as default. So when other fragment was loaded it was getting overlapped resulting in on click event on the button not working, I changed the
<Fragment> to
<FrameLayout> as a placeholder. And my problem was solved. | https://codedump.io/share/EXNeBlAMUTHQ/1/onclick-event-in-fragment-activity-not-working | CC-MAIN-2016-50 | en | refinedweb |
. The receive location using the AX Adapter is using the default xml receive pipeline, and the “Pass Through” property of the adapter is set to ‘False’.”.
RESOLUTION:
You can resolve this issue by installing an AX 2009 Kernel Hotfix, see this blog post for more details.
WORKAROUND:
We were able to workaround the issue so that the response message in the AX AIF Gateway queue does get consumed successfully by the BizTalk Adapter for AX (and hence release the resource channel lock), by implementing the following changes in our BizTalk solution:
- We consumed the whole message envelope instead of stripping out the xml envelope. The promoted properties are specified in the header section of the message within the envelope, hence consuming the whole message, will still allow the routing of the message within BizTalk when using the promoted properties.
- Furthermore since you can only have one receive location communicating to one AOS server, and hence with the following changes to the BizTalk solution meant that you will always have to consume the full message including the envelope and message headers and not be able to just consume the message body:
(1) In the properties of the AX Adapter in the BizTalk receive location, Set the Pass Through property value to ‘True‘
(2) In the properties of the BizTalk Receive Location using the AX adapter, set the Receive Pipeline to ‘PassThruReceive’
(3) Change all the receive shapes in the orchestration that receive messages from AX, such that the Message Type is set to DynamicsAX5.Message.Envelope schema.
(4) Where you are using correlation for the request/response of AX messages, the Correlation Type still needs to be set to DynamicsAx5.RequestMessageId to correlate asynchronous solicit/response messages correctly.
The above steps creates a subscription in BizTalk for where the message type is the DynamicsAX5.Message.Envelope and the BizTalk Adapter for AX consumes the message correctly (In this case it will be the whole message from AX including the envelope). Once the envelope is consumed, it will get routed to the orchestration instance based on the correlation setup on the RequestMessageId property. You can then use xpath statements to extract the message body or whatever data you need from the envelope.
For example, in my sample code to extract the response message I received after a succesful AIF Delete Action I did the following:
In my orchestration in BizTalk my response message gets assigned to a BizTalk Orchestration Message called SalesOrderDeleteResponseMsg. I created two variables called xmlResponseMsg of data type System.Xml.XmlDocument, and strResponse of data type string. I then used the following xpath statement in an Expression shape to extract the xml response message and assign it to xmlResponseMsg and then extract the content from the xml message and assign it to strResponse:
xmlResponseMsg = xpath(SalesOrderDeleteResponseMsg.ReturnValue,”/*[local-name()=’Envelope’ and namespace-uri()=’’]/*[local-name()=’Body’ and namespace-uri()=’’]/*[local-name()=’MessageParts’ and namespace-uri()=’’]”);
strResponse= xmlResponseMsg.OuterXml;
NOTE: You will encounter a similar issue when using the Synchronous Adapter (by using the Solicit-Response port in an orchestration) and a workaround for this is detailed in the white paper: Microsoft Dynamics AX 2009 White Paper: Application Integration Framework (AIF) BizTalk Adapter Configuration for Data Exchange, Part II
Thank you – is just struggling with the same problem. In addition – a lot of business connector users are left online – when this occours. | https://blogs.msdn.microsoft.com/emeadaxsupport/2009/09/17/you-get-the-following-warning-message-in-biztalk-server-2006-r22009-the-message-does-not-contain-a-body-part-part-1/ | CC-MAIN-2016-50 | en | refinedweb |
djangosnippets.org: Latest snippets tagged with 'queries' printer coroutine2009-04-25T11:49:30-05:00fnl<p>If you would like to see the latest queries you have done when running a unittest, this is not so easy. You have to initialize the queries list and set DEBUG to True manually. Then you have to figure out a way to print the queries you want to see ...</p> Freely redistributableMiddelware to remember sql query log from before a redirect2007-09-17T18:43:18-05:00miracle2k<p>Simple middelware that listens for redirect responses, store the request's query log in the session when it finds one, and starts the next request's log off with those queries from before the redirect.</p> Freely redistributableYet another SQL debugging facility2007-08-16T11:52:43-05:00miracle2k<p>Inspired by</p> <p>This context processor provides a new variable {{ sqldebug }}, which can be used as follows:</p> <p>{% if sqldebug %}...{% endif %} {% if sqldebug.enabled %}...{% endif %}</p> <pre><code>This checks settings.SQL_DEBUG and settings.DEBUG. Both need to be True, otherwise the above will evaluate to False and sql ...</code></pre> Freely redistributableTemplate Query Debug2007-03-08T18:04:39-06:00insin<p>I often find something like this lurking at the end of my base templates - it'll show you which queries were run while generating the current page, but they'll start out hidden so as not to be a pain.</p> <p>Of course, before this works, you'll need to satisfy ...</p> Freely redistributable | https://djangosnippets.org/feeds/tag/queries/ | CC-MAIN-2016-50 | en | refinedweb |
[Courtesy copy of Usenet posting] [Please Cc; I'm not a regular reader of comp.os.linux.powerpc or subscriber to debian-powerpc] Jean-Philippe Combe <combe@lmt.ens-cachan.fr> wrote: >I 'm very intrested in getting ddd 3.0 (a visual debugger based on gdb) on >my LinuxPPC's box. >However I haven't been able to compile the tar ball;-(( You're not exactly proving a lot of details, so I have no idea whether I encountered the same problem. I've tried building DDD on powerpc.debian.org, and ran into a conflict over ioctl. I've patched it thusly: --- ddd-3.0/ddd/TTYAgent.C Tue May 12 09:50:28 1998 +++ ../ddd-3.0/ddd/TTYAgent.C Thu Oct 15 12:34:42 1998 @@ -161,7 +161,11 @@ int tcsetpgrp(int fd, pid_t pgid); #endif #if HAVE_IOCTL && !HAVE_IOCTL_DECL && !defined(ioctl) +# if defined(linux) && defined(powerpc) + int ioctl(int fd, unsigned long int request, ...); +# else int ioctl(int fd, int request, ...); +# endif #endif #if HAVE_FCNTL && !HAVE_FCNTL_DECL && !defined(fcntl) int fcntl(int fd, int command, ...); which allows me to compile it (Debian GNU/Linux unstable, libc6 2.0.95-1.1). I'm sure this there's a better way of doing it, but I wouldn't know. I HTH, Ray -- Obsig: developing a new sig | https://lists.debian.org/debian-powerpc/1998/10/msg00042.html | CC-MAIN-2016-50 | en | refinedweb |
Geo::GoogleEarth::Pluggable::Plugin::Default - Geo::GoogleEarth::Pluggable Default Plugin Methods
Methods in this package are AUTOLOADed into the Geo::GoogleEarth::Pluggable::Folder namespace at runtime.);
$folder->LineString(name=>"My Placemark", coordinates=>[ [lat,lon,alt], {lat=>$lat,lon=>$lon,alt=>$alt}, ]);
$folder->LinearRing(name=>"My Placemark", coordinates=>[ [lat,lon,alt], {lat=>$lat,lon=>$lon,alt=>$alt}, ]);
Need to determine what methods should be in the Folder package and what should be on the Plugin/Default package and why.::Contrib::Point, Geo::GoogleEarth::Pluggable::Contrib::LineString, Geo::GoogleEarth::Pluggable::Contrib::LinearRing | http://search.cpan.org/dist/Geo-GoogleEarth-Pluggable/lib/Geo/GoogleEarth/Pluggable/Plugin/Default.pm | CC-MAIN-2016-50 | en | refinedweb |
HierMenus CENTRAL: HierMenus In Progress. HierMenus 5.3 Release Notes (5/7)
dir="rtl" Implementation Notes
As we worked through the various HM behavior problems that we saw in pages where directionality was set specifically to rtl, we discovered a number of cross-browser JavaScript/DOM quirks that may be of interest to all DHTML developers. Those quirks are the subject of the next two pages, and we'll divide 'em up by major browsers.
dir="rtl" in Internet Explorer
By far, the greater number of dir landmines sent our way was presented in Internet Explorer for Windows, version 5.0 or later (IE5 Mac doesn't seem to support rtl mode documents at all; nor does IE4 or earlier on Windows platforms). Some of the problems we encoutered in this particular browser were the result of coding assumptions on our part that probably shouldn't have happened, while others were the result of some unique positioning behaviors on the part of Internet Explorer.
x positioning not based on left of canvas
The biggest Internet Explorer difference in a page where directionality is set to rtl is that the x/y positioning of the page is altered so that position (0,0) is not the top left corner of the browser canvas. Instead, (0,0) is the top left corner of the browser window, when the browser window is fully scrolled to the right (or there is no horizontal scrollbar for the page). In other words, a left pixel position of 0 is located at a distance of clientWidth less than the right edge of the browser document.
This is not an easy point to visualize, so let's see if a simple graphic will help:
In the above graphic, we've opened an HTML document that renders wider than the width of our current browser window. In this scenario, with dir="rtl" in effect, Internet Explorer's default behavior is to move the vertical scroll bar to the left of the page, and then immediately "scroll" the page all the way to the right when initially displaying it. The net effect, then, is that the initial browser window is displayed with pixel position 0 in the top left corner of the screen, and in order to see the remaining portion of the document (to the left of the browser window), you must use the horizontal scrollbar.
Note that when the page is scrolled to the left, the left pixel positions become negative. Or, in other words, objects can be positioned in the area to the left of the initial browser window by setting negative left positions. However, if the browser window is resized, then position 0,0 is altered as described above--so that it's always positioned at:
(the right edge of the document) - (the width of the browser window)
This latter point is important. If you need to know what the offset between the left edge of the document and the actual pixel position 0 is (we'll revisit this in a moment), you'll need to refresh your calculation each time the window is resized (or simply retrieve it dynamically every time). Finally, note that this pixel positioning logic only applies when the document itself is wider than than the browser window. When the browser window is equal to or wider than the document, (i.e., when there is no need for horizontal scrolling) then pixel positioning on the document behaves as you would expect it to.
All this is well and good; but doesn't effect HierMenus directly, since all of our absolute pixel positions for permanently displayed menus are specified as simple x/y positions. And since the page content itself is right-aligned when dir="rtl", having the pixel positions be based on the right edge of the document allows the objects to appear within the user's default browser window--where they would expect them to appear. But understanding this scheme will help you understand the following points:
scrollLeft doesn't match pixel layout of page
In conjunction with the above, you might expect that the canvas's scrollLeft property (the property used by Internet Explorer to note the offset of the horizontal scrollbar) would initially be 0, to match the 0,0 pixel position of the left side of the window; and as you scroll the page to the left, scrollLeft would take on negative numbers. And, in fact, this is the behavior in IE 5.0.
In IE 5.5+, scrollLeft is never a negative number, and is initially set to whatever the distance is between the left edge of the canvas and the left edge of the browser window. As you scroll the page to the left, scrollLeft is gradually decremented until it reaches 0, the left edge of the document. We suspect Microsoft made this change between 5.0 and 5.5 to honor their documented scrollLeft behavior, which explicitly states that scrollLeft cannot be a negative number. In fact, specifically setting scrollLeft to a negative number results in it being automatically set to 0, a behavior that occurs in IE 5.0 as well (in IE 5.0, scrollLeft can have a negative number as the result of horizontal scrolling, but you cannot assign it a negative number). Microsoft's documentation for the scrollLeft parameter can be found here.
Perhaps the most common use of scrollLeft--and the use that is problematic
for us in HierMenus--is to add it to the position of the mouse to arrive at
a true x position for the mouse on the document, regardless of where the
page is scrolled (in IE, the event.clientX property represents the
position of the mouse in the window, not necessarily the x position of the mouse
in relationship to the document). To determine what the mouse position is in
Internet Explorer as it relates to the document, we might use this
calculation:
var mouse_x_position = document.documentElement.scrollLeft + event.clientX;
When dir="rtl" is used in IE5.5+ this calculation won't work; since scrollLeft is not necessarily in sync with the left x position of the document. Therefore, when these two conditions (IE5.5+ and dir="rtl") are true, we must subtract the horizontal offset--the distance between the left edge of the document and the left edge of the browser window--from the scrollLeft property to arrive at the position of the mouse as it relates to the actual document itself. Translated into HM code, our (abbreviated) adjustment looks like this:
var mouse_x_position = HM_Canvas.scrollLeft + event.clientX; if (HM_IE&&!HM_IE50W&&HM_f_RTLCheck()) mouse_x_position-= (HM_Canvas.scrollWidth-HM_Canvas.clientWidth);
where HM_IE50W is a new sniffing variable we set up to tell us if the browser in question is IE5.0 Windows and HM_f_RTLCheck is a new function that tells us if the browser document is currently rendering in rtl mode:
// 5.3 function HM_f_RTLCheck() { if(HM_IE5M) return false; var TempElement=HM_MenusTarget.document.body; while(!TempElement.dir&&TempElement.parentNode) TempElement=TempElement.parentNode; return ((typeof(TempElement.dir)=="string")&& (/^rtl$/i.test(TempElement.dir))) ? true : false; }
Note that simply referring to the offsetLeft property of the canvas will not be valid, since it is always zero (it is the outermost container and therefore its left pixel offset should be zero). And using the document.body.offsetLeft property directly would only be valid in pages where IE is running in standards mode.
Initial positioning of menus
When initially creating menus, we've always positioned them offscreen (way offscreen) so as to avoid a quirk in Internet Explorer where the initial horizontal/vertical scrollbars are expanded unnecessarily to make room for the menus (which are initially hidden and can't be seen anyways). Browsers do not expand their documents upwards or to the left of the initial browser window to accommodate these offscreen menus, making it an effective workaround.
When dir="rtl" in Internet Explorer, the positions to the left of the initial browser window (as described above), are actually negative pixel positions and therefore the browser will expand the canvas to accommodate them. This is not what we want, since the width of the document is then initially set to be much wider than it should. Therefore, when rtl mode is in effect, we'll create the menus at pixel position 0, instead of a left pixel position.
HM scrollParent and scrollbar inconsistencies
The automatic right-alignment of elements when in rtl mode in Internet Explorer caused some confusion with our internal elements, especially the scrollParent element and the individual scrollbars of scrolling menus. Specifically, in the past we've created these elements without an explicit left pixel position, assuming it would be 0 in all cases. Not true in Internet Explorer, where we found that both the scrollParent and scrollbars tended to drift slightly to the right or left of 0, causing some strange menu displays. To correct the problem we simply removed our original assumption and explicitly set the initial left pixel position of the newly created elements to 0px.
Similarly, with horizontal menus we never bothered to specifically adjust the width of scrollParent elements when we changed the width of the horizontal menus themselves. This resulted in horizontal menus where the menu border appeared in the proper dimensions, but the menu content--i.e., the individual menu items--were positioned as if the first menu item was in the rightmost slot of the menu. A picture's worth a thousand words:
In HM 5.3, we correct this bug by ensuring that the scrollParent width is always set when its corresponding menu's width is set. This HM bug affected all rtl capable browsers, not just Internet Explorer.
On page 6 we continue discussing rtl mode issues.
Created: October 23, 2003
Revised: October 23, 2003
URL: | http://www.webreference.com/dhtml/hiermenus/inprogress/9/5.html | CC-MAIN-2016-50 | en | refinedweb |
[
]
Dan Checkoway commented on NET-306:
-----------------------------------
Rory, can you please help me find a build that includes the fix? Not sure what "ages" means,
but I poked around on and wasn't able to find much...the nightly
builds link on this page is broken:
I also found it odd that the svn tree for commons-net doesn't even have a "utils" package
(just util, which doesn't contain SubnetUtils).
Man, I'm in the twilight zone here or something. I haven't felt so braindead when trying
to find other commons subprojects... :-)
Anyway, maybe you can toss me a clue and help me find *some* sort of build or svn tree that
has the code *and* the fix. All I could find was the 2.0 release of source, which doesn't
have the fix.
> SubnetUtils.SubnetInfo.isInRange is BRAINDEAD (a.k.a. FUBAR)
> ------------------------------------------------------------
>
> Key: NET-306
> URL:
> Project: Commons Net
> Issue Type: Bug
> Affects Versions: 2.0
> Reporter: Dan Checkoway
> Priority: Critical
> Fix For: Nightly Builds
>
>
> org.apache.commons.net.utils.SubnetUtils.SubnetInfo.isInRange() is totally broken. It
utterly ignores the fact that integer address values might be, um....negative?!
> SubnetUtils subnetUtils = new SubnetUtils("66.249.71.0/24");
> SubnetUtils.SubnetInfo subnetInfo = subnetUtils.getInfo();
> String ip = "213.139.63.227";
> if (subnetInfo.isInRange(ip)) {
> System.out.println("YES, " + ip + " is in the range: " + subnetInfo.getCidrSignature());
> }
> else {
> System.out.println("NO, " + ip + " is not in the range: " + subnetInfo.getCidrSignature());
> }
> YES, 213.139.63.227 is in the range: 66.249.71.0/24
> ?!?! WTF !?!?!
> This is the culprit in SubnetUtils.java:
> private boolean isInRange(int address) { return ((address-low()) <= (high()-low()));
}
> The integer values in the test case above are:
> 66.249.71.1 = 1123632897
> 66.249.71.254 = 1123633150
> 213.139.63.227 = -712294429
> So...you can see the issue (I hope). Please fix this by changing isInRange() to check
if the given value is truly *BETWEEN* high and low values.
> Thank you!!
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When I compile the attached source file, the s2_multiway_merge function gets apparently miscompiled. The do loop near the end of this function loses both of its terminating conditions and it is compiled to:
.L101:
addl $1, %esi
.L53:
movl -76(%ebp), %edi
movl -92(%ebp), %eax
movl -96(%ebp), %edx
movl -32(%ebp), %ecx
movl -36(%ebp), %ebx
movl %edi, -4(%eax,%esi,4)
movl -52(%ebp), %eax
movl -100(%ebp), %edi
movl %ecx, -4(%edx,%esi,4)
movl -40(%ebp), %edx
movl %eax, -4(%edi,%esi,4)
movl $-1, (%edx)
.L88:
shrl %ebx
je .L101
[... the s2_update_tree loop got inlined here, this test is its correct terminating condition ...]
It seems that gcc thinks that `i' never changes in the loop, so it has optimized out every expression which depends in its value.
I apologize for submitting a large source file, but the problem appears to be very chaotic and even removing parts of the source which are not referenced anywhere (see for example the block with the MAGIC comment attached) makes the problem disappear.
Compilation command: gcc-4.2.1 -v -std=gnu99 -O2 -S xxx.c -Wunused -fgnu89-inline
Output:
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ./configure --prefix=/opt/gcc-4.2.1 --enable-bootstrap
Thread model: posix
gcc version 4.2.1
/opt/gcc-4.2.1/libexec/gcc/i686-pc-linux-gnu/4.2.1/cc1 -quiet -v xxx.c -quiet -dumpbase xxx.c -mtune=generic -auxbase xxx -O2 -Wunused -std=gnu99 -version -fgnu89-inline -o xxx.s
ignoring nonexistent directory "/opt/gcc-4.2.1/lib/gcc/i686-pc-linux-gnu/4.2.1/../../../../i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/opt/gcc-4.2.1/include
/opt/gcc-4.2.1/lib/gcc/i686-pc-linux-gnu/4.2.1/include
/usr/include
End of search list.
GNU C version 4.2.1 (i686-pc-linux-gnu)
compiled by GNU C version 4.2.1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 9831b30df15d36dc669e016cd6c4ba43
Created attachment 14146 [details]
Source file triggering the problem
Can I do anything to help catch the bug?
Try with a recent GCC 4.2 version - GCC 4.2.4 is available. Also try
GCC 4.3.1. Try to reduce the testcase or at least make it executable and
arrange for it to abort () whenever the problem appears. | https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33262 | CC-MAIN-2016-50 | en | refinedweb |
How to create your first app for Windows Phone 8
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
This topic provides step-by-step instructions to help you create your first app for Windows Phone. You’re going to create a basic web browser. This simple app lets the user enter a URL, and then loads the web page when the user clicks the Go button.
You can download the complete Mini-browser Sample in C# or in Visual Basic.NET.
This topic contains the following sections.
This walkthrough assumes that you’re going to test your app in the emulator. If you want to test your app on a phone, you have to take some additional steps. For more info, see How to register your phone for development for Windows Phone 8.
The steps in this topic assume that you’re using Visual Studio Express 2012 for Windows Phone. You may see some variations in window layouts or menu commands if you’re using Visual Studio 2012 Professional or higher, or if you’ve already customized the layout or menus in Visual Studio.
The first step in creating a Windows Phone app is to create a new project in Visual Studio.
To create the project
Make sure you’ve.
In the New Project window, expand the installed Visual C# or Visual Basic templates, and then select the Windows Phone templates.
In the list of Windows Phone templates, select the Windows Phone App template.
At the bottom of the New Project window, type MiniBrowser as the project’s Name.
Click OK. In the New Windows Phone Application dialog box, select Windows Phone OS 8.0 for the Target Windows Phone OS Version.
When you select Windows Phone OS 8.0 as the target version, your app can only run on Windows Phone 8 devices.
When you select Windows Phone OS 7.1, your app can run on both Windows Phone OS 7.1 and Windows Phone 8 devices.
Click OK. The new project is created, and opens in Visual Studio. The designer displays MainPage.xaml, which contains the user interface for your app. The main Visual Studio window contains the following items:
The middle pane contains the XAML markup that defines the user interface for the page.
The left pane contains a skin that shows the output of the XAML markup.
The right pane includes Solution Explorer, which lists the files in the project.
The associated code-behind page, MainPage.xaml.cs or MainPage.xaml.vb, which contains the code to handle user interaction with the page, is not opened or displayed by default.
The next step is to lay out the controls that make up the UI of the app using the Visual Studio designer. After you add the controls, the final layout will look similar to the following screenshot.
To create the UI
Open the Properties window in Visual Studio, if it’s not already open, by selecting the VIEW | Properties Window menu command. The Properties window opens in the lower right corner of the Visual Studio window.
Change the app title.
In the Visual Studio designer, click to select the MY APPLICATION TextBlock control. The properties of the control are displayed in the Properties window.
In the Text property, change the name to MY FIRST APPLICATION to rename the app window title. If the properties are grouped by category in the Properties window, you can find Text in the Common category.
Change the name of the page.
Change the supported orientations.
In the XAML code window, click the first line of the XAML code. The properties of the PhoneApplicationPage are displayed in the Properties window.
Change the SupportedOrientations property to PortraitOrLandscape to add support for both portrait and landscape orientations. If the properties are grouped by category in the Properties window, you can find SupportedOrientations in the Common category.
Open the Toolbox in Visual Studio, if it’s not already open, by selecting the VIEW | Toolbox menu command. The Toolbox typically opens on the left side of the Visual Studio window and displays the list of available controls for building the user interface. By default the Toolbox is collapsed when you’re not using it.
Add a textbox for the URL.
From the Common Windows Phone Controls group in the Toolbox, add a TextBox control to the designer surface by dragging it from the Toolbox and dropping it onto the designer surface. Place the TextBox just below the Mini Browser text. Use the mouse to size the control to the approximate width shown in the layout image above. Leave room on the right for the Go button.
In the Properties window, set the following properties for the new text box.
With these settings, the control can size and position itself correctly in both portrait and landscape modes.
Add the Go button.
Resize the text box to make room for the Go button. Then, from the Common Windows Phone Controls group in the Toolbox, add a Button control by dragging and dropping it. Place it to the right of the text box you just added. Size the button to the approximate width shown in the preceding image.
In the Properties window, set the following properties for the new button.
With these settings, the control can size and position itself correctly in both portrait and landscape modes.
Add the WebBrowser control.
From the All Windows Phone Controls group in the Toolbox, add a WebBrowser control to your app by dragging and dropping it. Place it below the two controls you added in the previous steps. Use your mouse to size the control to fill the remaining space.
If you want to learn more about the WebBrowser control, see WebBrowser control for Windows Phone 8.
In the Properties window, set the following properties for the new WebBrowser control.
With these settings, the control can size and position itself correctly in both Portrait and Landscape modes.
Your layout is now complete. In the XAML code in MainPage.xaml, look for the grid that contains your controls. It will look similar to the following. If you want the layout exactly as shown in the preceding illustration, copy the following XAML and paste it to replace the grid layout in your MainPage.xaml file.
<!--ContentPanel - place additional content here--> <Grid x: <TextBox x: <Button x: <phone:WebBrowser x: </Grid>
The final step before testing your app is to add the code that implements the Go button.
To add the code
In the designer, double-click the Go button control that you added to create an empty event handler for the button’s Click event. You will see the empty event handler in a page of C# code on the MainPage.xaml.cs tab, or in a page of Visual Basic code on the MainPage.xaml.vb tab.
using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Navigation; using Microsoft.Phone.Controls; using Microsoft.Phone.Shell; using MiniBrowser.Resources; namespace MiniBrowser { public partial class MainPage : PhoneApplicationPage { // Constructor public MainPage() { InitializeComponent(); } private void Go_Click(object sender, RoutedEventArgs e) { } } }
When you double-click the Go button, Visual Studio also updates the XAML in MainPage.xaml to connect the button’s Click event to the Go_Click event handler.
In MainPage.xaml.cs or MainPage.xaml.vb, add the highlighted lines of code to the empty Go_Click event handler. This code takes the URL that the user enters in the text box and navigates to that URL in the MiniBrowser control.
Now you’ve finished your first Windows Phone app! Next you’ll build, run, and debug the app.
Before you test the app, make sure that your computer has Internet access to be able to test the Web browser control.
To run your app in the emulator 512MB.
Run the app by pressing F5 or by selecting the DEBUG | Start Debugging menu command. This opens the emulator window and launches the app. If this is the first time you’re starting the emulator, it might take a few seconds for it to start and launch your app.
The Windows Phone 8 Emulator has special hardware, software, and configuration requirements. If you have any problems with the emulator, see the following topics.
To test your running app, click the Go button and verify that the browser goes to the specified web site.
To test the app in landscape mode, press one of the rotation controls on the emulator toolbar.
Or
The emulator rotates to landscape mode. The controls resize themselves to fit the landscape screen format.
To stop debugging, you can select the DEBUG | Stop Debugging menu command in Visual Studio.
It’s better to leave the emulator running when you end a debugging session. The next time you run your app, the app starts more quickly because the emulator is already running.
Congratulations! You’ve now successfully completed your first Windows Phone app. | https://msdn.microsoft.com/en-us/library/ff402526(v=vs.105).aspx | CC-MAIN-2016-50 | en | refinedweb |
In today’s Programming Praxis exercise, our goal is to calculate the number of ways a number can be expressed as a McNugget number. Let’s get started, shall we?
A quick import:
import Control.Monad.Identity
We use the same basic technique of building up a table of numbers where each number is the sum of the number above it and the number x spaces to its left, with x being the size of the McNugget box. We construct it differently though; rather than explicitly setting array values we use a bit of laziness to express the whole thing as a fold. The first row is a 1 followed by zeroes. For each subsequent row, we use the same principle as for the typical implementation of the Fibonacci algorithm, namely zipping a list with itself (using the fix function to avoid having to name it). The first x spaces of the previous row are maintained by adding zero to them.
mcNuggetCount :: Num a => [Int] -> Int -> a mcNuggetCount xs n = foldl (\a x -> fix $ zipWith (+) a . (replicate x 0 ++)) (1 : repeat 0) xs !! n
Some tests to see if everything works properly:
main :: IO () main = do print $ mcNuggetCount [6,9,20] 1000000 == 462964815 print $ mcNuggetCount [1,5,10,25,50,100] 100 == 293 print $ mcNuggetCount [1,2,5,10,20,50,100,200] 200 == 73682
Tags: bonsai, code, combinator, fix, Haskell, kata, mcnugget, numbers, praxis, programming, y | http://bonsaicode.wordpress.com/2012/04/13/programming-praxis-mcnugget-numbers-revisited/ | CC-MAIN-2014-35 | en | refinedweb |
Using VSS Automated System Recovery for Disaster Recovery
A VSS backup-and-recovery application that performs disaster recovery (also called bare-metal recovery) can use the Automated System Recovery (ASR) writer together with Windows Preinstallation Environment (Windows PE) to back up and restore critical volumes and other components of the bootable system state. The backup application is implemented as a VSS requester.
Note Applications that use ASR must license Windows PE.
Windows Server 2003 and Windows XP: ASR is not implemented as a VSS writer.
For information about tracing tools that you can use with ASR, see Using Tracing Tools with VSS ASR Applications.
Overview of Backup Phase Tasks
At backupBackup method to initialize the instance to manage a backup.
- Call IVssBackupComponents::SetContext to set the context for the shadow copy operation.
- Call IVssBackupComponents::SetBackupState to configure the backup. Set the bBackupBootableSystemState parameter to true to indicate that the backup will include a bootable system state.
- Choose which critical components in the ASR writer's Writer Metadata Document to back up and call IVssBackupComponents::AddComponent for each of them.
- Call IVssBackupComponents::StartSnapshotSet to create a new, empty shadow copy set.
- Call IVssBackupComponents::GatherWriterMetadata to initiate asynchronous contact with writers.
- Call IVssBackupComponents::GetWriterMetadata to retrieve the ASR writer's Writer Metadata Document. The writer ID for the ASR writer is BE000CBE-11FE-4426-9C58-531AA6355FC4, and the writer name string is "ASR Writer".
- Call IVssExamineWriterMetadata::SaveAsXML to save a copy of the ASR writer's Writer Metadata Document.
- Call IVssBackupComponents::AddToSnapshotSet for each volume that can participate in shadow copies to add the volume to the shadow copy set.
- Call IVssBackupComponents::PrepareForBackup to notify writers to prepare for a backup operation.
- Call IVssBackupComponents::GatherWriterStatus and IVssBackupComponents::GetWriterStatus (or IVssBackupComponentsEx3::GetWriterStatus) to verify the status of the ASR writer.
- At this point, you can query for failure messages that were set by the writer in its CVssWriter::OnPrepareBackup method. For example code that shows how to view these messages, see IVssComponentEx::GetPrepareForBackupFailureMsg.
- Call IVssBackupComponents::DoSnapshotSet to create a volume shadow copy.
- Call IVssBackupComponents::GatherWriterStatus and IVssBackupComponents::GetWriterStatus to verify the status of the ASR writer.
- Back up the data.
- Indicate whether the backup operation succeeded by calling IVssBackupComponents::SetBackupSucceeded.
- Call IVssBackupComponents::BackupComplete to indicate that the backup operation has completed.
- Call IVssBackupComponents::GatherWriterStatus and IVssBackupComponents::GetWriterStatus. The writer session state memory is a limited resource, and writers must eventually reuse session states. This step marks the writer’s backup session state as completed and notifies VSS that this backup session slot can be reused by a subsequent backup operation.
Note This is only necessary on Windows Server 2008 with Service Pack 2 (SP2) and earlier.
- Call IVssBackupComponents::SaveAsXML to save a copy of the requester's Backup Components Document. The information in the Backup Components Document is used at restore time when the requester calls the IVssBackupComponents::InitializeForRestore method.
Choosing Which Critical Components to Back Up
In the backup initialization phase, the ASR writer reports the following types of components in its Writer Metadata Document:
- Critical volumes, such as the boot, system, and Windows Recovery Environment (Windows RE) volumes and the Windows RE partition that is associated with the instance of Windows Vista or Windows Server 2008 that is currently running.. For more information, see Backing Up and Restoring System State. Components for which the VSS_CF_NOT_SYSTEM_STATE flag is set are not system-critical.
Note The ASR component is a system-critical component that is reported by the ASR writer.
- Disks. Every fixed disk on the computer is exposed as a component in ASR. If a disk was not excluded during backup, it will be assigned during restore and can be re-created and reformatted. Note that during restore, the requester can still re-create a disk that was excluded during backup by calling the IVssBackupComponents::SetRestoreOptions method. If one disk in a dynamic disk pack is selected, all other disks in that pack must also be selected. If a volume is selected because it is a critical volume (that is, a volume that contains system state information), every disk that contains an extent for that volume must also be selected. To find the extents for a volume, use the IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS control code.
Note During backup, the requester should include all fixed disks. If the disk that contains the requester's backup set is a local disk, this disk should be included. During restore, the requester must exclude the disk that contains the requester's backup set to prevent it from being overwritten.
In a clustering environment, ASR does not re-create the layout of the cluster's shared disks. Those disks should be restored online after the operating system is restored in the Windows RE.
- Boot Configuration Data (BCD) store. This component specifies the path of the directory that contains the BCD store. The requester must specify this component and back up all of the files in the BCD store directory. For more information about the BCD store, see About BCD.
Note On computers that use the Extended Firmware Interface (EFI), the EFI System Partition (ESP) is always hidden and cannot be included in a volume shadow copy. The requester must back up the contents of this partition. Because this partition cannot be included in a volume shadow copy, the backup can only be performed from the live volume, not from the shadow copy. For more information about EFI and ESP, see UEFI and Windows.
The component names use the following formats:
- For disk components, the format is
<COMPONENT logicalPath="Disks" componentName="harddiskn" componentType="filegroup" />where n is the disk number. Only the disk number is recorded. To get the disk number, use the IOCTL_STORAGE_GET_DEVICE_NUMBER control code.
- For volume components, the format is
<COMPONENT logicalPath="Volumes" componentName="Volume{GUID}" componentType="filegroup" />where GUID is the volume GUID.
- For the BCD store component, the format is
<COMPONENT logicalPath="BCD" componentName="BCD" componentType="filegroup" componentCaption = "This is the path to the boot BCD store and the boot managers...All the files in this directory need to be backed up...">If the system partition has a volume GUID name, this component is selectable. Otherwise, it is not selectable.
Note ASR adds the files to the BCD store component's file group as follows:
- For EFI disks, ASR adds
SystemPartitionPath\EFI\Microsoft\Boot\*.*where SystemPartitionPath is the path to the system partition.
- For GPT disks, ASR adds
SystemPartitionPath\Boot\*.*where SystemPartitionPath is the path to the system partition.
- The system partition path can be found under the following registry key: HKEY_LOCAL_MACHINE\System\Setup\SystemPartition
On restore, all components that are marked as critical volumes must be restored. If one or more critical volumes cannot be restored, the restore operation fails.
In the PreRestore phase of the restore sequence, disks that were not excluded during backup are re-created and reformatted by default. However, they are not re-created or reformatted if they meet the following conditions:
- A basic disk is not re-created if its disk layout is intact or only additive changes have been made to it. The disk layout is intact if the following conditions are true:
- The disk signature, disk style (GPT or MBR), logical sector size, and volume start offset are not changed.
- The volume size is not decreased.
- For GPT disks, the partition identifier is not changed.
- A dynamic disk is not re-created if its disk layout is intact or only additive changes have been made to it. For a dynamic disk to be intact, all of the conditions for a basic disk must be met. In addition, the entire disk pack's volume structure must be intact. The disk pack's volume structure is intact if it meets the following conditions, which apply to both MBR and GPT disks:
- The number of volumes that are available in the physical pack during restore must be greater than or equal to the number of volumes that were specified in the ASR writer metadata during backup.
- The number of plexes per volume must be unchanged.
- The number of members must be unchanged.
- The number of physical disk extents must be greater than the number of disk extents specified in the ASR writer metadata.
- An intact pack remains intact when additional volumes are added, or if a volume in the pack is extended (for example, from a simple volume to a spanned volume).
Note If a simple volume is mirrored, the pack is not intact and will be re-created to ensure that the BCD and boot volume state remain consistent after restore. If volumes are deleted, the pack is re-created.
- If the dynamic disk pack's volume structure is intact and only additive changes have been made to it, the disks in the pack are not re-created.
Windows Vista: Dynamic disks are always re-created. Note that this behavior has changed with Windows Server 2008 and Windows Vista with Service Pack 1 (SP1).
At any time before the beginning of the restore phase, the requester can specify that the disks should be quick-formatted by setting the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ASR\RestoreSession registry key. Under this key, there is a value named QuickFormat with the data type REG_DWORD. If this value does not exist, you should create it. Set the data of the QuickFormat value to 1 for quick formatting or 0 for slow formatting.
If the QuickFormat value does not exist, the disks will be slow-formatted.
Quick formatting is significantly faster than slow formatting (also called full formatting). However, quick formatting does not verify each sector on the volume.
Overview of Restore Phase Tasks
At restoreRestore method to initialize the instance for restore by loading the requester's Backup Components Document into the instance.
- [This step is required only if the requester needs to change whether "IncludeDisk" or "ExcludeDisk" is specified for one or more disks.] Call IVssBackupComponents::SetRestoreOptions to set the restore options for the ASR writer components. The ASR writer supports the following options: "IncludeDisk" allows the requester to include a disk on the target system to be considered for restore, even if it was not selected during the backup phase. "ExcludeDisk" allows the requester to prevent a disk on the target system from being re-created. Note that if "ExcludeDisk" is specified for a disk that contains a critical volume, the subsequent call to IVssBackupComponents::PreRestore will fail.
The following example shows how to use SetRestoreOptions to prevent disk 0 and disk 1 from being re-created and inject third-party drivers into the restored boot volume.
Windows Server 2008, Windows Vista, Windows Server 2003, and Windows XP: Injection of third-party drivers is not supported.The example assumes that the IVssBackupComponents pointer, m_pBackupComponents, is valid.
To exclude all disks for a specified volume, see the following "Excluding All Disks for a Volume."
- Call IVssBackupComponents::PreRestore to notify the ASR writer to prepare for a restore operation. Call IVssAsync::QueryStatus as many times as necessary until the status value returned in the pHrResult parameter is not VSS_S_ASYNC_PENDING.
- Restore the data. In the restore phase, ASR reconfigures the volume GUID path (\\?\Volume{GUID}) for each volume to match the volume GUID path that was used during the backup phase. However, drive letters are not preserved, because this would cause collisions with the drive letters that are automatically assigned in the recovery environment. Thus, when restoring data, the requester must use volume GUID paths, not drive letters, to access the volumes.
- Set the HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ASR\RestoreSession registry key to indicate the set of volumes that have been restored or reformatted.
Under this key, there is a value named RestoredVolumes with the data type REG_MULTI_SZ. If this value does not exist, you should create it. Under this value, your requester should create a volume GUID entry for each volume that has been restored. This entry should be in the following format: \\?\Volume{78618c8f-aefd-11da-a898-806e6f6e6963}. Each time a bare-metal recovery is performed, ASR sets the RestoredVolumes value to the set of volumes that ASR restored. If the requester restored additional volumes, it should set this value to the union of the set of volumes that the requester restored and the set of volumes that ASR restored. If the requester did not use ASR, it should replace the list of volumes.
You should also create a value named LastInstance with the data type REG_SZ. This key should contain a random cookie that uniquely identifies the current restore operation. Such a cookie can be created by using the UuidCreate and UuidToString functions. Each time a bare-metal recovery is performed, ASR resets this registry value to notify requesters and non-VSS backup applications that the recovery has occurred.
- Call IVssBackupComponents::PostRestore to indicate the end of the restore operation. Call IVssAsync::QueryStatus as many times as necessary until the status value returned in the pHrResult parameter is not VSS_S_ASYNC_PENDING.
In the restore phase, ASR may create or remove partitions to restore the computer to its previous state. Requesters must not attempt to map disk numbers from the backup phase to the restore phase.
On restore, the requester must exclude the disk that contains the requester's backup set. Otherwise, the backup set can be overwritten by the restore operation.
On restore, a disk is excluded if it was not selected as a component during backup, or if it is explicitly excluded by calling IVssBackupComponents::SetRestoreOptions with the "ExcludeDisk" option during restore.
It is important to note that during WinPE disaster recovery, ASR writer functionality is present, but no other writers are available, and the VSS service is not running. After WinPE disaster recovery has completed, the computer has restarted, and the Windows operating system is running normally, the VSS service can be started, and the requester can perform any additional restore operations that require participation of writers other than the ASR writer.
If during the restore session the backup application detects that the volume unique IDs are unchanged, and therefore all volumes from the time of the backup are present and intact in WinPE, the backup application can proceed to restore only the contents of the volumes, without involving ASR. In this case, the backup application should indicate that the computer was restored by setting the following registry key in the restored operating system: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ASR\RestoreSession
Under this key, specify LastInstance for the value name, REG_SZ for the value type, and a random cookie (such as a GUID created by the UuidCreate function) for the value data.
If during the restore session the backup application detects that one or more volumes are changed or missing, the backup application should use ASR to perform the restore. ASR will re-create the volumes exactly the way they were at the time of the backup and set the RestoreSession registry key.
Excluding All Disks for a Volume
The following example shows how to exclude all disks for a specified volume.
HRESULT BuildRestoreOptionString ( const WCHAR *pwszVolumeNamePath, CMyString *pstrExclusionList ) { HANDLE hVolume = INVALID_HANDLE_VALUE; DWORD cbSize = 0; VOLUME_DISK_EXTENTS * pExtents = NULL; DISK_EXTENT * pExtent = NULL; ULONG i = 0; BOOL fIoRet = FALSE; WCHAR wszDest[MAX_PATH] = L""; CMyString strVolumeName; CMyString strRestoreOption; // Open a handle to the volume device. strVolumeName.Set( pwszVolumeNamePath ); // If the volume name contains a trailing backslash, remove it. strVolumeName.UnTrailing( L'\\' ); hVolume = ::CreateFile(strVolumeName, 0, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, NULL, 0); // Check whether the call to CreateFile succeeded. // Get the list of disks used by this volume. cbSize = sizeof(VOLUME_DISK_EXTENTS); pExtents = (VOLUME_DISK_EXTENTS *)::CoTaskMemAlloc(cbSize); ::ZeroMemory(pExtents, cbSize); fIoRet = ::DeviceIoControl(hVolume, IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, NULL, 0, pExtents, cbSize, &cbSize, 0); if ( !fIoRet && GetLastError() == ERROR_MORE_DATA ) { // Allocate more memory. cbSize = FIELD_OFFSET(VOLUME_DISK_EXTENTS, Extents) + pExtents->NumberOfDiskExtents * sizeof(DISK_EXTENT); ::CoTaskMemFree(pExtents); pExtents = NULL; pExtents = (VOLUME_DISK_EXTENTS *) ::CoTaskMemAlloc(cbSize); // Check whether CoTaskMemAlloc returned an out-of-memory error. ::ZeroMemory(pExtents, cbSize); // Now the buffer should be big enough. ::DeviceIoControl(hVolume, IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, NULL, 0, pExtents, cbSize, &cbSize, 0); // Check whether the IOCTL succeeded. } // Check for errors; note that the IOCTL can fail for a reason other than insufficient memory. // For each disk, mark it to be excluded in the Restore Option string. for (i = 0; i < pExtents->NumberOfDiskExtents; i++) { pExtent = &pExtents->Extents[i]; *wszDest = L'\0'; StringCchPrintf(wszDest, MAX_PATH, L"\"ExcludeDisk\"=\"%d\", ", pExtent->DiskNumber); // check errors strRestoreOption.Append(wszDest); // Check for an out-of-memory error. } // Remove the trailing comma. strRestoreOption.TrimRight(); strRestoreOption.UnTrailing(','); // Set the output parameter. strRestoreOption.Transfer( pstrExclusionList ); Exit: if( pExtents ) { ::CoTaskMemFree(pExtents); pExtents = NULL; } if( hVolume != INVALID_HANDLE_VALUE ) { ::CloseHandle(hVolume); hVolume = INVALID_HANDLE_VALUE; } return ( hr ); } | http://msdn.microsoft.com/en-us/library/aa384630(VS.85).aspx | CC-MAIN-2014-35 | en | refinedweb |
Document Object Model Prototypes, Part 2: Accessor (getter/setter) Support
As of December 2011, this topic has been archived. As a result, it is no longer actively maintained. For more information, see Archived Content. For information, recommendations, and guidance regarding the current version of Internet Explorer, see IE Developer Center.
Travis Leithead
Microsoft Corporation
November 1, 2008
Contents
- Introduction
- Two Kinds of Properties: Data and Accessor properties
- Syntax
- Accessor Properties and DOM Prototypes
- Special-case: Deleting Built-in DOM Properties
- Powerful Scenarios
- Relationship to Standards
- Restricted Properties
Introduction
This article is the second installment of a two-part series that introduces advanced JavaScript techniques in Windows Internet Explorer 8. This part of the series continues the introduction of Document Object Model (DOM) prototypes in Internet Explorer 8 by describing accessor properties.
An accessor property, introduced in the previous article defines all of its properties as built-in accessors. Web developers can also customize DOM built-in accessors to fine-tune the default behavior of the DOM. This article explains the new accessor property (or getter/setter property) syntax, provides a usage overview, and uses scenarios to demonstrate this property's value.
Two Kinds of Properties: Data and Accessor Properties
It is common practice among Web developers to add custom properties to the Document Object Model (DOM). This existing object extensibility allows added properties to save state, track application status, and so on. Prior to Internet Explorer 8, JavaScript supported only one type of property: one that could store and retrieve a value (ECMAScript 3.1 refers to these as "data properties," while other languages use terms such as "field" and "instance variable" to refer to this concept). In terms of implementation, these existing properties have one "variable slot" that holds a value. Data properties are automatically defined when the assignment operator (=) is used in JavaScript, as shown in this example:
document.data = 5; // Creates a data property named "data" console.log( document.data ); // Answer: 5 (you guessed it!)
The following figure illustrates the relationship between getter and setter accessors.
Figure 1: Visualizing JavaScript data properties
Prior to Internet Explorer 8, JavaScript developers could use only data properties in their code, yet it was clear that some built-in properties in JavaScript and the DOM were not data properties. For example, the built-in DOM property "innerHTML" does much more than simply store a value:
// Access the innerHTML property: // (gets the sub-element tree as a string) var str = document.getElementById('element1').innerHTML; // Assign a string to the innerHTML property: // (Causes the DOM to parse the string and create a // new sub-element tree under 'element1') document.getElementById('element2').innerHTML = str; // Getting (accessing) and setting (assigning to) yield different behavior: // (The same API "stringifies" and "parses" depending on if it is read or written to.)
Web developers cannot create similar properties (such as innerHTML) that mimic built-in DOM properties without new functionality in the JavaScript language. This functionality gap widens because many Web developers would like to extend and enhance the built-in properties already available in the DOM. To support this needed behavior, the JavaScript language has added "getter/setter" properties. For the purpose of brevity in this article, I will call getter/setter properties by their ECMAScript 3.1 name of "accessor" properties.
Instead of just storing or retrieving a value, accessor properties call a user-provided function each time they are set or retrieved. Unlike normal properties, accessor properties do not include an implicit "slot" to store a value. Instead, the accessor property itself stores a "getter" (a function that is executed when the property is retrieved) or a "setter" (a function that is executed when the property is assigned a value). The following figure depicts a mental model of an accessor property:
Figure 2: Visualizing JavaScript accessor properties
Syntax
A special syntax is necessary to define an accessor property because the assignment operator (=) defines a data property by default. Internet Explorer 8 is the first browser to adopt the ECMAScript 3.1 syntax for defining accessor properties:
Object.defineProperty( [(DOM object) object], [(string) property name], [(descriptor) property definition] ); All parameters are required. Return value: the first parameter (object) passed to the function.
A new syntax is also needed to retrieve an accessor property's definition (the getter or setter functions themselves) because simply reading an accessor property will invoke its getter function:
Object.getOwnPropertyDescriptor( [(DOM object) object], [(string) property name] ); All parameters are required. return value: A "property descriptor" object
Note the following restrictions:
Both of these new APIs are defined only on the JavaScript global "Object" constructor.
The first parameter (the object on which to attach the accessor) supports only DOM instances, interface objects and interface prototype objects in Internet Explorer 8; for more information, see Part 1 of this series. We plan to expand accessor support for custom and built-in JavaScript objects, constructors, and prototypes in a future release.
The following example demonstrates the defineProperty API by defining an accessor called "JSONposition" for an image. The "getter" for this new property converts the image's coordinates into a JSON string. The "setter" reads the JSON string and modifies the image's position accordingly:
// Create a property descriptor object var posPropDesc = new Object(); // Define the getter posPropDesc.get = function () { var coords = new Object(); coords.x = parseInt(this.currentStyle.left); coords.y = parseInt(this.currentStyle.top); coords.w = parseInt(this.currentStyle.width); coords.h = parseInt(this.currentStyle.height); return JSON.stringify(coords); } // Define the setter posPropDesc.set = the new accessor property "JSONposition" on a new image var img = Object.defineProperty(new Image(), "JSONposition", posPropDesc); img.src = "..."; // Call the new property img.JSONposition = '{"w":400,"h":100}'; // Read the image's current position console.log(img.JSONposition);
In this example, defineProperty creates a new accessor property on an image (first parameter) with the name "JSONposition"; the third parameter is an object called a property descriptor that defines the new property's behavior.
Property descriptors are a generic way of describing both the property "type" and its "attributes." As the previous example illustrates, the "getter" and "setter" are two of the possible properties in a property descriptor. Adding either of these properties to a property descriptor will cause defineProperty to create an accessor property. When a getter is not specified, accessing the property value returns the value undefined. Similarly, when a setter is not specified, assigning a value to the accessor does nothing. This is illustrated in the following table:Table 1: Possible access and assignment results for combinations of getter or setter functions on a JavaScript accessor property
Accessor properties can also be incrementally defined using multiple calls to the defineProperty API. For example, one call to defineProperty might define only a getter. Later, defineProperty might be called again on the same property name to define a setter. At this point, the property has both a getter and setter:
Object.defineProperty(window, "prop", { get: function() { return "Can get"; } } ); // ... Object.defineProperty(window, "prop", { set: function(x) { console.log("Can set " + x); } } ); // Now both getter and setter are defined for the property
Similarly, defining either a getter or setter to be undefined essentially unsets whatever getter or setter was previously in place:
Object.defineProperty( document.body, "secondChild", { get: function () { return this.firstChild.nextSibling; }, set: function ( element ) { throw new Error("Sorry! This property can't be " + "set. Better luck next time."); } } ); // Changed my mind: don't be so strict about throwing // an error when setting this property... Object.defineProperty( document.body, "secondChild", { set: undefined } );
Another keyword that is possible in a property descriptor is the "value" keyword; "value" signals the creation of a data property:
console.log( Object.defineProperty( document, "data", { value: 5 } ).data );
This code is exactly equivalent to the data property created in the first code sample in this article. Note that if a property descriptor contains a combination of "value" and "get/set" keywords, then the defineProperty API will return an error.
Property descriptors may also include additional keywords to control the "attributes" of the property. These are reserved for future use; currently Internet Explorer 8 supports only the following attribute keyword values:Table 2: Valid values for the writable, configurable, and enumerable property descriptor attributes on both a data and accessor property
If you get the combination wrong, the defineProperty API will return an error, as shown in the following code sample.
try { Object.defineProperty(document, "test", { get: function() { return 'This is just a test'; }, configurable: false; } ); } catch(e) { console.log(e.message); // 'configurable' attribute on the property // descriptor cannot be set to 'false' on this object }
To remove an accessor or data property, simply delete it from the object to which it was defined:
delete document.test; delete document.data;
Accessor Properties and DOM Prototypes
Accessor properties together with the DOM prototype hierarchy complete the scenario of allowing Web developers to have full customization of built-in DOM properties. Accessor properties are the means to customize the DOM's built-in functionality using user-defined JavaScript functionality; the DOM prototype hierarchy is the means for "scoping" the extent of these customizations.
DOM built-in properties are defined on interface prototype objects. As described in Part I, these objects are arranged into a hierarchy; all DOM instances inherit the properties defined at each level in their prototype chain.
One of those built-in properties and a prime target for customization is the innerHTML property.
Figure 3: Prototype chain for a div instance
With this view of the DOM prototype hierarchy, the Web developer can choose to customize the built-in innerHTML property itself, or override that property on a lower level in this hierarchy. To customize the built-in property, use the defineProperty API, passing in the Element.prototype object as the first parameter, the "innerHTML" string as the second, and the getter or setter functions as part of the property descriptor:
// Customize the built-in innerHTML property Object.defineProperty(Element.prototype, "innerHTML", /* property descriptor */);
In most cases, the Web developer's objective will not be to simply replace the innerHTML property with new functionality, but rather supplement the existing functionality of innerHTML. In these cases, it is important to be able to invoke the original behavior of innerHTML from within the new getter or setter code. Do this by caching the original accessor's property descriptor (before customizing it):
// Save (cache) the original behavior of innerHTML var originalInnerHTMLpropDesc = Object.getOwnPropertyDescriptor(Element.prototype, "innerHTML"); // Define my customizations, but use innerHTML when done... Object.defineProperty(Element.prototype, "innerHTML", { set: function ( htmlContent ) { // TODO: add new innerHTML getter code // Call original innerHTML when done... originalInnerHTMLpropDesc.set.call(this, htmlContent); } }
At this point, the setter for innerHTML has been customized for all DOM element instances. The getter for innerHTML continues to work as before.
Perhaps the goal of the Web developer is to customize innerHTML for only a subset of element types—only DIV elements, for example. By defining innerHTML at the HTMLDivElement.prototype level, the Web developer overrides the built-in innerHTML property (for DIV element instances only) because the override is found first when JavaScript visits a DIV element's prototype chain:
// Customize innerHTML for DIV Elements only // (other element types are unaffected) Object.defineProperty(HTMLDivElement.prototype, "innerHTML", /* property descriptor */);
A property override blocks the inheritance of any getter or setter functions from a same-named property at a higher level in the prototype chain. For example, if the property descriptor in the previous sample code contained only the definition for a getter, the setter for this override would be undefined; it would not inherit the setter from higher in the prototype chain.
Finally, when the Web developer wants to apply an override only to a DOM instance, use the defineProperty API with the instance directly:
// Create a div element instance // with a customized innerHTML property var div = Object.defineProperty(document.createElement('DIV'), "innerHTML", /* property descriptor */);
As described, accessor properties used together with DOM prototypes create very powerful scenarios. To be most effective, the Web developer should understand the Internet Explorer 8 DOM prototype hierarchy to learn what interface prototype objects define which properties.
Special Case: Deleting Built-in DOM Properties
In the previous section, I concluded by describing how the JavaScript delete operator will remove any accessor or data property. In some cases this may not appear to work. This is because the Internet Explorer 8 interface prototype objects first inherit from internal prototypes (unavailable to JavaScript) that implement internal versions of the same properties available on the "public" prototypes. This implementation detail is evident only when deleting built-in DOM properties from their prototype objects. The prototype hierarchy in the following figure depicts this implementation detail: deleting the innerHTML property from Element.prototype causes the internal innerHTML property to be inherited. This has the appearance of "restoring" (by inheritance) a built-in property to its default state.
Figure 4: Prototype chain for a div instance with implementation-specific internal prototypes
Powerful Scenarios
To demonstrate the capabilities of accessor properties in conjunction with DOM prototypes, consider two potential scenarios: in the first scenario, a Web page provides a mechanism for a user to make document annotations (such as for online document review and collaboration) and then injects those annotations into the Web page using innerHTML. In this scenario, the Web page has two criteria: the first is ensuring that the injected content is safe by using toStaticHTML; the second is removing certain stylistic elements and attributes of the HTML user-input to prevent layout problems on the page. To simplify this two-step process, the Web page replaces the default functionality of innerHTML with the following custom code (shortened for brevity):
// Save a copy of the built-in property var innerHTMLdescriptor = Object.getOwnPropertyDescriptor(Element.prototype, 'innerHTML'); // Define the new filter, which makes arbitrary HTML safe and then strips fancy formatting Object.defineProperty(Element.prototype, 'innerHTML', { set: function(htmlVal) { var safeHTML = toStaticHTML(htmlVal); // TODO: Code which filters out style attributes + removes stylistic tags from safeHTML // Invoke the built-in innerHTML behavior when done. innerHTMLdescriptor.set.call(this, safeHTML); } });
In the second scenario, a framework Web developer defines a new method to make Internet Explorer 8 more cross-browser compatible. Many JavaScript frameworks currently implement custom code to handle cross-browser incompatibilities or to implement abstractions that do the same. In this example, a Web developer adds an addEventListener API to Internet Explorer 8 (addEventListener is part of the W3C DOM L2 Events standard). Note that this example applies the new API at the appropriate places in the DOM prototype hierarchy to prevent the need for a separate abstraction layer of JavaScript code for consumers of the Web developer's framework to learn (code abbreviated for brevity):
// Apply addEventListener to all the prototypes where it should be available. HTMLDocument.prototype.addEventListener = Element.prototype.addEventListener = Window.prototype.addEventListener = function (type, fCallback, capture) { var modtypeForIE = "on" + type; if (capture) { throw new Error("This implementation of addEventListener does not support the capture phase"); } var nodeWithListener = this; this.attachEvent(modtypeForIE, function (e) { // Add some extensions directly to 'e' (the actual event instance) // Create the 'currentTarget' property (read-only) Object.defineProperty(e, 'currentTarget', { get: function() { // 'nodeWithListener' as defined at the time the listener was added. return nodeWithListener; } }); // Create the 'eventPhase' property (read-only) Object.defineProperty(e, 'eventPhase', { get: function() { return (e.srcElement == nodeWithListener) ? 2 : 3; // "AT_TARGET" = 2, "BUBBLING_PHASE" = 3 } }); // Create a 'timeStamp' (a read-only Date object) var time = new Date(); // The current time when this anonymous function is called. Object.defineProperty(e, 'timeStamp', { get: function() { return time; } }); // Call the function handler callback originally provided... fCallback.call(nodeWithListener, e); // Re-bases 'this' to be correct for the callback. }); } // Extend Event.prototype with a few of the W3C standard APIs on Event // Add 'target' object (read-only) Object.defineProperty(Event.prototype, 'target', { get: function() { return this.srcElement; } }); // Add 'stopPropagation' and 'preventDefault' methods Event.prototype.stopPropagation = function () { this.cancelBubble = true; }; Event.prototype.preventDefault = function () { this.returnValue = false; };
Relationship to Standards
Standards are an important factor to ensure browser interoperability for the Web developer. The accessor property syntax has only recently begun standardization. As such, many browsers support an older, legacy syntax:
// Legacy version of Object.defineProperty(document, "test", // { getter: /*...*/, setter: /*...*/ } ); document.__defineGetter__("test", /* getter function */ ); document.__defineSetter__("test", /* setter function */ ); // Legacy version of Object.getOwnPropertyDescriptor(document, "test"); document.__lookupGetter__("test"); document.__lookupSetter__("test");
One important difference to note in the behavior of __lookupGetter__/__lookupSetter__ is that these APIs visit the prototype chain of the given object to find the getter or setter functions, respectively, while getOwnPropertyDescriptor, as its name implies, checks only the object's "own" properties.
Until other browsers can support the standard accessor property syntax, we recommend using feature-level detection to handle browser interoperability issues (including checking the Internet Explorer 8 restriction of DOM objects only):
if (Object.defineProperty) { // Use the standards-based syntax var DOMonly = false; try { Object.defineProperty(new Object(), "test", {get:function(){return true;}}); } catch(e) { DOMonly = true; } } else if (document.__defineGetter__) { // Use the legacy syntax } else { //neither defineProperty or __defineGetter__ supported }
Restricted Properties
Some built-in DOM properties provide important information to Web applications that help them make security decisions, gather analytics, or provide customized functionality. For these reasons, the following properties cannot be be modified and have their "configurable" attribute set to false:
- location.hash
- location.host
- location.hostname
- location.href
- location.search
- document.domain
- document.referrer
- document.URL
- navigator.userAgent
- [properties of window]
Summary
Accessor properties (also known as getter/setter properties), give Web developers the power to create and customize built-in properties available in the DOM. This article has introduced the accessor property syntax, provided an overview of how to use these properties, and shown how they work together with the DOM prototype hierarchy to complete many Web developers' scenarios. | http://msdn.microsoft.com/en-us/library/dd229916(v=vs.85).aspx | CC-MAIN-2014-35 | en | refinedweb |
Generates random test problems for TSQR. More...
#include <TsqrRandomizer.hpp>
Generates random test problems for TSQR.
Randomizer knows how to fill in an instance of the given MultiVector class MV with a (pseudo)random test problem, using a generator of type Gen.
Definition at line 58 of file TsqrRandomizer.hpp.
Fill A with a (pseudo)random (distributed) matrix.
Fill the MultiVector A with a (pseudo)random (distributed) matrix with the given singular values. Given the same singular values and the same pseudorandom number sequence (produced by the Gen object), this function will always produce the same matrix, no matter the number of processors. It achieves this at the cost of scalability; only Proc 0 invokes the pseudorandom number generator.
Definition at line 88 of file TsqrRandomizer.hpp.
Like the constructor, except you're not supposed to call the constructor of a pure virtual class.
Definition at line 114 of file TsqrRandomizer.hpp. | http://trilinos.sandia.gov/packages/docs/r10.8/packages/anasazi/doc/html/classTSQR_1_1Trilinos_1_1Randomizer.html | CC-MAIN-2014-35 | en | refinedweb |
my ]
The solution is to recode your CGI to display a "you are logged out" message (which is good form anyway) instead of a redirect. Then you CAN pass the cookie, and all will be right with the world.
Gary Blackburn
Trained Killer
First,.
####.
as you can see, the cookie is the same...
Perhaps the problem is that $in{usr} and $usr
don't match?
THX
Li Tin O've Weedle
mad Tsort's philosopher
my $cache = File::Cache->;new({namespace => 'cookiemaker',
[download]
Should be without ";":
my $cache = File::Cache->new({namespace => 'cookiemaker',
[download]
This probabably happened by copying line 33.
Your servant
Li Tin O've Weedle
mad Tsort's philosopher
Tron
Wargames
Hackers (boo!)
The Net
Antitrust (gahhh!)
Electric dreams (yikes!)
Office Space
Jurassic Park
2001: A Space Odyssey
None of the above, please specify
Results (118 votes),
past polls | http://www.perlmonks.org/index.pl?node_id=72691 | CC-MAIN-2014-35 | en | refinedweb |
01 March 2011 13:50 [Source: ICIS news]
LONDON (ICIS)--SABIC’s proposed elastomers and carbon black joint venture (JV) with ExxonMobil in ?xml:namespace>
The companies have selected
This followed a comprehensive evaluation of numerous factors, including integration opportunities with their existing petrochemical JV at the Al-Jubail Petrochemical (Kemya) site, the company said in a statement.
“The project has reached the optimal industrial layout with the move to Jubail,” SABIC said.
“During FEED (front-end engineering and design) both partners, SABIC and ExxonMobil, are targeting development of a globally competitive project with best-in-class industry cost.”
The 50:50 project, originally announced in November 2008, will produce rubber, thermoplastic specialty polymers and carbon black for emerging local and international markets in Asia and the
($1 = €0.72)For more on SABIC | http://www.icis.com/Articles/2011/03/01/9439847/sabic-exxonmobil-saudi-elastomers-jv-at-engineering-design-stage.html | CC-MAIN-2014-35 | en | refinedweb |
07 September 2011 09:32 [Source: ICIS news]
SINGAPORE (ICIS)--?xml:namespace>
The exact date of shutdown of the 300,000 tonne/year facility was not disclosed by the source.
The lack of catalyst affected the company’s HDPE production, while the lack of butane-1 hit Jam Petrochemical’s LLDPE output, the source said.
The company has plans to secure sufficient butane-1 to resume production of LLDPE, said the source.
“We are unsure by when exactly the swing plant restart. This is subject to the operating status of its upstream cracker,” he said.
The company’s cracker with a 1.32m tonne/year ethylene capacity is currently running at lower operating rates than the 80-90% recorded in August, the source said.
Jam Petrochemical also has a stand-alone HDPE facility in Asaluyeh that produces blow moulding grade polymer for the Iranian market.
This plant is running at full capacity, | http://www.icis.com/Articles/2011/09/07/9490595/irans-jam-halts-hdpelldpe-swing-plant-ops-on-feedstock.html | CC-MAIN-2014-35 | en | refinedweb |
Reduce-and-Broadcast (RB) version of DistTsqr. More...
#include <Tsqr_DistTsqrRB.hpp>
Reduce-and-Broadcast (RB) version of DistTsqr.
Reduce-and-Broadcast (RB) version of DistTsqr, which factors a vertical stack of n by n R factors, one per MPI process. Only the final R factor is broadcast; the implicit Q factor data stay on the MPI process where they are computed.
Definition at line 29 of file Tsqr_DistTsqrRB.hpp.
Constructor
Definition at line 43 of file Tsqr_DistTsqrRB.hpp.
Fill in the timings vector with cumulative timings from factorExplicit(). The vector gets resized to fit all the timings.
Definition at line 56 of file Tsqr_DistTsqrRB.hpp.
Fill in the labels vector with the string labels for the timings from factorExplicit(). The vector gets resized to fit all the labels.
Definition at line 72 of file Tsqr_DistTsqrRB.hpp.
Whether or not all diagonal entries of the R factor computed by the QR factorization are guaranteed to be nonnegative.
Definition at line 86 of file Tsqr_DistTsqrRB.hpp.
Internode TSQR with explicit Q factor.
Definition at line 107 of file Tsqr_DistTsqrRB.hpp. | http://trilinos.sandia.gov/packages/docs/r10.6/packages/anasazi/doc/html/classTSQR_1_1DistTsqrRB.html | CC-MAIN-2014-35 | en | refinedweb |
@ Page
Defines page-specific (.aspx file) attributes used by the ASP.NET page parser and compiler.
Attributes
- AspCompat
- When set to true, this allows the page to be executed on a single-threaded apartment (STA) thread. This allows the page to call STA components, such as a component developed with Microsoft Visual Basic 6.0. Setting this attribute to true also allows the page to call COM+ Web Server Control Event Model.
- Buffer
- Determines whether HTTP response buffering is enabled. true if page buffering is enabled; otherwise, false. The default is true.
- ClassName
- Specifies the class name for the page that will be dynamically compiled automatically when the page is requested. This value can be any valid class name but should not include a namespace.
- ClientTarget
- Indicates the target user agent for which ASP.NET server controls should render content. This value can be any valid user agent or alias.
- CodeBehind
- Specifies the name of the compiled file that contains the class associated with the page. This attribute is used by the Visual Studio .NET Web Forms designer. It tells the designer where to find the page class so that the designer can create an instance of it for you to work with at design time. For example, if you create a Web Forms page in Visual Studio called WebForm1, the designer will assign the Codebehind attribute the value of WebForm1.aspx.vb, for Visual Basic, or WebForm1.aspx.cs, for C#. This attribute is not used at run time.
- CodePage
- Indicates the code page value for the response..
- CompilerOptions
- A string containing compiler options used to compile the page. In C# and Visual Basic .NET, this is a sequence of compiler command-line switches.
- ContentType
- Defines the HTTP content type of the response as a standard MIME type. Supports any valid HTTP content-type string. For a list of possible values, search for MIME in MSDN at.
- Culture
- Indicates the culture setting for the page. For information about culture settings and possible culture values, see the CultureInfo class.
- Debug
- Indicates whether the page should be compiled with debug symbols. true if the page should be compiled with debug symbols; otherwise, false.
- Description
- Provides a text description of the page. This value is ignored by the ASP.NET parser.
- EnableSessionState
- Defines session-state requirements for the page. true if session state is enabled; ReadOnly if session state can be read but not changed; otherwise, false. The default is true. These values are case-insensitive. For more information, see Session State.
- false.
Note.
- ErrorPage
- Defines a target URL for redirection if an unhandled page exception occurs.
- .NET. Also, this option is set to true in the Machine.config configuration file. For more information, see Machine Configuration Files.
- Inherits
- Defines a code-behind class for the page to inherit. This can be any class derived from the Page class. For information about code-behind classes, see Web Forms Code Model.
- Language
- Specifies the language used when compiling all inline rendering (<% %> and <%= %>) and code declaration blocks within the page. Values can represent any .NET-supported language, including Visual Basic, C#, or JScript .NET.
-. For more information about locales, search MSDN at.
- ResponseEncoding
- Indicates the response encoding of page content. Supports values from the Encoding.GetEncoding method.
- Src
- Specifies the source file name of the code-behind class to dynamically compile when the page is requested. You can choose to include programming logic for your page either in a code-behind class or in a code declaration block in the .aspx file.
Note RAD designers, such as Visual Studio .NET, do not use this attribute. Instead, they precompile code-behind classes and then use the Inherits attribute.
- SmartNavigation
- Indicates whether the page supports the smart navigation feature of Internet Explorer 5.5 or later..
Note For more information about smart navigation, see the Remarks section.
- Strict
- Indicates that the page should be compiled using the Visual Basic Option Strict mode. true if Option Strict is enabled; otherwise, false. The default is false.
Note This attribute is ignored by languages other than Visual Basic .NET.
- Trace
- Indicates whether tracing is enabled. true if tracing is enabled; otherwise, false. The default is false. For more information, see ASP.NET Trace.
- TraceMode
- Indicates how traces messages are to be displayed for the page when tracing is enabled. Possible values are SortByTime and SortByCategory. The default, when tracing is enabled, is SortByTime. For more information about tracing, see ASP.NET Trace.
- Transaction
- Indicates whether transactions are supported on the page. Possible values are Disabled, NotSupported, Supported, Required, and RequiresNew. The default is Disabled.
- UICulture
- Specifies the UI culture setting to use for the page. Supports any valid UI culture value.
- ValidateRequest
- Indicates whether request validation should occur. If true, request validation checks all input data against a hard-coded list of potentially dangerous values. If a match occurs, an HttpRequestValidationException Class.
- WarningLevel
- Indicates the compiler warning level at which you want the compiler to abort compilation for the page. Possible values are 0 through 4. For more information, see the CompilerParameters.WarningLevel Property property.
Remarks").
Smart navigation is an ASP.NET feature that is examples demonstrate the incorrect and correct way to instantiate a COM object in an AspCompat page.
MyComObject is the component, and
comObj is the instance of the component.
<%@ Page // Avoid this when using AspCompat. MyComObject comObj = new MyComObject(); public void Page_Load() { // comObj.DoSomething() } </script> [Visual Basic] <%@ Page ' Avoid this when using AspCompat. Dim comObj As MyComObject = New MyComObject() Public Sub Page_Load() ' comObj.DoSomething() End Sub </script>
The recommended way to instantiate(); // comObj.DoSomething(); } [Visual Basic] <%@ Page Dim comObj As MyComObject Public Sub Page_Load() comObj = New MyComObject() ' comObj.DoSomething() End Sub </script>
Example
The following code instructs the ASP.NET page compiler to use Visual Basic as the inline code language and sets the default HTTP MIME ContentType transmitted to the client to
"text/xml".
See Also
ASP.NET Web Forms Syntax | Introduction to Web Forms Pages | Directive Syntax | http://msdn.microsoft.com/en-us/library/ydy4x04a(vs.71).aspx | CC-MAIN-2014-35 | en | refinedweb |
Thanks again - one quick question about lazy pattern matching below! On 01/03/2009 23:56, "Daniel Fischer" <daniel.is.fischer at web.de> wrote: > > No, it's not that strict. If it were, we wouldn't need the bang on newStockSum > (but lots of applications needing some laziness would break). > > The Monad instance in Control.Monad.State.Strict is > > instance (Monad m) => Monad (StateT s m) where > return a = StateT $ \s -> return (a, s) > m >>= k = StateT $ \s -> do > (a, s') <- runStateT m s > runStateT (k a) s' > fail str = StateT $ \_ -> fail str > > (In the lazy instance, the second line of the >>= implementation is > ~(a,s') <- runStateT m s) > > The state will only be evaluated if "runStateT m" resp. "runStateT (k a)" > require it. However, it is truly separated from the return value a, which is > not the case in the lazy implementation. > The state is an expression of past states in both implementations, the > expression is just much more complicated for the lazy. >> I think I get this - so what the lazy monad is doing is delaying the evaluation of the *pattern* (a,s') until it is absolutely required. This means that each new (value,state) is just passed around as a thunk and not even evaluated to the point where a pair is constructed - it's just a blob, and could be anything as far as haskell is concerned. It follows that each new state cannot evaluated even if we make newStockSum strict as (by adding a bang) because the state tuple newStockSum is wrapped in is completely unevaluated - so even if newStockSum is evaluated INSIDE this blob, haskell will still keep the whole chain. Only when we actually print the result is each state required and then each pair is constructed and incremented as described by my transformer. This means that every tuple is held as a blob in memory right until the end of the full simulation. Now with the strict version each time a new state tuple is created, to check that the result of running the state is at least of the form (thunk,thunk). It won't actually see much improvement just doing this because even though you're constructing pairs on-the-fly we are still treating each state in a lazy fashion. Thus right at the end we still have huge memory bloat, and although we will not do all our pair construction in one go we will still value each state after ALL states have been created - performance improvement is therefore marginal, and I'd expect memory usage to be more or less the same as (thunk,thunk) and thunk must take up the same memory. So, we stick a bang on the state. This forces each state to evaluated at simulation time. This allows the garbage collector to throw away previous states as the present state is no longer a composite of previous states AND each state has been constructed inside it's pair - giving it Normal form. Assuming that is corrected, I think I've cracked it. One last question if we bang a variable i.e. !x = blah blah, can we assume that x will then ALWAYS be in Normal form or does it only evaluate to a given depth, giving us a stricter WHNF variable, but not necessarily absolutely valued? | http://www.haskell.org/pipermail/haskell-cafe/2009-March/056946.html | CC-MAIN-2014-35 | en | refinedweb |
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pascal-webdev
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Knave Bridge Scorer
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Francois's Game Library
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Verilog Perl
The Verilog-Perl distribution provides Perl preprocessing, parsing and utilities for the Verilog Language. It is also available from CPAN under the Verilog:: namespace.0 weekly downloads | http://sourceforge.net/directory/developmentstatus:production/os:windows/os:os_portable/license:artistic/ | CC-MAIN-2014-35 | en | refinedweb |
This article is a demo on developing MVVM Application Without any Frameworks.
The new framework to hit WPF world is the MVVM framework. MVVM stands for Model - View - ViewModel. I will not explain the theory stuff here, for that you can refer this article. We will build this MVVM application WITHOUT using any frameworks. Just our own good'ol C# code.
In short,
List<>
ObservableCollection<>
So lets get started. Fire-up Visual Studio 2011. Click on new Project. Select Metro and Blank Application. Hit Ok.
The first screen that you'll get is the default metro UI. Its nothing much than a blank black background. No buttons. Nothing. The code-behind contains few default lines of codes and a lot of comments. We will be using the code-behind only once, to write a single line of code in the constructor.
Now create 2 folders in the solution. Model and ViewModel. The Model folder will contain our "class" and ViewModel will contain, well, class but these classes will represent a collection of the Model's classes and will also contain code to wire the View with our ViewModel.
Next, we write our Model. For this application, I'll choose a simple Contact class having a Name and an Email and a GUID to identify it uniquely. So right click on Model folder, Add -> Class. Name the class as Contact.cs. Import the namespace System.ComponentModel, since we will be using the INotifyPropertyChanged interface. This will allow the ViewModel to communicate to the Model if something has changed. I'll keep the discussion simple.
System.ComponentModel
INotifyPropertyChanged
After the Model, lets now focus on ViewModel. Right-click on the ViewModel folder, add -> class. Since this ViewModel will work with our Contact.cs Model, we'll name it as "ContactViewModel.cs". Click Ok.
Now pay close attention, this is where the MVVM magic happens. Our ContactViewModel implements the INotifyPropertyChanged interface, this time to notify the changes in properties to the View and vice-versa. Import System.ComponentModel and implicitly implement INotifyPropertyChanged.I'll make it simple here on how-to construct a basic ViewModel.
ContactViewModel
ObservableCollection<Contact>
Contacts
System.Collections.ObjectModel
Mvvm2_Basic.Model
MyCommand
ICommand
Action<T>
Our View is a very simple UI. As mentioned earlier, we only have 5 buttons on our View. So lets go ahead and create our View. For our View, we will use the BlankPage.xaml. Open BlankPage.xaml.cs (the code-behind). We need to tell our View that whatever events will be raised on the view, they will be handled by our ViewModel.
The DataContext links the current UI with our ContactViewModel.
Now lets create our 5 buttons. They will be "Refresh", "Add New", "Save", "Update", "Delete"
Note the "Command" property on every button. The command property tells the View where to look for, when that button is clicked. In our Command property, we specify the ViewModel property that we want to invoke. That ViewModel property will then invoke the appropriate method.
Command
You should've understood by now that its the head-ache of the ViewModel property to invoke the appropriate method. This separates the concern of the UI about reacting to events. This entire setup allows us to test each "part" separately.
So when "Save" button is clicked, SaveCommand property is invoked. The SaveCommand property from ViewModel has the signature of OnSave() method passed in it. Hence ViewModel's SaveCommand will finally call the OnSave() method.
SaveCommand
OnSave()
You can see in the output window when each method is called, it outputs some text that we've written in Debug.WriteLine in every method.
Debug.WriteLine
Very well. This completes the basic skeleton for our MVVM XML Metro application. In the next series, we will see how to perform CRUD operations using XML file. Till then stay tuned.
If Images in this article isnt proper then please Download the. | http://www.codeproject.com/Articles/391783/An-Address-Book-Application-Made-in-MVVM-For-Metro?fid=1720626&df=90&mpp=10&sort=Position&tid=4262903 | CC-MAIN-2014-35 | en | refinedweb |
30 March 2012 11:41 [Source: ICIS news]
SINGAPORE (ICIS)--East China’s isomer-grade xylene (IX) inventory has dropped since the middle of March amid improved demand from the paraxylene (PX) sector, traders in east ?xml:namespace>
The IX inventory held by traders decreased from 70,000 tonnes on 15 March to 50,000 tonnes on 30 March, according to data from Chemease, an ICIS service in
“Some PX producers like Shanghai Petrochemical and Zhenhai Refining & Chemical purchased IX ahead of the restart at their PX units. IX is the feedstock for PX,” traders added.
“In addition, 10,000 tonnes of bonded IX cargoes were exported to Asian markets,” the trader added.
IX prices are at yuan (CNY) 9,200/tonne ($1,460/tonne) ex-tank Zhangjiagang on 30 March, compared to CNY9,300-9,350/tonne on 15 March, the data showed.
Solvent-grade xylene prices are at CNY8,950-9,050/tonne ex-tank Zhangjiagang on 30 March, compared to CNY9,175-9,200/tonne on 15 March, according to Chemease.
The inventory of solvent-grade xylenes is unchanged from the middle of March, the data showed.
The inventory of both grades of xylenes held by traders decreased from 125,000-130,000 tonnes on 15 March to 105,000-110,000 tonnes on 30 March, according to Cheme | http://www.icis.com/Articles/2012/03/30/9546250/east-china-isomer-grade-xylenes-stock-down-by-20000-tonnes.html | CC-MAIN-2014-35 | en | refinedweb |
This is a kind of 'diary' of my experiences converting my Ant-based build system into scons. You'll see that it is a combination of emails from the mailing list and some extra notes and bits of code that I tried.
John Arrizza
I am (still) new to scons. I've tried it on a couple of small projects and it seems to work well.
However, I'd like to roll it out in a bigger way and I'm stuck. I'd like to get some feedback from you all on how you'd proceed. I'd like to use it for my home setup which has some interesting twists and turns and so may pose a nice challenge for the scons gurus.
The basic scenario is that I have a whole bunch of little projects (50 or so?) and I use those to populate my web site (). I am currently running on Win2K, using Ant with some home-brew taskdefs, some helper exe's, scripts, etc. It's become a bit of a mess and I'd like to clean it up into something much more straightforward by using scons.
The directory structure looks like:
\projects\src\project1 \projects\src\project2 ... \projects\src\projectn (~20 projects) \projects\frozen\project1 (~20 projects.) \projects\neuralnets\project1 (~5 projects) \projects\debug\project1 (etc.) \projects\release\project1 (etc.) \projects\web\arrizza\html\ (etc.) \projects\web\arrizza\cgi-bin\ (etc.)
- The \projects\web\arrizza is a staging area where I collect all of the information prior to FTP'ing (via an Ant taskdef) to my web site. I've been working on a python based ftpmirror that will only send new/changed files.
- All of the projects under \projects\frozen are compiled and put in the staging area.
- Some -- not all -- of the projecs in \projects\src are compiled and put in the staging area.
- some projects don't have a compile step, there are just some files that get put in the staging area.
- there are some dependencies between the projects (e.g. unit testers are used by many projects) but generally they are isolated.
- I have projects written in in C# or C++ (VC7 or VC6 or gcc) or Java (jikes). Most projects are compiled in one and only one language but there are some (e.g. a cross-platform unit tester) that I compile in multiple languages.
- I have an xml file contains information that is used to create and generate zip files, the html page, etc. for a downloads area. I wrote a C# app to do all of this work. I'd like to replace it with some python code.
The public interface to this build system (i.e. what I can call from or do from the command line with Ant) is something like:
- compile (release mode) any given project
compile various groups of projects (see for example as one of these groups)
- compile all
- prepare a particular part of the staging area (e.g. put my resume in the html\resume directory)
- prepare all of the staging area
- send a particular part of the staging area (e.g. send an updated resume to my website)
- send all of the staging area to the website
- do it all, i.e. compile all, prepare all, send all
Given all that, how would you lay out the the scons files, what builders would I need, etc. to get this to work similar to the way I have the Ant system now?
I have source in several directories:
projects\src\projectn (etc.) projects\frozen\projectn (etc.)
I want the target directory to be either debug or release (siblings of the source root directories):
projects\debug\project projects\release\project
- 1 Should I have one conscript file at the root (i.e. \projects\conscript) and then one in each project, or is it better to put it all into one file at the root??
1) Should I have one conscript file at the root (i.e. \projects\conscript) and then one in each project, or is it better to put it all into one file at the root?
I'd go with separate SConscripts in each project. Modularity is your friend.?
Use the Alias() function to map the arguments you'd like people to specify on the command line to the underlying targets (subdirectories and/or individual files) that should be built for that argument.
Main sconstruct file has a list of Alias()'s with each project I care about. If I ever move a project, I change the Alias for it in one place -- done. I'll start setting this up...
My next question:
Once I have all of this set up, how do I group the Alias()'s into a few different groups? e.g. I need a command to compile all of the 'download' projects, another to compile all of the 'neuralnet' projects, etc. I'd also like a 'compile all'.
In make these are psuedo targets, in scons the right way to do this is to use ??
In make these are psuedo targets, in scons the right way to do this is to use ??
Aliases again. Aliases can "contain" other aliases.
a = Alias('A') b = Alias('B') all = Alias([a, b])
As Gary mentioned, use Aliases. You can also use the Alias call on the same alias multiple times... so your SConstruct could look like:
... Alias('neuralnet1','neurelnet1.exe') Alias('neuralnet','neuralnet1') ... Alias('neuralnet1','neurelnet2.exe') Alias('neuralnet','neuralnet2') ... Alias('neuralnet1','neurelnet3.exe') Alias('neuralnet','neuralnet3') ... Alias('neuralnet1','neurelnet4.exe') Alias('neuralnet','neuralnet4')
Is equivalent to,
... Alias('neuralnet1','neurelnet1.exe') ... Alias('neuralnet1','neurelnet2.exe') ... Alias('neuralnet1','neurelnet3.exe') ... Alias('neuralnet1','neurelnet4.exe') Alias('neuralnet',['neurelnet1','neurelnet2','neurelnet3','neuralnet4'])
The order you add tasks into the Alias is the order they will be executed.
In response to the emails, I tried the following. It did not work.
Sconscruct
import SCons.Script env = Environment() env.Alias('cppwiki', 'src/cppwiki') env.Alias('pso', 'src/pso/sconscript')
Sconscript
import sys print "In pso\sconscript" env = Environment(tools=['mingw']) project = 'pso' builddir = buildroot + '/' + project targetpath = builddir + '/' + project BuildDir('#' + builddir, "#.", duplicate=0) env.Program(targetpath, source=Split(map(lambda x: '#' + builddir + '/' + x, glob.glob('*.cpp'))))
Calling 'scons pso' just says that the target is up to date
D:\projects>scons pso scons: Reading SConscript files ... scons: done reading SConscript files. scons: Building targets ... scons: `pso' is up to date. scons: done building targets. D:\projects>
Made things simpler:
env = Environment() Export('env') env.Alias('cppwiki', 'src/cppwiki/sconscript') env.Alias('pso', 'src/pso/sconscript')
pso/sconscript
import sys Import('env') print "In pso/sconscript" project = 'pso'
Still no joy. Using SConscript works:
env = Environment() Export('env') env.Alias('cppwiki', 'src/cppwiki/sconscript') env.Alias('pso', 'src/pso/sconscript') SConscript('src/pso/sconscript') SConscript('src/cppwiki/sconscript')
but now builds both projects, no matter what I put on the command line.
Well it didn't really "build" both projects. It just read the sconscript files, which caused the 'print' statements to execute, which made it look like a compile was happening.
Here's a response to an email I sent out.
env = Environment() Export('env') env.Alias('cppwiki', 'src/cppwiki/sconscript') env.Alias('pso', 'src/pso/sconscript')
The Alias calls should not list the SConscript files, they should list whatever *targets* (files and/or subdirectories) you want built for the alias. So if you want the aliases to build all of the targets underneath the subdirectories in which those SConscript files live, you should list those subdirectories:
env.Alias('cppwiki', 'src/cppwiki') env.Alias('pso', 'src/pso') SConscript('src/cppwiki/sconscript') SConscript('src/pso')
You still need the SConscript() calls to tell SCons to read up and execute the SConscript files.
But I get this output no matter what's on the command line. So it looks like the SConscript() command is calling the sconscript not just a declaration. That is the conscript file is executed immediately when the SConscript() statement is seen.
It's actually not executed immediately, but it is executed. That's what the SConscript() call does; it says, "Here's a subsidiary configuration file, you need to read it and execute it so you have the right picture of the dependencies before you process the targets on the command line."
How do I "hook up" the command line to the Alias to the sconscript file? In other words, I need to declare that whenever I type 'pso' on the command line, there is a mapping from that to a real directory (via the Alias)
Right, to a directory, not an SConscript file.
and there is a mapping from the directory name to the invocation of the correct sconscript file (via ???).
No, SConscript files just get read up to establish the global picture of the dependencies. You don't need to map specific names to specific SConscript files.
But those are only declarations. I also need a way to say, ok, for this invocation of scons, I need to compile a target, e.g. pso, and no others.
That's what you specify on the command line. They can be files, or directories (in which case everything under the directory is built) or Aliases (which expand to files or directories).
Based on the above email and more reading of the manual, here is the latest sconstruct:
import SCons.Script env = Environment() Export('env') env.Alias('cppwiki', 'src/cppwiki') env.Alias('pso', 'src/pso') SConscript('src/pso/sconscript') SConscript('src/cppwiki/sconscript')
and sconscripts (only one, the other is similar):
Import('env') print "In pso/sconscript" project = 'pso' env.Program(target = 'pso', source = ['acs-tsp2003.cpp', 'solution.cpp', 'utilities.cpp'])
Current Status
It currently builds one or the other target based on the command line, and 'scons .' builds both.
Notes
- the sconscript files are read and, since they are python, they are 'executed'. However, that does not cause a build to actually occur.
- the Program() causes the build to occur but only if the command line target (through an Alias() if it exists) matches the "target=" parameter to the Program() call.
Questions (more or less priority order)
the Program() is defaulting to VC7 (i.e. 2003 .Net), I need to force a different compiler in each case (gcc for pso, VC6 for cppwiki). How do I do that? Create different construction environments, possibly from a common ancestor using env.Copy(), and then call env.Tool(tool) on each environment with different values of tool
how do I specify an alternate build directory? e.g. \projects\debug\pso Read about env.BuildDir
how do I specify debug vs release? Leanid: I use the same env.BuildDir and add Release or Debug into path, I set it by using ARGUMENTS.get('mode', 'Release') and invoking "scons mode=Debug", also I put this value in envMODE and alter compiler flags based on this setting.
- there is a .dsp available for cppwiki. I believe I can use that. How do I do it?
Leanid: I have written wrapers for Program,SharedLibrary,StaticLibrary and use something like this inside. Now "scons dsp=yes" build dsp files
class Dev(Environment): def _devBuildDsp(self, buildtype, target, source, duplicate=0): # Split source in group ... buildtarget = self.Program(target, src['Source'],duplicate=duplicate) self.MSVSProject(target = target + self['MSVSPROJECTSUFFIX'], srcs = src['Source'], incs = src['Header'], localincs = src['Local Headers'], resources = src['Resource'], misc = src['Other'], buildtarget = buildtarget, variant = self["MODE"]) def DevProgram(self, target = None, source = None, pattern=None, duplicate=0): if ARGUMENTS.get('dsp', 'no') == 'yes': self._devBuildDsp('exec',target, source, duplicate=duplicate) else: self.Program(target, source, duplicate=duplicate)
why are all the sconscript files being read when I only specify one on the command line? Is there a workaround? SCons, by default, reads everything so that it can build a full dependency tree. This is good. If you are clever then you can do things like if env['BUILD_PSO']: SConscript('src/pso/sconscript'); to only read the SConscripts of the targets you're interested in, but be careful.
some of my projects require me to build with more than one compiler. How do I do that? See the answer to your first question :-)
do I have to name each and every .cpp? Try import glob; Program('pso', glob.glob('*.cpp'))
class Dev(Environment): def DevGetSourceFiles(self, patterns=None): files = [] if patterns is None: patterns=['*'+self["CXXFILESUFFIX"],'*'+self["CFILESUFFIX"], '*'+self["QT_UISUFFIX"]] for file in os.listdir(self.Dir('.').srcnode().abspath): for pattern in patterns: if fnmatch.fnmatchcase(file, pattern): files.append(file) return files
how do I add other compile and link parameters? Use env.Append(CCFLAGS = ['-g', '-O2']) and similar.
Made some further changes based on comments above and another email:
I find it's simpler to do most of the work in the SConstruct: in SConstruct:
mode = ARGUMENTS['mode'] # also set up tools according to mode here build_dir = os.path.join('#Build', mode, 'projectx') SConscript('projectx/SConscript', build_dir=build_dir, ...)
then the projectx/SConscript doesn't have to know about the mode at all. And your build dir can go wherever you like, just set up the build_dir arg properly. The SConscripts can just look like this:
foo = Project(...) Alias('projectx', foo) bar = OtherThing(...) Alias('projectx', bar) # add each target to the projectx alias
If all your targets (and only those) are under '.' (the current build dir), you could just do
Alias('projectx', '.')
instead. Of course only the final targets need to be added to the Alias; everything else needed by those will automatically built as needed.
The current code is here ExtendedExampleSource1
Current Status
It currently builds one or the other target based on the command line, e.g. 'scons pso mode=debug', and 'scons .' builds everything.
Todo
- finish setting up the correct Tool() for each project or should I use the .dsp builder?
finish adding appropriate compile & link parms to each project; Look into having a centralized list of parms
- figure out which tool to use for C# or use something to run devenv against the .sln
- disallow command lines like 'scons pso mode=fred' this causes a \projects\fred\pso\... tree to be created. mode should be 'debug' or 'release' only.
-
- heh. no questions. just work.
The current code is here ExtendedExampleSource2
Current Status
- Added Leonid's Dev() class rather than using glob.glob. Seems to have simplified the sconscripts a bit
- I disallowed command lines like 'scons pso mode=fred' this causes a \projects\fred\pso\... tree to be created. mode must be 'debug' or 'release' only.
Todo
- finish setting up the correct Tool() for each project or should I use the .dsp builder?
- No builtin tool for C#, see if I can use Erling's C# Tool.
finish adding appropriate compile & link parms to each project; Look into having a centralized list of parms
-
- more work
Just tried MSVSProject(). Compiled ok but did not generate any files. Read the Manpage, looked at Leonid's Dev() class again, still no joy... Hmmm.
The current code is here ExtendedExampleSource3
In general, the sconstruct has become the repository for all the helper functions the sconscripts need and also it has become the driver/coordinator of the sconscripts. I wanted it this way to ensure that I can move projects from one directory tree to another with very little effort. I think this is the right direction:
- sconscripts hold as little information as possible except for project-specific stuff
- everything else in the sconstruct
I'm working on getting the Install() to start building a staging area where the website files will eventually reside. When that staging area is complete, I will then need to find a way to transfer it to my website server.
Current Status
- gave up on MSCSProject() for now. set up a Command() for building sln's and dsp's. Used Depends() to make the target depend on source files (.cpps, .h's etc.) not just the project file (.dsp, .sln)
- added almost all Alias() and projects that I want to use
Todo
-
- started working on understanding Install()
Questions
- I have some files that get "installed" by just a straight copy from a source directory to the staging area
- I also need to see if I can use ftp to transfer the staging area to the remote server
The current code is here ExtendedExampleSource4
The Install() works nicely with either targets (e.g. Program(), etc.) or with existing files (e.g. File(), Dir()).
I created three helper functions that might be useful to others:
GetFiles(dir, includes, excludes=None) returns a list of files in 'dir' that matches the patterns in 'includes' and doesn't match the patterns in 'excludes'. see InstallFiles() for an example of how to use it.
InstallFiles(env, dest_dir, src_dir, includes, excludes) returns a Node of the dest_dir to use in an Alias(). It gets all of the files in 'src_dir' that matches the patterns in 'includes' and doesn't match the patterns in 'excludes' and adds an Install() for each one in the given 'env'. It's used something like this:
env.Alias('prepare_main', [ InstallFiles(env, dest_dir = arrizza_local_root, src_dir = arrizza_websrc_root + '/main', includes = ['*'], excludes = ['.svn']), InstallFiles(env, dest_dir = arrizza_local_html, src_dir = arrizza_websrc_root + '/htmlmain', includes = ['*'], excludes = ['.svn']) ])
Now 'scons prepare_main' will copy all files from the directories in .../main and in .../htmlmain and put them in their respective destination directories held in the variables 'arrizza_local_root' and 'arrizza_local_html'. All the files in the source directories are copied expect those that match the .svn (this is from the SubVersion version control, see).
InstallTree(env, dest_dir, src_dir, includes, excludes) is similar to InstallFiles() except that it traverses the entire directory tree.
Current Status
- finished most of the Installs() I need
- started using SConsignFile()
Todo
- some remaining Installs require a complete tree to be moved over, then a few files deleted, a few files overwritten, etc. need to work out how to do that.
-
- I also need to see if I can use ftp to transfer the staging area to the remote server
- Need to look into Zip()
It seems that there a few categories of soncs commands:
- commands that return Nodes, e.g. Dir(), File(), Alias(), Depends(), etc. These commands are used to create, organize or otherwise manipulate Nodes.
commands that have a file-system side-effect, e.g. Program(), Install(), InstallAs(), Command(), etc. These commands take a Node and do something with them, OR do something and return a Node to indicate what it did. They effect files and directories on the file-system. More precisely, they effect the file-system if they are part of the final target Node list.
- commands used for admin/bookkeeping purposes, e.g. SConscript(), SConsignFile(), Export(), Import(), etc. These commands provide "glue" between the various bits of the build system.
hmmm. more categories to come as I learn about them...
The current code is here ExtendedExampleSource5
Lots of changes occurred since I updated here last. I have done the following:
- modified Zip() to optionally prevent the directory from being put into the zip path
- generated HTML files from sconscript calls
- found out about Value() too late to use it. Value(s) returns a node, the "source" is the string 's' and, best of all, it creates a dependency against it. In other words, if you change the string parameter in Value(s), it will cause a re-build to occur. Perfect for generating HTML files!
created a bunch of wrapper functions to help spew out the files and the matching index pages. see for an example of the index page. This page sets up a table that contains hrefs to a bunch of project pages. Each project page contains a main page, a zip file, and a page that lists source code.
- sconstruct is roughly 1200 lines and the individual sconscripts have become more complex. However the structure is pretty simple and the sconscripts are more or less independent of where they're located in the directory structure. This means I can move projects around if I want to with very little change to the build system.
To do:
finish doing the snippets page and projects . This is a bit more complicated index than the others but should be still fairly straightforward.
- start working on sending the files from the staging area to the actual website
- tighten up some of the dependencies. It's still relatively loosely defined what gets built and what doesn't when a target is named
- extract out some of the HTML generating code into it's own .py | http://www.scons.org/wiki/ExtendedExample?highlight=GetFiles | CC-MAIN-2014-35 | en | refinedweb |
Very often I see one question flooding in all forums, “How to upload a File using WCF REST Service? “, so I thought let me write a post on the same.
Essentially, there is nothing specific to do to upload file, but the below steps
1. Create a service with Post operation
2. Pass file data as Input Stream
3. Pass name of the File
4. Host the service in console application [Note : You can host wherever you want though]
Let us first create Service Contract.
If you notice above Service contract is creating a REST resource with POST method. One of the input parameter is Stream.
For your reference, contract interface would look like as below, [You can copyJ]
IService1.cs
using System.ServiceModel; using System.ServiceModel.Web; using System.IO; namespace RESTImageUpload { [ServiceContract] public interface IImageUpload { [OperationContract] [WebInvoke(Method = "POST", UriTemplate = "FileUpload/{fileName}")] void FileUpload(string fileName, Stream fileStream); } }
Once Contract is defined we need to implement service to save a file on sever location.
You need to make sure you have a folder FileUpload created on D drive of your server else you would get “Device not ready “exception.
Since Write () method takes byte array as input to write data in a file and input parameter of our service is Stream , so we need to do a conversion between Stream to Bye Array
Final Service implementation would look like below [You can CopyJ]
Service1.svc.cs
using System.IO; namespace RESTImageUpload { public class ImageUploadService : IImageUpload { public void FileUpload(string fileName, Stream fileStream) { FileStream fileToupload = new FileStream("D:\\FileUpload\\" + fileName, FileMode.Create); byte[] bytearray = new byte[10000]; int bytesRead, totalBytesRead = 0; do { bytesRead = fileStream.Read(bytearray, 0, bytearray.Length); totalBytesRead += bytesRead; } while (bytesRead > 0); fileToupload.Write(bytearray, 0, bytearray.Length); fileToupload.Close(); fileToupload.Dispose(); } } }
So far we are done with Service definition and implementation and now we need to host the service. I am going to host service in a console application. Host program would have reference of System.ServiceModel and System.ServiceModel.Web. If you are not able to find System.ServiceModel.Web reference to add in your console application then change the target framework to .Net Framework 4.0 from .Net Framework 4.0 client profile.
Program.cs
using System; using System.ServiceModel; using RESTImageUpload; using System.ServiceModel.Description; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string baseAddress = "http://" + Environment.MachineName + ":8000/Service"; ServiceHost host = new ServiceHost(typeof(ImageUploadService), new Uri(baseAddress)); host.AddServiceEndpoint(typeof(IImageUpload), new WebHttpBinding(), "").Behaviors.Add(new WebHttpBehavior()); host.Open(); Console.WriteLine("Host opened"); Console.ReadKey(true); } } }
Press F5 to run the service hosted in console application.
Service is up and running so let us call this service to upload the file.
I am creating a simple ASP.Net Web Application with File Upload control and a button. ASPX page looks like below
Default.aspx
u<%@ Page</a>" title="ASP.NET Website"></a>. </p> <p> You can also find <a href="<a href=""></a>" title="MSDN ASP.NET Docs">documentation on ASP.NET at MSDN</a>. </p> <asp:FileUpload <asp:Button </asp:Content>
On click event of button we need to make a call to the service to upload the file.
In above code, I am making a HTTP Web Request and explicitly specifying method is POST and content type is text/plain. We need to get the Request Stream and write the byte array in that. As HTTP response you can get the status code.
For your reference client code would look like as below,
Default.aspx.cs
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.IO; using System.Web.UI.WebControls; using System.Net; namespace WebApplication1 { public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Button1.Click += new EventHandler(Button1_Click); } void Button1_Click(object sender, EventArgs e) { byte[] bytearray=null ; string name = ""; //throw new NotImplementedException(); if (FileUpload1.HasFile) { name = FileUpload1.FileName; Stream stream = FileUpload1.FileContent; stream.Seek(0, SeekOrigin.Begin); bytearray = new byte[stream.Length]; int count = 0; while (count < stream.Length) { bytearray[count++] = Convert.ToByte(stream.ReadByte()); } } string baseAddress = "http://" + Environment.MachineName + ":8000/Service/FileUpload/"; HttpWebRequest request = (HttpWebRequest) HttpWebRequest.Create(baseAddress+name); request.Method = "POST"; request.ContentType = "text/plain"; Stream serverStream = request.GetRequestStream(); serverStream.Write(bytearray, 0, bytearray.Length); serverStream.Close(); using ( HttpWebResponse response = request.GetResponse() as HttpWebResponse ) { int statusCode =(int) response.StatusCode; StreamReader reader = new StreamReader( response.GetResponseStream() ); } } } }
I hope this post was useful and saved your time to upload a file. In next post I will show you how to upload an image from Silverlight client.
Very nice
Thanks sir :)
Thanks … It’s Very Useful …
Thanks..very useful, it would really helpful for me to upload image file on server…. Thanks lot.. I will implement this….
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Why so much code?
public void FileUpload(string fileName, Stream fileStream)
{
using(var fileToupload =
new FileStream(
string.Concat(“D:\\FileUpload\\”, fileName),
FileMode.Create))
{
fileStream.CopyTo(fileToupload);
}
}
:-)
…and for the upload on the client again just two lines :-)
Hi Daniel ,
was that coded not needed ? please share if you have lesser code to share?
I don’t understand. I can only get 1 parameter when using streaming. It won’t let me add the fileName parameter.
How do I fix this?
Really great post
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Anyone knows why I can’t upload files bigger than 4 Mo ? I’ve setup both asp.net and wcf web config to accept about 2 Go
Here’s the asp
Here’s the WCF on the binding used by myservice
And here’s the standard endpoint
I’m stuck on that issue for 3 days, can anyone help me ?
Thanks
Hi ,
I hope this blog post of mine may help you
I’m sorry which post ?
This post
Thanks for the great article. However, I keep getting this Error with your (unmodified) code:
“The remote server returned an error: (400) Bad Request.” at Default.aspx.cs at line 47:
(line 47:)
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
Checking the Server Trace, I see: an exception.6be8a0e4-1-129737975619047947System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
The service operation ‘Post’ expected a value assignable to type ‘Stream’ for input parameter ‘fileStream’ but received a value of type ‘HttpRequestMessage`1′.
at Microsoft.ApplicationServer.Http.Dispatcher.OperationHandlerPipelineInfo.ServiceOperationHandler.ValidateAndConvertInput(Object[] values)
at Microsoft.ApplicationServer.Http.Dispatcher.OperationHandlerPipelineInfo.GetInputValuesForHandler(Int32 handlerIndex, Object[] pipelineValues)
at Microsoft.ApplicationServer.Http.Dispatcher.OperationHandlerPipeline.ExecuteRequestPipeline(HttpRequestMessage request, Object[] parameters)
at Microsoft.ApplicationServer.Http.Dispatcher.OperationHandlerFormatter.OnDeserializeRequest(HttpRequestMessage request, Object[] parameters)
at Microsoft.ApplicationServer.Http.Dispatcher.HttpMessageFormatter.DeserializeRequest(HttpRequestMessage request, Object[] parameters)
at … (etc.)
any idea how I can fix this? I’m stuck with this problem for a few days now.
Thanks,
Arie
The remote server returned an error: (404) Not Found.
I think Mr. Fisher’s idea to use fileStream.CopyTo to save the incoming stream is good. I just tried his idea out on my own code and it seemed to work for me.
BTW (Rant): It would be nice if this site supported Windows Live Authentication. I’m getting tired of being forced to lug my Google Credentials around when I mostly use Microsoft Products. For one, Google asked me to supply the month and day of my birthday for everyone on Google Plus to see. There is no need for people to see my birthday. That’s just one more piece of information hackers can use to steal my identity. I’ll be glad when Microsoft obliterates Google and Apple off the face of this planet!!!?
And I also removed the filename parameter, still getting error “The remote server returned an error: (400) Bad Request.” at webform1.aspx.cs at :
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
Please help me fix these. | http://debugmode.net/2011/05/01/uploading-file-to-server-from-asp-net-client-using-wcf-rest-service/ | CC-MAIN-2014-35 | en | refinedweb |
Answered by:
Windows 8.1 Preview GetVersionEx reports 6.2.9200
Can anyone comment on why the GetVersionEx API on Windows 8.1 Preview reports 6.2.9200 instead of 6.3.x?
C:\>getversionex.exe
6.2.9200 N/A Build 9200
systeminfo.exe obtains the version information through WMI: Win32_OperatingSystem and reports the "correct" version:
C:\>systeminfo
Host Name: WIN-QJNHK7TGRV7
OS Name: Microsoft Windows Server 2012 R2 Datacenter Preview
OS Version: 6.3.9431 N/A Build 9431
OS Manufacturer: Microsoft Corporation
getversionex.cpp
#include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { OSVERSIONINFOEX osvi = {0}; osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX); ::GetVersionEx((OSVERSIONINFO*)&osvi); if(osvi.szCSDVersion[0] == _T('\0')) { _tcscpy_s(osvi.szCSDVersion, L"N/A"); } CString version; version.Format(L"%u.%u.%u %s Build %u", osvi.dwMajorVersion, osvi.dwMinorVersion, osvi.dwBuildNumber, osvi.szCSDVersion, osvi.dwBuildNumber & 0xFFFF); _tprintf_s(version.GetString()); return 0; }
- Edited by Euclid Tuesday, June 25, 2013 7:06 AM
- Moved by HCK Moderator Friday, June 28, 2013 6:04 PM This is an API question. Not related to HCK.
Question
Answers
All replies
... but the "IsWindows* macros from VersionHelpers." are not defined in VS2012.
Just what I expected - sorry, but I'm tired of the loops we have to jump through just because "compatibility" problems of other people, or that MS thinks that could happen.
Is there any way to detect the presence of such a manifest (that is, if you're lied to), if you're a plugin? Otherwise people will start looking at other ways to detect the "real" version (at least, in our case, just for a LOG file that shows the "real" environment) - we do it by querying the KERNEL32 version, which is a hack that is forced by MS just because they have no way to switch off that intermediate layer.
A new TRUEOSVERSIONINFOEX struct that tells Windows to return the "real" values (different size to the OSVERSIONINFOEX structure) would resolve the issue.
);
If you're a plugin, you must conform to the process environment you live in. If the process believes the world is NT 6.2, it is no other than NT 6.2.
If you need your own environment to see the real world, why don't you use your own process for that purpose?
Imagine it's a plugin that can execute things the application cannot (most of the times, that's what plugins are for). And imagine, the plugin knows it can use a feature under 8.1 (or whatever version) that the application if not built for? Why should the application (created by developers I don't even know) foresee all features my plugin (unknown to the app's creators) would like to use? That makes no sense, it limits the usefulness of plugins (external modules etc).
To make it clearer, assume you have a printing plugin. And the app does not know what the printing plugin could use to do its job. Why should the application foresee the APIs (or other features of "the process environment") it uses to fulfill the job? Imaginge different plugins, some more sophisticated (using newer APIs) and some older ones...
Chuck: There are a few problems with the GetVersionEx API:
1. As it is declared as deprecated we cannot easily use in an application when using the Windows 8.1 SDK. Hacks are required to suppress just this one warning/error and not all others.
2. What guarantee do we have that the correct version is reported for post Windows 8.1 versions? If a new compatibility/application/supportedOS entry is required in the manifest for every new Windows version, we will have the same problem again.
Yes, WMI reports the correct information regardless of the appcompat shims.
What you describe is "By Design". Unless your application has the GUID to indicate compatibility with the current OS, then the OS may provide older information to avoid app compat bugs.
It is not a 'hack' to use #pragma warning(push) #pragma warning(disable:4995) #pragma warning (pop) around code, but you at least know that the API in question is deprecated and you should look to see if (a) you really need to call this API and (b) if there are better alternatives. How about the GetFileVersionInfo on kernel32.dll recommendation from MSDN?
- Proposed as answer by Chuck Walbourn - MSFT Monday, July 08, 2013 8:09 PM
Yes, but Plugins/DLLs etc are not "the app".
They might have different requirements.
Otherwise it sounds as if you're not allowed to modify your car with newer accessories as the ones that existed when the car was designed (no navigation kit for cars older than 10 years!).
No, this is bad design, IMHO.
Hello)
Be calm) All problems solved with simple solution!
If VerifyVersionInfo recommended, so then we will use it and one more numeric method - bisection method.
New api the same. Function name is GetVersionExEx, sources available here -
Implemented in C. Test app available too.
Heh, write in C, let it C)))
Thanks)
- Edited by iContribute Monday, July 08, 2013 6:14 PM addition
VerifyVersionInfo is intended for simple "you must be this high to ride this ride" compatibility tests or to exclude specific versions. It's not a great option if you are just trying to capture a version string for use in logging or diagnostics.
If you read the MSDN link I provided above, getting the File Version info off the KERNEL32.DLL is probably the best way to get just the version for logging. I would NOT guard any feature app or installer behavior based on this.
iContribute's post just recreates the same problem that deprecating GetVersionEx was fixing in the first place. Please don't use this kind of thing...
- Edited by Chuck Walbourn - MSFT Monday, July 08, 2013 8:07 PM note
- Proposed as answer by Chuck Walbourn - MSFT Monday, July 08, 2013 8:09 PM
At least two big projects that I know will start accept some bug requests related to this deprecation.
One of them is Mono Project - alternative .NET implementation.
It's used by Environment.OSVersion property. To be fair an official .NET version does not have this issue and mentioned property returns valid info under Windows 8.1.
So, VerifyVersionInfo and numeric bisection method are better friends here.
Guidelines - good, deprecation without alternative - not. And let's users/developers choose what is better.
And finally... I want super-duper about dialog with valid version numbers.
Chuck, to be fair again.. I don't recreate problem, I fix her. It's custom solution, You want it - You get it.
Oh, and "getting the File Version info off the KERNEL32.DLL" What is it? Joke? Seriously? Only bad words. Embedding manifest, WMI win32 class, system file version - it's all - Kung Fu.
Write, Compile, Copy, Run = Fun.
Thank you very much for your attention!
P.S.: Deprecation it's really bad decision.
P.P.S: Numeric methods rulz!
- Edited by iContribute Monday, July 08, 2013 8:59 PM addition 2
My point is that going the route iContribute recommends will result in a future version of Windows having to lie to VerifyVersionInfo to avoid appcompat problems..
The key question gets back to why you are calling GetVersionInfo(Ex) in the first place... Most use of this function is problematic and probably not needed, so the API has been deprecated.
The MSDN link provides the alternatives.
- Edited by Chuck Walbourn - MSFT Monday, July 08, 2013 11:13 PM link
In that case VerifyVersionInfo,GetFileVersionInfo, VerQueryValue, WMI win32 class... even.NET assembly that can be consumed in code - good candidates to be deprecated... (heh, kernel32.dll will be deprecated too?). Instead simple os api call, we need write a spaghetti code that does the same and even in this case used api maybe will deprecated. Sure.... Yeah... it's right way. Code above uses: simple code, recommended api (ms725492(v=vs.85).aspx "It is preferable to use VerifyVersionInfo rather than calling the GetVersionEx function to perform your own comparisons." and others places on MSDN), same api that in VersionHelpers.h (Who need this header?), precise algo and good old plain C. Oh, no.. it's good... definitely will be deprecated.
So, provided above "alternatives" also will be deprecated if will widely used?Tightening the screws is the right way)
- Edited by iContribute Tuesday, July 09, 2013 4:19 AM addition 3
The right solution is for developers to step back and look at why they are trying to determine the OS version.
For logging and diagnostics, the GetFileVersionInfo solution seems to be the recommended approach given a fallback that can handle 'version information unknown' as a failure case instead of crashing the application. WMI is also a robust way to achieve this.
For install 'you must be this high to ride this ride' checks, that would be best handled with VerifyVersionInfo.
Otherwise, developers should try to eliminate use of GetVersion(Ex) entirely. Often there are other methods for detecting the presence of features that are much more robust. For example, an error return code on a factory method or a failed attempt to QueryInterface. These are the scenarios that deprecating GetVersion(Ex) is explicitly trying to address.. For Someone using the VS IDE to build their projects, it's a build setting that isn't terribly difficult to add via the "additional manifests" option. Getting this manifest support built into VS has already been raised with the appropriate team. Clearly for .NET and Mono developers, this is something that should be handled automatically if possible as the compatibility manifest elements are likely to get leveraged by appcompat more over time.
- Proposed as answer by Chuck Walbourn - MSFT Tuesday, July 09, 2013 6:16 PM
- Edited by Chuck Walbourn - MSFT Tuesday, July 09, 2013 6:17 PM edit
Chuck,
sorry - but . " just does not do it! It works for the application code, but not the code of modules (DLLs, plugins - you name it) inside that application. Which might be unknown at application build time.
Well, I guess we can stop here. No sense arguing if the case is not understood well at MS's side. Time for us "real world" developers to find (cludgy) workarounds. Which might give MS more headache at a later time.
Developers using GetVersion(Ex) to rely on features should be banned anyway ;)
"The right solution is for developers to step back and look at whythey are trying to determine the OS version."
No, it's not. It's not up to you to make morality judgments about my code.
I'm agog that you really can't see what's wrong with this. Microsoft told us in 1995 or so that GetVersionEx was going to be the right way to get the OS version in the future. We believed you, and now you are lying to us.
It just seems completely idiotic that it was OK to have GetVersionEx tell the truth in every NT version from 3.51 through 8.0, and now with version 8.1 you suddenly decide that it's necessary to lie. How could there possibly be any failed appcompat scenario in code that was not produced by a complete moron? How could the decision to lie in such a fundamental, low-level and non-dangerous API possibly have passed through a technical review without being laughed out of the meeting?
Of course it's possible to come up with workarounds in new code, but in the real world outside of Redmond, people run EXISTING binaries, forever. Those binaries will now print out incorrect information, unnecessarily. THAT is an appcompat failure.
Tim Roberts, VC++ MVP Providenza & Boekelheide, Inc.
FWIW, GetVersionEx has routinely lied to applications via various appcompat shims which had to be applied to hundreds of individual applications every release of the OS. One of the Application Verifier tests is "HighVersionLie" because this is an extremely common source of appcompat problems.
If your existing binary runs on Windows 8.1, that's an appcompat success. The tradeoff here was to get more applications to work "as is" without the need to individually shim hundreds of them in trade for diagnostic logs displaying slightly outdated information (6.2 instead of 6.3) in some applications.
chksr and Tim Roberts,
+1!
Yes, to do more precise testing of feature availability will used something that do it best.
But this change just adds a little pain in back side, nothing new or useful.
The best <<How could the decision to lie in such a fundamental, low-level and non-dangerous API possibly have passed through a technical review without being laughed out of the meeting?>>. Getting version number of core OS(not its features) via system file info and much longer code - not bad too.
The lie it's allways very bad.
Technical note: You can use the Manifest Tool (MT.EXE) to inject a manifest into an existing EXE (i.e. without having to rebuild it). The only downside is if the EXE was code-signed which would of course modify it and invalidate the signature.
RE: plug-ins, the best option if you can't avoid the need to use GetVersoin(Ex) would be to get the host application manifested--assuming that's an option.
- Edited by Chuck Walbourn - MSFT Wednesday, July 10, 2013 11:36 PM edit
"RE: plug-ins, the best option if you can't avoid the need to use GetVersoin(Ex) would be to get the host application manifested--assuming that's an option."
More often than not, this is no option. We sell add-on tools for other developers - no way to ask them to do that, they would react correctly and ask if we're crazy.
We use GetVersionEx for "large" changes like theming availability, which are definitely version-bound, all other features are decided upon API or interface availability. And the wrong descriptions in the MSDN (a lot of APIs that existed in NT2000 are not "supported starting Windows XP") does not make life easier for us programmers. Why does the documentation change for the worse?
For me, this is a theoretical discussion, as I think Microsoft should leave some decisions to the developers, and also give them the blame if they do something wrong. I know there are a lot of developers out there which make your hair stand on end, but suppressing mistakes of these will not raise the level to be considered a "developer", to the contrary. And the others will make workarounds that make compatibility harder at a later time.
In Germany, we say "gut gemeint ist das Gegenteil von gut", which means "well-meant is the contrary of well-done".
"We sell add-on tools for other developers - no way to ask them to do that, they would react correctly and ask if we're crazy."
Why would that be 'crazy' exactly? Presumably the host application(s) are intended to be fully compatible with Windows 8.1?
I fully appreciate that relying on the host application doing this in a timely fashion for your add-ons is unrealistic, but longer-term the intent is for every application that explicitly supports Windows 8.1 to have these elements in an embedded manifest.
- Edited by Chuck Walbourn - MSFT Thursday, July 11, 2013 6:38 PM edit
- chksr, ... or ... well are determined to make life complicated
- Edited by iContribute Thursday, July 11, 2013 7:16 PM 777888
Why not? Stable frozen API. Embedded manifest does not guarantee anything for app or add-on. All bugs remain in its places.
New feature - old bugs adapted for new OS (proved by manifest). That what we need)
- Edited by iContribute Thursday, July 11, 2013 7:15 PM 12345
So I used the below code and now everything's alright!
However, where to find supportedOS Id for Win XP, Server 2008, Server 2008 R2 to add to manifest?
<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1"> <application> <!-- Windows 8.1 --> <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da}"/> </application> </compatibility>
These manifest elements were introduced in Windows Vista. Windows XP ignores them.
The Windows Vista GUID applies to both Windows Vista and Windows Server 2008.
The Windows 7 GUID applies to both Windows 7 and Windows Server 2008 R2
The Windows 8 GUID applies to both Windows 8 and Windows Server 2012
The Windows 8.1 GUID applies to both Windows 8.1 and Windows Server 2012 R2
- I don't know for sure, but the Windows 8 GUID was fixed as of the Developer Preview. There's not much reason to change it...
- Edited by Chuck Walbourn - MSFT Monday, July 15, 2013 2:45 AM edit
Assuming you would a photoshop plugin, would you really ask Adobe to alter the manifest of Photoshop (although they might gain nothing out of it, even if they are "fully compatible" -> principle "never change a running system")? If your plugin will/should also work in an older, non-maintained version?
I guess not. You can try anyway, but you will not succeed.
Still you would like to get the "correct" Windows version (8.1) in your plugin, if only for debugging purposes if your plugin has problems and you would like to reproduce the problem using the correct environment (and, say, assuming the problem is problem appearing in 8.1 only - and YES, that might happen, even if MS does not like it).
So now MS has the problem that all modules wanting to be independent of the app (i.e. third-party tools) must use some other way to get the correct Windows version, and there's no way to "virtualize" these calls later if MS wants to. Whatever for.
What do you expect that tool developers should do? Remain at the stage of the host app, even if they know they can or must exploit the OS more? No sir. Add-ons might know better what to do, depending on the host OS ;)
OTOH, at least for debugging purposes, we need the real version number. The rest (API flavours etc) is queried on demand (at least, most of it). So as I said it's irrelevant, except it shows some app-centric thinking.
(And why does this control change the font size when I kill a superfluous line break? Sigh.)
The process is the resource partition and the application is the owner of the process. In-process modules must obey the process environment created for the application. It is as simple as that.
If you need independent freedom, you can have it in your own process.
- I would love to know why you think that.
Might make sense in some cases, but obviously not for developer tools (some customers use - yes - VB 6, Access, Alaska xBase, ...). Do you really think MS will add a corresponding "Win 8.1-compatible" manifest to VB6? ;)
Well as long as it's only a "GetVersion()" lie, we can live with it, use the workaround, and feel good. But otherwise, if "real" features themselves are limited according to some application-only manifest, I will send a **** (NSA blackened no-no-word of an explosive) to Redmond.
"If you need independent freedom, you can have it in your own process."
You think we need to rewrite customer's applications or whole development environments just to allow them to use new OS features?
See my comment above. This would cost us a lot of customers who cannot change their IDE/development environment just as their underwear. For some applications, these are fixed for a whole lifetime of that application. Still the customers like new features of our tool, of course!
The obvious solution would be an out-of-process server, but that would be overkill and a speed brake.
You think we need to rewrite customer's applications or whole development environments just to allow them to use new OS features?
VB6 is long out of support:
In all technical environments there comes a time to cut old stuff to medernize. That is the way...
You should be able to solve your problem if you add an manifest as resource to your application (maybe in a post build process, if you can not add user resources in VB!?!? - I',m no VB user). Than GetVersionEx will work. I did this manifest stuff for an old VC++6 application some time ago, and it worked without problems. Why not doing the same in VB?
Best regards
Bordon
Note: Posted code pieces may not have a good programming style and may not perfect. It is also possible that they do not work in all situations. Code pieces are only indended to explain something particualar.
You think we need to rewrite customer's applications or whole development environments just to allow them to use new OS features?
No. The applications should run just fine on the new OS. That's exactly why the version lie is there. It enables the application to work flawlessly on the new OS without rewrinting the application at all.
- Sorry, but is it that hard to understand that "You should be able to solve your problem if you add an manifest as resource to your application " is not possible, as the application is not MINE, but from a customer that just uses our tool to print nice reports?
Yes. The application.
But I'm talking about our DLL in a host application not written by us. And our DLL would like to see all OS features (right now we can see everything, but once Windows "lies" about features, we get into troubles), and the true OS version (for now, just for debug logging).
So right now, it's a non-issue, but it makes me wonder what the MS developers think. There used to be a "divide the work and reuse these parts"-pattern, that's what DLLs are for, and now MS becomes EXE-centric and forgets about the myriad of DLLs that do not care about the OS version that is presented to the application. If at all, they would need their own small "lie" according to a manifest in the DLL.
Imagine, the host application says "well, I can live with and use Windows 8.1's features", but then one of these DLLs gets into trouble as it can NOT support these? Will the developer of the EXE (even be able to!) ask all DLL manufacturers about their attitude towards an entry in the manifest that he likes to set because HE likes to express new Windows-compatibility with HIS application?
It just does not fit the system of Application and DLLs.
An EXE that consumes 3rd party DLLs already has to take responsibility for integration testing. If they add the manifest entry to the EXE that declares support for Windows 8.1, then presumably they actually tested it on Windows 8.1. This is why the compat manifests use a GUID so that developers can't just throw in "I support all the Windows" and then fail to actually test it on a future OS that believes it is compatible.
There are of course special challenges for an EXE that use as-yet-unseen 3rd party DLLs as a 'plug-in' model. The point here is that the host application is not declaring full support for Windows 8.1, so the whole process is treated as if it in a compatibility mode.
- Edited by Chuck Walbourn - MSFT Thursday, August 15, 2013 6:19 PM edit
Here is a new CodeProject article about detection of "true" Windows version.
Still it is a mystery why we have to take all these hoops. Doesn't this mean that the next OS technically is not "Windows" or "Windows NT" any more, so the query becomes meaningless?
-- pa
This seems to be a case of "the cure is worse than the disease".
For most people, the solution is pretty easy.
* Remove use of GetVersion and GetVersionEx everywhere you can. Use built-in versioning mechanisms like gracefully failing to initialize a component.
* Use VersionHelpers.h if you can or the VerifyVersionInfo() API for 'you must be this high to ride this ride' style of checks.
* If you still need it for a reason other than logging, then add the manifest elements and continue to call GetVersion/GetVersionEx.
* For logging, just grab the version string from kernel32.dll and use it as an opaque string (i.e. don't try to parse it).
I do understand that people who are writing plug-ins are in a bind until the core application updates itself with the manifest elements, but that doesn't mean the rest of world of application developers should go crazy over this.
- Edited by Chuck Walbourn - MSFT Tuesday, November 12, 2013 6:51 AM edit
I guess fundamentally you don't get it, which is why the guys are jumping on you about it. Don't lie in your API calls. Period. Some of us have written stable, unchanging, working, industrial code that may be even older than you are. the API is a contract and you broke it. Don't go defending that change. What the developers are doing with the information is their own bad or good decisions and the OS manufacturer has no place in handling our code. Of course, maybe it's that your own MICROSOFT applications have issues and your trying to help your brethren out.
Regardless, there are business reasons we have customers that do not permit changes to released/paid-for code that they put on newer operating systems. If Microsoft built buildings like they do software, the buildings would fall down yearly and require reconstruction. Great for employment, bad for business.
There are a number of appcompat behaviors contingent on application manifests spanning the past few releases of Windows. A summary of the key ones is covered by this blog post.
- Proposed as answer by Chuck Walbourn - MSFT Wednesday, January 08, 2014 6:37 PM | http://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/c471de52-611f-435d-ab44-56064e5fd7d5/windows-81-preview-getversionex-reports-629200?forum=windowssdk | CC-MAIN-2014-35 | en | refinedweb |
Compiler Construction/Lexical analysis
Lexical Analysis
Lexical analysis is the process of analyzing a stream of individual characters (normally arranged as lines), into a sequence of lexical tokens (tokenization. for instance of "words" and punctuation symbols that make up source code) to feed into the parser. Roughly the equivalent of splitting ordinary text written in a natural language (e.g. English) into a sequence of words and punctuation symbols. Lexical analysis is often done with tools such as lex, flex and jflex.
Strictly speaking, tokenization may be handled by the parser. The reason why we tend to bother with tokenising in practice is that it makes the parser simpler, and decouples it from the character encoding used for the source code.
For example given the input string:
integer aardvark := 2, b;
A tokeniser might output the following tokens:
keyword integer word aardvark assignment operator integer 2 comma word b semi_colon
What is a token
In computing,.
Consider the following table:.
Following tokenizing is parsing. From there, the interpreted data may be loaded into data structures, for general use, interpretation, or compiling.
Consider a text describing a calculation : "46 - number_of(cows);". The lexemes here might be: "46", "-", "number_of", "(", "cows", ")", and ";". The lexical analyzer will denote lexemes 4 and 6 as 'number' and - as character, and 'number_of ' as a separate token. Even the lexeme ';' in some languages (such as C) has some special meaning.
The whitespace lexemes are sometimes ignored later by the syntax analyzer. A token doesn't need to be valid, in order to be recognized as a token. "cows" may be nonsense to the language, "number_of" may be nonsense. But they are tokens nonetheless, in this example.
Finite State Automaton
We first study what is called a finite state automaton, or FSA for short. An FSA is usually used to do lexical analysis.
An FSA consists of states, starting state, accept state and transition table. The automaton reads an input symbol and moves the state accordingly. If the FSA reaches the accept state after the input string is read until its end, the string is said to be accepted or recognized. A set of recognized strings is said to be a language recognized by the FSA.
Suppose this language in which each string starts with 'ab' and ends with one or more 'c'. With state class, this can be written like this:
State s0 = new State (), s1 = new State (), s2 = new State (), s3 = new State (); s0.setTransition ('a', s1); s1.setTransition ('b', s2); s2.setTransition ('c', s3); s3.setTransition ('c', s3); State r[] = s0.move (inputString); if (Arrays.asList (r).contains (s3)) System.out.println ("the input string is accepted."); else System.out.println ("the input string is not accepted.");
Suppose an input string "abccc". Then the automaton moves like: s0 -> s1 -> s2 -> s3 -> s3 -> s3.
Simple Hand-Written Scanning
In this section, we'll create a simple, object-oriented scanner / lexer for a simple language implemented in Object Pascal. Consider the following EBNF:
program ::= { instruction } instruction ::= "print" expr | "var" IDENTIFIER ":=" expr expr ::= simple-expr [ ("<" | "<>" ) simple-expr ] simple-expr ::= factor { ( "+" | "-" ) factor } factor ::= INTEGER | IDENTIFIER
where
INTEGER = [0-9]+ IDENTIFIER = [A-Za-z_][A-Za-z0-9_]*
From the above EBNF, The tokens we're about to recognize are: IDENTIFIER, INTEGER, keyword "print", keyword "var", :=, +, -, <, <>, EOF and unknown token. The chosen tokens are intended for both brevity and the ability to recognize all types of token's lexeme: exact single character (+, -, <, EOF and unknown), exact multiple character (print, var, := and <>), infinitely many (IDENTIFIER, INTEGER and unknown), overlapping prefix (< and <>) and overlapping as a whole (IDENTIFIER and keywords). Identifier and keywords here are case-insensitive. Note that some lexemes are classified to more than one type of lexeme.
The Token Class
TToken = class protected FLine, FCol: LongWord; public constructor Create(const ALine, ACol: LongWord); destructor Destroy; override; end;
The base class of a token is simply an object containing line and column number where it's declared. From this base class, tokens with exact lexeme (either single or multiple characters) could be implemented as direct descendants.
TEOFToken = class(TToken) end; TPlusToken = class(TToken) end; TMinusToken = class(TToken) end; TAssignToken = class(TToken) end; TLessToken = class(TToken) end; TNotEqualToken = class(TToken) end; TPrintToken = class(TToken) end; TVarToken = class(TToken) end; TEOFToken = class(TToken) end;
Next, we need to create descendant for token with variadic lexeme:
TVariadicToken = class(TToken) protected FLexeme: String; public constructor Create(const ALine, ACol: LongWord; const ALexeme: String); destructor Destroy; override; end;
The only difference from the base token class is the lexeme property, since it possibly has infinitely many forms. From here, we create descendant classes for tokens whose lexeme is infinitely many:
TUnknownToken = class(TVariadicToken) end; TIdentifierToken = class(TVariadicToken) end; TIntegerToken = class(TVariadicToken) end;
That's all for the token, on to the lexer.
The Lexer Class
TLexer = class private FLine: LongWord; FCol: LongWord; FStream: TStream; FCurrentToken: TToken; FLastChar: Char; function GetChar: Char; public constructor Create(AStream: TStream); destructor Destroy; override; procedure NextToken; property CurrentToken: TToken read FCurrentToken; end;
A lexer consists of its position in the source code (line and column), the stream representing the source code, current (or last recognized / formed) token and last character read. To encapsulate the movement in the source code, reading character from the stream is implemented in GetChar method. Despite its maybe simple look, the implementation could be complicated as we'll see soon. GetChar is used by public method NextToken, whose job is to advance lexer movement by 1 token ahead. On to GetChar implementation:
function TLexer.GetChar: Char; begin try FLastChar := Chr(FStream.ReadByte); Inc(FCol); // Handles 3 types of line endings if FLastChar in [#13, #10] then begin FCol := 0; Inc(FLine); // CR met, probably CRLF if FLastChar = #13 then begin FLastChar := Chr(FStream.ReadByte); // Not CRLF, but CR only, move backward 1 position if FLastChar <> #10 then FStream.Seek(-1,soFromCurrent); end; // Always returns as LF for consistency FLastChar := #10; end; except // Exception? Returns EOF FLastChar := #26; end; GetChar := FLastChar; end;
As stated earlier, GetChar's job is not as simple as its name. First, it has to read one character from the input stream and increment the lexer's column position. Then it has to check whether this character is one of the possible line endings (our lexer is capable of handling CR-, LF- and CRLF-style line ending). Next is the core of our lexer, NextToken:
procedure TLexer.NextToken; var StartLine,StartCol: LongWord; function GetNumber: TIntegerToken; var NumLex: String; begin NumLex := ''; repeat NumLex := NumLex + FLastChar; FLastChar := GetChar; until not (FLastChar in ['0' .. '9']); Result := TIntegerToken.Create(StartLine, StartCol, NumLex); end; function GetIdentifierOrKeyword: TVariadicToken; var IdLex: String; begin IdLex := ''; repeat IdLex := IdLex + FLastChar; // This is how we handle case-insensitiveness FLastChar := LowerCase(GetChar); until not (FLastChar in ['a' .. 'z','0' .. '9','_']); // Need to check for keywords case IdLex of 'print' : Result := TPrintToken.Create(StartLine,StartCol); 'var' : Result := TVarToken.Create(StartLine,StartCol); otherwise Result := TIdentifier.Create(StartLine,StartCol,IdLex); end; end; begin // Eat whitespaces while FLastChar in [#32,#9,#13,#10] do FLastChar := GetChar; // Save first token position, since GetChar would change FLine and FCol StartLine := FLine; StartCol := FCol; if FLastChar = #26 then FCurrentToken := TEOFToken.Create(StartLine, StartCol) else case LowerCase(FLastChar) of // Exact single character '+': begin FCurrentToken := TPlusToken.Create(StartLine, StartCol); FLastChar := GetChar; end; '-': begin FCurrentToken := TMinusToken.Create(StartLine, StartCol); FLastChar := GetChar; end; // Exact multiple character ':': begin FLastChar := GetChar; if' then FCurrentToken := TNotEqualToken.Create(StartLine, StartCol) // '<' else FCurrentToken := TLessToken.Create(StartLine, StartCol); end; // Infinitely many is handled in its own function to cut down line length here '0' .. '9': begin FCurrentToken := GetNumber; end; 'a' .. 'z','_': begin FCurrentToken := GetIdentifierOrKeyword; end; else begin FCurrentToken := TUnknownToken.Create(StartLine, StartCol, FLastChar); FLastChar := GetChar; end; end; end;
As you can see, the core is a (probably big) case statement. The other parts is quite self documenting and well commented. Last but not least, the constructor:
constructor TLexer.Create(AStream: TStream; AErrorList: TErrorList); begin FStream := AStream; FLine := 1; FCol := 0; FLastChar := GetChar; NextToken; end;
It sets up the initial line and column position (guess why it's 1 for line but 0 for column :)), and also sets up the first token available so CurrentToken would be available after calling the constructor, no need to explicitly call NextToken after that.
Test Program
uses Classes,SysUtils,lexer,tokens; var Stream: TStream; lex: TLexer; begin Stream := THandleStream.Create(StdInputHandle); lex := TLexer.Create(Stream,nil); while not(lex.CurrentToken is TEOFToken) do begin WriteLn(lex.CurrentToken.ToString); lex.NextToken; end; lex.Free; Stream.Free; end.
As an exercise, you could try extending the lexer with floating point numbers, strings, numbers with base other than 10, scientific notation, comments, etc.
Table-Driven Hand-Written Scanning
Compiling Channel Constant
Lexical Analysis Tool
Scanning via a Tool - lex/flex
Scanning via a Tool - JavaCC
JavaCC is the standard Java compiler-compiler. Unlike the other tools presented in this chapter, JavaCC is a parser and a scanner (lexer) generator in one. JavaCC takes just one input file (called the grammar file), which is then used to create both classes for lexical analysis, as well as for the parser.
In JavaCC's terminology the scanner/lexical analyser is called the token manager. And in fact the generated class that contains the token manager is called ParserNameTokenManager. Of course, following the usual Java file name requirements, the class is stored in a file called ParserNameTokenManager.java. The ParserName part is taken from the input file. In addition, JavaCC creates a second class, called ParserNameConstants. That second class, as the name implies, contains definitions of constants, especially token constants. JavaCC also generates a boilerplate class called Token. That one is always the same, and contains the class used to represent tokens. One also gets a class called ParseError. This is an exception which is thrown if something went wrong.
It is possible to instruct JavaCC not to generate the ParserNameTokenManger, and instead provide your own, hand-written, token manager. Usually - this holds for all the tools presented in this chapter - a hand-written scanner/lexical analyser/token manager is much more efficient. So, if you figure out that your generated compiler gets too large, give the generated scanner/lexical analyzer/token manager a good look. Rolling your own token manager is also handy if you need to parse binary data and feed it to the parsing layer.
Since, however, this section is about using JavaCC to generate a token manager, and not about writing one by hand, this is not discussed any further here.
Defining Tokens in the JavaCC Grammar File
A JavaCC grammar file usually starts with code which is relevant for the parser, and not the scanner. For simple grammars files it looks similar to:
options { LOOKAHEAD=1; }
PARSER_BEGIN(ParserName) public class ParserName { // code to enter the parser goes here } PARSER_END(ParserName)
This is usually followed by the definitions for tokens. These definitions are the information we are interested in in this chapter. Four different kinds, indicated by four different keywords are understood by JavaCC when it comes to the definition of tokens:
- TOKEN
- Regular expressions which specify the tokens the token manager should be able to recognize.
- SPECIAL_TOKEN
- SPECIAL_TOKENs are similar to TOKENS. Only, that the parser ignores them. This is useful to e.g. specify comments, which are supposed to be understood, but have no significance to the parser.
- SKIP
- Tokens (input data) which is supposed to be completely ignored by the token manager. This is commonly used to ignore whitespace. A SKIP token still breaks up other tokens. E.g. if one skips white space, has a token "else" defined, and if the input is "el se", then the token is not matched.
- MORE
- This is used for an advanced technique, where a token is gradually built. MORE tokens are put in a buffer until the next TOKEN or SPECIAL_TOKEN matches. Then all data, the accumulated token in the buffer, as well as the last TOKEN or SPECIAL_TOKEN is returned.
- One example, where the usage of MORE tokens is useful are constructs where one would like to match for some start string, arbitrary data, and some end string. Comments or string literals in many programming languages match this form. E.g. to match string literals, delimited by ", one would not return the first found " as a token. Instead, one would accumulate more tokens, until the closing " of the string literal is found. Then the complete literal would be returned. See Comment Example for an example where this is used to scan comments.
Each of the above mentioned keywords can be used as often as desired. This makes it possible to group the tokens, e.g. in a list for operators and another list for keywords. All sections of the same kind are merged together as if just one section had been specified.
Every specification of a token consists of the token's symbolic name, and a regular expression. If the regular expression matches, the symbol is returned by the token manager.
Simple Example
Lets see an example:
// // Skip whitespace in input // if the input matches space, carriage return, new line or a tab, // it is just ignored // SKIP: { " " | "\r" | "\n" | "\t" }
// Define the tokens representing our operators // TOKEN: { < PLUS: "+" > | < MINUS: "-" > | < MUL: "*" > | < DIV: "/" > }
// // Define the tokens representing our keywords // TOKEN: { < IF: "if" > | < THEN: "then" > | < ELSE: "else" > }
All the above token definitions use simple regular expressions, where just constants are matched. It is recommended to study the JavaCC documentation for the full set of possible regular expressions.
When the above file is run through JavaCC, a token manager is generated which understands the above declared tokens.
Comment Example
Eliminating (ignoring) comments in a programming language is a common task for a lexical analyzer. Of course, when JavaCC is used, this task is usually given to the token manager, by specifying special tokens.
Basically, a standard idiom for JavaCC has evolved on how to ignore comments. It combines tokens of kind SPECIAL_TOKEN and MORE with a lexical state. Lets assume we e.g. have a programming language where comments start with a --, and either end with another -- or the end of the line (this is the comment schema of ASN.1 and several other languages). Then a way to construct a scanner for this would be:
// // Start of comment. Don't return as token, instead // shift to special lexical state. // SPECIAL_TOKEN: { <"--"> : WithinComment }
// // While inside the comment lexicals state, look for end // of comment (either another '--' or EOL). Don't return // the (accumulated data). Instead switch back to normal // lexical state // <WithinComment> SPECIAL_TOKEN: { <("--" | "\n" )> : DEFAULT }
// // While inside the comment state, accumulate all contents // <WithinComment> MORE: { <~[]> } | http://en.wikibooks.org/wiki/Compiler_Construction/Lexical_analysis | CC-MAIN-2014-35 | en | refinedweb |
SC_Client_CreateRankingController()
Creates a ranking controller, which can be used to retrieve a rank.
Synopsis:
#include <scoreloop/sc_client.h>
SC_DEPRECATED SC_PUBLISHED SC_Error_t SC_Client_CreateRankingController(SC_Client_h self, SC_RankingController_h *pRankingController, SC_RequestControllerCompletionCallback_t callback, void *cookie)
Since:
BlackBerry 10.0.0
Deprecated in BlackBerry 10.3.0
Arguments:
- self
Opaque handle for the current client instance.
- pRankingController_RankingController. The controller is used to retrieve ranks from the server.
Last modified: 2014-06-24
Got questions about leaving a comment? Get answers from our Disqus FAQ.comments powered by Disqus | http://developer.blackberry.com/native/reference/core/com.qnx.doc.scoreloop.lib_ref/topic/sc_client_createrankingcontroller.html | CC-MAIN-2014-35 | en | refinedweb |
Chapter 8. Adding the Red Hat Ceph Storage Dashboard to an overcloud deployment
Red Hat Ceph Storage Dashboard is disabled by default but you can now enable it in your overcloud with the Red Hat OpenStack Platform director. The Ceph Dashboard is a built-in, web-based Ceph management and monitoring application to administer various aspects and objects in your cluster. Red Hat Ceph Storage Dashboard comprises the Ceph Dashboard manager module, which provides the user interface and embeds Grafana, the front end of the platform, Prometheus as a monitoring plugin, Alertmanager and Node Exporters that are deployed throughout the cluster and send alerts and export cluster data to the Dashboard.
- Note
- This feature is supported with Ceph Storage 4.1 or later. For more information about how to determine the version of Ceph Storage installed on your system, see Red Hat Ceph Storage releases and corresponding Ceph package versions.
- Note
- The Red Hat Ceph Storage Dashboard is always colocated on the same nodes as the other Ceph manager components.
- Note
- If you want to add Ceph Dashboard during your initial overcloud deployment, complete the procedures in this chapter before you deploy your initial overcloud in Section 7.2, “Initiating overcloud deployment”.
The following diagram shows the architecture of Ceph Dashboard on Red Hat OpenStack Platform:
For more information about the Dashboard and its features and limitations, see Dashboard features in the Red Hat Ceph Storage Dashboard Guide.
TLS everywhere with Ceph Dashboard
The dashboard front end is fully integrated with the TLS everywhere framework. You can enable TLS everywhere provided that you have the required environment files and they are included in the overcloud deploy command. This triggers the certificate request for both Grafana and the Ceph Dashboard and the generated certificate and key files are passed to
ceph-ansible during the overcloud deployment. For instructions and more information about how to enable TLS for the Dashboard as well as for other openstack services, see the following locations in the Advanced Overcloud Customization guide:
- Enabling SSL/TLS on Overcloud Public Endpoints.
Enabling SSL/TLS on Internal and Public Endpoints with Identity Management.
- Note
- The port to reach the Ceph Dashboard remains the same even in the TLS-everywhere context.
8.1. Including the necessary containers for the Ceph Dashboard
Before you can add the Ceph Dashboard templates to your overcloud, you must include the necessary containers by using the
containers-prepare-parameter.yaml file. To generate the
containers-prepare-parameter.yaml file to prepare your container images, complete the following steps:
Procedure
- Log in to your undercloud host as the
stackuser.
Generate the default container image preparation file:
$ openstack tripleo container image prepare default \ --local-push-destination \ --output-env-file containers-prepare-parameter.yaml
Edit the
containers-prepare-parameter.yamlfile and make the modifications to suit your requirements. The following example
containers-prepare-parameter.yamlfile contains the image locations and tags related to the Dashboard services including Grafana, Prometheus, Alertmanager, and Node Exporter. Edit the values depending on your specific scenario:
parameter_defaults: ContainerImagePrepare: - push_destination: true set: ceph_alertmanager_image: ose-prometheus-alertmanager ceph_alertmanager_namespace: registry.redhat.io/openshift4 ceph_alertmanager_tag: v4.1 ceph_grafana_image: rhceph-3-dashboard-rhel7 ceph_grafana_namespace: registry.redhat.io/rhceph ceph_grafana_tag: 3 ceph_image: rhceph-4-rhel8 ceph_namespace: registry.redhat.io/rhceph ceph_node_exporter_image: ose-prometheus-node-exporter ceph_node_exporter_namespace: registry.redhat.io/openshift4 ceph_node_exporter_tag: v4.1 ceph_prometheus_image: ose-prometheus ceph_prometheus_namespace: registry.redhat.io/openshift4 ceph_prometheus_tag: v4.1 ceph_tag: latest
For more information about registry and image configuration with the
containers-prepare-parameter.yaml file, see Container image preparation parameters in the Transitioning to Containerized Services guide.
8.2. Deploying Ceph Dashboard
- Note
- The Ceph Dashboard admin user role is set to read-only mode by default. To change the Ceph Dashboard admin default mode, see Section 8.3, “Changing the default permissions”.
Procedure
- Log in to the undercloud node as the
stackuser.
Include the following environment files, with all environment files that are part of your existing deployment, in the
openstack overcloud deploycommand:
$ openstack overcloud deploy \ --templates \ -e <existing_overcloud_environment_files> \ -e /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible.yaml \ -e /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-dashboard.yaml
Replace
<existing_overcloud_environment_files>with the list of environment files that are part of your existing deployment.
- Result
- The resulting deployment comprises an external stack with the grafana, prometheus, alertmanager, and node-exporter containers. The Ceph Dashboard manager module is the back end for this stack and embeds the grafana layouts to provide ceph cluster specific metrics to the end users.
8.3. Changing the default permissions
The Ceph Dashboard admin user role is set to read-only mode by default for safe monitoring of the Ceph cluster. To permit an admin user to have elevated privileges so that they can alter elements of the Ceph cluster with the Dashboard, you can use the
CephDashboardAdminRO parameter to change the default admin permissions.
- Warning
- A user with full permissions might alter elements of your cluster that director configures. This can cause a conflict with director-configured options when you run a stack update. To avoid this problem, do not alter director-configured options with Ceph Dashboard, for example, Ceph OSP pools attributes.
Procedure
- Log in to the undercloud as the
stackuser.
Create the following
ceph_dashboard_admin.yamlenvironment file:
parameter_defaults: CephDashboardAdminRO: false
Run the overcloud deploy command to update the existing stack and include the environment file you created with all other environment files that are part of your existing deployment:
$ openstack overcloud deploy \ --templates \ -e <existing_overcloud_environment_files> \ -e ceph_dashboard_admin.yml
Replace
<existing_overcloud_environment_files>with the list of environment files that are part of your existing deployment.
8.4. Accessing Ceph Dashboard
To test that Ceph Dashboard is running correctly, complete the following verification steps to access it and check that the data it displays from the Ceph cluster is correct.
Procedure
- Log in to the undercloud node as the
stackuser.
Retrieve the dashboard admin login credentials:
[stack@undercloud ~]$ grep dashboard_admin_password /var/lib/mistral/overcloud/ceph-ansible/group_vars/all.yml
Retrieve the VIP address to access the Ceph Dashboard:
[stack@undercloud-0 ~]$ grep dashboard_frontend /var/lib/mistral/overcloud/ceph-ansible/group_vars/mgrs.yml
Use a web browser to point to the front end VIP and access the Dashboard. Director configures and exposes the Dashboard on the provisioning network, so you can use the VIP that you retrieved in step 2 to access the dashboard directly on TCP port 8444. Ensure that the following conditions are met:
- The Web client host is layer 2 connected to the provisioning network.
The provisioning network is properly routed or proxied, and it can be reached from the web client host. If these conditions are not met, you can still open a SSH tunnel to reach the Dashboard VIP on the overcloud:
client_host$ ssh -L 8444:<dashboard vip>:8444 stack@<your undercloud>
Replace <dashboard vip> with the IP address of the control plane VIP that you retrieved in step 3.
Access the Dashboard by pointing your web browser to. The default user that
ceph-ansiblecreates is admin. You can retrieve the password in
/var/lib/mistral/overcloud/ceph-ansible/group_vars/all.yml.
- Results
- You can access the Ceph Dashboard.
- The numbers and graphs that the Dashboard displays reflect the same cluster status that the CLI command,
ceph -s, returns.
For more information about the Red Hat Ceph Storage Dashboard, see the Red Hat Ceph Storage Administration Guide | https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.0/html/deploying_an_overcloud_with_containerized_red_hat_ceph/adding-ceph-dashboard | CC-MAIN-2020-50 | en | refinedweb |
How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 2, 2020 1:06 AM
I'm having a pair of CYW954907EVAL-1F boards and need to program them so that files stored on the SD card of one such module can be transferred to another such module using 802.11 protocol (802.11ac to be more specific). In WICED Studio 6.4, I could find the sd_filesystems program that can be used for routing data to and from the SD card. What I'm looking for is how do I program CYW954907EVAL-1F for various 802.11 PHY and MAC so that I can establish a connection between both the modules and transfer the data.
Attached are some of the contents I've already referred to but couldn't make out much as in from where to start.
Also, the other controllers that I've used have a set of instructions and programming well defined which helps the beginner to start with the development. For CYW954907EVAL-1F also, if any such literature is available which best fits the marked application, please suggest that as well.
P.S. I've already gone through the video tutorials available from Cypress which gives a good start for sure, however, the same is not having the details I'm looking for and hence the question.
1. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?RaktimR_11
May 2, 2020 9:23 AM (in response to HaTr_4568521)
What are the 11ac specific features you are trying to enable?
The idea is to use the sd_filesystem application and use tcp/udp to transmit data b/w two CYW54907.
2. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 3, 2020 5:04 AM (in response to RaktimR_11)
Dear RaktimR_11 Following features of 802.11ac I want to implement:
- use of 5 GHz frequency band for communication
- bandwidth of communicaion = 40 MHz
- modulation scheme: QPSK
- channel coding rate: 1/2 or 3/4
- Guard interval: 400 nsec
- Spatial stream: 1 (however, I'd also like to program for more number of spatial streams)
- transmit power: 15 dBm or more
another query: how would I pair / connect two devices?
Also, is there any literature available for programming the CYW954907 using WICED studio, cause referring to the code directly doesn't help much to me.
Thanks.
3. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?RaktimR_11
May 4, 2020 12:12 AM (in response to HaTr_4568521)
use of 5 GHz frequency band for communication
- wwd_wifi_set_preferred_association_band( WLC_BAND_5G );
bandwidth of communicaion = 40 MHz
- wwd_wifi_set_bandwidth(40)
modulation scheme: QPSK channel coding rate: 1/2 or 3/4
I am guessing that you mean to use MCS 0-7
- wwd_wifi_set_mcs_rate( wwd_interface_t interface, int32_t mcs, wiced_bool_t mcsonly);
Guard interval: 400 nsec
Re: (CYW43907) How to set GI(guard interval) for 802.11n If you need APIs find the ioctls and use them accordingly. More help on ioctls: How to use IOCTL commands in CYW43907
Spatial stream: 1 (however, I'd also like to program for more number of spatial streams)
Since this is a SISO chip, only NSS 1 is supported which is the default configuration.
transmit power: 15 dBm or more
Country specific. Usually fixed by regulatory authorities of each country. Determined by clm_blob in Cypress WLAN solutions. More on clm_blob: If it's within per-defined limit set according to the ccode, wl txpwr1 or wwd_wifi_set_tx_power() can be used.
another query: how would I pair / connect two devices?
pairing/connect usually exists for BT/BLE devices. For WLAN it is more like ap-sta connection which goes through the auth-assoc process. You can setup a CYW54907 as a softAP and host a udp_server on the same interface; simultaneously, you can configure the other CYW54907 as a STA, connect to the softAP and use it as a udp_client to connect to the udp_server.
For getting started with WICED, we do provide a quick-start-guide, which can be found in 43xxx_Wi-Fi/doc/WICED-QSG.pdf
You can also refer to the product guide: CYW43907/CYW54907 Product Guide
WICED can be a little tricky to get started with. But once you are comfortable after going through the above mentioned literature and the WICED-WiFi videos, it will warm up to you.
4. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 4, 2020 2:20 AM (in response to RaktimR_11)
Dear RaktimR_11,
Thanks for the prompt response.
wwd_wifi_set_preferred_association_band( WLC_BAND_5G );
wwd_wifi_set_bandwidth(40);
wwd_wifi_set_mcs_rate( wwd_interface_t interface, int32_t mcs, wiced_bool_t mcsonly);
This seems to be helpful.
Another thing is, I could find the code snippet for TCP Server and TCP client. What modifications shall I do to implement a UDP server and a UDP client?
Quick start guide and product guide are definitely good to start with, however, doesn't help much for a specific application development.
5. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?RaktimR_11
May 4, 2020 2:25 AM (in response to HaTr_4568521)
6. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 4, 2020 2:54 AM (in response to RaktimR_11)
In the same folder, you can find udp_receive and transmit operation (i.e, server and client). Those documents can only help you to get started with but for each user-specific application, you need to refer to the numerous applications spread across snip, demo, waf, wwd folder etc.
Ohh!! Sounds good. I'll refer to it and get back in case of queries.
One more thing, what determines the parameter value? for example, while referring to the TCP Server code, I could find the TCP_PACKET_MAX_DATA_LENGTH value as 30 and the same thing I also observed for UDP_MAX_DATA_LENGTH as well. So how would I be able to determine what is the appropriate value of such parameters?
Thanks again for the help.
7. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 4, 2020 7:24 AM (in response to HaTr_4568521)
some queries I had RaktimR_11
- could not understand the difference between the soft AP used for device configuration and soft AP used for normal operation
- while working on the code, I commented the line UDP_TARGET_IS_BROADCAST and assigned the IP address to the receiver as The code snap is also attached below:
SSID: WICED UDP Transmit App
Protocol: Wi-Fi 4 (802.11n)
Security type: WPA2-Personal
Network band: 2.4 GHz
Network channel: 1
Link-local IPv6 address: fe80::55a:5607:c3b8:b260%21
IPv4 address: 192.168.0.2
IPv4 DNS servers: 192.168.0.1
//commented out #define UDP_TARGET_IS_BROADCAST
//commented out #define GET_UDP_RESPONSE
#ifdef UDP_TARGET_IS_BROADCAST
#define UDP_TARGET_IP MAKE_IPV4_ADDRESS(192,168,0,255)
#else
#define UDP_TARGET_IP MAKE_IPV4_ADDRESS(192,168,0,25)
#endif
- What determines whether the device will work as a UDP server or as a UDP client? Cause I checked for the code of wifi_config_dct.h and they both looked similar to me.
- Where shall I be mentioning this? cause while editing wifi_config_dct.h, I found "WICED_802_11_BAND_2_4GHZ" as a CLIENT_AP_BAND and "1" as CLIENT_AP_CHANNEL. Shall we not set all such things for the server as well?
wwd_wifi_set_preferred_association_band( WLC_BAND_5G );
wwd_wifi_set_bandwidth(40);
wwd_wifi_set_mcs_rate( wwd_interface_t interface, int32_t mcs, wiced_bool_t mcsonly);
Thanks!
8. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?RaktimR_11
May 6, 2020 2:10 AM (in response to HaTr_4568521)
If you have multiple questions pertaining to different topics relevant to same project, its always recommended to create separate threads and increase the outreach; so that others can also help. Trying to list down the answers
- config_interface softap is mainly to configure the device during startup; say you want the device to connect to an AP after starting up. You can enter the credentials hosted on a webserver running on the config interface
- softap: it is more generic functionality allowing clients(STAs) to join and communicate with each other in server-client model.
Typically, transmit operation is attributed to client and the receive operation is attributed to server with some exceptions as always. So, when you use wiced_udp_receive, it means the socket is waiting on data to be sent by some clients on that particular IP addr; if not broadcast (If you don't want broadcast, you just need to comment out the UDP_TARGET_IS_BROADCAST as you have rightly done).
wifi_config_dct.h is provided so that you can modify the basic wlan related parameters like ssid, passphrase, band, channel which is stored in DCT ( a dedicated section of ext flash). What you had asked primarily, is more to leverage the 11ac specific features which is why I recommended wwd apis. All of these APIs need to be incorporated in both client, server application(specifically .c file) by following the guidelines mentioned in 43xxx_Wi-Fi/WICED/WWD/include/wwd_wifi.h. Essentially, you can create a single application with two threads, one for tx, one for rx and control the thread spawning from command line along with the 11ac specific common settings that has been mentioned earlier.
9. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 11, 2020 5:55 AM (in response to RaktimR_11)
Hello RaktimR_11, I've now gone through wwd_wifi.h and could find that many functions that I'd been looking for are defined in this header file. As a solution to my problem statement, I further broke down the code and now trying to create an access point with some of the PHY parameters of 802.11ac. Code for the same is as follows:
#include "wiced.h"
#include "wiced_wifi.h"
#include "wwd_wifi.h"
#define SOFT_AP_SSID "Try1_802.11ac"
#define SOFT_AP_PASSPHRASE "80211AC"
#define SOFT_AP_SECURITY WICED_SECURITY_WPA2_AES_PSK
#define SOFT_AP_CHANNEL 1
static const wiced_ip_setting_t device) ),
};
void application_start(void)
{
wiced_init( );
wiced_ssid_t* ssid;
wiced_security_t auth_type;
const uint8_t* security_key;
uint8_t key_length;
uint8_t channel;
uint8_t tx_power = 15;
wiced_antenna_t antenna_type = 3;
uint8_t bandwidth_value = 40;
int32_t mcs_value = 7;
wiced_interface_t interface;
wwd_result_t result;
wiced_bool_t mcsonly;
&ssid = SOFT_AP_SSID;
auth_type = WICED_SECURITY_WPA2_AES_PSK;
&security_key = SOFT_AP_PASSPHRASE;
key_length = 8;
channel = SOFT_AP_CHANNEL;
result = wiced_network_up_default( &interface, &device_init_ip_settings );
if( result != WICED_SUCCESS )
{
printf("Bringing up network interface failed !\r\n");
}
result = wwd_wifi_start_ap(&ssid, auth_type, &security_key, key_length, channel);
if( result != WWD_SUCCESS )
{
printf("Bringing up AP failed !\r\n");
}
result = wwd_wifi_set_tx_power( tx_power );
if( result != WWD_SUCCESS )
{
printf("Tx power set to 15 dBm failed !\r\n");
}
result = wwd_wifi_select_antenna( antenna_type );
if( result != WWD_SUCCESS )
{
printf("Antena Selection for diversity receiver failed !\r\n");
}
wwd_wifi_set_preferred_association_band( WLC_BAND_5G );
wwd_result_t wwd_wifi_set_bandwidth( bandwidth_value );
result = wwd_wifi_set_mcs_rate( interface, mcs_value, mcsonly);
}
In the project folder, .c, .mk and wifi_config_dct.h are there.
.mk file is as follows:
NAME := apps_802.11ac_configuration
$(NAME)_SOURCES := 802.11ac_configuration.c
WIFI_CONFIG_DCT_H := wifi_config_dct.h
However, upon making the target, I'm getting the following error.
tools/makefiles/wiced_config.mk:267: *** Unknown component: Harsh_May.802.11ac_configuration. Stop.
make: *** No rule to make target 'build/Harsh_May.802.11ac_configuration-CYW954907AEVAL1F/config.mk', needed by 'main_app'. Stop.
I'm really not sure what error(s) are there in the code. I'd appreciate it if you could please through some light on the same?
10. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?HaTr_4568521 May 19, 2020 1:55 AM (in response to HaTr_4568521)
Hello RaktimR_11, could you please look into this?
11. Re: How to program CYW954907EVAL-1F for data transfer between two modules using 802.11?RaktimR_11
May 19, 2020 7:52 AM (in response to HaTr_4568521)1 of 1 people found this helpful
I don't see the makefile error in my case. Probably, this is occurring because of some extra space issue in some line in the .mk. But I am not clear on the application side what you are trying to do; since most of the commands are supposed to be executed when the driver down. But I see that you are trying to do wiced_network_up with the dct settings and then again trying to initialize the softap with wwd_wifi_* commands. You should do either or and use the wwd specific apis while the driver is down.. Then do the driver up and host the ap.
Alternatively, you can use the wl commands and explore the versatile nature of test.console example to test all 11ac specific features. The application can be located at 43xxx_Wi-Fi/apps/test/console. To use this example application, you would need to set CONSOLE_ENABLE_WL ?= 1 in line #380 of console.mk file.
For ap specific case, you can use the start_ap command. I used something like this
start_ap softap wpa2 12345678 38 40 no_wps 192.168.2.1 255.255.255.0
What this command essentially did is setup a softap, named "softap" ironically with wpa2 security and can be found in a 40 MHz channel in 5GHz (in this case channel 38). Look at the chart below to understand the channel in UNII bands.
Additionally for guard interval, mcs rates etc, you can refer to the wl documentation as found in WL Tool for Embedded 802.11 Systems: CYW43xx Technical Information. Now you should be able to implement your ap with the desired settings. Additionally, if you want to convert this to an api based application you can just check the wl tool and command console implementation and try referring to the wwd_wifi_* apis to perform your application. | https://community.cypress.com/thread/54374 | CC-MAIN-2020-50 | en | refinedweb |
Jira integrations
Introduction
GitLab Issues are a tool for discussing ideas and planning and tracking work. However, your organization may already use Jira for these purposes, with extensive, established data and business processes they rely on.
Although you can migrate your Jira issues and work exclusively in GitLab, you also have the option of continuing to use Jira by using GitLab’s Jira integrations.
Integrations
The following Jira integrations allow different types of cross-referencing between GitLab activity and Jira issues, with additional features:
- Jira integration - This is built in to GitLab. In a given GitLab project, it can be configured to connect to any Jira instance, self-managed or Cloud.
- Jira development panel integration - This connects all GitLab projects under a specified group or personal namespace.
- If you’re using Jira Cloud and GitLab.com, install the GitLab for Jira app in the Atlassian Marketplace and see its documentation.
- For all other environments, use the Jira DVCS Connector configuration instructions. | https://docs.gitlab.com/ee/user/project/integrations/jira_integrations.html | CC-MAIN-2020-50 | en | refinedweb |
Working with SQLite as your database in Xamarin.Forms is not difficult but it does involve some specific steps:
- Add the SQLite-.Net PCL library to all three projects
- Create the ISQLite interface
- Add a singleton to your app class
- Open your database in the appropriate directory and use DependencyService to access it
- Create your table(s)
- Write your CRUD operations
Piece of cake.
In this and the next posting I’ll go over these steps in detail and in context.
Implementing a SQLite Database – Getting Started
Begin by creating a new Xamarin.Forms application called DataBases. Add the NuGet package SQLite-net PCL. There are a number of similarly named packages, you want the one with a single author, Frank A. Krueger, as shown below:
Add this to all of your projects.
Create the normal Model, View and ViewModel folders and add a Data folder. In the Data folder, add the interface ISQLite.cs
public interface ISQLite { SQLiteConnection GetConnection(); }
Next, open DataBases.cs and create a singleton to hold the PersonDatabase
static PersonDatabase database; public static PersonDatabase Database { get { if (database == null) { database = new PersonDatabase(); } return database; } }
Create a file in your iOS application named SQLite_iOS.cs and in that file put the address for your database. In the code below, the correct string is commented out and I’m using a location on my computer to make debugging easier,
public class SQLite_iOS : ISQLite { public SQLite.SQLiteConnection GetConnection() { //var sqliteFilename = "Person.db"; // documents folder // string documentsPath = Environment.GetFolderPath ( // Environment.SpecialFolder.Personal); // Library folder // string libraryPath = Path.Combine ( // documentsPath, "..", "Library"); // var path = Path.Combine(libraryPath, sqliteFilename); var path = "/users/jesseliberty/Data/Person.db"; File.Open(path, FileMode.OpenOrCreate); var conn = new SQLite.SQLiteConnection(path); return conn; }
Implementing CRUD operations
In your model folder create a new class Person,
public class Person { [PrimaryKeyAttribute, AutoIncrement] public int ID { get; set; } public string FirstName { get; set; } public string LastName { get; set; } }
Notice the attributes on the ID. These will be used by SQLite to make the ID the primary key and to ensure that it is incremented for each record.
Create a new file in the Data folder named PersonDatabase.cs. In this file we’ll create an instance of the SQLiteConnection that we’ll call database and we’ll instantiate an object that we’ll call locker that we will use to “lock” the database during our operations.
public class PersonDatabase { SQLiteConnection database; static object locker = new object();
In the constructor we’ll instantiate the database, getting the path from the platform-specific code we saw above. We’ll then tell the database to create our Person table, which it will do from the Person class.
public PersonDatabase() { database = DependencyService.Get<ISQLite>().GetConnection(); database.CreateTable<Person>(); }
We’re now ready for our CRUD operations. We’ll just implement the Save and Get operations for now. SavePerson takes a Person object (we’ll look at how the ViewModel passes this in next week) and locks the database. It then examines the ID to see if this Person already exists in the database. If so, it updates that record, otherwise it returns a new record. In either case, it returns the record ID.
public int SavePerson(Person person) { lock (locker) { if (person.ID != 0) { database.Update(person); return person.ID; } else { return database.Insert(person); } } }
Similarly, GetPeople reaches into the database, and returns a list of Person objects. It does this by using a lamda expression against the Table<Person> we created earlier,
public IEnumerable<Person> GetPeople() { lock (locker) { return (from c in database.Table<Person>() select c).ToList(); } }
Note that for “ToList()” to work, you’ll have to add a using System.Linq statement.
Finally, we’ll implement GetPerson to return a single Person object based on ID,
public Person GetPerson(int id) { lock (locker) { return database.Table<Person>().Where(c => c.ID == id).FirstOrDefault(); } }
That’s it. Next week we’ll implement the User Interface (View and ViewModel) to see this at work.
Hi jesse Please could you kindly explain the lock(locker) concept clearly.
Pingback: Jesse Liberty: 52 Weeks of Xamarin: Week 10 – The UI for our database program | XamGeek.com
Is Lazy instantiation syntax supported? Couldn’t that be used instead of that singleton logic (assuming the Lazy mechanism is thread-safe / btw, even your singleton isn’t thread-safe, would need a lock or other way to impose a critical section) | http://jesseliberty.com/2015/10/06/52-weeks-of-xamarin-week-9-databases-part-1/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+JesseLiberty-SilverlightGeek+%28Jesse+Liberty%29 | CC-MAIN-2020-50 | en | refinedweb |
1 //2 //Informa -- RSS Library for Java3 //Copyright (c) 2002-2003 package de.nava.informa.utils;26 27 /**28 * Handy Dandy Test Data generator. There are two ways of using this. By calling 'generate()' we29 * just generate a stream of different rss urls to use for testing. The stream wraps around30 * eventually. Calling reset() we start the stream up again. Or, you can just call 'get(int)' to get31 * the nth url.32 * 33 */34 public class RssUrlTestData35 {36 37 static int current = 0;38 static String [] xmlURLs = static public String get(int i)98 {99 return xmlURLs[i % xmlURLs.length];100 }101 102 static public String generate()103 {104 return get(current++);105 }106 107 static public void reset()108 {109 current = 0;110 }111 112 }
Java API By Example, From Geeks To Geeks. | Our Blog | Conditions of Use | About Us_ | | http://kickjava.com/src/de/nava/informa/utils/RssUrlTestData.java.htm | CC-MAIN-2020-50 | en | refinedweb |
Hi,
I would like to use #stardist (3D) for the segmentation of a large (290, 1024, 1024) (z, y, x) confocal microscope image, but during the prediction the #jupyter kernel of the notebook crashes without any error message.
What I did so far:
I started to used an edged detection method (LoG) to create an initial data. Due to under-segmentation, the results are not usable for the type of analysis we have in mind. So we manually curated the data set with #napari.
After one week of curating and annotating, we ended up with a fully annotated volume with the dimensions (100, 476, 714) which contains approx 1000 rod-shaped bacteria.
This volume I split into 7 sub-volumes with (100, 476, 102) px each:
- 6 for training
- 1 for validation
- 1 for later testing
Thanks to data augmentation, I succeeded to train a stardist3d network with the following configurations:
anisotropy=(1.6521739130434783, 1.0, 1.1875), axes='ZYXC' backbone='resnet' grid=(1, 2, 2) n_channel_in=1 n_channel_out=97 n_dim=3 n_rays=96 net_conv_after_resnet=128 net_input_shape=(None, None, None, 1) net_mask_shape=(None, None, None, 1) rays_json={ 'name': 'Rays_GoldenSpiral', 'kwargs': { 'n': 96, 'anisotropy': (1.6521739130434783, 1.0, 1.1875)}} resnet_activation='relu' resnet_batch_norm=False resnet_kernel_init='he_normal' resnet_kernel_size=(3, 3, 3) resnet_n_blocks=4 resnet_n_conv_per_block=3 resnet_n_filter_base=32 train_background_reg=0.0001 train_batch_size=1 train_checkpoint='weights_best.h5' train_checkpoint_epoch='weights_now.h5' train_checkpoint_last='weights_last.h5' train_dist_loss='mae' train_epochs=400 train_learning_rate=0.0003 train_loss_weights=(1, 0.2) train_n_val_patches=None train_patch_size=(100, 100, 100) train_reduce_lr={'factor': 0.5, 'patience': 40, 'min_delta': 0}, train_steps_per_epoch=100 train_tensorboard=True use_gpu=True)
For the training I used a single GTX 980 with 4 GBs of VRAM. This is the reason why I limited the patch size to (100, 100, 100). This was simply the first patch size which worked.
Technically I have access to GPUs with larger VRAM (and longer waiting times …), but I always prefer quick iterations over perfect results during testing.
In tensorboard I got the following loss curves:
The prediction with the test image (here cropped) works quite nice. To only draw-back are over-segmented cells (i.e the marked ones).
Compared with our previous efforts to tackle our problems with a classical segmentation pipeline in MATLAB; 1.5 weeks for annotation, python coding, setup, and training is ridiculously fast.
Finally I gave the larger volume a try:
from __future__ import print_function, unicode_literals, absolute_import, division import sys, os import numpy as np import matplotlib.pyplot as plt %matplotlib inline %config InlineBackend.figure_format = 'retina' from glob import glob from tifffile import imread from csbdeep.utils import Path, normalize from stardist import random_label_cmap from stardist.models import StarDist3D np.random.seed(6) lbl_cmap = random_label_cmap() model = StarDist3D(None, name='stardist', basedir='models') # contains only a single tif stack: X = glob('largedatasets/*.tif') X = list(map(imread, X) X= [normalize(x, 1,99.8) for x in X] print(X[0].shape) # returns (290, 1024, 1024) labels= model.predict(X[0], n_tiles=(3, 11, 11))
(Heavily inspired by the corresponding stardist example notebook)
Shortly after the final progress bar reaches 100%, the #jupyter kernel dies and all labels are lost …
My questions so far:
- Has anyone an idea what could cause the kernel to crash?
- Has anyone seen over-segmentation like the one shown above and knows how to deal with it? (Would be awesome if we could eliminate this without post-processing or - even worst - by annotating more training data)
- (Are there other improvements possible?)
Eric | https://forum.image.sc/t/stardist-prediction-kernel-dies/34798 | CC-MAIN-2020-50 | en | refinedweb |
Host callback types needed by the service discovery procedure. More...
#include <ServiceDiscovery.h>
Host callback types needed by the service discovery procedure.
This class is also an interface that may be used in vendor port to model the service discovery process. This interface is not used in user code.
Definition at line 45 of file ServiceDiscovery.h.
Characteristic discovered event handler.
The callback accepts a pointer to a DiscoveredCharacteristic as parameter.
Definition at line 72 of file ServiceDiscovery.h.
Service discovered event handler.
The callback accepts a pointer to a DiscoveredService as parameter.
Definition at line 58 of file ServiceDiscovery.h.
Service discovery ended event.
The callback accepts a connection handle as parameter. This parameter is used to identify on which connection the service discovery process ended.
Definition at line 81 of file ServiceDiscovery.h.
Check whether service-discovery is currently active.
Launch service discovery.
Once launched, service discovery remains active with callbacks being issued back into the application for matching services or characteristics. isActive() can be used to determine status, and a termination callback (if set up) is invoked at the end. Service discovery can be terminated prematurely, if needed, using terminate().
Set up a callback to be invoked when service discovery is terminated.
Clear all ServiceDiscovery state of the associated object.
This function is meant to be overridden in the platform-specific subclass. Nevertheless, the subclass is only expected to reset its state and not the data held in ServiceDiscovery members. This is achieved by a call to ServiceDiscovery::reset() from the subclass' reset() implementation.
Definition at line 171 of file ServiceDiscovery.h.
Terminate an ongoing service discovery.
This should result in an invocation of the TerminationCallback if service discovery is active.
The registered callback handler for when a matching characteristic is found during service-discovery.
Definition at line 205 of file ServiceDiscovery.h.
Connection handle as provided by the SoftDevice.
Definition at line 185 of file ServiceDiscovery.h.
UUID-based filter that specifies the characteristic that the application is interested in.
Definition at line 200 of file ServiceDiscovery.h.
UUID-based filter that specifies the service that the application is interested in.
Definition at line 190 of file ServiceDiscovery.h.
The registered callback handle for when a matching service is found during service-discovery.
Definition at line 195 of file ServiceDiscovery.h. | https://os.mbed.com/docs/mbed-os/v6.1/mbed-os-api-doxy/class_service_discovery.html | CC-MAIN-2020-50 | en | refinedweb |
RichText control¶
This control provides rich text editing and display capability.
How to use this control in your solutions¶
- Check that you installed the
@pnp/spfx-controls-reactdependency. Check out the getting started page for more information about installing the dependency.
- Import the following modules to your component:
import { RichText } from "@pnp/spfx-controls-react/lib/RichText";
- The simplest way to use the
RichTextcontrol in your code is as follows:
<RichText value={this.props.value} onChange={(text)=>this.props.onChange(text)} />
- The
valueproperty should contain the HTML that you wish to display
- The
onChangehandler will be called every time a user changes the text. For example, to have your web part store the rich text as it is updated, you would use the following code:
private onTextChange = (newText: string) => { this.properties.myRichText = newText; return newText; }
It is possible to use the
onChange handler as users type -- for example, the following code replaces all instance of the word
bold with bold text.
private onTextChange = (newText: string) => { newText = newText.replace(" bold ", " <strong>bold</strong> "); this.properties.description = newText; return newText; }
Implementation¶
The RichText control can be configured with the following properties:
StyleOptions interface
Note that setting
showAlign,
showBold,
showItalic,
showLink,
showList,
showStyles, or
showUnderlineto
falsedoes not remove the user's ability to apply the button's associated formatting -- it only hides the toolbar option. Also, if
showMoreis
true, all options remain available in the formatting pane -- regardless whether they were turned off using
show___. To prevent users from applying specific formats, use the
onChangehandler to parse the rich text and remove the formatting as desired. | https://pnp.github.io/sp-dev-fx-controls-react/controls/RichText/ | CC-MAIN-2020-50 | en | refinedweb |
I like to develop small proof of concept applications. Although just validating, some security stuff may be necessary sometimes. Most often than not I also want to have 2 or more users...
So if you're using Spring and Thymeleaf, for the most basic and quick setup for a Spring MVC web app, just do:
Add the
pom.xml dependency
Just add this to the file:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-security</artifactId> </dependency>
Create the most basic security config ever
@EnableWebSecurity @Configuration public class WebSecurityConfig extends WebSecurityConfigurerAdapter { @Override protected void configure(AuthenticationManagerBuilder auth) throws Exception { auth .inMemoryAuthentication() .withUser("username").password("{noop}password").roles("USER").and() .withUser("username2").password("{noop}password").roles("USER"); } }
Additional stuff
Well, you're mostly done, but there're a few things that I believe are important to consider.
CSRF protection
The first thing is that with the current config you won't be able to make a HTTP POST request because Spring is automatically protecting your app from CSRF attacks. You must add the
csrf token already provided by Spring when POSTing.
You do that by adding the following inside your
<form> and
</form> tags:
<input type="hidden" th:
Logout link
The current configuration provides you a login page that may be enough for demonstrations. But having more than one user makes you want to logout and show some behavior with the other users.
For this, just add the following form somewhere in your app:
<div class="text-light"> <form action="/logout" method="post"> <input class="btn btn-link" type="submit" value="Log out" /> <input type="hidden" th: </form> </div>
Getting the logged user
Finally, if you want to know which user is logged, inject a
Principal instance on your controller methods. Here's an example:
@GetMapping public String homePage(Principal principal, Model model) { String username = principal.getName(); model.addAttribute("username", username); return "index"; }
Now you can show the logged user right on your homepage.
AQAP Series
As Quickly As Possible (AQAP) is a series of quick posts on something I find interesting. I encourage (and take part on) the discussions on the comments to further explore the technology, library or code quickly explained here.
Image by Jason King por Pixabay
Discussion | https://dev.to/brunodrugowick/the-most-basic-security-for-spring-boot-with-thymeleaf-339h | CC-MAIN-2020-50 | en | refinedweb |
A simple way to approach this problem would be to consider all ranges of the input array and determine the largest number that can be produced in that range. However, most ranges aren't actually interesting as they could never be combined into one.
To see this it helps to look at the equivalent problem where each of the array elements are powers of two and instead of combining x and x to produce x + 1 you produced 2x. Now it's clear that a range must sum to a power of two to be interesting. In fact, an interesting range can be better described by its starting position and the power of two it sums to.
This informs a simple Dynamic Programming solution. We let DP[p][i] give the ending index of the range starting at i that can combine to p, or -1 if it doesn't exist. DP[p + 1][i] is then calculated as DP[p + 1][i] = DP[p][DP[p][i]] provided DP[p][i] is valid.
Here's my solution to this problem.
#include <iostream> #include <cstdio> #include <vector> using namespace std; #define MAXN ((1 << 18) + 10) #define MAXSZ 70 int dp[MAXSZ + 1][MAXN]; int A[MAXN]; int main() { int N; cin >> N; vector<int> A(N); for (int i = 0; i < N; i++) { cin >> A[i]; } int result = 0; for (int i = 0; i <= MAXSZ; i++) { for (int j = 0; j < N; j++) { if (A[j] == i) { dp[i][j] = j + 1; result = max(result, i); } else { if (i == 0 || dp[i - 1][j] == -1 || dp[i - 1][dp[i - 1][j]] == -1) { dp[i][j] = -1; } else { dp[i][j] = dp[i - 1][dp[i - 1][j]]; result = max(result, i); } } } dp[i][N] = -1; } cout << result << endl; return 0; }
Further analysis contributed by Kyle Liu: There is an alternative $O(N)$ greedy approach. An $O(N \log N)$ greedy solution is obvious. We can remove the lowest value ($M$) by greedily combining $K$ consecutive pairs of $M$ into $K/2$ pairs of ($M+1$). In case that $K$ is odd, we can simply break the sequence into two and assign the $K/2$ pairs of $M+1$ to both sequences. Repeating this process will give us an $O(N \log N)$ solution, using appropriate data structures.
$O(N)$ can be achieved since we don't have to always find lowest value to remove. Consider the sequence of numbers as heights of hills. We can simply find the "valley points" (point whose heights are below its neighbours') to remove. We first condense the sequence into consecutive intervals of same heights. We use a stack to keep track of the sequence and "valley point". As we go through the list of intervals, if the stack is empty or the incoming height is below the height in the top of stack (downhill), we simply push the incoming interval to the stack. If the incoming height is above the height in the top of stack (uphill), the point at the top of the stack is a "valley point", and it needs to be removed by combining into its neighbouring intervals. Its left neighbours are in the stack and its right neighbour is the incoming interval. If any combination needs to break into two sequences. We can calculate the optimal value of the first sequence by "collapsing" the stack. We then start the second sequence with only the "valley point" in the stack.
Here is my code implementing this approach:
#include <stdio.h> #include <iostream> #include <math.h> using namespace std; #define MAXN 262144+10 struct Node { int val; int tot; }; Node ar[MAXN]; Node s[MAXN]; int N, top = 0, res = 0; void collapse_stack(void) // calculate value for first squence and reset stack { for (; top > 1; top--) s[top-2].tot += s[top-1].tot / (1 << (s[top-2].val - s[top-1].val)); res = max(res, s[top-1].val + (int)log2(s[top-1].tot)); top--; } void combine_left(int val) // combine the left side until height reaches val { for (; top > 1; top--) { if(s[top-2].val > val) break; int num = 1 << (s[top-2].val - s[top-1].val); if (s[top-1].tot % num) { Node tmp = s[top-1]; collapse_stack(); s[top++] = tmp; // start second sequence with the "valley point" break; } s[top-2].tot += s[top-1].tot / num; } } int main(void) { freopen("262144.in","r",stdin); freopen("262144.out","w",stdout); cin >> N; int st = 0; for(int i=1; i<=N; i++) { int a; cin >> a; res = max(res, a); if(a == ar[st].val) ar[st].tot++; else { ar[++st].val = a; ar[st].tot++; } } for(int i=1; i<=st; i++) { if (top == 0 || (ar[i].val < s[top-1].val)) { // downhill, add to stack s[top++] = ar[i]; continue; } combine_left(ar[i].val); int num = 1 << (ar[i].val - s[top-1].val); if (s[top-1].tot % num == 0) { // combine new interval into stack s[top-1].val = ar[i].val; s[top-1].tot = ar[i].tot + s[top-1].tot / num; } else { // new intervals cannot be merged to intervals already in stack ar[i].tot += s[top-1].tot / num; collapse_stack(); s[top++] = ar[i]; } } collapse_stack(); // obtain answer for remaining intervals in stack cout << res << endl; return 0; } | http://usaco.org/current/data/sol_262144_platinum_open16.html | CC-MAIN-2018-17 | en | refinedweb |
TypeScript 2.8 is here and brings a few features that we think you’ll love unconditionally!
If you’re not familiar with TypeScript, it’s a language that adds optional static types to JavaScript. Those static types help make guarantees about your code to avoid typos and other silly errors. They can also help provide nice things like code completions and easier project navigation thanks to tooling built around those types. When your code is run through the TypeScript compiler, you’re left with clean, readable, and standards-compliant JavaScript code, potentially rewritten to support much older browsers that only support ECMAScript 5 or even ECMAScript 3. To learn more about TypeScript, check out our documentation. following instructions here.
Other editors may have different update schedules, but should all have excellent TypeScript support soon as well.
To get a quick glance at what we’re shipping in this release, we put this handy list together to navigate our blog post:
- Conditional types
- Declaration-only emit
@jsxpragma comments
JSXnow resolved within factory functions
- Granular control on mapped type modifiers
- Organize imports
- Fixing uninitialized properties
We also have some minor breaking changes that you should keep in mind if upgrading.
But otherwise, let’s look at what new features come with TypeScript 2.8!
Conditional types
Conditional types are a new construct in TypeScript that allow us to choose types based on other types. They take the form
A extends B ? C : D
where
A,
B,
C, and
D are all types. You should read that as “when the type
A is assignable to
B, then this type is
C; otherwise, it’s
D. If you’ve used conditional syntax in JavaScript, this will feel familiar to you.
Let’s take two specific examples:
interface Animal { live(): void; } interface Dog extends Animal { woof(): void; } // Has type 'number' type Foo = Dog extends Animal ? number : string; // Has type 'string' type Bar = RegExp extends Dog ? number : string;
You might wonder why this is immediately useful. We can tell that
Foo will be
number, and
Bar will be
string, so we might as well write that out explicitly. But the real power of conditional types comes from using them with generics.
For example, let’s take the following function:
interface Id { id: number, /* other fields */ } interface Name { name: string, /* other fields */ } declare function createLabel(id: number): Id; declare function createLabel(name: string): Name; declare function createLabel(name: string | number): Id | Name;
These overloads for
createLabel describe a single JavaScript function that makes a choice based on the types of its inputs. Note two things:
- If a library has to make the same sort of choice over and over throughout its API, this becomes cumbersome.
- We have to create three overloads: one for each case when we’re sure of the type, and one for the most general case. For every other case we’d have to handle, the number of overloads would grow exponentially.
Instead, we can use a conditional type to smoosh both of our overloads down to one, and create a type alias so that we can reuse that logic.
type IdOrName<T extends number | string> = T extends number ? Id : Name; declare function createLabel<T extends number | string>(idOrName: T): T extends number ? Id : Name; let a = createLabel("typescript"); // Name let b = createLabel(2.8); // Id let c = createLabel("" as any); // Id | Name let d = createLabel("" as never); // never
Just like how JavaScript can make decisions at runtime based on the characteristics of a value, conditional types let TypeScript make decisions in the type system based on the characteristics of other types.
As another example, we could also write a type called
Flatten that flattens array types to their element types, but leaves them alone otherwise:
// If we have an array, get the type when we index with a 'number'. // Otherwise, leave the type alone. type Flatten<T> = T extends any[] ? T[number] : T;
Inferring within conditional types
Conditional types also provide us with a way to infer from types we compare against in the true branch using the
infer keyword. For example, we could have inferred the element type in
Flatten instead of fetching it out manually:
// We also could also have used '(infer U)[]' instead of 'Array<infer U>' type Flatten<T> = T extends Array<infer U> ? U : T;
Here, we’ve declaratively introduced a new generic type variable named
U instead of specifying how to retrieve the element type of
T. This frees us from having to think about how to get the types we’re interested in.
Distributing on unions with conditionals
When conditional types act on a single type parameter, they distribute across unions. So in the following example,
Bar has the type
string[] | number[] because
Foo is applied to the union type
string | number.
type Foo<T> = T extends any ? T[] : never; /** * Foo distributes on 'string | number' to the type * * (string extends any ? string[] : never) | * (number extends any ? number[] : never) * * which boils down to * * string[] | number[] */ type Bar = Foo<string | number>;
In case you ever need to avoid distributing on unions, you can surround each side of the
extends keyword with square brackets:
type Foo<T> = [T] extends [any] ? T[] : never; // Boils down to Array<string | number> type Bar = Foo<string | number>;
While conditional types can be a little intimidating at first, we believe they’ll bring a ton of flexibility for moments when you need to push the type system a little further to get accurate types.
New built-in helpers
TypeScript 2.8 provides several new type aliases in
lib.d.ts that take advantage of conditional types:
// These are all now built into lib.d.ts! /** * Exclude from T those types that are assignable to U */ type Exclude<T, U> = T extends U ? never : T; /** * Extract from T those types that are assignable to U */ type Extract<T, U> = T extends U ? T : never; /** * Exclude null and undefined from T */ type NonNullable<T> = T extends null | undefined ? never : T; /** * Obtain the return type of a function type */ type ReturnType<T extends (...args: any[]) => any> = T extends (...args: any[]) => infer R ? R : any; /** * Obtain the return type of a constructor function type */ type InstanceType<T extends new (...args: any[]) => any> = T extends new (...args: any[]) => infer R ? R : any;
While
NonNullable,
ReturnType, and
InstanceType are relatively self-explanatory,
Exclude and
Extract are a bit more interesting.
Extract selects types from its first argument that are assignable to its second argument:
// string[] | number[] type Foo = Extract<boolean | string[] | number[], any[]>;
Exclude does the opposite; it removes types from its first argument that are not assignable to its second:
// boolean type Bar = Exclude<boolean | string[] | number[], any[]>;
Declaration-only emit
Thanks to a pull request from Manoj Patel, TypeScript now features an
--emitDeclarationOnly flag which can be used for cases when you have an alternative build step for emitting JavaScript files, but need to emit declaration files separately. Under this mode no JavaScript files nor sourcemap files will be generated; just
.d.ts files that can be used for library consumers.
One use-case for this is when using alternate compilers for TypeScript such as Babel 7. For an example of repositories taking advantage of this flag, check out urql from Formidable Labs, or take a look at our Babel starter repo.
@jsx pragma comments
Typically, users of JSX expect to have their JSX tags rewritten to
React.createElement. However, if you’re using libraries that have a React-like factory API, such as Preact, Stencil, Inferno, Cycle, and others, you might want to tweak that emit slightly.
Previously, TypeScript only allowed users to control the emit for JSX at a global level using the
jsxFactory option (as well as the deprecated
reactNamespace option). However, if you needed to mix any of these libraries in the same application, you’d have been out of luck using JSX for both.
Luckily, TypeScript 2.8 now allows you to set your JSX factory on a file-by-file basis by adding an
// @jsx comment at the top of your file. If you’ve used the same functionality in Babel, this should look slightly familiar.
/** @jsx dom */ import { dom } from "./renderer" <h></h>
The above sample imports a function named
dom, and uses the
jsx pragma to select
dom as the factory for all JSX expressions in the file. TypeScript 2.8 will rewrite it to the following when compiling to CommonJS and ES5:
var renderer_1 = require("./renderer"); renderer_1.dom("h", null);
JSX is resolved via the JSX Factory
Currently, when TypeScript uses JSX, it looks up a global
JSX namespace to look up certain types (e.g. “what’s the type of a JSX component?”). In TypeScript 2.8, the compiler will try to look up the
JSX namespace based on the location of your JSX factory. For example, if your JSX factory is
React.createElement, TypeScript will try to first resolve
React.JSX, and then resolve
JSX from within the current scope.
This can be helpful when mixing and matching different libraries (e.g. React and Preact) or different versions of a specific library (e.g. React 14 and React 16), as placing the JSX namespace in the global scope can cause issues.
Going forward, we recommend that new JSX-oriented libraries avoid placing
JSX in the global scope, and instead export it from the same location as the respective factory function. However, for backward compatibility, TypeScript will continue falling back to the global scope when necessary.
Granular control on mapped type modifiers
TypeScript’s mapped object types are an incredibly powerful construct. One handy feature is that they allow users to create new types that have modifiers set for all their properties. For example, the following type creates a new type based on
T and where every property in
T becomes
readonly and optional (
?).
// Creates a type with all the properties in T, // but marked both readonly and optional. type ReadonlyAndPartial<T> = { readonly [P in keyof T]?: T[P] }
So mapped object types can add modifiers, but up until this point, there was no way to remove modifiers from
T.
TypeScript 2.8 provides a new syntax for removing modifiers in mapped types with the
- operator, and a new more explicit syntax for adding modifiers with the
+ operator. For example,
type Mutable<T> = { -readonly [P in keyof T]: T[P] } interface Foo { readonly abc: number; def?: string; } // 'abc' is no longer read-only, but 'def' is still optional. type TotallyMutableFoo = Mutable<Foo>
In the above,
Mutable removes
readonly from each property of the type that it maps over.
Similarly, TypeScript now provides a new
Required type in
lib.d.ts that removes optionality from each property:
/** * Make all properties in T required */ type Required<T> = { [P in keyof T]-?: T[P]; }
The
+ operator can be handy when you want to call out that a mapped type is adding modifiers. For example, our
ReadonlyAndPartial from above could be defined as follows:
type ReadonlyAndPartial<T> = { +readonly [P in keyof T]+?: T[P]; }
Organize imports
TypeScript’s language service now provides functionality to organize imports. This feature will remove any unused imports, sort existing imports by file paths, and sort named imports as well.
Fixing uninitialized properties
TypeScript 2.7 introduced extra checking for uninitialized properties in classes. Thanks to a pull request by Wenlu Wang TypeScript 2.8 brings some helpful quick fixes to make it easier to add to your codebase.
Breaking changes
Unused type parameters are checked under
--noUnusedParameters
Unused type parameters were previously reported under
--noUnusedLocals, but are now instead reported under
--noUnusedParameters.
HTMLObjectElement no longer has an
alt attribute
Such behavior is not covered by the WHATWG standard.
What’s next?
We hope that TypeScript 2.8 pushes the envelope further to provide a type system that can truly represent the nature of JavaScript as a language. With that, we believe we can provide you with an experience that continues to make you more productive and happier as you code.
Over the next few weeks, we’ll have a clearer picture of what’s in store for TypeScript 2.9, but as always, you can keep an eye on the TypeScript roadmap to see what we’re working on for our next release. You can also try out our nightly releases to try out the future today! For example, generic JSX elements are already out in TypeScript’s recent nightly releases!
Let us know what you think of this release over on Twitter or in the comments below, and feel free to report issues and suggestions filing a GitHub issue.
Happy Hacking!
Join the conversationAdd Comment
The type syntax is getting insane.
Insanely great. First time I played with mapped types I encountered the problem of wanting to treat some properties differently from others, or adding/removing readonly. Now I can. It’s excellent. The features introduced here play extremely well with other existing features and enable a ton of scenarios by combining them.
I’m not able to invoke the “organize imports” from within Visual Studio. How do you invoke this command?
Does it also consolidate redundant imports? As in, a different object is request from the same file on different lines.
To enable or disable the new language service:
1. Open the Tools > Options dialog.
2. Navigate to “Text Editor” > “JavaScript/TypeScript” > “Language Service”.3. Toggle the option titled “Enable the new JavaScript language service.”
Then follow this guide to update TypeScript to 2.8 in your project:
Not sure how to invoke the command though. | https://blogs.msdn.microsoft.com/typescript/2018/03/27/announcing-typescript-2-8/ | CC-MAIN-2018-17 | en | refinedweb |
Testing deployment of pre-built .war to various web serversJonathan Fuerth Apr 18, 2012 10:53 AM
Hi testing enthusiasts,
I'm itching to automate deployment testing of several Errai quickstart projects. Here's what we're doing by hand:
* Launch in Dev Mode and poke at the app (this can be handled already by the tooling we have)
* Build a WAR and deploy it to Jetty 7, Jetty 8, Tomcat 7, JBoss AS 6, and JBoss AS 7. (Each server has its own Maven profile, so we need to do a clean build for each)
* Test that "mvn clean" properly deletes all generated files, bringing the project back to its pristine state
HtmlUnit is powerful enough to verify the app deployed correctly. Real browser testing is not important because the quickstarts are not intricately styled.
I feel like Arquillian has probably solved this problem already. Can I use Arquillian to deploy the target/${myapp}.war to an Arquillian Managed container, then load the page and poke at the DOM (fill in a form field, press a button, check for response) with HtmlUnit? It's a different use case than the docs and tutorials focus on: I explicitly don't want to use ShrinkWrap in this case, because the thing I'm testing is that the .war was assembled correctly. I also don't want to inject anything into my test case. I just want to load the page into HtmlUnit and poke at it.
I greatly appreciate any and all ideas about how to automate away this tedious job.
-Jonathan
1. Re: Testing deployment of pre-built .war to various web serversMarek Schmidt Apr 18, 2012 11:20 AM (in response to Jonathan Fuerth)
It is easy to deploy an existing war with ShrinkWrap:
ShrinkWrap.create(ZipImporter.class, "foo.war").importFrom(new File("target/foo.war"))
(you just have to make sure your test runs in the integration-test maven phase, that is after "package", .. you will probably run the test itself in a completely different maven project anyway)
You can use HtmlUnitDriver with Arquillian Drone:
(just replace the "WebDriver" in the example with )
2. Re: Testing deployment of pre-built .war to various web serversJonathan Fuerth Apr 23, 2012 1:42 PM (in response to Marek Schmidt)
Thanks, Marek. I tried that and it worked great.
I'm just now grappling with whether or not a Maven build is the appropriate vehicle for this type of deployment testing. It's a lot of baggage to add to the main pom generated by the archetype. Putting it in a second "deployment testing" pom alongside the main pom might be an option. It could be useful to show how to approach deployment testing, or it could be a big distraction from the quickstart itself.
Maybe just a script in the parent project that creates the archetype?
How have others approached testing of quickstarts that must be deployable to various containers?
-Jonathan
3. Re: Testing deployment of pre-built .war to various web serversKarel Piwko Apr 24, 2012 3:37 AM (in response to Jonathan Fuerth)
ShrinkWrap Maven Resolver contains a MavenImporter. Not really so much useful at this point of view, as it basically automagically picks up the result of "mvn package", however with possibility to select profiles and spawning a completely different Maven execution from Surefire (in upcoming versions), it should allow you to construct JAR/WAR/EAR easily.
See following for further details:
4. Re: Testing deployment of pre-built .war to various web serversDan Allen Apr 24, 2012 3:57 AM (in response to Karel Piwko)
This is very nice:
WebArchive archive = ShrinkWrap.create(MavenImporter.class, "test.war") .loadEffectivePom("pom.xml").importBuildOutput() .as(WebArchive.class);
Since this is a case which can come up quite often, and in some test suites be used over and over again, I'd like to see an annotation for this scenario (which activates this build chain under the covers). Something like:
@RunWith(Arquillian.class) @DeployBuildOutput public class MyFunctionalTest { @ArquillianResource private URL url; @Test public void shouldBehaveSomeWay() { // make a request to the url } }
Of course, in this case, a @Deployment method would not be required (which is possible through an extension). Thoughts?
5. Re: Testing deployment of pre-built .war to various web serversDan Allen Apr 24, 2012 4:03 AM (in response to Dan Allen)
I had hacked up an extension prototype a while back that implements this idea, though it uses the older ShrinkWrap Resolver...which would be replaced w/ Karel's snippet.
It reminded me I had a better name for the deploy annotation:
@RunWith(Arquillian.class) @DeployProjectArtifact public class MyFunctionalTest { ... }
If we pursue this, where do you think this belongs? In Drone? In a module by itself?
6. Re: Testing deployment of pre-built .war to various web serversKarel Piwko Apr 24, 2012 4:06 AM (in response to Dan Allen)
Such requirement exists for a pretty long time here: .
Now we have a ShrinkWrap Resolver Maven Plugin, @DeployBuildOutput might work without specifying path to the pom, active profiles, etc. However, IDE support for the plugin is still an open question here.
This is an actual show-stopper for the moment . If implemented, creating an Arquillian extension with @DeployBuildOuput annotation would be an easy task.
7. Re: Testing deployment of pre-built .war to various web serversKarel Piwko Apr 24, 2012 4:15 AM (in response to Dan Allen)
I think it should be a part of ShrinkWrap Maven Resolver. Once on classpath, you can do Maven magic for deployments.
8. Re: Testing deployment of pre-built .war to various web serversSamuel Santos Apr 24, 2012 9:48 AM (in response to Karel Piwko)
+1 to add this to ShrinkWrap Maven Resolver.
Can you create a Jira entry to make it easier to follow?
9. Re: Testing deployment of pre-built .war to various web serversDan Allen May 1, 2012 10:40 PM (in response to Samuel Santos)
It turns out, there was already a JIRA...it just was before its time - Base test deployment on project in which test is run | https://developer.jboss.org/thread/198551?tstart=0 | CC-MAIN-2018-17 | en | refinedweb |
Concurrency handling is a technique that allows you to detect and resolve conflicts that arise out of two concurrent requests to the same resource..
Interdependent transactions – a real life example
Imagine a situation in which you were to transfer funds from your bank account to your friend’s account. Now at the time when the transaction is in execution, consider what would happen if you were to check your account balance. Or, imagine what should be displayed as an account balance while your friend is checking his account balance while the funds transfer is in progress. Also, what would happen if your friend is trying to withdraw funds from his account while the transfer is in progress?
These are examples of interdependent transactions, i.e. transactions which are dependent on one another. Another typical example is when a particular record has been deleted by a user while the same record is being updated by another user. To avoid such conflicts, database and record level locks are implemented. Note that the amount of time it takes for release of a database lock after it was set previously to mitigate such conflicts depends primarily upon the transaction time. As such, it is recommended to make transactions as short as possible (fewer statements) in order to keep the lock time minimal. Also, if a transaction takes an extensive amount of time there could be serious locking issues as other users might want to access the same data. Working on the data without transactions may help but it does not guarantee that the updates made by you are the latest.
Strategies
Basically, there are three approaches to handling concurrency conflicts – pessimistic concurrency control, optimistic concurrency control and “last saved wins”. In the first case, a particular record is made unavailable to the users from the time it was last fetched until the time it is updated in the database. In optimistic concurrency, the last updated value is saved. In other words, the last saved record, “wins”. In this mode, it is assumed that resource conflicts amongst concurrent users are unlikely, but, not impossible.
In essence, it is assumed that when you are updating a particular record, no other user is updating the record at the same point in time. If a conflict occurs while a particular record is being updated, the latest data is re-read from the database and the change is re-attempted. The update checks for any concurrency violation by determining the changes to the record from the time it was last read for the update operation to be performed. In the “last saved wins” situation, no checks are made for concurrent updates for the same record. The record is overwritten – any changes made to the record by other concurrent users are simply ignored as they are overwritten.
ADO.NET uses optimistic concurrency mode as its architecture is based on the disconnected model of data through the usage of DataSets and Data Adapters. In pessimistic concurrency, a check is made to see if any changes to a particular record have been made while it is being updated. In essence, pessimistic concurrency uses ROWVERSION or TIMESTAMP to check for updates to a particular record by other concurrent users. In the pessimistic concurrency mode it is assumed that a conflict will arise while concurrent data updates are taking place – so, locks are imposed on the requested data to ensure that the access to the data is blocked to other concurrent users. On the contrary, optimistic concurrency doesn’t check for concurrency violations or concurrent updates, the last updated record is the one that is saved last to the database – and hence, it is the recent one too!
Handling concurrency conflicts in the connected mode
Concurrency conflicts can be resolved in ADO.NET while it is working in the connected and in the disconnected modes. In the connected mode, you can resolve concurrency conflicts and ensure data security and integrity by using the transactions efficiently. So, what is a transaction, anyway? A transaction is actually a group of operations/statements combined into a logical unit of work that is either guaranteed to be executed as a whole or rolled back. Transactions help ensure data integrity and security.
Transaction isolation levels
SQL Server follows the following isolation levels:
- Read Committed – this is the default isolation level and it specifies that transactions attempting to update the data would be blocked until the lock acquired on the data by other concurrent threads are released
- Read Uncommitted – in this mode, the transactions are not blocked and there are no exclusive locks on the data
- Repeatable Read – this states that all transactions that are currently being executed in this isolation level cannot read data that has been modified but not yet committed by other concurrent threads. Also, other concurrent executing threads cannot modify the data that a thread has thread but not yet modified
- Serializable – this is similar to the repeatable read isolation level with the addition that any new rows that tend to violate data consistency for the currently executing threads are aborted
- Snapshot – this offers a perfect balance between data consistency and performance. You can get a snapshot of a previous copy of the data that was last modified whilst in the middle of a transaction
You can start a transaction in ADO.NET using the BeginTransaction method on the connection instance. This method returns an object of type SqlTransaction. You should then commit or rollback a transaction a transaction depending on whether or not the transaction was a success or a failure. It should be noted that you have to have an open connection to work with transactions in ADO.NET. The following piece of code illustrates how you can implement transaction management in the connected mode to enforce data consistency.
string connectionString = ""; //Some connection string SqlConnection sqlConnection = new SqlConnection(connectionString); sqlConnection.Open(); SqlTransaction sqlTransaction = sqlConnection.BeginTransaction(); SqlCommand sqlCommand = new SqlCommand(); sqlCommand.Transaction = sqlTransaction; try { sqlCommand.CommandText = "Insert into Sales (ItemCode, SalesmanCode) vALUES ('I001', 1)"; sqlCommand.ExecuteNonQuery(); sqlCommand.CommandText = "Update Stock Set Quantity = Quantity - 1 Where ItemCode = 'I001'"; sqlCommand.ExecuteNonQuery(); sqlTransaction.Commit(); } catch(Exception e) { sqlTransaction.Rollback(); //Write your exception handling code here } finally { sqlConnection.Close(); }
A better approach would be to use the TransactionScope class of the System.Transactions namespace for flexible transaction management. Here is an example:
using (TransactionScope transactionScope = new TransactionScope()) { using (SqlConnection firstConnection = new SqlConnection( connectionString)) { SqlCommand firstCommand = firstConnection.CreateCommand(); firstCommand.CommandText = "Insert into Sales (ItemCode, SalesmanCode) Values('I001', 1)"; firstConnection.Open(); firstCommand.ExecuteNonQuery(); firstConnection.Close(); } using (SqlConnection secondConnection = new SqlConnection(connectionString)) { SqlCommand secondCommand = secondConnection.CreateCommand(); firstCommand.CommandText = "Update Stock Set Quantity = Quantity - 1 Where ItemCode = 'I001'"; secondConnection.Open(); secondCommand.ExecuteNonQuery(); secondConnection.Close(); } transactionScope.Complete(); }
Though transactions are a good choice for preserving database integrity and data consistency, they should be used with utmost care. It should be noted that transactions hold locks and may cause contention issues; they should be as short as it is possible. Also, transactions require an open connection and hence they consume resources for a larger amount of time.
Handling concurrency conflicts in the disconnected mode
In the optimistic concurrency model, a check is made to see if the record being updated is the most recent one, or, if it has been modified by any other concurrent user. In order to do this, the data provider in use maintains two sets of data – one is the original, i.e. it contains the data that was last read from the database, and the other is the most recent or the changed data.
A check is then made using the WHERE clause in the update or delete statement to see if the data in the original set matches with the one in the database. If it does, the update or delete is performed – else, a concurrency violation is reported and the update or delete statement is aborted. Here is a typical example of an update statement with optimistic concurrency turned on:
dbCommand.CommandText = "UPDATE Employee Set FirstName = ?, LastName = ?, Age = ? WHERE (EmployeeID= ?) AND (FirstName = ?) AND (LastName = ?) AND (Age = ?)";
Note that whereas the most recent data is used in the SET statement, the WHERE clause of the UPDATE statement in the example shown above would contain the original data that was read from the database prior to performing the update operation. With optimistic concurrency turned off, the same update statement can be re-written as shown below:
dbCommand.CommandText = "UPDATE employee Set FirstName = ?, LastName = ?, Age = ? WHERE (EmployeeID= ?) ";
In essence, when using optimistic concurrency, a check is made to see if the data being updated of deleted from the database is the most recent one. This works fine as long as your queries contain fewer fields for an update. However, if you have long queries with a large number of fields, this approach would work, but at the cost of performance.
A better approach
A better approach in such cases would be to have a TimeStamp column in each of your database tables. Note that the TimeStamp column contains binary data that is unique within the database. You could re-create your employee table as shown below:
CREATE TABLE Patient ( EmployeeID int, FirstName nvarchar(50), LastName nvarchar(50), Age int, TStamp timestamp )
As and when a record becomes dirty, i.e. is modified from the time it was last read, the value in the TimeStamp column would change. You can then just check for whether the value of the TimeStamp column for a particular record has changed from the time you last read the record. Here is how you can check for concurrency violations now:
UPDATE Patient SET FirstName=?, LastName=? WHERE ((EmployeeID=?) AND (TStamp = ?) )
Note that the value for the TStamp in the WHERE clause would be checked with the one in the original version of the data. If no change is made to the record being updated from the time it was last read from the database, the value of the TStamp column for that record would remain the same. You can use this approach irrespective of the number of fields you have in your update statement. And, you are done!
So, what then is the right choice? It is advisable not to have transactions that run for a long time. If you need to access large data in a transaction that needs to be sent to the client, then you can have that operation at the end of the transaction. Transactions that require user input to commit are also a degrading factor, ensure that explicit transactions are either committed or rollback at some point of time. Also, you could find a boost in the performance if the resources are accessed in the same order. Proper utilization of isolation levels helps minimize locking.
Concurrency conflicts can also be handled by locking mechanisms – the database table or the record to be updated can be locked from other users until the transaction is complete in its entirety. The major pitfall to this approach however is that a continuous connection needs to be maintained with the underlying database and that the wait times can be significantly large when the data to be handled is more with more concurrent users connected. Hence, this is not a recommended approach in high data driven applications with large number of concurrent users connected.
Choosing the right type of concurrency is a tough proposition – you need to achieve a perfect balance between performance and data availability. You need to select a strategy that ensures that you require fewer locks on your resources and at the same time you should be able to get the right data with minimal locking time involved. There isn’t a common rule which insists on one over the other, as each has its pros and cons, instead you need to balance the demands of the normal and critical scenarios in your application and then choose a one over the other.
Note that SQL Server follows a pessimistic concurrency model by default – it assumes that a conflict can arise when a read request comes for a piece of data and doesn’t allow other transactions to read the data unless the current session commits – this is what we call a writer block. In the optimistic concurrency model an assumption is made that parallel updates to the same piece of data may or may not occur.
Summary
The ability of ADO.NET to work with data in a disconnected mode is great – you can have an in-memory representation of your data that even comprises the data relationships. The disconnected model of ADO.NET has brought about revolutionary changes in the way applications interact with the database. You can use ADO.NET to store disconnected in-memory collections of data locally. However, it brings in major concerns too – concurrency violations. This article has had a look at what concurrency violations are, the types of concurrency violations, the strategies to mitigate such issues and the performance issues involved. | https://www.developerfusion.com/article/84418/concurrency-handling-techniques-in-adonet/ | CC-MAIN-2018-17 | en | refinedweb |
Continued from page 1.
Using the Cloud Foundry CLI you can get details about your app and any services bound to it. In this case, we’re interested in the ie-traffic service. More specifically we need to run cf env <my-predix-current-app> to retrieve the url and Predix-Zone-Id.
"ie-traffic": [ { "credentials": { "url": "", "zone": { "http-header-name": "Predix-Zone-Id", "http-header-value": "123-abc", "oauth-scope": "ie-traffic.zones.123-abc.user" }
Combined with our token from before we have the authorization and access needed to start retrieving traffic data by using these headers in all future requests.
uaa = '' token = get_client_token(uaa, "myapp", "mysecret") traffic_url = "" traffic_zone = "123-abc" headers = { 'Authorization': 'Bearer ' + token, 'Predix-Zone-Id': zone }
But where is the data coming from?
/v1/assets/search
If you picture a streetlight, this is something Predix would refer to as an Asset. An Asset is a generic term like widget or foobar that helps us organize a directed graph of nodes. There is an entire Asset API if you wanted to create an asset model for your own use cases – but for our purposes we have a streetlight node that has a camera and other sensors all represented as assets.
Before we can start observing traffic events, we need to identify the asset we want to listen to. After all, there is more than one streetlight in a city therefore, we have to search for an asset of interest.
The Traffic API provides an endpoint with a relative URI of /v1/assets/search that requires a few parameters. We can query by device-type, media-type, or an event-type. We also want to narrow our search down by location with a bounding box (bbox) though we could walk the entire graph and page through results if we wanted to be thorough.
San Diego, that place where Happiness is Calling, has been a pioneer in adopting a smart city prototype scattered around the city. Some helpful simulated data can be retrieved with a bbox that correlates data from that geolocation.
Let’s find an interesting asset (or maybe just the first one).
def get_assets(url, headers, bbox, device_type): url = url + '/v1/assets/search' params = { 'q': 'device-type:' + device_type, 'bbox': bbox, } response = requests.get(url, headers=headers, params=params) return json.loads(response.text)['_embedded']['assets']
The original API design follows a HATEOAS pattern where the assets retrieved by this function have _links to follow for finding additional information. This includes links to retrieve live-events or continue to search-events or search-media. For much more detail you should review the online documentation.
Putting that all together again, we get our UAA token and then query for some assets at a given location like so:
bbox = '32.715675:-117.161230,32.708498:-117.151681' assets = get_assets(traffic_url, headers, bbox, 'DATASIM')
We can use the data in assets[0]['_links']['live-events']['href'] to get the Websocket address. This is needed in order to listen to the stream of events identifying when cars drive by with the Traffic Flow API.
from websocket import create_connection wss = get_asset_live_stream(assets[0], headers) ws = create_connection(wss, header=headers) event = ws.recv() ws.close()
This example is just grabbing the next event to explore. The JSON includes an epoch timestamp, traffic lane, vehicle type, count, speed, and direction.
{ "event-uid":"fe5742c0-aff2-4747-8cb2-54e2dac8c758", "timestamp":1468481476061, "event-type":"TFEVT", "device-uid":"HYP1040-75", "location-uid":"HYP1040-75-Lane2", "properties":{ "vehicle-type":"car" }, "measures":[ {"tag":"vehicleCount", "value":4}, {"tag":"speed", "value":19, "unit":"MPS"}, {"tag":"direction","value":271,"unit":"DEGREE"} ] }
Naturally you’d want to adapt this to listen to all the events and assets you are interested in for your use cases.
Wrapping Up
I hope this walkthrough was helpful and the source code snippets from this post can be found on GitHub.
The TrafficSeedApp takes some of these APIs and wraps them all up in a nice user interface demo. This can be a helpful resource to launch your own exploration of the APIs. It is built with a toolchain including node.js, gulp, and bower for those looking for an example other than Python.
Get the source so you can review the README.md and hack at it yourself:
git clone
There is a digital gold rush for developers to build intelligent applications for the Industrial Internet of Things. APIs like these for traffic, parking, pedestrians, and general safety are the building blocks for more sophisticated applications.
Learn more about case studies using the APIs at the Predix Transform conference track on Intelligent Environments July 25-27, 2016 or jump right in on the Intelligent World Hackathon which is open to all developers and running now with $58,000 in prizes. The hackathon ends August 2, 2016 so don’t procrastinate too long, but given what Ciklum did in 48 hours you have plenty of time. | https://www.programmableweb.com/news/how-ge-current-apis-power-smart-city-applications/sponsored-content/2016/07/21?page=2 | CC-MAIN-2018-17 | en | refinedweb |
Currently, the FreeBSD ports make the following change when building python:
Advertising
--- src/pl/plpython/Makefile.orig Fri Nov 19 20:23:01 2004 +++ src/pl/plpython/Makefile Tue Dec 28 23:32:16 2004 @@ -9,7 +9,7 @@ # shared library. Since there is no official way to determine this # (at least not in pre-2.3 Python), we see if there is a file that is # named like a shared library. -ifneq (,$(wildcard $(python_libdir)/libpython*$(DLSUFFIX)*)) +ifneq (,$(wildcard $(python_libdir)/../../libpython*$(DLSUFFIX)*)) shared_libpython = yes endif If that's not in-place, plpython won't build if the python that's installed is multi-threaded: I'm turning off threading in my python for now, but ISTM it'd be good to allow for building plpython from source. (This is python2.5 and FreeBSD 6.1). I looked around the config files but didn't see a clean way to handle this (and maybe the issue is actually with autoconf...) -- Jim Nasby [EMAIL PROTECTED] EnterpriseDB 512.569.9461 (cell) ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? | https://www.mail-archive.com/pgsql-hackers@postgresql.org/msg83911.html | CC-MAIN-2018-17 | en | refinedweb |
Error adding a Menu in QML
I have the following code:
import QtQuick 2.4 import QtQuick.Window 2.2 import QtQuick.Dialogs 1.2 import QtQuick.Controls 1.4 ApplicationWindow { title: qsTr("Hello World!") width: 640 height: 480 visible: true menuBar: MenuBar { id: menuBar } MouseArea { anchors.fill: parent onClicked: { menuBar.menus.addItem("test") } } }
When I run it and click, the following message appears:
qrc:/main.qml:19: TypeError: Property 'addItem' of object [object Object] is not a function
Why is this?
This one is discussed on ; there's some stuff there on how hard (impossible?) it is to dynamically add a Menu to a MenuBar, but maybe we're both missing some other trick. | https://forum.qt.io/topic/57948/error-adding-a-menu-in-qml | CC-MAIN-2018-17 | en | refinedweb |
Session;
Let’s have a look into a quick example where I will show how you can change the session state based on the different member types of your web site. Let’s say you have 3 different types of member (Gold, Silver and Platinum) and You want for Platinum member you want to maintain the session for some specific pages not for other. To start with this first, create an new HTTP Module by implementing IHttpModule Interface.
using System; using System.Web; /// <summary> /// Summary description for SessionModule /// </summary> public class SessionModule : IHttpModule { /// <summary> /// Disposes of the resources (other than memory) used by the module that implements <see cref="T:System.Web.IHttpModule"/>. /// </summary> public void Dispose() { } /// .BeginRequest += new EventHandler(context_BeginRequest); } /// <summary> /// Handles the BeginRequest event of the context control. /// </summary> /// <param name="sender">The source of the event.</param> /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param> have done with implementation of HTTP Module, you have to configure web.config for the same.
Again, you have to make sure that,y ou can only use SetSessionStateBehavior until the AcquireRequestState event is fired.
And, not only with Query string, you can enable or disable session state based on the different page as show in below
To know more about ASP.NET 4.0 State management, you can read my Session notes on Microsoft Community Tech Days – Hyderabad
Download ASP.NET 4.0 State Management – Deep Dive PPT
You will get the complete demo application on runtime session state change from above download.
Hope this will help you !
Cheers !
AJ
That was very informational read!!!
Very nice article. I really enjoying it, and it also cleared lot of my doubts about Asp.Net session state. Thanks for sharing with us. Following link also helped me lot to understand the Asp.Net Session
State…
Thanks everyone for your precious post!! | https://abhijitjana.net/2011/01/15/programmatically-changing-session-state-behavior-in-asp-net-4-0/ | CC-MAIN-2018-17 | en | refinedweb |
Generate wsdl from JSR 181 POJODan Smith Feb 12, 2007 11:38 AM
Is it possible to generate the WSDL file from a JSR-181 POJO endpoint using wstools or some other tool?
I was able to do this using Suns wsgen tool, but when I use the client based on that generated WSDL I get a org.jboss.ws.jaxb.UnmarshalException thrown from the server.
1. Re: Generate wsdl from JSR 181 POJOmonowai Feb 14, 2007 10:32 PM (in response to Dan Smith)
I too am now strugling with this. Seems to be that the Axis project bundled one - Java2WSDL - but JBoss is no longer supporting that release (ws4?) in the jboss-ws version shipping since AS 4.0.4.
It would be nice if the creation of WSDL files, or lack there of, were a little more clearly documented in what's offered. Even if it was just a simple NO! it would save a bit of searching :)
Seems to be nothing in the Wiki FAQ. my search continues....
2. Re: Generate wsdl from JSR 181 POJOmonowai Feb 14, 2007 10:44 PM (in response to Dan Smith)
Having just posted that, checkout, it may help you on the way.
3. Re: Generate wsdl from JSR 181 POJOmonowai Feb 15, 2007 7:45 PM (in response to Dan Smith)
I assume by the deafening silence on this, that this is either a really stupid question, or we're the only suckers doing this ¯\(°_o)/¯
Here's how it works for me. Create a file called wstools-java-to-wsdl.xml based upon wstools-config.xml but have it include the <java-wsdl> tags. Here is an example based on the 181ejb example:
<java-wsdl> <service name="TestService" style="rpc" endpoint="org.jboss.test.ws.jaxws.samples.jsr181ejb.EndpointInterface"/> <namespaces target- <mapping file="jaxrpc-mapping.xml"/> <webservices servlet- </java-wsdl>
Then, run the wstools with the following arguments:
-cp [FULL_PATH_TO_CLASS_FILE] -config ./resources/wstools-config.xml -dest ./resources/META-INF
My paths are relative to the folder jbossws-samples-1.0.4.GA\jaxws\jsr181ejb folder.
When run, it will create the META-INF/wsdl/TestServices.wsdl file.
It seems that wstools is not selective in what it creates. If you specify <java-wsdl> in your main wstools-config file, and you run the JBOSS sample ANT build files, then the WSDL will be recreated each time, overwriting your <soap:address location=.../> tag, which is not what you probably want to happen. I haven't looked in to how this works yet.
Likewise if the .wsdl file doesn't exist, then when you run your java2wsdl command, it will error complaining that it "can't load wsdl file" if your config contains the <wsdl-java> tags; Bit of a circular refrence going on there!
hth
4. Re: Generate wsdl from JSR 181 POJODavid Win Feb 15, 2007 9:52 PM (in response to Dan Smith)
To make it easier, you guys may want to consider using SOAPUI
if you use eclipse, you simply right click on the POJO and generate the webservice from it.
5. Re: Generate wsdl from JSR 181 POJOmonowai Feb 16, 2007 3:50 PM (in response to Dan Smith)
Indeed. Still it's nice to know what's going on behind the scenes, and a good UI is not really a substitute for clear doco.
I'm an Intellij user and with these IDE's being the memory hogs they are, running eclipse simply to maintain a few XML files is a bit of a pain; Soap's IntelliJ support is pretty basic, so I'll continue with the full UI I guess.
On the side, having just checked out the source for SOAPUI - and most of the jboss projects - it really feels like stepping back in time using ANT over Maven; All that configuration in your IDE, it's Like going from an automatic car to a manual. Geeze I've lost track of how many commons-collections and jaxb jars I've got lying around for all these o/s projects. Maven's on demand centralized repository structure is pure magic.
Oh well. The fun continues.
6. Re: Generate wsdl from JSR 181 POJOSammy Stag Feb 26, 2007 6:22 AM (in response to Dan Smith)
Hi,
I've been looking at this too over the last few days. The easiest way I can find is to do the following:
1) Compile your annotated JSR 181 pojo
2) Create a war file containing just the pojo class and web.xml
3) Deploy the war file and use your browser to get the WSDL by browsing to, for example,
4) Save the WSDL and use this to generate the endpoint interface, JAX-RPC mapping, etc as per the example in the JBossWS user guide.
If you look at the war file created by the JSR181 POJO example, you will see that it doesn't include the supplied WSDL file. The WSDL file is provided just for use by wstools, and is basically identical to the one you will get from your browser.
jar tvf output/libs/jaxws-samples-jsr181pojo.war META-INF/ META-INF/MANIFEST.MF WEB-INF/ WEB-INF/web.xml/samples/ WEB-INF/classes/org/jboss/test/ws/jaxws/samples/jsr181pojo/ WEB-INF/classes/org/jboss/test/ws/jaxws/samples/jsr181pojo/JSEBean01.class
It ought to be possible to get hold of the WSDL some other way, but I haven't figured it out yet. A bit of a shortcoming in the example I think.
7. Re: Generate wsdl from JSR 181 POJOSammy Stag Feb 26, 2007 9:49 AM (in response to Dan Smith)
Two more comments to make about this:
1) In wstools-config.xml, "location" can be a URL, so you don't need to save the WSDL to a file.
2) In wstools-config.xml, you might need to substitute "location" for "file" depending on your version of jbossws-client.jar. The version supplied with JBoss 4.0.5 GA expects "file". The version (in the "thirdparty" directory) which the example compiles against expects "location".
8. Re: Generate wsdl from JSR 181 POJOThomas Diesler Mar 1, 2007 10:20 AM (in response to Dan Smith)
This should be fixed in jbossws-1.2.0
9. Re: Generate wsdl from JSR 181 POJOmonowai Mar 7, 2007 12:46 AM (in response to Dan Smith)
"thomas.diesler@jboss.com" wrote:
This should be fixed in jbossws-1.2.0
Having moved to 1.2, things seem a lot smoother. thanks for all the effort Thomas, I can only imagine what goes in to getting this right.
wsproduce and wsconsume seem to do a fine job and the reduced level of annotations to get things right is a real boon.
Allan's suggestions were also valuable. Obtaining the wsdl straight from the server makes a lot of sense, and the fact you don't need to generate this to deploy your webservices is v. useful
cheers all | https://developer.jboss.org/thread/101743 | CC-MAIN-2018-17 | en | refinedweb |
Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 10, 2012 4:36 PM
Hello all,
We are running 2.2.5.Final (HQ_2_2_5_FINAL_AS7, 121) integrated with Jboss AS 5.1.0-Final. This configuration has been running since about 3-4 weeks now. However, we're run into a problem where we're now seeing serveral ( > 2500 ) messages getting stuck in the queue. It seems as though some messages are going through while other remain stuck.
Is there a way to determine / debug what's going on and why these messages are 'stuck' ? There are other queues that have different consumers and those messages are being consumed. It's just one of the queues that don't seem to be passing messages to its consumer. The consumer is a MDB deployed in the same instance of Horner!
A messages typically take a few milliseconds to process (consume). At this point the queue's message count and Schedule message count are both 'fixed' at 2602 messages. The 'MessagesAdded' count however seems to keep incrementing slowly. And the logs do show that new messages are being consumed and processed.
Is there a way to 'inspect' the queue's state to see what's causing the messages to stay in the queue ? When I try to inspect the queue using Hermes, it shows that the queue is empty.
Any help will be appreciated.
Thanks
Groove
1. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 10, 2012 11:45 PM (in response to Gurvinderpal Narula)
On invoking the 'listScheduledMessagesAsJSON' the first few messages list as follows:
{,"_HQ_SCHED_DELIVERY":1341949019203,,"_HQ_SCHED_DELIVERY":1341949019186,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014159,"userID":"ID:9a7612d9-cac6-11e1-8ddc-005056a500c1","messageID":32215946663,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019159,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014140,"userID":"ID:9a732ca5-cac6-11e1-8ddc-005056a500c1","messageID":32215946658,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019140,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014107,"userID":"ID:9a6e2391-cac6-11e1-8ddc-005056a500c1","messageID":32215946653,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019107,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014067,"userID":"ID:9a68090d-cac6-11e1-8ddc-005056a500c1","messageID":32215946648,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019067,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014049,"userID":"ID:9a6549e9-cac6-11e1-8ddc-005056a500c1","messageID":32215946643,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019049,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014031,"userID":"ID:9a628ac5-cac6-11e1-8ddc-005056a500c1","messageID":32215946638,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019031,"pricing_upload_listener_value":1,"durable":true,"type":5},{"timestamp":1341949014013,"userID":"ID:9a5fcba1-cac6-11e1-8ddc-005056a500c1","messageID":32215946633,"expiration":0,"address":"jms.queue.RetailPriceRequestQueue","priority":4,"_HQ_SCHED_DELIVERY":1341949019013,"pricing_upload_listener_value":1,"durable":true,"type":5}
When I try to remove/expire any messages using corresponding messageid, the response I get is 'false' and the messages stay in the queue. Even changing message priority does not help and the messages stay stuck in the queue and their priority also does not change.
Is there any other steps that can be taken to try and release or remove these messages ?
Any assistance/insight/help will truly be appreciated.
Thanks in advance,
Gurvinder
2. Re: Durable messages getting stuck in Queue.Andy Taylor Jul 11, 2012 4:01 AM (in response to Gurvinderpal Narula)
The messages you have shown look like they arent in the queue yet and scheduled for delivery, however they should be removed using the ID, could you provide a test so we can take a look.
3. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 11, 2012 4:58 AM (in response to Andy Taylor)
Andy.
Thank you for a response.
Here's an update - we tried restarting the server earlier in the morning today. The 'state' of the messages seems to have changed :
{,"pricing_upload_listener_value":1,"durable":true,"type":5}
I no-longer see '_HQ_SCHED_DELIVERY' property in the message headers. Also after we restarted the server, we noticed that about 11 messages getting processed (I can't tell if these are new messages that got processed or if these were existing messages that were stuck earlier that went through).
I'm not sure how to provide a test ! When I said that I tried to remove/expire these messages, I tried doing that throught the application servers (jboss-5.1.0 + Hornetq) jmx-console. If you think that's not the right way to adminster these message and I should try something else, then please let me know. Or if you think zipping up the jboss-folder and uploading it here so that you'll can take a look at what's going on would help, then I can do that as well.
4. Re: Durable messages getting stuck in Queue.Andy Taylor Jul 11, 2012 5:09 AM (in response to Gurvinderpal Narula)
that implies that the scheduled messages were put on the queue and consumed, these will be new messages. Why do you think that they are stuck? are the MDB's still active (you can check to see if the queue has any consumers in the console).
5. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 11, 2012 5:52 AM (in response to Andy Taylor)
We have 1 MDB (the backend system that processes our messages is only capable of processing one dataset at a time via a web service) configured and it's active :
This is the output from invoking listConsumersAsJSON :
[{"sessionID":"3e51326c-cb26-11e1-9bbd-005056a50108","connectionID":"3e4e734b-cb26-11e1-9bbd-005056a50108","creationTime":1341990091300,"browseOnly":false,"consumerID":0}]
The reason why I believe they're stuck is because :
1. Our messages don't take more than about a second to process. Right now there is little to-no actvity, yet the message counts (MessageCount / ScheduledMessageCount) has not dropped at all in the last hour or so. The count has stayed fixed at 2465 since the server was restarted earlier today.
2. Even though the messages are there in the queue, there is no actvity (in coming requests) being registered in the backend system.
When I do not see the message count or schedule message count reducing, I'm assuming that they're 'stuck'. I can't tell why they're not process at this point. Our MDB logs a lot of status information in the logs and we see these updates in the logs when messages are consumed. At this point I only see very little messages coming from this consumer - I should see a lot more activity in the logs.
If the messages were consumed, why is the MessageCount still showing 2465 ? Our messageCount never exceed 5-7 at any given point in time. Yes our ScheduleMessage Count does rise when our backend service goes down. But then when it comes backup, we normally see that drop down as well (in 2-4 hours typically). But it's now been 2 days and we have not seen these numbers dropped.
6. Re: Durable messages getting stuck in Queue.Andy Taylor Jul 11, 2012 6:34 AM (in response to Gurvinderpal Narula)
What is your MDB pool size, the reason I ask is that the defailt pool size is 15 and you should 15 consumers.
also, there may be a bug in message count when a server is restarted.
Also are you using transactions for the MDB, check prepared tx's to make sure there are no pending tx's, i.e. the messages have been consumed but not commited.
7. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 11, 2012 7:23 AM (in response to Andy Taylor)
We have set our pool size to 1 and session size to 1.
Here are the annotations we have defined for the MDB.
@MessageDriven(
activationConfig = {
@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
@ActivationConfigProperty(propertyName = "destination", propertyValue = "queue/RetailPriceRequestQueue"),
@ActivationConfigProperty(propertyName = "maxSession",propertyValue = "1" )
})
@Pool(value=PoolDefaults.POOL_IMPLEMENTATION_STRICTMAX, maxSize=1)
public class ForwardResponse implements MessageListener {
Can you please let me know how to check for pending tx's ?
I don't think the messages have been consumed since even our backend service has not registered the data in these messages. In our system, we keep a log of the messages that are 'send' by the producer and we also log this data in our backend system. So what we're see is that several of the messages that have been sent by our produced have never made it to our backend system. I will still check the pending txs once I've figured out how to. If you send me some pointers on how to do that, it would be great.
Andy, I would like to thank you for your effort in helping me out. Truely appreciate it.
Thanks again.
8. Re: Durable messages getting stuck in Queue.Clebert Suconic Jul 11, 2012 3:26 PM (in response to Gurvinderpal Narula)1 of 1 people found this helpful
You are using 2.2.5.. there were a few fixes since them.
One of the fixes was around PriorityLinkedList. The Queue would lose messages (until you restarted the system), and there were another ocurrency where this could occur after a redelivery.
9. Re: Durable messages getting stuck in Queue.Clebert Suconic Jul 11, 2012 3:27 PM (in response to Clebert Suconic)
BTW: I"m not saying you're hitting the bug. Just that if you moved to a later version maybe the issue will go away.
10. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 11, 2012 4:49 PM (in response to Clebert Suconic)
Thanks for the update Clebert. We'll work on upgrading to the later release. In the mean time, is there anyway to 'clear' out the existing queue ? The reason I ask is becuase when we tried to 'resubmit' these messages for processing, the resumitted messages simply piled up in the queue again. From our logs we can make out that there are ~ 750 requests that have not been processed. Yesterday the queue had about 1500 messages that were in the 'stuck' state. When we resumitted our requests for process, the 750 requests simply got added to the queue and did not process. So now our queue is sitting at ~ 2250 unprocessed messages. We need to get these 750 requests processed ASAP. So is there a way we can 'reset' the PriorityLinkedList so that we can re-sumit the ~750 requests ?
Again, thank you and Andy for your help and would really appreciate any addtional assistance you can provide to resolve this. Unfortunately upgarding to a new-release is going to mean quite bit of testing and we can't wait that long to process the 750 pending requests. So if there's a way to clear the current queue (like renaming the existing queue and creating a new one with the same name etc), it will be of tremendeous value to us.
11. Re: Durable messages getting stuck in Queue.Andy Taylor Jul 12, 2012 8:31 AM (in response to Gurvinderpal Narula)
if you use the console and delete using the ID that would work, if it doesnt then without some sort of test its hard to really help. Ive never seen an issue before of this tho.
12. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 16, 2012 10:22 AM (in response to Andy Taylor)
This is getting even worst - we're seeing the same behaiour now on a completely different server. We submitted about 700 messages to a test server on Friday (7/13). We normally see these messages being processed in about 45 mins. But the queue has just processed about 200 messages until now. I'm going to try to delete these messages etc.
I'm prepared to provide a test. Just not sure how to go about this ? Can you just provide me guidance on all the artifacts needed for the test ?
13. Re: Durable messages getting stuck in Queue.Clebert Suconic Jul 16, 2012 11:00 AM (in response to Gurvinderpal Narula)
With all the indications so far it seems that you are hitting a bug fixed after 2.2.5. It will be hard to fix a bug that was already fixed...
if you replicate it on the latest.. then we can fix it.
14. Re: Durable messages getting stuck in Queue.Gurvinderpal Narula Jul 16, 2012 1:08 PM (in response to Clebert Suconic)
Thanks Clebert,
Is it possible to use 2.2.14 with Jboss 5.1.0.GA ? I've tried to deploy 2.2.14 into a clean install of 5.1.0 and have run into this issue :
How do I resolve this ScopeKey issue ?
I can't move forward to 7.1.1 until the entire application is migrated. We do have a seperate initiative going towards that, but that's going to be take several weeks and we can't really wait so long to resolve this issue. | https://developer.jboss.org/thread/202426 | CC-MAIN-2018-17 | en | refinedweb |
configure your Tomcat environment in the Elastic Beanstalk console
Open the Elastic Beanstalk console.
Navigate to the management page for your environment.
Choose Configuration.
On the Software configuration card, choose Modify. endpoint = System.getProperty("API_ENDPOINT");
See Environment Properties and Other Software Settings for more information.
Tomcat Configuration Namespaces
You can use a configuration file to set configuration options and perform other instance configuration tasks during deployments. Configuration options can be defined by the Elastic Beanstalk service or the platform that you use and are organized into namespaces.
Elastic Beanstalk provides many configuration options for customizing your environment. In addition to configuration files, you can also set configuration options using the console, saved configurations, the EB CLI, or the AWS CLI. See Configuration Options for more information. | https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/java-tomcat-platform.html | CC-MAIN-2018-17 | en | refinedweb |
In this article I will explain you how to use ADO.NET technology to connect .NET console application and MS Access 2007 database.
Step 1: Create a Console Application in your .NET Framework. Select File -> New Project as shown in figure.
The application uses OleDb data providers to work with Microsoft Access database.
The second step is to add reference to the assembly and include the namespaces in your project. Select Project -> Add Reference option. The below figure shows how to add a reference to the System.Data.dll assembly.
Step 4: Include namespaces
After adding a reference to the assembly you need to include namespaces to the project by using the using namespace as below:
using System;
using System.Data;
using System.Data.Common;
using System.Data.OleDb;
You have to create a connection using the data provider Connection class. I have used Ms Access 2007 database. Below is the code to make the connection:
string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\\Testing.accdb";
Step 6: Creating a command Object
Next step is to create a Command object. OleDBCommand class is used for it.
The OleDbCommand constructor takes two parameters. The first is a SQL query and the second is the Connection object.
I have created a SELECT SQL query from the Test_table in the Testing.accdb database of MS Access 2007.
OleDbConnection conn = new OleDbConnection(connectionString);
string sql = "select Name, Address, Salary from Test_table";
OleDbCommand cmd = new OleDbCommand(sql, conn);
The next step is to open connection by calling Open method of the Connection object and than reading data from the Command object.
The ExecuteReader method, OleDbCommand, returns data in an OleDataReader object. The DataReader object reads fast and forward only cached data.
conn.Open();
OleDbDataReader reader;
reader = cmd.ExecuteReader();
The Read method of OleDbDataReader reads the data. The DataReader class has Getxxx methods, which return different types of data. The Getxxx methods takes and index of the field you want to read data of.
while (reader.Read())
{
Console.Write(reader.GetString(0).ToString() + "\t \t");
Console.Write(reader.GetString(1).ToString() + "\t \t ");
Console.WriteLine(reader.GetDecimal(2));
}
Here we close the reader and connection objects by calling their Close methods.
reader.Close();
conn.Close();
namespace ADO_MSAccess_test
{
class Program
{
static void Main(string[] args)
{
string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\\Testing.accdb";
OleDbConnection conn = new OleDbConnection(connectionString);
string sql = "select Name, Address, Salary from Test_table";
OleDbCommand cmd = new OleDbCommand(sql, conn);
conn.Open();
OleDbDataReader reader;
reader = cmd.ExecuteReader();
Console.WriteLine("Person Name \tAddress\t\t Salary");
Console.WriteLine("==============================================");
while (reader.Read())
}
Console.ReadLine();
reader.Close();
conn.Close();
}
}
}
Hope the article would have helped you in using ADO.NET connectivity in your .NET application with MS Access 2007.
Your feedback and constructive contributions are welcome. Please feel free to contact me for feedback or comments you may have about this article.
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Build smarter apps with Machine Learning, Bots, Cognitive Services - Start free. | https://www.c-sharpcorner.com/uploadfile/puranindia/ado-net-application-using-ms-access-2007-database/ | CC-MAIN-2018-17 | en | refinedweb |
Prevent BOBJ data loss when Business user leaves
When a business user leaves the company the HR systems will trigger user deletion process which will eventually lock or remove the SAP user accounts in SAP ERP systems. Business Objects systems whose authentication is set to SAP will have only SAP aliases in BOBJ. This blog explains how to create Enterprise aliases to safeguard all SAP user accounts and their report objects in Business Objects systems. This is not applicable for those who Active Directory based login to their BOBJ systems.
Refer to SAP notr#note#1804839 — How to add or remove an Enterprise alias through a script in SAP BI 4.0. Use this sample code from to adapt to your requirements.
You can download the source code from GITHUB url:
Follow the below screen print steps to create the needed Enterprise Aliases with complex random passwords.
Create a JAVA Project in Eclipse and as show below.
Add the appropriate JRE. In this case, remove the JRE 1.8 and add the sapjvm JRE which is similar to one used by BOBJ Server.
Make Sure you have same sapjvm version in your machine as that of BOBJ server
Select the newly configured SAPJVM and remove any other jvm from the screen above.
Click Finish
Here you will add BOBJ Library files. For this you need BOBJ Client tools installed on your machine or you can get the library files form BOBJ Windows server.
Click Finish
Create a new Class
Copy and Past the Source Code
Export the code to JAR format
Import the JAR file to BOBJ as Program file object
The BOBJ part starts from here. No need for any login credentials inside the source code as the Program can run in the logged-in user context of BOBJ system.
Class name should match the namespace and class of the Source Code
Schedule now
Program running. | https://blogs.sap.com/2017/10/02/prevent-bobj-data-loss-when-business-user-leaves/ | CC-MAIN-2018-17 | en | refinedweb |
I am using the October CMS () that is based on the Laravel Framework for my web app.
Explanation:
First I am calling an external server and getting an XML array which I translate and insert into my local database. Then I pull these values from my local database and try to display them on the front-end. The issue is, that I have 2 languages that I need to cater to.
Example:
{% if activeLocale == "si" %}
{{ record.estate_type_SI|raw }}
{% elseif activeLocale == "en" %}
{{ record.estate_type_EN|raw }}
{% endif %}
{{ record.estate_type_{{"SI"|trans}}|raw }} | https://codedump.io/share/gYeJ0Uh5gv5n/1/translate-dynamic-valuestring-from-database-twig-laravel | CC-MAIN-2018-17 | en | refinedweb |
- Looping
- Difference between preprocessor and namespace
- How come I can use strcmp without including <cstring> ?
- Need help with time
- Difference between Structure and Class
- I have some problems about AVL tree...Please help me....
- Another problem with ftream
- Problems using ostringstreams
- Need help with reading from .txt
- Why are classes useful?
- Missing library? | http://cboard.cprogramming.com/sitemap/f-3-p-427.html?s=89c27c61047bae59d290dfa73dcce39a | CC-MAIN-2015-35 | en | refinedweb |
Spring for Apache Hadoop provides for each Hadoop interaction type, whether it is vanilla Map/Reduce, Cascading, Hive or Pig, a runner, a dedicated class used for declarative (or programmatic) interaction. The list below illustrates the existing runner classes for each type, their name and namespace element.
While most of the configuration depends on the underlying type, the runners share common attributes and behaviour so one can use them in a predictive, consistent way. Below is a list of common features:
declaration does not imply execution
The runner allows a script, a job, a cascade to run but the execution can be triggered either programmatically or by the container at start-up.
run-at-startup
Each runner can execute its action at start-up. By default, this flag is set to
false. For multiple or on demand execution (such as scheduling) use the
Callable contract (see below).
JDK
Callable interface
Each runner implements the JDK
Callable interface. Thus one can inject the runner into other beans or its own classes to trigger the execution
(as many or as little times as she wants).
pre and
Each runner allows one or multiple, pre or/and post actions to be specified (to chain them together such as executing a job after another or perfoming clean up). Typically other runners can be used but any
Callable can be specified. The actions will be executed
before and after the main action, in the declaration order. The runner uses a fail-safe behaviour meaning, any exception will interrupt the run and will propagated immediately to the caller.
consider Spring Batch
The runners are meant as a way to execute basic tasks. When multiple executions need to be coordinated and the flow becomes non-trivial, we strongly recommend using Spring Batch which provides all the features of the runners and more (a complete, mature framework for batch execution). | http://docs.spring.io/spring-data/hadoop/docs/2.0.0.M1/reference/html/runners.html | CC-MAIN-2015-35 | en | refinedweb |
- Windows (129)
- Linux (127)
- Mac (104)
- Grouping and Descriptive Categories (80)
- Modern (31)
- BSD (24)
- Other Operating Systems (9)
Site Management Software
VertrigoServ WAMP
Complete WAMP Server - PHP Apache MySQL for Windows.2,662 weekly downloads
CMS Pro Web Shop
Online shopping cms, Website template, website builder free download]6 weekly downloads
Vertex CMS
A small and flexible portals system
Nstag
Namespaced Template Engine (PHP extension) - An extremely powerful Tokenizer driven Template engine with XSL-like syntax. Nstag works based on the idea to have special tags in a separate namespace to apply view related logic or just assignments
Kim Websites
CMS Website whose graphics and design can be easily changed, optimized for SEO, internal search engine, user registration, backup, photo galery... Including FCKEditor. Installed in fifteen minutes.1 weekly downloads
Enom PHP
Enom PHP is an advanced system for account managing and several others resources, developed for Open Tibia Server.2 weekly downloads
PHPPublisher
The PHP Web Publisher offers a simple-to-use web interface for site managementDebugger - interactive PHP debugger
TDebugger - an interactive debugger for the PHP language. - Step through your PHP code - Stop on breakpoints - Inspectors for all global, local and idividual variables - View stack trace2 weekly downloads | http://sourceforge.net/directory/internet/www/sitemanagement/license:php-license/license:osi/ | CC-MAIN-2015-35 | en | refinedweb |
I am looking for a open source of free tool that I could execute from the command line. It should take a screen shot of the screen and save it to a file. Operating system is Windows. Something like this:
C:\>screenshot.exe screen1.png
Download imagemagick. Many command line image manipulation tools are included. import allows you to capture some or all of a screen and save the image to a file. For example, to save the entire screen as a jpeg:
import -window root screen.jpeg
If you want to use the mouse to click inside a window or select a screen region & save a a png, just use:
import box.png
This question's already been answered, but I thought I'd throw this in as well. NirCmd (freeware, sadly, not open source) can take screenshots from the command line, in conjunction with the numerous other functions it can do.
Running this from the command line either in nircmd.exe's directory or if you copied it to your system32 folder:
nircmd.exe savescreenshot screen1.png
does what you want. You can also delay it like this:
nircmd.exe cmdwait 2000 savescreenshot screen1.png
That will wait 2000 milliseconds (2 seconds), and then capture and save the screenshot.
Nircmd
Other suggestions are fine -- you could also try MiniCap, which is free and has some other features like flexible file naming and some different capture modes:
(disclaimer: I'm the author of MiniCap).
Screenshot-cmd
OPTIONS:
-wt WINDOW_TITLE
Select window with this title.
Title must not contain space (" ").
-wh WINDOW_HANDLE
Select window by it's handle
(representad as hex string - f.e. "0012079E")
-rc LEFT TOP RIGHT BOTTOM
Crop source. If no WINDOW_TITLE is provided
(0,0) is left top corner of desktop,
else if WINDOW_TITLE maches a desktop window
(0,0) is it's top left corner.
-o FILENAME
Output file name, if none, the image will be saved
as "screenshot.png" in the current working directory.
-h
Shows this help info.
You can try the boxcutter tool:
usage: boxcutter [OPTIONS] [OUTPUT_FILENAME]
Saves a bitmap screenshot to 'OUTPUT_FILENAME' if given. Otherwise,
screenshot is stored on clipboard by default.
OPTIONS
-c, --coords X1,Y1,X2,Y2 capture the rectange (X1,Y1)-(X2,Y2)
-f, --fullscreen fullscreen screenshot
-v, --version display version information
-h, --help display help message
Try IrfanView.
You can run it via command-line. You can specify which window to capture – such as whole window or just the current/active window – and you can also do some basic editing such as sharpening, cropping or resizing the images.
Here are the command line options, particularly interesting is
i_view32 /capture=0 /convert=wholescreen.png
You can use snapit to take awesome screenshots from the command line.
it can be done without external tools (you just need installed .net framework ,which is installed by default on everything from vista and above) - screenCapture.bat. It is a selfcompiled C# program and you can save the output in few formats and capture only the active window or the whole screen:
screenCapture- captures the screen or the active window and saves it to a file
Usage:
screenCapture filename [format] [Y|N]
filename - the file where the screen capture will be saved
format - Bmp,Emf,Exif,Gif,Icon,Jpeg,Png,Tiff and are supported - default is bmp
Y|N - either or not the whole screen to be captured (if no only active window will be processed).Defalut is Y
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1 month ago | http://superuser.com/questions/75614/take-a-screen-shot-from-command-line-in-windows | CC-MAIN-2015-35 | en | refinedweb |
NAME
unshare - disassociate parts of the process execution context
SYNOPSIS
#define _GNU_SOURCE #include <sched.h> int unshare(int flags);
DESCRIPTION
unshare() allows a process to disassociate parts of its execution context that are currently being shared with other processes. Part of the execution context, such as theNS This flag has the same effect as the clone(2) CLONE_NEWNS flag. Unshare the namespace, so that the calling process has a private copy of its namespace which is not shared with any other process. Specifying this flag automatically implies CLONE_FS as well. flags specified CLONE_NEWNS but the calling process was not privileged (did not have the CAP_SYS_ADMIN capability). 2.77 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at. | http://manpages.ubuntu.com/manpages/hardy/man2/unshare.2.html | CC-MAIN-2015-35 | en | refinedweb |
UIConfig
Since: BlackBerry 10.3.0
#include <bb/cascades/UIConfig>
Provides UI configuration properties for a UiObject.
This class provides functions for converting design units into pixels and for exposing the ui palette used within the current context.
Design units are device-independent values that are converted into explicit pixel values optimized for the screen density and resolution of a particular device. Both the du() and sdu() methods convert a design unit into pixels, with the difference being that sdu() rounds the value off to the nearest whole number.
Overview
QML properties
QML signals
Properties Index
Public Functions Index
Signals Index
Properties
bool
Specifies whether the UI should use the compact mode concept to define the appearance of visual components.
BlackBerry 10.3.0
float
A scale factor that depends on the information density context.
The dynamic design factor is a modifier with the base of 1.0 that can be used to adapt UI dimensions when the information density changes. One way that information density changes is through the system font (as the system font becomes smaller, information density rises).
If your app contains a lot of text, you might want other dimensions (margins, padding, and so on) to change as the size of text changes. By updating other dimensions along with the text, your app is always making the best use of the space that's available.
Some controls, such as the StandardListItem, are automatically updated when the information density changes. Other controls require that you update them yourself. To allow your app to update these controls as the information density changes, you can add the information density factor to your existing du() and sdu() methods by multiplying the design unit value with the dduFactor.
topPadding: ui.du(11.5)
topPadding: ui.du(11.5 * ui.dduFactor)
You can also replace your existing du() and sdu() methods with ddu() and sddu() respectively, but this approach requires that you connect to the dduFactorChanged() signal to monitor changes and update the required values.
BlackBerry 10.3.1
bb::cascades::UIPalette
BlackBerry 10.3.0
Public Functions
Q_INVOKABLE float
float
A float stating the information density factor.
BlackBerry 10.3.1
Q_INVOKABLE float
Converts a design unit value into a pixel value.
The converted pixel value.
BlackBerry 10.3.0
bool
Returns the isCompact property of the UI context.
A bool indicating whether the UI should be shown in compact mode.
BlackBerry 10.3.0
bb::cascades::UIPalette *
Retrieves the ui palette.
Q_INVOKABLE float
Converts a pixel value to a pixel value.
This method doesn't change the value of the measurement. It's simply used as a way to explicitly show that the value is a pixel value.
In future versions of Cascades, API changes may require that pixel values are specified explicitly by using this method. Using this API reduces the effort to adapt to those changes, and your code may be source compatible with future versions.
The pixel value.
BlackBerry 10.3.0
Q_INVOKABLE float
Converts a design unit value into a pixel value while taking the dduFactor into account and rounding the result to the nearest whole pixel.
Q_INVOKABLE float
Converts a design unit value into a pixel value, while rounding to the nearest whole pixel.
The converted pixel value, rounded to the nearest whole pixel.
BlackBerry 10.3.0
Signals
void
Emitted after the isCompact of the UI has changed.
BlackBerry 10.3.0
void
Emitted after the dduFactor of the UI has changed.
BlackBerry 10.3.1
void
Here's how to connect a slot to a button and listen for changes to its ui palette:
Button *button7 = new Button(); Color baseColor = button7->ui()->palette()->primaryBase(); // set primary base color as button color button7->setColor(baseColor); // listen to palette changed signal QObject::connect(button7->ui(), SIGNAL(paletteChanged(const bb::cascades::UIPalette*)), this, SLOT(onPaletteChanged(const bb::cascades::UIPalette*))); // update button color in onPrimaryPaletteChanged() slot ...
BlackBerry 10.3.0
Got questions about leaving a comment? Get answers from our Disqus FAQ.comments powered by Disqus | http://developer.blackberry.com/native/reference/cascades/bb__cascades__uiconfig.html | CC-MAIN-2015-35 | en | refinedweb |
Hi. Apologies for not answering earlier, this got buried in my inbox. I think you are right; we are expecting qsort() to be stable - the built-in comparison functions go to extra work to make the results be stable. The test should probably be enhanced to something like: function comp_val_num(s1, v1, s2, v2, num) { num = "^[-+]?([0-9]+[.]?[0-9]*|[.][0-9]+)([eE][-+]?[0-9]+)?$" # force stable sort, compare as strings if not numeric if ((v1 - v2) == 0 && (v1 !~ num || v2 !~ num)) return v1 < v2 return (v1 - v2) } Thanks, Arnold >. > -- > Peter Fales > Alcatel-Lucent > Member of Technical Staff > 1960 Lucent Lane > Room: 9H-505 > Naperville, IL 60566-7033 > Email: address@hidden > Phone: 630 979 8031 | http://lists.gnu.org/archive/html/bug-gawk/2011-07/msg00025.html | CC-MAIN-2015-35 | en | refinedweb |
"getopt" is a familiar function in C programming on UNIX-like operating systems, but outside of that (i.e., Windows, Mac OS), it is nearly non-existent. The purpose of getopt is to help the programmer parse options and their arguments when passed to the application via the command line.
CpGetOpt is the name of this little project that provides a (partial for now) getopt implementation for .NET, that is written in C#. CpGetOpt is POSIX compliant and can, optionally, emulate glibc's version of getopt almost exactly. Currently, long options are not supported, but will be in the very near future.
For more information on getopt, visit the glibc documentation at.
Also, visit my blog for more of my work.
Getopt has been around for a very long time, and helps deal with what can turn into a complex task: parsing program arguments, and the arguments that they, themselves, can take. Getopt is part of most C runtime libraries, and implementations exist in many programming languages. Normally, getopt supports only Unix-style command options, but support for Windows style options isn't that difficult to implement (see the last paragraph in this section).
Options allow the programmer to handle optional program arguments in a more structured manner. In essence, options are special kinds of command line arguments that are meant to give meaning to flags or variables in the program itself, and as their name implies, are optional. Options allow the programmer to handle optional program arguments in a more structured manner.
The same kind of functionality can be achieved by just checking the number of program arguments given, and interpreting them based on that. However, obviously, that is much more complex and time consuming, whereas using getopt is much more simplistic.
Simple; an option is just prefixed with a dash ("-"), and then a character that identifies the option being specified, and then an argument to give that option, if any arguments are allowed. Additionally, an argument can be supplied to an option in two separate ways. In the first: the option is followed by a white space, and then the argument; in the second form: the option is followed by the argument with no white space (when using this form, the option character must immediately follow the dash, and the character following must not be an option itself; "-afoo" would not work as expected if 'f' were also a valid option).
# In this example, both commands are equivalent.
Example:
app.exe -a foo
app.exe -afoo
Furthermore, assuming that you use the first form to specify the options being passed to a program, you can combine multiple options into one string.
# In this example, both commands are equivalent.
Example:
app.exe -abc
app.exe -a -b -c
In the event in which options 'b' and 'c' require an argument, the option string can stay as it is, and the arguments need only follow the options in their respective order.
# In this example, both commands are equivalent.
Example:
app.exe -abc foo bar
app.exe -a -b foo -c bar
Long options are exactly like regular options, with the exception that they can be more than one character in length (i.e., --verb instead of -v). And, when including an option argument in the option string, you separate the two by an equals sign ("=") with no white space.
# For an application where options 'i' and 'include' have the same meaning,
# the commands below are all equivalent.
Example:
app.exe -iarg
app.exe -i arg
app.exe --include=arg
app.exe --include arg
Unfortunately, CpGetOpt does not yet support long options, but will very soon.
"getopt" is a standard component of most libc libraries, and is also a part of the POSIX specification; but as previously stated, it is absent from Microsoft's C run-time. Windows does use the concept of options when invoking commands, with one slight difference: instead of specifying an option with a prefixed "-" or long options with a "-", all options are simply prefixed with a single forward slash ("/"); and instead of using an "=" where supplying an option argument with the option itself, a colon (":") is used.
# UNIX-style
app -a -b -c foo --longopt=arg
# Windows-style
app.exe /a /b /c foo /longopt:arg
Currently, CpGetOpt defines two types: GetOptionsSettings and GetOpt.
GetOptionsSettings
GetOpt
GetOptionsSettings provides an enumeration that can be given as a set of flags to the GetOpt.GetOptions function to control how the options are parsed.
GetOpt.GetOptions
GlibcCorrect
GetOptions
PosixCorrect
ThrowOnError
ApplicationException
PrintOnError
None
GetOpt is the container class that provides the getopt implementation.
The GetOptions method of the GetOpt class is what must be used to consecutively parse command line arguments, and it takes three arguments, with the third being optional.
int GetOptions(string[] args, string options, [GetOptionsSettings settings])
args
Main
options
settings
GetOptions returns the character (cast as an int) that identifies the option, '?' when the current option has resulted in an error, and returns -1 when all options have been parsed.
int
By default, after every successful call to GetOptions, the option name can be accessed through the GetOpt.Item property. However, when GetOptionsSettings.GlibcCorrect is specified, this behavior is only true when parsing that option that resulted in an error.
GetOpt.Item
GetOptionsSettings.GlibcCorrect
If the option returned has an argument, then that argument can be accessed using the GetOpt.Text property.
GetOpt.Text
After all options have been parsed and -1 has been returned by GetOptions, access the GetOpt.Index property to get the index within the args array at which you can resume normal argument processing.
GetOpt.Index
Important: All state information maintained by the GetOptions method is thread-static. This means that calls to GetOptions in different threads of execution will behave independently of one another.
Simple; call GetOpt.GetOptions in a loop until it returns -1, and use the character returned to handle the options given to the application.
//
// Normally, getopt is called in a loop. When getopt returns -1, indicating
// no more options are present, the loop terminates.
//
// A switch statement is used to dispatch on the return value from getopt.
// In typical use, each case just sets a variable that is used later in the program.
//
// A second loop is used to process the remaining non-option arguments.
//
// Make sure to add CpGetOpt.dll as an assembly reference in your project
// and then just add a "using CodePoints;" statement.
using CodePoints;
using System;
...
public static void Main ( string [] args ) {
int c = 0, aflag = 0, bflag = 0;
string cvalue = "(null)";
while ( ( c = GetOpt.GetOptions(args, "abc:") ) != ( -1 ) ) {
switch ( ( char ) c ) {
case 'a':
aflag = 1;
break;
case 'b':
bflag = 1;
break;
case 'c':
cvalue = GetOpt.Text;
break;
case '?':
Console.WriteLine("Error in parsing option '{0}'", GetOpt.Item);
break;
default:
return;
}
}
Console.WriteLine("aflag = {0}, bflag = {1}, cvalue = {2}", aflag, bflag, cvalue);
for ( int n = GetOpt.Index ; n < args.Length ; n++ )
Console.WriteLine("Non-option argument: {0}", args [n]);
}
...
Here are some examples showing what this program prints with different combinations of arguments:
% testopt.exe
aflag = 0, bflag = 0, cvalue = (null)
% testopt.exe -a -b
aflag = 1, bflag = 1, cvalue = (null)
% testopt.exe -ab
aflag = 1, bflag = 1, cvalue = (null)
% testopt.exe -c foo
aflag = 0, bflag = 0, cvalue = foo
% testopt.exe -cfoo
aflag = 0, bflag = 0, cvalue = foo
% testopt.exe arg1
aflag = 0, bflag = 0, cvalue = (null)
Non-option argument: arg1
% testopt.exe -a arg1
aflag = 1, bflag = 0, cvalue = (null)
Non-option argument: arg1
% testopt.exe -c foo arg1
aflag = 0, bflag = 0, cvalue = foo
Non-option argument: arg1
% testopt.exe -a -- -b
aflag = 1, bflag = 0, cvalue = (null)
Non-option argument: -b
% testopt.exe -a -
aflag = 1, bflag = 0, cvalue = (null)
Non-option argument: -
Take a look at the source if you want to see how I implemented getopt. I'll say this: implementing getopt correctly and functionally is not as easy as it seems at first glance. Anyways, I hope someone can utilize and find some use for CpGetOpt.. | http://www.codeproject.com/Articles/26502/GetOpt-for-NET?fid=1364246&df=90&mpp=10&noise=1&prof=True&sort=Position&view=Expanded&spc=None | CC-MAIN-2015-35 | en | refinedweb |
Excellent that kind of makes sense now thanks alot.
Excellent that kind of makes sense now thanks alot.
ok in a essenses a constructors allows you initalise a variable with different values?
public class User {
private String Name;
public User(String name) { // constructor
...
Ok so I think I get waht your saying could you give me an example?
How and why would I use it?
Hello All
I cannot express how happy I am to have found a platform to ask all my Java related questions and there is many.
first off I am complete beginner in the software... | http://www.javaprogrammingforums.com/search.php?s=3a66fbe96d32739885e522b16636ba4b&searchid=1724741 | CC-MAIN-2015-35 | en | refinedweb |
- Author:
- nstrite
- Posted:
- March 23, 2007
- Language:
- Python
- Version:
- .96
- templatetag ifnotequal ifequal template if conditional tag
- Score:
- 12 (after 12 ratings).
More like this
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- Easy Conditional Template Tags by fragsworth 6 years, 3 months ago
For the sake of clarity in my templates, I've replaced the two instances of
'endif'with
'end'+TAGNAME. So for now it's
endpyifinstead of
endif. Didn't want to confuse it with any regular
{% endif %}in my templates.
#
Please login first before commenting. | https://djangosnippets.org/snippets/130/ | CC-MAIN-2015-35 | en | refinedweb |
Created on 2010-08-27.03:18:49 by esatterwhite, last changed 2014-05-10.05:44:53 by zyasoft.
the data structure deque from the collections module is documented as allowing a maxlen argument.
code:
from collections import deque
d = deque([], 5)
results in:
deque() takes at most 1 arguments (2 given)
deque([], maxlen=5)
deque() does not take keyword arguments.
Either way, there is no way to specify a maximum length on the deque object
maxlen becomes available as of Python 2.6; Jython 2.5.x only implements 2.5 functionality.
So this is a documentation issue. (For a number of reasons, we backported the 2.6 docs, but haven't completed revising them to 2.5.)
2.5.2 final must have this and related issues resolved.
Generalized title. This will ideally be resolved by a doc sprint we are planning sometime in October.
Similar bug has been noted in issue #1590. Plan to address these issues with a community sprint for documentation cleanup.
Duplicate of #1590 | http://bugs.jython.org/issue1650 | CC-MAIN-2015-35 | en | refinedweb |
{-# LANGUAGE ScopedTypeVariables , UndecidableInstances, FlexibleInstances #-} module Data.TCache.IResource where import Data.Typeable import System.IO.Unsafe import Control.Concurrent.STM import Control.Concurrent import System.Directory import Control.Exception as Exception import System.IO import System.IO.Error import Data.List(elemIndices) import Control.Monad(when,replicateM) import Data.List(isInfixOf) --instance (Typeable a, Typeable b) => Typeable (HashTable a b) where -- typeOf _=mkTyConApp (mkTyCon "Data.HashTable.HashTable") [Data.Typeable.typeOf (undefined ::a), Data.Typeable.typeOf (undefined ::b)] --import Debug.Trace --debug a b= trace b a {- | An IResource instance that must be defined for every object being cached. there are a set of implicit IResource instance trough utiliy classes (See below) -} class IResource a where {- define the fields used by keyResource. For example @ readResource Person {name="John", surname= "Adams"}@ leaving the rest of the fields undefined when using default file persistence, the key is used as file name. so it must contain valid filename characters -} keyResource :: a -> String -- ^ must be defined {- | -} readResourceByKey :: String -> IO(Maybe a) -- |') writeResource:: a-> IO() -- | is called syncronously. It must autocommit delResource:: a-> IO() {- | idempotentProperty k= do r <- readResourceByKey k r' <- readResourceByKey k return (r == r') idempotentProperty :: (IResource a) => a -> IO Bool idempotentProperty x= do r <- readResourceByKey $ keyResource x r' <- readResourceByKey $ keyResource x return (r == r') readResource :: IResource a => a-> IO (Maybe a) readResource x= readResourceByKey $ keyResource x -} -- | Resources data definition used by 'withSTMResources' data Resources a b = Retry -- ^ forces a retry | Resources { toAdd :: [a] -- ^ resources to be inserted back in the cache , toDelete :: [a] -- ^ resources to be deleted from the cache and from permanent storage , toReturn :: b -- ^ result to be returned } -- | Empty resources: @resources= Resources [] [] ()@ resources :: Resources a () resources = Resources [] [] () {- | @ -} class Indexable a where key:: a -> String defPath :: a -> String -- ^ additional extension for default file paths. -- The default value is "data/". -- IMPORTANT: defPath must depend on the datatype, not the value (must be constant). Default is "TCacheData/" defPath = const "TCacheData/" --instance IResource a => Indexable a where -- key x= keyResource x {- |/deserialization is to/from ordinary Strings serialization/deserialization are not performance critical in TCache -} class Serializable a where serialize :: a -> String deserialize :: String -> a {- | Read, Show, instances are implicit instances of Serializable instance (Show a, Read a) => Serializable a where serialize= show deserialize= read -} defaultReadResource :: (Serializable a, Indexable a, Typeable a) => a -> IO (Maybe a) defaultReadResource x= defaultReadResourceByKey $ key x castErr a= r where r= case cast a of Nothing -> error $ "Type error: " ++ (show $ typeOf a) ++ " does not match "++ (show $ typeOf r) ++ "\nThis means that objects of these two types have the same key \nor the retrieved object type is not the stored one for the same key\n" Just x -> x defaultReadResourceByKey :: (Serializable a, Indexable a) => String-> IO (Maybe a) defaultReadResourceByKey k= iox where iox = handle handler $ do s <- readFileStrict filename :: IO String return $ Just (deserialize s ) -- `debug` ("read "++ filename) filename= defPathIO iox ++ k defPathIO ::(Serializable a, Indexable a)=> IO (Maybe a) -> String defPathIO iox= defPath x where Just x= unsafePerformIO $ (return $ Just undefined) `asTypeOf` iox handler :: (Serializable a, Indexable a) => IOError -> IO (Maybe a) handler e | isAlreadyInUseError e = defaultReadResourceByKey k | isDoesNotExistError e = return Nothing | otherwise= if ("invalid" `isInfixOf` ioeGetErrorString e) then error $ ( "readResource: " ++ show e) ++ " defPath and/or keyResource are not suitable for a file path" else defaultReadResourceByKey k defaultWriteResource :: (Serializable a, Indexable a) => a-> IO() defaultWriteResource x= safeWrite filename (serialize x) -- `debug` ("write "++filename) where filename= defPath x ++ key x safeWrite filename str= handle handler $ writeFile filename str where handler (e :: IOError) | isDoesNotExistError e=do createDirectoryIfMissing True $ take (1+(last $ elemIndices '/' filename)) filename --maybe the path does not exist safeWrite filename str | otherwise =do --phPutStrLn stderr $ "defaultWriteResource: " ++ show e ++ " in file: " ++ filename ++ " retrying" safeWrite filename str defaultDelResource :: (Indexable a) => a -> IO() defaultDelResource x= handle (handler filename) $ removeFile filename --`debug` ("delete "++filename) where filename= defPath x ++ key x handler :: String -> IOError -> IO () handler file e | isDoesNotExistError e= return () | isAlreadyInUseError e= do --hPutStrLn stderr $ "defaultDelResource: busy" ++ " in file: " ++ filename ++ " retrying" threadDelay 1000000 defaultDelResource x | otherwise = do --hPutStrLn stderr $ "defaultDelResource: " ++ show e ++ " in file: " ++ filename ++ " retrying" threadDelay 1000000 defaultDelResource x -- Strict read from file, needed for default file persistence readFileStrict f = openFile f ReadMode >>= \ h -> readIt h `finally` hClose h where readIt h= do s <- hFileSize h let n= fromIntegral s str <- replicateM n (hGetChar h) return str | http://hackage.haskell.org/package/TCache-0.8.0.1/docs/src/Data-TCache-IResource.html | CC-MAIN-2015-35 | en | refinedweb |
# SoapUI Open Source 5.2
xop:Include href
testrunner.batfrom another directory
Proxy settings can now be auto-detected (SOAP-454)
Please see for an overview of all the new great features and more details on fixes in the final release!
Major New Features: - Test Debugging (Pro) - Assertion TestSteps (Pro) - Message Content Assertion (Pro) - TestOnDemand. Run your tests from the Cloud - Multi Environment Support (Pro) - Floating Licenses (Pro)
Minor Improvements - HTTP Monitor now works for all HTTP Methods - Improved the XPath Assertion to support wildcards within elements - Improved the XQuery Assertion to support wildcards within elements - Added possibility to override JUnitReportCollector for creating custom JUnit style reports - Enlarged the controls in Security Test - Added support for SAML 2 - Added support for NTLM 2 and Kerberos - Added line numbers when having a Groovy Null Pointer
Bug Fixes - Changed SOAP message to put elements in WSDL Defined proper sequence of when when elements were of complex type - Updates to Schema Compliance - Fixes to WSDL handling that was changed between 3.6.1 and 4.0.0 - Under some ciscumstances you could get NullPointerException when doing a Show Message - Exchange for XML Bomb security test - Fixes to TestRunner for the HTTP test step when using 3.0.1 project files in 4.0.0 Fixed a SoapUI Pro Testrunner bug, When you overrode Global Properties you could get a ClassCastException - Under some circumstance a HTTP Redirect with path as location was not followed correctly - When trying to export Complex Project with many external dependencies you could get a Null pointer - Fixed and error loading WSDLs containing UTF-8 Characters - Corrected JDBC connections when the uses used regexp in configurations - Fixed NPEs when the users tried to start JMS in the context menu of a project - Fixed contains assertion to work with multi lines - Fixed issues with the maven2 plugin dependencies - The maven2 plugin would fail for composite projects if global properties were specified - Fixed SoapUI problems on Java 7 - Made Datasource Row or Column windows to be resizable - Optional recursive elements or types were not shown in form editor - Under some conditions it was not possible to delete multiple assertions using the keyboard delete button - REST TestSteps weren't saving their assigned REST Resource and Method in some cases - Small Spelling and Language fixes... - Under some conditions the password in service endpoints and environments could be visible to the end user - Testcase that contains " (quotation mark) in its label weren't executed in composite projects - Fixed a problem where a combination of SoapUI composite project and SVN when renaming test suites - Custom Assertion weren't visible in the list of available assertions - Corrected Mock War Packaging Issues - Pre encoded endpoints setting wasn't working for REST or HTTP URLs - REST URLs weren't calculated correctly when endPoints had context - Importing WADL generated by SoapUI could break method names - Fixed GUI glitches for Assertion Display and Highlighting of List Items - Form view did not not create container elements for sequence of complex type containing only attributes - You could get a stackoverflow when calling selectFromCurrent from script assertion - The empty report template was missing language="groovy" attribute which gave the reporting engine issues - The Execution of Parallel TestCases in the Command Line runner did not execute any of the tests - If response message contains the text "u0000" then the Outline view did not work anymore - NPE when creating Command Line report for failed REST requests - Corrected an inconsistent numbering of TestStep index
Please see for an overview of the bugs fixed in this release.
Please see for an overview of all the new great features and more details on fixes in the final release!
2010-10-18 : 3.6.1
Major New Features: - None!
Minor New Features: - Improved SoapUI <-> loadUI integration (loadUI) - automatic detection of paths - improved component generation - Multiple Parameter value support for REST requests (REST)
Bugs Fixed: - Improved Web Recording with Forms (Web) - Fixed HTTP Header overrides (SoapUI) - Command-line runners don't execute all tests on misspelling (Automation) - Multiple spelling and usability issues (SoapUI) - File DataSink IOException (Functional Testing) - Project Script Library now works on project load (Scripting)
Updated Libraries: - Groovy 1.7.5
2010-09-14 : 3.6
Major New Features: - loadUI Integration - Web Testing and Recording - Manual TestStep
Minor New Features:
- Improved WADL importer
- Improved viewing of attachments
- Improved support for huge file attachments (>200mb) - Fixed many memory leaks for long-running tests - Added support for project-level script libraries - Added setting to enable wordwrap in Raw message views - Increased default memory setting in .sh files
- Added action to clear the current Workspace - Added option to show namespaces in refactoring wizard
- Improved web-recording functionality: - wizards for generating web tests when creating new projects - possibility to exclude HTTP Headers - support for multiple recording sessions Improved loadUI project generation from functional TestCases
Major bugs fixed:
- Fixed adding of HTTP Query Parameters
- Fixed JDBC Assertions to handle connection errors
- Several fixes to JDBC-connection related functionality
- Fixed showing of passwords in UI
- Several UI cleanups and minor bug-fixes
- Fixed preview of -f argument in runner dialogs - Fixed usage of correct soap version when refactoring
- Fixed parameter resolving in script properties - Fixed saving of reordered TestCases - Fixed SSL Support for SoapUI TestCases in loadUI - Fixed bundling of external resources in generated War files - Fixed all code-generation to work from command-line tools
Updated Libraries: - Groovy 1.7.4 - JxBrowser 2.4
2010-04-09 : 3.5.1
SoapUI 3.5.1 is mainly a bug-fix release with dozens of minor improvements and fixes: - Added support for JMS Message Selector to filter messages with arbitrary queries - Added support for sending and receiving BytesMessages for SOAP requests - Added option to propagate SOAPAction as JMS Property - Added support for WS-Addressing and WS-Security for outgoing JMS messages - Received MapMessages are converted to XML - Added initial support for importing SOAP/JMS and TIBCO/JMS bindings - Added ResponseAsXml property for accessing XML results for JDBC and AMF TestSteps - Many many memory fixes - Added a "Discard" Response property to all requests that allow for improved memory mgmt - Improved multi-threaded dispatching in SOAP Monitor - Fixed cloning of property-transfers to include all settings - Fixed property-transfer logic when source is empty - Added UI Setting to disable tooltips - Added property-expansion support in SLA Assertion - Fixed Conditional Goto to work with all Sampler TestSteps - Fixed keeping of whitespaces in XML generated from JDBC results - Added SOAP Request assertion for MockResponse TestSteps - Fixed closing of opened files in MockEngine - Fixed Find-and-Replace - Added multi-actions for enabling and disabling TestSteps, TestCases and TestSuites - Fixed forward slashed in .sh launchers - Improved moving of TestSteps - Improved generation of XPath statements to always include namespaces - Fixed JDBC Connection errors with missing password - Fixed incorrect JDBC Connection string templates - Added missing actions in menus - Improved error-logging from event-handlers - Added TestSuiteRequirements Reporting DataSource - Fixed DataSources to detect changes in configuration and re-initialize if neccessary - Spelling mistakes... - Updated Groovy to 1.7.2 (Library) - and more minor fixes..
Thanks to all our customers and users for once again helping us make SoapUI and SoapUI Pro even better!
2010-03-01 : 3.5 - the Protocol Release
SoapUI 3.5 adds support for JMS, JDBC and AMF for both functional and load-testing
Major New Features
JDBC Testing (Protocol) - A JDBC TestStep has been added for functional database testing, all standard xml and xpath related functionality applies to query results (assertions, transfers, etc).
JMS Testing (Protocol) - A JMS protocol has been added for sending and receiving both text (SOAP,etc) and binary messages via JMS. Provider configuration and extended JMS monitoring and debugging functionality is provided via the HermesJMS integration.
AMF Testing (Protocol) - An AMF TestStep has been added for functional and load testing of Flex server applications, all standard xml and xpath related functionality applies to response messages (assertions, transfers, etc).
Query Builder (Data Driven testing) Component for visually building Database queries used in the JDBC Teststep and JDBC related DataSources and DataSinks.
Deploy as War (Mocking) SoapUI Projects can now be packaged as WAR files to be deployed on any standard servlet container, which will host the contained MockServices and display a simple Web interface for statistics, log output, etc.
Minor new features - Greatly improved performance of Excel DataSource/DataSinks (Functional Testing) - Greatly improved performance of script library (General) - added global option to disable proxy (General) - improved automatic adding of template parameters to rest resources (REST) - added raw-message-size settings (General) - improved update-interface stability (General) - improved thread-stability related to endpoints during loadtests (LoadTesting) - improved statistics calculation during loadtests (LoadTesting) - Pressing return in httprequest endpoint field submits request (User Interface) - Added timeout property at request level (General) - RunTestCase TestStep improvements: (Functional Testing) o Copy LoadTest Properties o Copy HTTPSession o Ignore Empty - Added caching of WSDL Credentials (SOAP) - Improved performance of script-property-expansions (General) - Added -A option to TestCase runner; for exporting of all results using folders instead of long filenames (Test Automation) - memory improvements (General) - improved XML generation from HTML (REST) - allowed rename of rest services from properties panel (REST) - Renamed porttype property to "Name" in interface properties (WSDL) - Improved Mock-related APIs to allow rewriting of incoming requests (Mocking) - Forced redirect functionality for PUT and POST requests (REST) - Improved TestRun Log output at TestSuite and Project levels (Functional Testing) - Added "RemoveEmptyXsiNil" and "RemoveEmptyRecursive" config properties for removal of empty content (WSDL) - Fixed handling of long property/testcase popup/drop-down menus (User Interface) - Added getter and setter for ExcelDataSource.ignoreEmpty property (API) - changed forum-search to use forums and not google (User Interface) - set minimum toolbar size for better resizing of splitpanels (User Interface) - added check that files in schema directory are actually schemas (General)
Major bugs fixed:
Updated libraries:
As always we owe our users and the community so much for all their help and support! Thank you all!
Beta2 fixes: - JXBrowser 1.4 update - Groovy 1.7.0 update - JDK 1.6_18 update - Hermes 1.14 update () - Support for named parameters in SQL queries and Stored Procedure calls - Support for JMS Session authentication - Improved JMS endpoint naming scheme - Added durableSubscriber and ClientID to JMS Request Inspector - Added fetchSize property to JDBC TestStep - Fixed inlining of attachments if inline files is enabled - Improved Delay TestStep execution timing - Fixed automatic GC to run for command-line tools also - Fixed elapsed time to show correct value in LoadTest output - Fixed synchronization of Table Inspector and XML Editor Views - Added JDBC Assertions - Added build-checksum to nightly builds - Improved session-handling for AMF Requests - Added soapui.scripting.library system property to override script library path from commandline - Added possibility to override Jetty Connector properties via soapui.mock.connector.XX system properties - Fixed bugs related to REST parameter reordering and inheritance
Final Release fixes: - Fixed times precision in Junit reports to be up to 3 decimals - Updated IDW dependency to 1.6.1 - Updated Groovy to 1.7.1 - Update JasperReports to 3.7.1 - Fixed TestStepResults for WSS processed requests to contain the unprocessed request in the requestContent property - Addes ResponseAsXml properties to JDBC and AMF TestSteps - Fixed TIBCO EMS support - Removed a bunch of memory-leaks - Fixed LoadTest Reports for LoadTests with long names - Introduced soapui.mtom.strict system property for enabling strict MTOM processing - Fixed command-line TestCase runners to not ignore Fail on Abort setting - Fixed restore of ignoreNamespacePrefixes in XPath assertions - Fixed success indicator of MockResponse TestSteps - Added uninstall of Hermes to Uninstaller - Fixed endpoint in SOAP Monitor tunnel mode - Improved command-line scripts on linux / mac - Added page in mac/linux installers to disable JXBrowser component - Fixed Script Assertion editor to update on OK and added Cancel button - Added JMS Message Selector field to JMS properties Inspector
2009-08-09 : 3.0.1 release
bug-fixes galore! and a bunch of improvements :-)
Who can we thank more than our customers and users? no-one! Thank you all!
/eviware-soapui-team
2009-07-06 : 3.0 final release
Please check out for all the details on this release!
/eviware-soapui-team
2008-11-18 : 2.5 Final
A bunch of bug-fixes and minor improvements, thanks to our awesome customers and community for testing and reporting... we owe you another great release!
/eviware-soapui-team
2008-11-05 : 2.5 beta2 release thanks to all our great customers and community!
Thanks to all of you!
2008-09-26 : 2.5-beta1 release!
Finally a new version! - REST/HTTP Support - WADL import / export / generation - JSON/HTML to XML conversion for assertions, transfers, etc.. - REST / HTTP Request TestStep - Generate both code and documentation for WADLs - WS-Addressing support - Request, MockResponse, Assertion - MockService improvements - onRequest / afterRequest scripts - improved WSDL exposure with ?WSDL endpoint - docroot for serving static content - HEAD request support - Encrypted Project Files and hidden password fields - LoadTest before/afterRun scripts - Import/Export TestCases/TestSuites for sharing - Relative paths to project resources - Improved SOAP Monitor now supports keep-alive and chunked encoding - Dump-File for response message automatically saves responses to a local file - Unique keystores on request-level - Improved XPath Contains Assertion with option to ignore namespace prefixes - Improved compression algorithm support - Extended HTTP-related settings - ..
Backup your existing projects before testing and please don't hesitate to contact us if you have any issues, suggestions, complaints, etc!
2008-01-28 : 2.0.2 bug-fix release..
As always thanks to you all reporting for making SoapUI better and better!
2008-01-15 : 2.0.1 bug-fix release..
SoapUI Pro
- Fixed generation of indexed XPath expressions
- Fixed refactoring issues with namespaces and multiple updates
- Improved WSDL Coverage:
- Added possibility to exclude elements from coverage calculation
- Fixed handling of empty elements
- Moved settings to be at project-level
- Added option to skip to closing DataSource Loop when no data is available in a DataSource
TestStep
- Improved import/export of requirements to include testcases and links - etc..
2007-12-12 : 2.0 final release!
A bunch of minor improvements and a large number of bug-fixes made it into the final release - thanks to all who have reported, tested and helped us out!
2007-12-02 : 2.0 beta2 release!
Overhauled WS-Security support and many minor improvements; - WS-Security support has been greatly enhanced and is now managed at Project-level for application to Requests, MockServices/Responses and SOAP Monitors - Raw message viewer for viewing actual data sent/received - Aut Request inspector for editing authentication-related settings - Interface Viewer has been extended with new Overview, Endpoints and WS-I Compliance tabs - LoadTests can now continuously export statistics for post-processing - Improved Message-Inspector for logged messages - TestRun Log has been visually improved
2007-11-14 : 2.0 beta1 Release!
This is the first beta of SoapUI 2.0, boasting a large number of new features. Please backup your existing project-files before testing and report any issues at the sourceforge forums.
2007-09-26 : 1.7.6 Release!
The intermediary 1.7.6 release focuses on general functionality and many UI improvements
Improvements: Default authentication settings on endpoint level XQuery support in assertions and property-transfers Dialogs for launching command-line runners Apache CXF wsdl2java integration Regular expression support in Contains/NotContains assertions Improved editors with line-numbers, find-and-replace, etc.. Greatly improved project/workspace management including support for open/closed projects Support for remote projects over http(s) Improved/laxed up MTOM functionality Global/System-property access in property-expansions Very preliminary and inital extension API And a large number of UI improvements and minor adjustements
Bug-Fixes: Much-improved support for one-way operations Property Expansion is now supported in Conditional Goto Steps XPath Fixed save of empty properties in Properties Step Fixed URL decoding of WSDL port locations Fixed correct setting of SOAPAction / Content-Type headers for SOAP 1.2 Mockservice fault with http response code 500 Generate TestSuite does not use existing Requests OutOfMemory error when creating backup requests
As always we are grateful to our enthusiastic users! You Rock!
2007-08-06 : 1.7.5 Final!
The final release of SoapUI 1.7.5 adds a small number of features and fixes a number of bugs:
Improvements: Action to change the operation of a TestRequest. Improved MockService log with own toolbar and options to set size and clear. Possibility to set the local address both globally and on a request level. Option to pretty-print project files for easier SCM integration. Added requestContext variable to MockOperation-dispatch scripts allowing for thread-safe passing of values from dispatch script to response script Added option to enable interactive utilities when running from command-line.
Bug-Fixes: Fixed UpdateInterface to not set all TestRequests to same operation Fixed cloning of Assertions to be persistant Fixed Memory-Leaks in MockService Log Fixed Display of correct Response Message Size Fixed Dependencies for Eclipse Plugin Fixed PropertyExpansion to support xpath expansion also for Context Properties Fixed Form Editor to not pretty-print message and correctly hande nillable values (SoapUI Pro) Fixed initializing of external libraries to be before intializing of Groovy Script Library when running any of the command-line runners (SoapUI Pro) Fixed XPath creation when nodes exist with same name at different positions in hierarchy etc..
2007-07-11 : 1.7.5 beta2
Bug-Fixes: Fixed move TestCase up/down with keyboard Fixed validation mocking of RPC operation requests with attachments Fixed Termination of CommandLine TestRunners Fixed null column values in JDBC DataSource results to be replaced with empty string Fixed spawning of HTML Reports to use default system browser on Windows Fixed stripping of whitespaces to also remove comments Fixed attachments tab title update for mock responses Fixed skipping of projects with running tests when auto-saving Fixed form-editor to insert xsi:nil="true" on empty nillable fields etc..
As always, a huge Thank You to our community, and please don't hesitate to report any issues, etc...
2007-07-02 : 1.7.5 beta1
SoapUI 1.7.5 is another intermediate version which addresses a large number of community feature requests and stability issues.
Major improvements in SoapUI 1.7.5 are
Also a large number of bugs have been fixed, including MimeBinding not read correctly Bad mock operation for operation within mimeBinding Error referencing included schema types in the default ns WsdlMockResult.setRe_ponseContent HTTP headers do not get copied to TestCase Loadtest thread count has UI limit of 100 threads, SoapUI uses startinfo XOP header rather than start-info Junit Report times incorrect * and many more...
As always we owe great thanks to our users for testing and giving us feedback on bug-fixes and improvements...
2007-05-04 : 1.7.1 release
This is a bug-fix release which fixes some urgent issues in the 1.7 release
As always we owe great thanks to our users for testing and giving us feedback on bug-fixes and improvements...
2007-04-10 : 1.7 final release
Many more major and minor issues have been fixed with the last snapshot releases, see the snapshot release page for details. Since the last snapshot, the following have been fixed/added;
As always we owe great thanks to our users for testing and giving us feedback on bug-fixes and improvements...
2007-03-14 : 1.7 beta2 release
The beta2 release adds the following features above those accumulated fixes in the recent snapshot releases ()
As always our huge thanks goes out to all our users who have helped us identify and fix many of the above issues. Keep your reports coming!
2007-02-09 : 1.7 beta1 release
We are happy to release this intermediate version with several key improvements to SoapUI functionality.
As always, please make backups of your project files before testing and let us know if you have any issues!
2006-11-12 : 1.6 final release
We are extremely happy to finally release SoapUI 1.6 final which introduces a large number of fixes and many minor improvements since the beta2 release, including;
2006-09-12 : 1.6 beta 2 release
Welcome to SoapUI 1.6 beta2 which introduces a large number of fixes and many minor improvements, including; | http://sourceforge.net/projects/soapui/files/ | CC-MAIN-2015-35 | en | refinedweb |
0
Hi, I am given this assignment that should be run in Jython. The assignment says that the program consists of a Java application with a canvas and a textarea for turtle code. I need to create a Jython application that takes turtle code from the Java application, parses it with regular expressions and calls setPixel(x,y)
in the Java application to draw a rectangle. the Java program ,setPixel(x, y) is used to control the painting and getCode() to get the code entered in to the turtle code textarea. These methods are both defined in the DYPL Java class.
import Translater class Jtrans(Translater): def __init__(self): pass def actionPerformed(self, event): print("Button clicked. Got event:") self.obj.setPixel(100,10) self.obj.setPixel(101,10) self.obj.setPixel(102,10) def move(self, x,y): move(50, 90) move(100, 90) move(50, 90) move(100, 90) def put(self, x,y,a): put(150, 150, 0) for x in range(0,4): move(50, 90) end eval("self."+self.obj.getCode()+"()")#why do we need this? def setDYPL( self, obj ): print("Got a DYPL instance: ") print(obj) if __name__ == '__main__': import DYPL DYPL(Jtrans())
I also attach a zip file containing classes like Translater.class,DYPLCanvas.java etc if you need it. so does anyone know how I should start? | https://www.daniweb.com/software-development/python/threads/447560/how-to-draw-a-rectangle-in-jython | CC-MAIN-2015-35 | en | refinedweb |
I had an idea for a feature that I believe will allow more elegant multi-directory Makefiles to be written. An alternate include directive, rinclude' (for relative include) that treats all targets described in the included makefile as relative to the included path. [ Note: in this email, code samples are bracketed in <<<...>>> ] So in my main Makefile, I can have <<< foo.out: foo/bar >>> Where bar foo/bar does not exist, and is not described in the Makefile. However, I <<< rinclude foo/Makefile >>> which does describe bar, but without the `foo/'. However, since I used rinclude, all the targets (and dependencies) have `foo/' prefixed to them. Of course, there are other considerations, such as if the target/dependency is an absolute filename. Currently, this can be emulated two ways, by using recursive make: <<< rinclude = $1/%:$1/Makefile; $(MAKE) -C '$1' '$*' >>> and is used: <<< $(call rinclude,mysubdir) >>> Using this method, issues can arise with parallelization. The alternative is by using include, and prefixing all targets/dependencies with a variable that stores the current directory: <<< ifndef THISFILE THISFILE=$(CURDIR)/Makefile endif THISDIR=$(patsubst %/,%,$(dir $(THISFILE))) rinclude=$(foreach THISFILE,$(abspath $1),\ $(eval include $(THISFILE))) >>> and is used: <<< $(call rinclude,mysubdir) $(THISDIR)/all: ... >>> Which creates precisely the desired behavior, but requires you to muck up your Makefiles by prefixing everything with `$(THISDIR)/'. Further, it might be desirable to have to two implementations, one where variables in the included file get passed back to the main file, following normal include behavior; and one where they are ignored, as the recursive option above does. The benefit of separating them is that it would allow a component that was not designed with this feature in mind to be incorporated into a larger system without modification. If you think this feature would be a good addition to GNU Make, I would be willing to implement it. -- ~ LukeShu | http://lists.gnu.org/archive/html/bug-make/2011-02/msg00005.html | CC-MAIN-2015-35 | en | refinedweb |
I am a high school student doing a summer project in AI. I am not experienced in Linked Lists, and I need your help to put some values into the linked list.
I would like to make 4 linked lists (superarrays). Can I use this one function below for all 4 linked lists?
What is the headRef variable for? Does it contain the name of the linked list?
Please help me build a linked list that would seek 2nd, 3rd, 4th, and 42nd field in the following line and append each new value within that field to this field's linked list. Fields are groups of values that are between commas.
// I decided to use linked lists rather than arrays because in the array you have to know the length of the array, but I do not know how many values each field has.
Also, I am working in the linux environment and use g++ compiler (both C and C++)... but I doubt that this compiler is any different from the Turbo C++ compiler
--------------------------------------------------------------------------------------------------------
For example:
the lines are:
0,tcp,http,SF,241,259,0,0,1,0,0,etc...,0,normal.
0,tcp,smtp,SF,432,543,0,0,1,0,0,etc...,0,normal.
0,udp,ftp,SF,511,777,0,1,1,0,0,etc...,0,normal.
(the actual dataset is much longer and consists of 43 fields)
The program should put the values of second field (tcp,udp,etc...) into the linked list #2 (because the source file is huge and I dont know how many values each field has), and values of field 3 (http, smtp, ftp, etc...) into a separate linked list #3. Provided that the code for extracting these fields is known and each field is stored in char buff[50] (I am not asking you to create a whole program), can you please help me put nonnumerical fields into linked list that after going through all source file would assign different values within the same field different numbers. If for example, for field 3 http was the first value added to liked list #3, it would be assigned 1, smtp would be assigned 2, and ftp would be assigned 3, and so on depending on the order these values were extracted from the source file.
Below is the function that would append new fields to the linked list. And below that, there is a complete code of the program that extracts nonnumerical fields from the source file.
================================================== ======================
Function for appending new values to the linked lists.
--------------------------------------------------------------------------------------------------------------
================================================== ============================================================== ============Code:
struct node* AppendNode(struct node** headRef, char var[50]) {
struct node* current = *headRef;
struct node* newNode;
newNode = malloc(sizeof(struct node));
newNode->data = var;
newNode->next = NULL;
// special case for length 0
if (current == NULL) {
*headRef = newNode;
}
else {
// Locate the last node
while (current->next != NULL) {
current = current->next;
}
current->next = newNode;
}
}
The actual code of field seeking program
-------------------------------------------------------
----------------------------------------------------------------------------------Code:
#include <string.h>
#include<iostream.h>
#include<fstream.h>
#include<ctype.h>
int main()
{
const long BUFF_SIZE = 1000000;
int a, b, c;
ifstream infile;
ofstream outfile;
char buff[BUFF_SIZE];
char outbuff[BUFF_SIZE];
char output[50][50]; // using an array of char arrays.
// open the files
infile.open("data.txt");
outfile.open("output.txt");
// make sure the files are open
if(!infile.is_open()){
cerr << "error opening input file";
return 1;
}
if(!outfile.is_open()){
cerr << "error opening output file";
return 1;
}
// loop until the end of the input file
for(a=0; !infile.eof(){
// read in one line
infile.get(buff, BUFF_SIZE, '.');
infile.ignore(1);
// loop through each char in the current line
for(b=c=0; buff[b]; ++b){
// eat whitespace
while(buff[b] == ' ')
++b;
// ignore numbers and commas in the input
// copy everything else to the output buffer.
if(!isdigit(buff[b]) && buff[b] != ','){
outbuff[c++] = buff[b];
}
// when we come to a comma or the end of the input buffer
// AND there is something in the output buffer,
// move contents of output buffer to the next array in the output 2D array.
// print the output to the screen and the output file
if((buff[b] == ',' !buff[b+1]) && strlen(outbuff) > 0){
outbuff[c] = '\0';
strcpy(output[a], outbuff);
cout << output[a] << endl;
outfile << output[a] << endl;
// increment the end output array counter
++a;
// start the output buffer counter again
c = 0;
// reset the output buffer
outbuff[0] = '\0';
}
}
}
// close the files
infile.close();
outfile.close();
// pause so you can see the output on the screen
cout << " **** All done! ****\n";
cin.get();
return 0;
}
Thanks alot! =),
:) | http://cboard.cprogramming.com/cplusplus-programming/22947-how-use-linked-list-printable-thread.html | CC-MAIN-2015-35 | en | refinedweb |
Type: Posts; User: emmanuel1400
I wrote the following code:
columnaProducto = new CType(dataGridViewDetalle.Columns[0], new DataGridViewComboBoxColumn());
The type or namespace name 'CType' could not be found (are you missing...
Hi... is this code functional in C#? Hope someone can help me, I've been google-ing for over a week... I will try to addapt the code to C# and I'll let you know if it works. | http://forums.codeguru.com/search.php?s=40d1357b50f817e79c9d6860c9d08a68&searchid=7648371 | CC-MAIN-2015-35 | en | refinedweb |
The following module functions all construct and return iterators. Some provide streams of infinite length, so they should only be accessed by functions or loops that truncate the stream.
def chain(*iterables): # chain('ABC', 'DEF') --> A B C D E F for it in iterables: for element in it: yield element
def count(n=0): # count(10) --> 10 11 12 13 14 ... while True: yield n n += 1
Note, count() does not check for overflow and will return
negative numbers after exceeding
sys.maxint. This behavior
may change in the future.).
def dropwhile(predicate, iterable): # dropwhile(lambda x: x<5, [1,4,6,4,1]) --> 6 4 1 iterable = iter(iterable) for x in iterable: if not predicate(x): yield x break for x in iterable: yield x
None, key defaults to an identity function and returns the element unchanged. Generally, the iterable needs to already be sorted on the same key function. = xrange(0) def __iter__(self): return self def next(self): while self.currkey == self.tgtkey: self.currvalue = self.it.next() # = self.it.next() # Exit on StopIteration self.currkey = self.keyfunc(self.currvalue) =.
Note, the left-to-right evaluation order of the iterables is guaranteed. This makes possible an idiom for clustering a data series into n-length groups using "izip(*[iter(s)]*n)". For data that doesn't fit n-length groups exactly, the last tuple can be pre-padded with fill values using "izip(*[chain(s, [None]*(n-1))]*n)".
Note, when izip() is used with unequal length inputs, subsequent
iteration over the longer iterables cannot reliably be continued after
izip() terminates. Potentially, up to one entry will be missing
from each of the left-over iterables. This occurs because a value is fetched
from each iterator in-turn, but the process ends when one of the iterators
terminates. This leaves the last fetched values in limbo (they cannot be
returned in a final, incomplete tuple and they are cannot be pushed back
into the iterator for retrieval with
it.next()). In general,
izip() should only be used with unequal length inputs when you
don't care about trailing, unmatched values from the longer iterables.
def repeat(object, times=None): # repeat(10, 3) --> 10 10 10 if times is None: while True: yield object else: for i in xrange(times): yield object
function(a,b)and
function(*c). Equivalent to:
def starmap(function, iterable): # starmap(pow, [(2,5), (3,2), (10,3)]) --> 32 9 1000 iterable = iter(iterable) while True: yield function(*iterable.next())
def takewhile(predicate, iterable): # takewhile(lambda x: x<5, [1,4,6,4,1]) --> 1 4 for x in iterable: if predicate(x): yield x else: break
n==2is equivalent to:
def tee(iterable): def gen(next, data={}, cnt=[0]): for i in count(): if i == cnt[0]: item = data[i] = next() cnt[0] += 1 else: item = data.pop(i) yield item.
See About this document... for information on suggesting changes.See About this document... for information on suggesting changes. | http://wingware.com/psupport/python-manual/2.5/lib/itertools-functions.html | CC-MAIN-2015-35 | en | refinedweb |
A specialized TFileCacheRead object for a TTree.
This class acts as a file cache, registering automatically the baskets from the branches being processed (TTree::Draw or TTree::Process and TSelectors) when in the learning phase. The learning phase is by default 100 entries. It can be changed via TTreeCache::SetLearnEntries.
This cache speeds-up considerably the performance, in particular when the Tree is accessed remotely via a high latency network.
The default cache size (10 Mbytes) may be changed via the function TTree::SetCacheSize
Only the baskets for the requested entry range are put in the cache
For each Tree being processed a TTreeCache object is created. This object is automatically deleted when the Tree is deleted or when the file is deleted.
The learning period is started or restarted when:
The learning period is stopped (and prefetching is actually started) when:
Further, the TreeCache can optimize its behavior on a cache miss. When miss optimization is enabled, it will track all branches utilized after the learning phase (those that cause a cache miss). When one cache miss occurs, then all the utilized branches will be prefetched for that event. This optimization utilizes the observation that infrequently accessed branches are often accessed together. For example, this will greatly speed up an analysis where the results of a trigger are read out for every branch, but the majority of event collections are read only when the trigger results pass a set of filters. NOTE - when this mode is enabled, the memory dedicated to the cache will up to double in the case of cache miss. Additionally, on the first miss of an event, we must iterate through all the "active branches" for the miss cache and find the correct basket. This can be potentially a CPU-expensive operation compared to, e.g., the latency of a SSD. This is why the miss cache is currently disabled by default. transferring take advantage of the TreeCache in reading ahead as much data as they can and return to the application the maximum data specified in the cache and have the next chunk of data ready when the next request comes.
A few use cases are discussed below. A cache may be created with automatic sizing when a TTree is used:
Caches are created and automatically sized for TTrees when TTreeCache.Size or the environment variable ROOT_TTREECACHE_SIZE is set to a sizing factor.
But there are many possible configurations where manual control may be wanted.
//<<<
the TreeCache is automatically used by TTree::Draw. The function knows which branches are used in the query and it puts automatically these branches in the cache. The entry range is also known automatically.
in the Process function we read a subset of the branches. Only the branches used in the first entry will be put in the cache
in your analysis loop, you always use 2 branches. You want to prefetch the branch buffers for these 2 branches only..
When reading only a small fraction of all entries such that not all branch buffers are read, it might be faster to run without a cache.
Once your analysis loop has terminated, you can access/print the number of effective system reads for a given file with a code like (where TFile* f is a pointer to your file)
Definition at line 35 of file TTreeCache.h.
#include <TTreeCache.h>
Definition at line 38 of file TTreeCache.h.
this class cannot be copied
Default Constructor.
Definition at line 271 of file TTreeCache.cxx.
Constructor.
Definition at line 278 of file TTreeCache.cxx.
Destructor. (in general called by the TFile destructor)
Definition at line 290 of file TTreeCache.cxx.
Add a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket Returns:
Reimplemented from TFileCacheRead.
Reimplemented in TTreeCacheUnzip.
Definition at line 307 of file TTreeCache.cxx.
Add:
Reimplemented from TFileCacheRead.
Reimplemented in TTreeCacheUnzip.
Definition at line 387 of file TTreeCache.cxx.
Calculate the appropriate miss cache to fetch; helper function for FillMissCache.
Given an file read, try to determine the corresponding branch.
Given a particular IO description (offset / length) representing a 'miss' of the TTreeCache's primary cache, calculate all the corresponding IO that should be performed.
all indicates that this function should search the set of all branches in this TTree. When set to false, we only search through branches that have previously incurred a miss.
Returns:
Definition at line 731 of file TTreeCache.cxx.
Check the miss cache for a particular buffer, fetching if deemed necessary.
Given an IO operation (pos, len) that was a cache miss in the primary TTC, try the operation again with the miss cache.
Returns true if the IO operation was successful and the contents of buf were populated with the requested data.
Definition at line 862 of file TTreeCache.cxx.
Definition at line 137 of file TTreeCache.h.
Remove a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket.
Returns:
Definition at line 482 of file TTreeCache.cxx.
Remove:
Definition at line 527 of file TTreeCache.cxx.
Definition at line 138 of file TTreeCache.h.
Fill the cache buffer with the branches in the cache.
Reimplemented in TTreeCacheUnzip.
Definition at line 1055 of file TTreeCache.cxx.
Fill the miss cache from the current set of active branches.
Given a branch and an entry, determine the file location (offset / size) of the corresponding basket.
For the event currently being fetched into the miss cache, find the IO (offset / length tuple) to pull in the current basket for a given branch.
Returns:
Definition at line 657 of file TTreeCache.cxx.
Definition at line 140 of file TTreeCache.h.
Return the desired prefill type from the environment or resource variable.
Definition at line 1730 of file TTreeCache.cxx.
Give the total efficiency of the primary cache...
defined as the ratio of blocks found in the cache vs. the number of blocks prefetched ( it could be more than 1 if we read the same block from the cache more than once )
Note: This should eb used at the end of the processing or we will get incomplete stats
Definition at line 1753 of file TTreeCache.cxx.
This will indicate a sort of relative efficiency...
a ratio of the reads found in the cache to the number of reads so far
Definition at line 1777 of file TTreeCache.cxx.
Definition at line 145 of file TTreeCache.h.
Definition at line 144 of file TTreeCache.h.
Static function returning the number of entries used to train the cache see SetLearnEntries.
Definition at line 1802 of file TTreeCache.cxx.
Definition at line 147 of file TTreeCache.h.
The total efficiency of the 'miss cache' - defined as the ratio of blocks found in the cache versus the number of blocks prefetched.
Definition at line 1765 of file TTreeCache.cxx.
Relative efficiency of the 'miss cache' - ratio of the reads found in cache to the number of reads so far.
Definition at line 1789 of file TTreeCache.cxx.
Definition at line 139 of file TTreeCache.h.
Definition at line 150 of file TTreeCache.h.
Definition at line 151 of file TTreeCache.h.
Definition at line 152 of file TTreeCache.h.
Reimplemented from TFileCacheRead.
Definition at line 153 of file TTreeCache.h.
Perform an initial prefetch, attempting to read as much of the learning phase baskets for all branches at once.
Definition at line 2165 of file TTreeCache.cxx.
Print cache statistics.
Like:
Reimplemented from TFileCacheRead.
Reimplemented in TTreeCacheUnzip.
Definition at line 1827 of file TTreeCache.cxx.
! Given a file read not in the miss cache, handle (possibly) loading the data.
Process a cache miss; (pos, len) isn't in the buffer.
The first time we have a miss, we buffer as many baskets we can (up to the maximum size of the TTreeCache) in memory from all branches that are not in the prefetch list.
Subsequent times, we fetch all the buffers corresponding to branches that had previously seen misses. If it turns out the (pos, len) isn't in the list of branches, we treat this as if it was the first miss.
Returns true if we were able to pull the data into the miss cache.
Definition at line 804 of file TTreeCache.cxx.
Read buffer at position pos if the request is in the list of prefetched blocks read from fBuffer.
Otherwise try to fill the cache from the list of selected branches, and recheck if pos is now in the list. Returns:
Reimplemented from TFileCacheRead.
Definition at line 1955 of file TTreeCache.cxx.
Old method ReadBuffer before the addition of the prefetch mechanism.
Definition at line 1855 of file TTreeCache.cxx.
Used to read a chunk from a block previously fetched.
It will call FillBuffer even if the cache lookup succeeds, because it will try to prefetch the next block as soon as we start reading from the current block.
Definition at line 1914 of file TTreeCache.cxx.
This will simply clear the cache.
Reimplemented in TTreeCacheUnzip.
Definition at line 1968 of file TTreeCache.cxx.
Reset all the miss cache training.
The contents of the miss cache will be emptied as well as the list of branches used.
Definition at line 638 of file TTreeCache.cxx.
Definition at line 164 of file TTreeCache.h.
Change the underlying buffer size of the cache.
If the change of size means some cache content is lost, or if the buffer is now larger, setup for a cache refill the next time there is a read Returns:
Reimplemented from TFileCacheRead.
Reimplemented in TTreeCacheUnzip.
Definition at line 1987 of file TTreeCache.cxx.
Set the minimum and maximum entry number to be processed this information helps to optimize the number of baskets to read when prefetching the branch buffers.
Reimplemented in TTreeCacheUnzip.
Definition at line 2020 of file TTreeCache.cxx.
Overload to make sure that the object specific.
Reimplemented from TFileCacheRead.
Definition at line 2042 of file TTreeCache.cxx.
Static function to set the number of entries to be used in learning mode The default value for n is 10.
n must be >= 1
Definition at line 2059 of file TTreeCache.cxx.
Set whether the learning period is started with a prefilling of the cache and which type of prefilling is used.
The two value currently supported are:
Definition at line 2074 of file TTreeCache.cxx.
Start of methods for the miss cache.
Enable / disable the miss cache.
The first time this is called on a TTreeCache object, the corresponding data structures will be allocated. Subsequent enable / disables will simply turn the functionality on/off.
Definition at line 624 of file TTreeCache.cxx.
The name should be enough to explain the method.
The only additional comments is that the cache is cleaned before the new learning phase.
Definition at line 2084 of file TTreeCache.cxx.
This is the counterpart of StartLearningPhase() and can be used to stop the learning phase.
It's useful when the user knows exactly what branches they are going to use. For the moment it's just a call to FillBuffer() since that method will create the buffer lists from the specified branches.
Reimplemented in TTreeCacheUnzip.
Definition at line 2101 of file TTreeCache.cxx.
Update pointer to current Tree and recompute pointers to the branches in the cache.
Reimplemented in TTreeCacheUnzip.
Definition at line 2125 of file TTreeCache.cxx.
! true if cache was automatically created
Definition at line 69 of file TTreeCache.h.
! List of branches to be stored in the cache
Definition at line 54 of file TTreeCache.h.
! list of branch names in the cache
Definition at line 55 of file TTreeCache.h.
! Start of the cluster(s) where the current content was picked out
Definition at line 45 of file TTreeCache.h.
! cache enabled for cached reading
Definition at line 66 of file TTreeCache.h.
! current lowest entry number in the cache
Definition at line 43 of file TTreeCache.h.
! last entry in the cache
Definition at line 42 of file TTreeCache.h.
! first entry in the cache
Definition at line 41 of file TTreeCache.h.
! next entry number where cache must be filled
Definition at line 44 of file TTreeCache.h.
! how many times we can fill the current buffer
Definition at line 62 of file TTreeCache.h.
! true if first buffer is used for prefetching
Definition at line 59 of file TTreeCache.h.
! save the value of the first entry
Definition at line 64 of file TTreeCache.h.
! set to the event # of the first miss.
Definition at line 74 of file TTreeCache.h.
! save the fact that we processes the first entry
Definition at line 63 of file TTreeCache.h.
number of entries used for learning mode
Definition at line 68 of file TTreeCache.h.
! true if cache is in learning mode
Definition at line 57 of file TTreeCache.h.
! true if cache is StopLearningPhase was used
Definition at line 58 of file TTreeCache.h.
! set to the event # of the last miss.
Definition at line 75 of file TTreeCache.h.
! Cache contents for misses
Definition at line 106 of file TTreeCache.h.
! Number of branches in the cache
Definition at line 47 of file TTreeCache.h.
! End+1 of the cluster(s) where the current content was picked out
Definition at line 46 of file TTreeCache.h.
Number of blocks read and not found in either cache.
Definition at line 51 of file TTreeCache.h.
Number of blocks read, not found in the primary cache, and found in the secondary cache.
Definition at line 49 of file TTreeCache.h.
Number of blocks read into the secondary ("miss") cache.
Definition at line 53 of file TTreeCache.h.
Number of blocks read and not found in the cache.
Definition at line 50 of file TTreeCache.h.
Number of blocks read and found in the cache.
Definition at line 48 of file TTreeCache.h.
Number of blocks that were prefetched.
Definition at line 52 of file TTreeCache.h.
! used in the learning phase
Definition at line 60 of file TTreeCache.h.
! true if we should optimize cache misses.
Definition at line 73 of file TTreeCache.h.
Whether a pre-filling is enabled (and if applicable which type)
Definition at line 67 of file TTreeCache.h.
! read direction established
Definition at line 65 of file TTreeCache.h.
! reading in reverse mode
Definition at line 61 of file TTreeCache.h.
! pointer to the current Tree
Definition at line 56 of file TTreeCache.h. | https://root.cern.ch/doc/v614/classTTreeCache.html | CC-MAIN-2022-21 | en | refinedweb |
Integrating data using ingest and BBKNN¶
The following tutorial describes a simple PCA-based method for integrating data we call ingest and compares it with BBKNN [Polanski19]. BBKNN integrates well with the Scanpy workflow and is accessible through the bbknn function.
The ingest function assumes an annotated reference dataset that captures the biological variability of interest. The rational is to fit a model on the reference data and use it to project new data. For the time being, this model is a PCA combined with a neighbor lookup search tree, for which we use UMAP’s implementation [McInnes18]. Similar PCA-based integrations have been used before, for instance, in [Weinreb18].
- As ingest is simple and the procedure clear, the workflow is transparent and fast.
- Like BBKNN, ingest leaves the data matrix itself invariant.
- Unlike BBKNN, ingest solves the label mapping problem (like scmap) and maintains an embedding that might have desired properties like specific clusters or trajectories.
We refer to this asymmetric dataset integration as ingesting annotations from an annotated reference
adata_ref into an
adata that still lacks this annotation. It is different from learning a joint representation that integrates datasets in a symmetric way as BBKNN, Scanorma, Conos, CCA (e.g. in Seurat) or a conditional VAE (e.g. in scVI, trVAE) would do, but comparable to the initiall MNN implementation in scran. Take a look at tools in the
external API or at the ecoystem page to get a start with other tools.
[1]:
import scanpy as sc import pandas as pd import seaborn as sns
[2]:
sc.settings.verbosity = 1 # verbosity: errors (0), warnings (1), info (2), hints (3) sc.logging.print_versions() sc.settings.set_figure_params(dpi=80, frameon=False, figsize=(3, 3))
scanpy==1.4.5.dev225+gcf4cdab anndata==0.7rc2.dev9+g5928e64 umap==0.3.8 numpy==1.16.3 scipy==1.3.0 pandas==0.25.3 scikit-learn==0.22 statsmodels==0.10.0 python-igraph==0.7.1 louvain==0.6.1
PBMCs¶
We consider an annotated reference dataset
adata_ref and a dataset for which you want to query labels and embeddings
adata.
[3]:
adata_ref = sc.datasets.pbmc3k_processed() # this is an earlier version of the dataset from the pbmc3k tutorial adata = sc.datasets.pbmc68k_reduced()
To use
sc.tl.ingest, the datasets need to be defined on the same variables.
[4]:
var_names = adata_ref.var_names.intersection(adata.var_names) adata_ref = adata_ref[:, var_names] adata = adata[:, var_names]
The model and graph (here PCA, neighbors, UMAP) trained on the reference data will explain the biological variation observed within it.
[5]:
sc.pp.pca(adata_ref) sc.pp.neighbors(adata_ref) sc.tl.umap(adata_ref)
The manifold still looks essentially the same as in the clustering tutorial.
[6]:
sc.pl.umap(adata_ref, color='louvain')
Mapping PBMCs using ingest¶
Let’s map labels and embeddings from
adata_ref to
adata based on a chosen representation. Here, we use
adata_ref.obsm['X_pca'] to map cluster labels and the UMAP coordinates.
[7]:
sc.tl.ingest(adata, adata_ref, obs='louvain')
[8]:
adata.uns['louvain_colors'] = adata_ref.uns['louvain_colors'] # fix colors
[9]:
sc.pl.umap(adata, color=['louvain', 'bulk_labels'], wspace=0.5)
By comparing the ‘bulk_labels’ annotation with ‘louvain’, we see that the data has been reasonably mapped, only the annotation of dendritic cells seems ambiguous and might have been ambiiguous in
adata already.
[10]:
adata_concat = adata_ref.concatenate(adata, batch_categories=['ref', 'new'])
[11]:
adata_concat.obs.louvain = adata_concat.obs.louvain.astype('category') adata_concat.obs.louvain.cat.reorder_categories(adata_ref.obs.louvain.cat.categories, inplace=True) # fix category ordering adata_concat.uns['louvain_colors'] = adata_ref.uns['louvain_colors'] # fix category colors
[12]:
sc.pl.umap(adata_concat, color=['batch', 'louvain'])
While there seems to be some batch-effect in the monocytes and dendritic cell clusters, the new data is otherwise mapped relatively homogeneously.
The megakaryoctes are only present in
adata_ref and no cells from
adata map onto them. If interchanging reference data and query data, Megakaryocytes do not appear as a separate cluster anymore. This is an extreme case as the reference data is very small; but one should always question if the reference data contain enough biological variation to meaningfully accomodate query data.
Using BBKNN¶
[13]:
sc.tl.pca(adata_concat)
[14]:
%%time sc.external.pp.bbknn(adata_concat, batch_key='batch') # running bbknn 1.3.6
CPU times: user 3.96 s, sys: 520 ms, total: 4.48 s Wall time: 3.67 s
[15]:
sc.tl.umap(adata_concat)
[16]:
sc.pl.umap(adata_concat, color=['batch', 'louvain'])
Also BBKNN doesn’t maintain the Megakaryocytes cluster. However, it seems to mix cells more homogeneously.
Pancreas¶
The following data has been used in the scGen paper [Lotfollahi19], has been used here, was curated here and can be downloaded from here (the BBKNN paper).
It contains data for human pancreas from 4 different studies (Segerstolpe16, Baron16, Wang16, Muraro16), which have been used in the seminal papers on single-cell dataset integration (Butler18, Haghverdi18) and many times ever since.
[17]:
# note that this collection of batches is already intersected on the genes adata_all = sc.read('data/pancreas.h5ad', backup_url='
[18]:
adata_all.shape
[18]:
(14693, 2448)
Inspect the cell types observed in these studies.
[19]:
counts = adata_all.obs.celltype.value_counts() counts
[19]:
alpha 4214 beta 3354 ductal 1804 acinar 1368 not applicable 1154 delta 917 gamma 571 endothelial 289 activated_stellate 284 dropped 178 quiescent_stellate 173 mesenchymal 80 macrophage 55 PSC 54 unclassified endocrine 41 co-expression 39 mast 32 epsilon 28 mesenchyme 27 schwann 13 t_cell 7 MHC class II 5 unclear 4 unclassified 2 Name: celltype, dtype: int64
To simplify visualization, let’s remove the 5 minority classes.
[20]:
minority_classes = counts.index[-5:].tolist() # get the minority classes adata_all = adata_all[ # actually subset ~adata_all.obs.celltype.isin(minority_classes)] adata_all.obs.celltype.cat.reorder_categories( # reorder according to abundance counts.index[:-5].tolist(), inplace=True)
Seeing the batch effect¶
[21]:
sc.pp.pca(adata_all) sc.pp.neighbors(adata_all) sc.tl.umap(adata_all)
We observe a batch effect.
[22]:
sc.pl.umap(adata_all, color=['batch', 'celltype'], palette=sc.pl.palettes.vega_20_scanpy)
BBKNN¶
It can be well-resolved using BBKNN [Polanski19].
[23]:
%%time sc.external.pp.bbknn(adata_all, batch_key='batch')
CPU times: user 2.11 s, sys: 1.53 s, total: 3.63 s Wall time: 2.28 s
[24]:
sc.tl.umap(adata_all)
[25]:
sc.pl.umap(adata_all, color=['batch', 'celltype'])
If one prefers to work more iteratively starting from one reference dataset, one can use ingest.
Mapping onto a reference batch using ingest¶
Choose one reference batch for training the model and setting up the neighborhood graph (here, a PCA) and separate out all other batches.
As before, the model trained on the reference batch will explain the biological variation observed within it.
[26]:
adata_ref = adata_all[adata_all.obs.batch == '0']
Compute the PCA, neighbors and UMAP on the reference data.
[27]:
sc.pp.pca(adata_ref) sc.pp.neighbors(adata_ref) sc.tl.umap(adata_ref)
The reference batch contains 12 of the 19 cell types across all batches.
[28]:
sc.pl.umap(adata_ref, color='celltype')
Iteratively map labels (such as ‘celltype’) and embeddings (such as ‘X_pca’ and ‘X_umap’) from the reference data onto the query batches.
[29]:
adatas = [adata_all[adata_all.obs.batch == i].copy() for i in ['1', '2', '3']]
[30]:
sc.settings.verbosity = 2 # a bit more logging for iadata, adata in enumerate(adatas): print(f'... integrating batch {iadata+1}') adata.obs['celltype_orig'] = adata.obs.celltype # save the original cell type sc.tl.ingest(adata, adata_ref, obs='celltype')
... integrating batch 1 running ingest finished (0:00:06) ... integrating batch 2 running ingest finished (0:00:04) ... integrating batch 3 running ingest finished (0:00:01)
Each of the query batches now carries annotation that has been contextualized with
adata_ref. By concatenating, we can view it together.
[31]:
adata_concat = adata_ref.concatenate(adatas)
[32]:
adata_concat.obs.celltype = adata_concat.obs.celltype.astype('category') adata_concat.obs.celltype.cat.reorder_categories(adata_ref.obs.celltype.cat.categories, inplace=True) # fix category ordering adata_concat.uns['celltype_colors'] = adata_ref.uns['celltype_colors'] # fix category coloring
[33]:
sc.pl.umap(adata_concat, color=['batch', 'celltype'])
Compared to the BBKNN result, this is maintained clusters in a much more pronounced fashion. If one already observed a desired continuous structure (as in the hematopoietic datasets, for instance),
ingest allows to easily maintain this structure.
Evaluating consistency¶
Let us subset the data to the query batches.
[34]:
adata_query = adata_concat[adata_concat.obs.batch.isin(['1', '2', '3'])]
The following plot is a bit hard to read, hence, move on to confusion matrices below.
[35]:
sc.pl.umap( adata_query, color=['batch', 'celltype', 'celltype_orig'], wspace=0.4)
Cell types conserved across batches¶
Let us first focus on cell types that are conserved with the reference, to simplify reading of the confusion matrix.
[36]:
obs_query = adata_query.obs conserved_categories = obs_query.celltype.cat.categories.intersection(obs_query.celltype_orig.cat.categories) # intersected categories obs_query_conserved = obs_query.loc[obs_query.celltype.isin(conserved_categories) & obs_query.celltype_orig.isin(conserved_categories)] # intersect categories obs_query_conserved.celltype.cat.remove_unused_categories(inplace=True) # remove unused categoriyes obs_query_conserved.celltype_orig.cat.remove_unused_categories(inplace=True) # remove unused categoriyes obs_query_conserved.celltype_orig.cat.reorder_categories(obs_query_conserved.celltype.cat.categories, inplace=True) # fix category ordering
[37]:
pd.crosstab(obs_query_conserved.celltype, obs_query_conserved.celltype_orig)
[37]:
Overall, the conserved cell types are also mapped as expected. The main exception are some acinar cells in the original annotation that appear as acinar cells. However, already the reference data is observed to feature a cluster of both acinar and ductal cells, which explains the discrepancy, and indicates a potential inconsistency in the initial annotation.
All cell types¶
Let us now move on to look at all cell types.
[38]:
pd.crosstab(adata_query.obs.celltype, adata_query.obs.celltype_orig)
[38]:
We observe that PSC (pancreatic stellate cells) cells are in fact just inconsistently annotated and correctly mapped on ‘activated_stellate’ cells.
Also, it’s nice to see that ‘mesenchyme’ and ‘mesenchymal’ cells both map onto the same category. However, that category is again ‘activated_stellate’ and likely incorrect.
Visualizing distributions across batches¶
Often, batches correspond to experiments that one wants to compare. Scanpy offers to convenient visualization possibilities for this.
- a density plot
- a partial visualization of a subset of categories/groups in an emnbedding
Density plot¶
[39]:
sc.tl.embedding_density(adata_concat, groupby='batch')
computing density on 'umap'
[40]:
sc.pl.embedding_density(adata_concat, groupby='batch') | https://scanpy-tutorials.readthedocs.io/en/multiomics/integrating-data-using-ingest.html | CC-MAIN-2022-21 | en | refinedweb |
FitPara-INI
The Levenberg-Marquardt iterative algorithm requires initial values to start the fitting procedure. Good parameter initialization results in fast and reliable model/data convergence. When defining a fitting function in the Function Organizer, you can assign the initial values in the Parameter Settings box, or enter an Origin C routine in the Parameter Initialization box with which the initial values can be estimated.
The NLFit in Origin provides automatic parameter initialization code for all built-in functions. For user-defined functions, you must add your own parameter initialization code. If no parameter initialization code is provided, all parameter values will be missing values when NLFit starts. In this case, you must enter "guesstimated" parameter values to start the iterative fitting process.
Note that initial parameter values estimated by parameter initial routines will be used even if different initial values are specified in Parameter Settings.
Click the button beside Parameter Settings box to bring up the Parameter Settings dialog. Then you can enter proper initial values for the parameters in the Value column of Parameters tab:
To initialize parameters by initial formula (column statistics values, label rows, .etc), you can check the Initial Formula column check box and select the desired initial formula or metadata from the fly-out menu.
The text box in Parameter Initialization contains the parameter initialization code. For built-in functions, these routines can effectively estimate parameter values prior to fitting by generating dataset-specific parameter estimates. When defining a new Origin C fitting function, you can edit the initial codes in the code builder by clicking the button.
Although there many methods to estimate the parameter initial values, in general we will transform the function and deduce the value based on the raw data. For example, we can define a fitting model, named MyFunc, as:
(This is the same function like the built-in Allometric1 function in Origin)
And then transform the equation by:
After the transformation, we will have a linear relationship between ln(y) and ln(x), and the intercept and slope is ln(a) and b respectively. Then we just need to do a simple linear fitting to get the estimated parameter values. The initial code can be:
#include <origin.h>
void _nlsfParamMyFunc(
// Fit Parameter(s):
double& a, double& b,
// Independent Dataset(s):
vector& x_data,
// Dependent Dataset(s):
vector& y_data,
// Curve(s):
Curve x_y_curve,
// Auxilary error code:
int& nErr)
{ // Beginning of editable part
sort( x_y_curve ); // Sort the curve
Dataset dx;
x_y_curve.AttachX(dx); // Attach an Dataset object to the X data
dx = ln(dx); // Set x = ln(x)
x_y_curve = ln( x_y_curve ); // Set y = ln(y)
vector coeff(2);
fitpoly(x_data, y_data, 1, coeff); // One order (simple linear) polynomial fit
a = exp( coeff[0] ); // Estimate parameter a
b = coeff[1]; // Estimate parameter b
// End of editable part
}
In the Code Builder, you just need to edit the function body. The parameters, independent variables and dependent variables are declared in the function definition. In addition, a few Origin objects are also declared: A dataset object is declared for each of the independent and dependent variables and a curve object is declared for each xy data pair:
vector& x_data;
vector& y_data;
Curve x_y_curve;
The vectors represent cached input x and y values, which should never be changed. And the curve object is a copy of the dataset curve that is comprised of an x dataset and a y dataset for which you are trying to find a best fit.
Below these declaration statements, there is an editable section; the white area; which is reserved for the initialization code. Note that the function definition follows the C syntax.
Initialization is accomplished by calling built-in functions that take a vector or a curve object as an argument. Once the initialization function is defined, you should verify that the syntax is correct. To do this, click the Compile button at the top of the workspace. This compiles the function code using the Origin C compiler. Any errors generated in the compile process are reported in the Code Builder Output window at the bottom of the workspace.
Once the initialization code has been defined and compiled, you can return to the Function Organizer interface by clicking on the Return to Dialog button at the top of the workspace.
area
Get the area under a curve.
Curve_MinMax
Get X and Y range of the Curve.
Curve_x
Get X value of Curve at specified index.
Curve_xfromY
Get interpolated/extrapolated X value of Curve at specified Y value.
Curve_y
Get Y value of Curve at specified index.
Curve_yfromX
For given Curve returns interpolated/extrapolated value of Y at specified value of X.
fitpoly
Fit a polynomial equation to a curve (or XY vector) and return the coefficients and statistical results.
fit_polyline
Fit the curve to a polyline, where n is the number of sections, and get the average value of X-coordinates of each section.
fitpoly_range
Fit a polynomial equation to a range of a curve.
find_roots
Find the points with specified height.
fwhm
Get the peak width of a curve at half the maximum Y value.
get_exponent
This functions is used to estimate y0, R0 and A in y = y0 + A*exp(R0*x).
get_interpolated_xz_yz_curves_from_3D_data
Interperate 3D data and returns smoothed xz, yz curves.
ocmath_xatasymt
Get the value of X at a vertical asymptote.
ocmath_yatasymt
Get the value of Y at a horizontal asymptote.
peak_pos
This function is used to estimate the peak's XY coordinate, peak's width, area.etc.
sort
Use a Curve object to sort a Y data set according to an X data set.
Vectorbase::GetMinMax
Get min and max values and their indices from the vector
xatasymt
xaty50
Get the interpolated value of X at the average of minimum and maximum of Y values of a curve.
xatymax
Get the value of X at the maximum Y value of a curve.
xatymin
Get the value of X at the minimum Y value of a curve.
yatasymt
Get the value of Y at a horizontal asymptote.
yatxmax
Get the value of Y at the maximum X value of a curve.
yatxmin
Get the value of Y at the minimum X value of a curve.
Sample Function
Equation
Initialization Code
int sign;
t1 = get_exponent(x_data, y_data, &y0, &A1, &sign);
t1 = t2 = -1 / t1;
A1 = A2 = sign * exp(A1) / 2;
Description
Because most of the exponential curves are similar, we can use a simple exponential function to approach complex equations. This EXPDEC2 function can be treated as the combination of two basic exponential function, whose parameters comes from get_exponent.
xc = peak_pos(x_y_curve, &w, &y0, NULL, &A);
A *= 1.57*w;
Description
In this initialization code, we firstly evaluate the peak width , baseline value , peak center and peak height, which is originally assign to the variable , by the peak_pos function. And then compute the peak area, A, by the following deduction:
Let is the value where , then we have:
and
Where H is the peak height.
sort(x_y_curve);
A1 = min( y_data );
A2 = max( y_data );
LOGx0 = xaty50( x_y_curve );
double xmin, xmax;
x_data.GetMinMax(xmin, xmax);
double range = xmax - xmin;
if ( yatxmax(x_y_curve) - yatxmin(x_y_curve) > 0)
p = 5.0 / range;
else
p = -5.0 / range;
Description
Knowing the parameter meanings is very helpful and important for parameter initialization. In the does-response reaction, A1 and A2 means the bottom and top asymptote respectively, so we can initialize them by the minimum and maximum Y values. The parameter LOGx0 in the reaction is a typical value that 50% reaction happens, that's why we use the xaty50 function here. Regards to the slope, p, it doesn't matter how you compute this value, however, the sign of the slope is important.
Curve x_curve, y_curve;
bool bRes = get_interpolated_xz_yz_curves_from_3D_data(x_curve, y_curve, x_data, y_data, z_data, true);
if(!bRes) return;
xc = peak_pos(x_curve, &w1, &z0, NULL, &A);
yc = peak_pos(y_curve, &w2);
Description
One idea for evaluating surface function initial values is solving the problem in a plane. Take this Gauss2D function as example, it's quite obviously that the maximum Z value is on the point (xc, yc), so we can use the get_interpolated_xz_yz_curves_from_3D_data function to get the characteristic curve on XZ and YZ plane. And then use the peak_pos function to evaluate the other peak attributes, like peak width, peak height, etc. | http://cloud.originlab.com/doc/en/Origin-Help/FitPara-INI | CC-MAIN-2022-21 | en | refinedweb |
One of the benefits of adopting a message-based design is being able to easily layer functionality and generically add value to all Services, we've seen this recently with Auto Batched Requests which automatically enables each Service to be batched and executed in a single HTTP Request. Similarly the new Encrypted Messaging feature enables a secure channel for all Services (inc Auto Batched Requests 😃 offering protection to clients who can now easily send and receive encrypted messages over unsecured HTTP!
Encrypted Messaging Overview
Configuration
Encrypted Messaging support is enabled by registering the plugin:
Plugins.Add(new EncryptedMessagesFeature { PrivateKeyXml = ServerRsaPrivateKeyXml });
Where
PrivateKeyXml is the Servers RSA Private Key Serialized as XML.
Generate a new Private Key
If you don't have an existing one, a new one can be generated with:
var rsaKeyPair = RsaUtils.CreatePublicAndPrivateKeyPair(); string ServerRsaPrivateKeyXml = rsaKeyPair.PrivateKey;
Once generated, it's important the Private Key is kept confidential as anyone with access will be able to decrypt the encrypted messages! Whilst most obfuscation efforts are ultimately futile the goal should be to contain the private key to your running Web Application, limiting access as much as possible.
Once registered, the EncryptedMessagesFeature enables the 2 Services below:
GetPublicKey- Returns the Serialized XML of your Public Key (extracted from the configured Private Key)
EncryptedMessage- The Request DTO which encapsulates all encrypted Requests (can't be called directly)
Giving Clients the Public Key
To communicate clients need access to the Server's Public Key, it doesn't matter who has accessed the Public Key only that clients use the real Servers Public Key. It's therefore not advisable to download the Public Key over unsecure
where traffic can potentially be intercepted and the key spoofed, subjecting them to a Man-in-the-middle attack.
It's safer instead to download the public key over a trusted
url where the servers origin is verified by a trusted CA. Sharing the Public Key over Dropbox, Google Drive, OneDrive or other encrypted channels are also good options.
Since
GetPublicKey is just a ServiceStack Service it's easily downloadable using a Service Client:
var client = new JsonServiceClient(BaseUrl); string publicKeyXml = client.Get(new GetPublicKey());
If the registered
EncryptedMessagesFeature.PublicKeyPath has been changed from its default
/publickey, it can be dowloaded with:
string publicKeyXml = client.Get<string>("/my-publickey"); //or with HttpUtils string publicKeyXml = BaseUrl.CombineWith("/my-publickey").GetStringFromUrl();
INFO
To help with verification the SHA256 Hash of the PublicKey is returned in
X-PublicKey-Hash HTTP Header
Encrypted Service Client
Once they have the Server's Public Key, clients can use it to get an
EncryptedServiceClient via the
GetEncryptedClient() extension method on
JsonServiceClient or new
JsonHttpClient, e.g:
var client = new JsonServiceClient(BaseUrl); IEncryptedClient encryptedClient = client.GetEncryptedClient(publicKeyXml);
Once configured, clients have access to the familiar typed Service Client API's and productive workflow they're used to with the generic Service Clients, sending typed Request DTO's and returning the typed Response DTO's - rendering the underlying encrypted messages a transparent implementation detail:
HelloResponse response = encryptedClient.Send(new Hello { Name = "World" }); response.Result.Print(); //Hello, World!
REST Services Example:
HelloResponse response = encryptedClient.Get(new Hello { Name = "World" });
Auto-Batched Requests Example:
var requests = new[] { "Foo", "Bar", "Baz" }.Map(x => new HelloSecure { Name = x }); var responses = encryptedClient.SendAll(requests);
When using the
IEncryptedClient, the entire Request and Response bodies are encrypted including Exceptions which continue to throw a populated
WebServiceException:
try { var response = encryptedClient.Send(new Hello()); } catch (WebServiceException ex) { ex.ResponseStatus.ErrorCode.Print(); //= ArgumentNullException ex.ResponseStatus.Message.Print(); //= Value cannot be null. }
Authentication with Encrypted Messaging
Many encrypted messaging solutions use Client Certificates which Servers can use to cryptographically verify a client's identity - providing an alternative to HTTP-based Authentication. We've decided against using this as it would've forced an opinionated implementation and increased burden of PKI certificate management and configuration onto Clients and Servers - reducing the applicability and instant utility of this feature.
We can instead leverage the existing Session-based Authentication Model in ServiceStack letting clients continue to use the existing Auth functionality and Auth Providers they're already used to, e.g:
var authResponse = encryptedClient.Send(new Authenticate { provider = CredentialsAuthProvider.Name, UserName = "test@gmail.com", Password = "p@55w0rd", });
Encrypted Messages have their cookies stripped so they're no longer visible in the clear which minimizes their exposure to Session hijacking. This does pose the problem of how we can call authenticated Services if the encrypted HTTP Client is no longer sending Session Cookies?
Without the use of clear-text Cookies or HTTP Headers there's no longer an established Authenticated Session for the
encryptedClient to use to make subsequent Authenticated requests. What we can do instead is pass the Session Id in the encrypted body for Request DTO's that implement the new
IHasSessionId interface, e.g:
[Authenticate] public class HelloAuthenticated : IReturn<HelloAuthenticatedResponse>, IHasSessionId { public string SessionId { get; set; } public string Name { get; set; } } var response = encryptedClient.Send(new HelloAuthenticated { SessionId = authResponse.SessionId, Name = "World" });
Here we're injecting the returned Authenticated
SessionId to access the
[Authenticate] protected Request DTO. However remembering to do this for every authenticated request can get tedious, a nicer alternative is just setting it once on the
encryptedClient which will then use it to automatically populate any
IHasSessionId Request DTO's:
encryptedClient.SessionId = authResponse.SessionId; var response = encryptedClient.Send(new HelloAuthenticated { Name = "World" });
INFO
This feature is now supported in all Service Clients
Combined Authentication Strategy
Another potential use-case is to only use Encrypted Messaging when sending any sensitive information and the normal Service Client for other requests. In which case we can Authenticate and send the user's password with the
encryptedClient:
var authResponse = encryptedClient.Send(new Authenticate { provider = CredentialsAuthProvider.Name, UserName = "test@gmail.com", Password = "p@55w0rd", });
But then fallback to using the normal
IServiceClient for subsequent requests. But as the
encryptedClient doesn't receive cookies we'd need to set it explicitly on the client ourselves with:
client.SetSessionId(authResponse.SessionId); //Equivalent to: client.SetCookie("ss-id", authResponse.SessionId);
After which the ServiceClient "establishes an authenticated session" and can be used to make Authenticated requests, e.g:
var response = await client.GetAsync(new HelloAuthenticated { Name = "World" });
BearerToken in Request DTOs
Similar to the
IHasSessionId interface Request DTOs can" });
RSA and AES Hybrid Encryption verified with HMAC SHA-256
The Encrypted Messaging Feature follows a Hybrid Cryptosystem which uses RSA Public Keys for Asymmetric Encryption combined with the performance of AES Symmetric Encryption making it suitable for encrypting large message payloads. The authenticity of Encrypted Data are then verified with HMAC SHA-256, essentially following an Encrypt-then-MAC strategy.
The key steps in the process are outlined below:
- Client creates a new
IEncryptedClientconfigured with the Server Public Key
- Client uses the
IEncryptedClientto create a EncryptedMessage Request DTO:
- Generates a new AES 256bit/CBC/PKCS7 Crypt Key (Kc), Auth Key (Ka) and IV
- Encrypts Crypt Key (Kc), Auth Key (Ka) with Servers Public Key padded with OAEP = (Kc+Ka+P)e
- Authenticates (Kc+Ka+P)e with IV using HMAC SHA-256 = IV+(Kc+Ka+P)e+Tag
- Serializes Request DTO to JSON packed with current
Timestamp,
Verband
Operation= (M)
- Encrypts (M) with Crypt Key (Kc) and IV = (M)e
- Authenticates (M)e with Auth Key (Ka) and IV = IV+(M)e+Tag
- Creates
EncryptedMessageDTO with Servers
KeyId, IV+(Kc+Ka+P)e+Tag and IV+(M)e+Tag
- Client uses the
IEncryptedClientto send the populated
EncryptedMessageto the remote Server
On the Server, the
EncryptedMessagingFeature Request Converter processes the
EncryptedMessage DTO:
- Uses Private Key identified by KeyId or the current Private Key if KeyId wasn't provided
- Request Converter Extracts IV+(Kc+Ka+P)e+Tag into IV and (Kc+Ka+P)e+Tag
- Decrypts (Kc+Ka+P)e+Tag with Private Key into (Kc) and (Ka)
- The IV is checked against the nonce Cache, verified it's never been used before, then cached
- The IV+(Kc+Ka+P)e+Tag is verified it hasn't been tampered with using Auth Key (Ka)
- The IV+(M)e+Tag is verified it hasn't been tampered with using Auth Key (Ka)
- The IV+(M)e+Tag is decrypted using Crypt Key (Kc) = (M)
- The timestamp is verified it's not older than
EncryptedMessagingFeature.MaxRequestAge
- Any expired nonces are removed. (The timestamp and IV are used to prevent replay attacks)
- The JSON body is deserialized and resulting Request DTO returned from the Request Converter
- The converted Request DTO is executed in ServiceStack's Request Pipeline as normal
- The Response DTO is picked up by the EncryptedMessagingFeature Response Converter:
- Any Cookies set during the Request are removed
- The Response DTO is serialized with the AES Key and returned in an
EncryptedMessageResponse
- The
IEncryptedClientdecrypts the
EncryptedMessageResponsewith the AES Key
- The Response DTO is extracted and returned to the caller
A visual of how this all fits together in captured in the high-level diagram below:
- Components in Yellow show the encapsulated Encrypted Messaging functionality where all encryption and decryption is performed
- Components in Blue show Unencrypted DTO's
- Components in Green show Encrypted content:
- The AES Keys and IV in Dark Green is encrypted by the client using the Server's Public Key
- The EncryptedRequest in Light Green is encrypted with a new AES Key generated by the client on each Request
- Components in Dark Grey depict existing ServiceStack functionality where Requests are executed as normal through the Service Client and Request Pipeline
All Request and Response DTO's get encrypted and embedded in the
EncryptedMessage and
EncryptedMessageResponse DTO's below:
public class EncryptedMessage : IReturn<EncryptedMessageResponse> { public string KeyId { get; set; } public string EncryptedSymmetricKey { get; set; } public string EncryptedBody { get; set; } } public class EncryptedMessageResponse { public string EncryptedBody { get; set; } }
The diagram also expands the
EncryptedBody Content containing the EncryptedRequest consisting of the following parts:
- Timestamp - Unix Timestamp of the Request
- Verb - Target HTTP Method
- Operation - Request DTO Name
- JSON - Request DTO serialized as JSON
Support for versioning Private Keys with Key Rotations
One artifact visible in the above process was the use of a
KeyId. This is a human readable string used to identify the Servers Public Key using the first 7 characters of the Public Key Modulus (visible when viewing the Private Key serialized as XML). This is automatically sent by
IEncryptedClient to tell the
EncryptedMessagingFeature which Private Key should be used to decrypt the AES Crypt and Auth Keys.
By supporting multiple private keys, the Encrypted Messaging feature allows the seamless transition to a new Private Key without affecting existing clients who have yet to adopt the latest Public Key.
Transitioning to a new Private Key just involves taking the existing Private Key and adding it to the
FallbackPrivateKeys collection whilst introducing a new Private Key, e.g:
Plugins.Add(new EncryptedMessagesFeature { PrivateKey = NewPrivateKey, FallbackPrivateKeys = { PreviousKey2015, PreviousKey2014, }, });
Why Rotate Private Keys?
Since anyone who has a copy of the Private Key can decrypt encrypted messages, rotating the private key clients use limits the amount of exposure an adversary who has managed to get a hold of a compromised private key has. i.e. if the current Private Key was somehow compromised, an attacker with access to the encrypted network packets will be able to read each message sent that was encrypted with the compromised private key up until the Server introduces a new Private Key which clients switches over to.
Source Code
- The Client implementation is available in EncryptedServiceClient.cs
- The Server implementation is available in EncryptedMessagesFeature.cs
- The Crypto Utils used are available in the RsaUtils.cs and AesUtils.cs
- Tests are available in EncryptedMessagesTests.cs | https://docs.servicestack.net/encrypted-messaging | CC-MAIN-2022-21 | en | refinedweb |
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README
RösHTTP
A human-readable scala http client API compatible with:
THIS PACKAGE IS NO LONGER MAINTAINED
I moved on to different ventures and I can no longer afford the time to maintain this package. Feel free to use it as-is, or drop a comment in #58 if you would like me to endorse your fork.
Installation
Add a dependency in your build.sbt:
Resolver.bintrayRepo("hmil", "maven") libraryDependencies += "fr.hmil" %%% "ros % "3.0.0"
Usage
The following is a simplified usage guide. You may find useful information in the API doc too.
Basic usage
import fr.hmil.ros import monix.execution.Scheduler.Implicits.global import scala.util.{Failure, Success} import fr.hmil.ros // Runs consistently on the jvm, in node.js and in the browser! val request = HttpRequest(" request.send().onComplete({ case res:Success[SimpleHttpResponse] => println(res.get.body) case e: Failure[SimpleHttpResponse] => println("Houston, we got a problem!") })
Configuring requests
HttpRequests
are immutable objects. They expose methods named
.withXXX which can be used to
create more complex requests.
URIs
import fr.hmil.ros request.withMethod(PUT).send()
Headers
Set individual headers using
.withHeader
request.withHeader("Accept", "text/html")
Or multiple headers at once using
.withHeaders
request.withHeaders( "Accept" -> "text/html", "User-Agent" -> "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)" )
Backend configuration
Some low-level configuration settings are available in BackendConfig.
Each request can use a specific backend configuration using
.withBackendConfig.
example:
import fr.hmil.ros HttpRequest("long.source.of/data") .withBackendConfig(BackendConfig( // Uses stream chunks of at most 1024 bytes maxChunkSize = 1024 )) .stream()
Cross-domain authorization information
For security reasons, cross-domain requests are not sent with authorization headers or cookies. If
despite security concerns, this feature is needed, it can be enabled using
withCrossDomainCookies,
which internally uses the
XMLHttpRequest.withCredentials
method, but has no effect in non-browser environments. Also for same-site requests, setting it to
true has no effect either.
request.withCrossDomainCookies(true)
Response headers
A map of response headers is available on the
HttpResponse object:
request.send().map({res => println(res.headers("Set-Cookie")) })
Sendings import fr.hmil.ros val urlEncodedData = URLEncodedBody( "answer" -> "42", "platform" -> "jvm" ) request.post(urlEncodedData) // or request.put(urlEncodedData)
Create JSON requests easily using implicit conversions.
import fr.hmil.ros import fr.hmil.ros val jsonData = JSONObject( "answer" -> 42, "platform" -> "node" ) request.post(jsonData)
File upload
To send file data you must turn a file into a ByteBuffer and then send it in a ByteBufferBody. For instance, on the jvm you could do:
import java.nio.ByteBuffer import fr.hmil.ross import fr.hmil.ros import fr.hmil.ros
Warning: Even though the streaming API works flawlessly on the JVM, it is an experimental feature as the JS implementation may leak memory or buffer things in the background.
Downloads methods
There is no shortcut method such as
.post to get a streaming response. You can
still achieve that by using the constructor methods as shown below:
import fr.hmil.ros request .withMethod(POST) .withBody(PlainTextBody("My upload data")) .stream() // The response will be streamed
Upload: <!-- Defining an inputStream for the tests
val inputStream = new java.io.ByteArrayInputStream(new Array[Byte](1))
-->
import fr.hmil.ros // On the JVM: // val inputStream = new java.io.FileInputStream("video.avi") request .post(inputStream) .onComplete({ case _:Success[SimpleHttpResponse] => println("Data successfully uploaded") case _:Failure[SimpleHttpResponse] => println("Error: Could not upload stream") })
Errors
Please read the contributing guide.
Changelog
v3.0.0
- Move to Scala.js 1.0
v2.2.4
- Update to monix v2.3.3
v2.2.0
- Add withCrossDomainCookies (by @nondeterministic)
MIT
*Note that all licence references and agreements mentioned in the RösHTTP README section above are relevant to that project's source code only. | https://scala.libhunt.com/roshttp-alternatives | CC-MAIN-2022-21 | en | refinedweb |
On Tue, Jan 20, 2009 at 4:32 PM, Anders Backman <andersb@cs.umu.se> wrote: > > > On Tue, Jan 20, 2009 at 7:07 PM, Ariel Manzur <puntob@gmail.com> wrote: >> >> Hi. >> >> On Tue, Jan 20, 2009 at 11:13 AM, Anders Backman <andersb@cs.umu.se> >> wrote: >> > - LuaBind >> [...] >> > * Full support of virtual methods >> >> do you know if this is documented? I didn't see anything on their >> manual, but I'd love to see how this kind of thing is implemented. > > Hm, I guess it was only one way. > right, this is what I saw, which explains how to do it manually.. > > I implemented this together with tolua a while back though. For me it was > important that I could create a class in lua, implement the virtual method, > register the class to a listener, and then this (virtual) method was > executed from C++. > To do this, I had to implement a class: > namespace { > LuaClass: public Class { > bool virtual keyboard( int key, int modkey, float x, float y, bool keyDown > ) > { > vrutils::LuaCall lc(m_lua, "namespace::LuaClass", this, "lua_keyboard", > false); > if (!lc.isValid()) > return false; > > // Rest is arguments > lc.pushNumber(key); > lc.pushNumber(modKey); > lc.pushNumber(x); > lc.pushNumber(y); > lc.pushBoolean(keydown); > if (lc.call(1)) // Make the call return 1 value > error("keyboard", "Error during execution of luafunction lua_keyboard"); > // Is there a value on the stack? > if (!lua_gettop (m_lua)) > return false; //error("keyboard", "Lua function call does not return a > value, expecting bool"); > // Is there a value on the stack? > if (!lua_isboolean (m_lua,-1)) > return false; //error("keyboard", "Lua function call does not return a > value, expecting bool"); > > // Get it > bool f = tolua_toboolean (m_lua, -1, 0) ? true : false; > lua_pop(m_lua, 1); > return f; > } > }; > } > This could of course be automated through xml2cpp and tolua... > SO whenever tolua encounters a virtual method, it creates the above code > automatically and implements a class which can be used from lua: This is exactly what the code on the wiki page does :) It also tries to handle some cases you'll find when parsing "real life" c++ objects, like protected virtual methods, classes with pure virtual methods and constructors, etc. I think lua_qt also had a 'class.lua' module that provides objects with inheritance that uses this (to avoid all the metatable manipulation on the wiki example). I see using something like xml2cpp as an alternative to expose a big api with minimal effort, but the tolua support is already there. > > test.lua: > listener = namespace.LuaClass:new(); > function listener:lua_keyboard(key, modKey, x,y,down) > print("key is: "..key) > end > listenerManager:add( listener ) > > > Now the listenerManager can trigger the listener, and it doesnt matter > whether the virtual method (keyboard/lua_keyboard) is implemented in c++ or > Lua, it will be executed no matter what. > The drawback is that I dont think it will work to have the same name (or > perhaps it will?) of the method keyboard in lua...I dont recall why I had to > add the lua_ prefix. You probably had infinite recursion when the lua method didn't exist, and you'd call the tolua generated wrapper function instead. >> >> And it would solve the main problem with the solution to implement >> virtual methods on lua, which is acquiring all the methods at all >> levels of inheritance. This would probably make the qt bindings _huge_ >> tho. > > You mean each and every virtual method in QT would be bound to this code... > But isnt that the problem already in lqt? And also every class (that might not have any virtual methods) that derives from a class with virtual methods. I wouldn't call this a problem really for desktop applications.. we have enough memory to load big shared objects. > >> >> > >> > Looking for quite some feedback because I know this is a hot issue! >> > >> > Cheers, Anders >> > >> > >> >> Ariel. > > > > > | http://lua-users.org/lists/lua-l/2009-01/msg00376.html | CC-MAIN-2022-21 | en | refinedweb |
In this Python tutorial, we will learn about Fractal Python Turtle and we will also cover different examples related to fractal turtles. And, we will cover these topics.
- Fractal python turtle
- Fractal tree python turtle
- Fractal recursion python turtle
- Fractal drawing turtle
Fractal python turtle
In this section, we will learn about the fractal turtle in Python Turtle.
Fractal python turtle is used to make geometrical shapes with different scales and sizes. In this, it makes repeating shapes in geometry form which works on a different scale and size it is not same in shape.
Code:
In the following code, we have used the fractal python turtle which indicated to make geometrical shapes. To create this we import the turtle library.
We use speed(), penup(), pendown(), forward(), left() goto(), getscreen(), and bgcolor() functions to make this geometry shape.
- speed() is used to give the speed at which we are creating a geometry shape.
- penup() is used to stop the drawing.
- pendown() is used to start the drawing.
- goto() is used to move the turtle.
- forward() is used to move the turtle forward.
- left() is used to move the turtle to left direction.
from turtle import * import turtle tur = turtle.Turtle() tur.speed(6) tur.getscreen().bgcolor("black") tur.color("cyan") tur.penup() tur.goto((-200, 50)) tur.pendown() def star(turtle, size): if size <= 10: return else: for i in range(5): turtle.forward(size) star(turtle, size/3) turtle.left(216) star(tur, 360) turtle.done()
Output:
In the following output, we can see the different geometry shapes and different scales that we can see in this gif, We use speed(), penup(), pendown(), forward(), left() and goto() functions to make this geometry shape.
Also, check: Python Turtle Dot
Fractal tree python turtle
In this section, we will learn about how to create a fractal tree turtle in a python turtle.
In this, we are creating a tree using python fractal we created sub-branches (Left and right) and we shorten the new sub-branches until we reach the minimum end to create a tree.
Code:
In the following code, we import the turtle module from turtle import *, import turtle for creating this fractal tree.
To create a tree we assign the x-axis and y-axis that defined the acute angle between the branch of Y.
We assigned the speed() function that helps to draw the shape in what speed a user has assigned.
- speed() is used to define the speed of the pen to draw the shape.
- y-axis() is used to plot a Y
- pencolor() is used for setting color according to color level.
from turtle import * import turtle speed('fastest') right(-90) angle = 30 def yaxis(size, lvl): if lvl > 0: colormode(255) pencolor(0, 255//lvl, 0) forward(size) right(angle) yaxis(0.8 * size, lvl-1) pencolor(0, 255//lvl, 0) lt( 2 * angle ) yaxis(0.8 * size, lvl-1) pencolor(0, 255//lvl, 0) right(angle) forward(-size) yaxis(80, 7) turtle.done()
Output:
After running the above code, we get the following output in which we can see the fractal tree is created with size 80 and level 7.
Read: Python turtle onclick
Fractal recursion python turtle
In this section, we will learn about fractal recursion in python turtle.
Recursion is the process of repeating units in a similar way fractal is used to generate an infinite amount of copies of pictures that form a fractal pattern.
Code:
In the following code, we imported a turtle library we have defined the title to a window with the name “Python Guides” assigning the bg_color and giving the screen height and width.
We define the drawline() which is drawing from pos1 to pos2 (Position is a phrase of pos) after that we assigned the recursive() which is used to generate multiple copies of the same picture.
from turtle import * import turtle speed = 5 bg_color = "black" pen_color = "red" screen_width = 800 screen_height = 800 drawing_width= 700 drawing_height = 700 pen_width = 5 title = "Python Guides" fractal_depth = 3 def drawline(tur, pos1, pos2): tracing the algorithm. tur.penup() tur.goto(pos1[0], pos1[1]) tur.pendown() tur.goto(pos2[0], pos2[1]) def recursivedraw(tur, x, y, width, height, count): drawline( tur, [x + width * 0.25, height // 2 + y], [x + width * 0.75, height // 2 + y], ) drawline( tur, [x + width * 0.25, (height * 0.5) // 2 + y], [x + width * 0.25, (height * 1.5) // 2 + y], ) drawline( tur, [x + width * 0.75, (height * 0.5) // 2 + y], [x + width * 0.75, (height * 1.5) // 2 + y], ) if count <= 0: # The base case return else: # The recursive step count -= 1 recursivedraw(tur, x, y, width // 2, height // 2, count) recursivedraw(tur, x + width // 2, y, width // 2, height // 2, count) recursivedraw(tur, x, y + width // 2, width // 2, height // 2, count) recursivedraw(tur, x + width // 2, y + width // 2, width // 2, height // 2, count) if __name__ == "__main__": screenset = turtle.Screen() screenset.setup(screen_width, screen_height) screenset.title(title) screenset.bgcolor(bg_color) artistpen = turtle.Turtle() artistpen.hideturtle() artistpen.pensize(pen_width) artistpen.color(pen_color) artistpen.speed(speed) recursivedraw(artistpen, - drawing_width / 2, - drawing_height / 2, drawing_width, drawing_height, fractal_depth) turtle.done()
Output:
In the following output, we can see that how recursion is working and making the same copies of a single picture.
Read: Python Turtle Race
Fractal drawing turtle
In this section, we will learn about how to draw fractal drawings in python turtle.
Fractal is used to generate an infinite amount of copies of pictures that form a fractal pattern. This fractal drawing is drawn with the help of a turtle.
Code:
In the following code, we have imported the turtle library and after that, we have defined the fractdraw() later we use the left() right() forward() to give direction to the pattern.
from turtle import * import turtle def fractdraw(stp, rule, ang, dept, t): if dept > 0: x = lambda: fractdraw(stp, "a", ang, dept - 1, t) y = lambda: fractdraw(stp, "b", ang, dept - 1, t) left = lambda: t.left(ang) right = lambda: t.right(ang) forward = lambda: t.forward(stp) if rule == "a": left(); y(); forward(); right(); x(); forward(); x(); right(); forward(); y(); left(); if rule == "b": right(); x(); forward(); left(); y(); forward(); y(); left(); forward(); x(); right(); turtle = turtle.Turtle() turtle.speed(0) fractdraw(5, "a", 90, 5, turtle)
Output:
In the following output, we can see how we draw the fractal turtle and how it is working to create the same picture multiple times using the fractal pattern.
You may also like to read the following tutorials.
- Python Turtle Tracer
- Python Turtle Window
- Python Turtle Triangle
- Replit Python Turtle
- Python Turtle Oval
- Python Turtle Size
- Python Turtle Mouse
- Python Turtle Font
- Python Turtle Get Position
Here, we will discuss Fractal Python Turtle and we have also covered different examples related to its implementation. Here is the list of examples that we have covered.
- Fractal python turtle
- Fractal tree python turtle
- Fractal recursion python turtle
- Fractal drawing turtle
Entrepreneur, Founder, Author, Blogger, Trainer, and more. Check out my profile. | https://pythonguides.com/fractal-python-turtle/ | CC-MAIN-2022-21 | en | refinedweb |
Linux
2017-09-15
NAME
sem_init - initialize an unnamed semaphore
SYNOPSIS
#include <semaphore.h>
int sem_init(sem_t *sem, int pshared, unsigned int value);
Link), and so on.
Initializing a semaphore that has already been initialized results in undefined behavior.
RETURN VALUE
sem_init() returns 0 on success; on error, -1 is returned, and errno is set to indicate the error.
ERRORS. | https://reposcope.com/man/en/3/sem_init | CC-MAIN-2022-21 | en | refinedweb |
README
jupyterlab-vega2Requirements
- JupyterLab >= 3.0
InstallInstall
pip install jupyterlab-vega2
UsageUsage
To render Vega 2 or Vega-lite 1 output in IPython:
from IPython.display import display display({ "application/vnd.vegalite.v1"} } } }, raw=True)
To render a
.vg,
.vl,
.vg.json,
.vl.json file, simply open it.-vega-vega2 | https://www.skypack.dev/view/@jupyterlab/vega2-extension | CC-MAIN-2022-21 | en | refinedweb |
Couchbase Lite is a full-featured NoSQL database that runs locally on mobile devices. The Offline Storage plugin, built and maintained by Ionic as part of Ionic Native, makes it easy to take advantage of the Couchbase Lite database to create your application using an offline-first architecture. This allows you to offer your users a fast and seamless experience regardless of their connectivity at the time.
New! View a live demo of Offline Storage here. Complete documentation available here.
In this article, I will demonstrate how to create an application supporting the full set of Create, Read, Update, and Delete (CRUD) operations. For simplicity, I will focus on the use of the database itself and will not get into more advanced topics such as data synchronization with a cloud-based API.
Demo Application
To demonstrate the power of the Offline Storage solution, I will use an application that displays different categories of tea. It allows the user to add new categories of tea, edit existing categories, and delete categories they no longer care about.
The complete source code for this application is available here.
Install Ionic Native
In order to use Ionic Native plugins, make sure you’re using the Ionic Enterprise Cordova CLI:
npm uninstall -g cordova npm install -g @ionic-enterprise/cordova
Once you’ve installed the Ionic Enterprise Cordova CLI, you can register a native key, then install the Offline Storage plugin:
ionic enterprise register ionic cordova plugin add @ionic-enterprise/offline-storage
NOTE: Ionic Native includes a reliable set of Native APIs & functionality that you can use in your Ionic app, quality controlled and maintained by the Ionic Team. Sign up here.
Initialize a Database
Create a Service
The first thing we will do is create a service, allowing us to abstract the data storage logic away from the rest of the pages and components in our application. Over time, this becomes easier to make changes to how data is stored without affecting the whole code base.
We will just be storing tea categories with this application so we will create a single service called
TeaCategoriesService which will handle all of the CRUD operations. For now, it will only use a Couchbase Lite database for storage and retrieval, but could easily be updated to include cloud-based storage in the future. Within an Ionic application, run the
generate service command:
ionic g service services/tea-categories/tea-categories > ng generate service services/tea-categories/tea-categories CREATE src/app/services/tea-categories/tea-categories.service.spec.ts (369 bytes) CREATE src/app/services/tea-categories/tea-categories.service.ts (142 bytes) [OK] Generated service!
Open the Database
The next step involves opening and initializing the database within
TeaCategoriesService. The
initializeDatabase() method below shows the basic steps required to open a database. The
readyPromise is stored for use in other methods to ensure that the database has been initialized properly before we perform other operations.
import { Injectable } from '@angular/core'; import { Database, DatabaseConfiguration, IonicCBL, CordovaEngine } from 'ionic-enterprise-couchbase-lite'; @Injectable({ providedIn: 'root' }) export class TeaCategoriesService { private readyPromise: Promise<void>; private database: Database; constructor() { this.readyPromise = this.initializeDatabase(); }('teacategories', config); this.database.setEngine(new CordovaEngine({ allResultsChunkSize: 9999 })); await this.database.open(); console.log(“DB Name: “ + this.database.getName()); console.log(“DB Path: “ + await this.database.getPath()); resolve(); }); }); } }
Notice that no specific mobile platform has been mentioned in the code above. The plugin abstracts away those details from the Ionic web developer, providing a true cross-platform solution. To demonstrate this, build and run the application on a mobile device or in an emulator. Upon examination of the console log, you will see the iOS and Android-specific file paths to the newly created database:
On iOS:
DB Name: teacategories DB Path: /var/mobile/Containers/Data/Application/EC31A8DD-863B-4894-BC64-B89A370377F9/ Library/Application Support/CouchbaseLite/teacategories.cblite2/
On Android:
DB Name: teacategories DB Path: /data/user/0/io.ionic.cs_demo_couchbase_lite/files/teacategories.cblite2/
Storing Data
TeaCategory Model
A generic data model –
TeaCategory – is used to communicate between the
TeaCategoriesService and its consumers. This allows us to decouple the data from the actual storage mechanism, making the application more maintainable as we add features in the future.
export interface TeaCategory { id?: string; name: string; description: string; }
The “id” property is optional since newly created objects will not have any ID until they are added to the database.
Back to the TeaCategoriesService
When adding a new document to the database, we create a
MutableDocument object. As the name implies, this is a document object that can be changed. After the object is created, set the properties we are concerned with and save the document:
private async add(category: TeaCategory): Promise<void> { await this.readyPromise; const doc = new MutableDocument() .setString('name', category.name) .setString('description', category.description); return this.database.save(doc); }
Notice that the
id property is not set – it will be automatically assigned by the database.
TeaCategoryEditorPage
The
TeaCategoryEditorPage needs to pass the appropriate data to the service, await the completion of the save, and then navigate back to the
async save() { await this.teaCategories.save({ name: this.name, description: this.description }); this.navController.back(); }
Querying Documents
Now that we are able to create documents, we need to be able to display them on the app’s
HomePage. In order to retrieve all of the documents from the database, we can build a query that returns the data we need, execute the query, and then unpack the data into the generic
TeaCategory model that we use to pass data back and forth.
TeaCategoryService: GetAll()
The bulk of the work is performed by the service, which returns a promise that resolves to an array of tea categories. This allows us to hide the details of the storage mechanism from the consumers of the service.
async getAll(): Promise<Array<TeaCategory>> { await this.readyPromise; const query = QueryBuilder.select( SelectResult.property('name'), SelectResult.property('description'), SelectResult.expression(Meta.id) ).from(DataSource.database(this.database)) .orderBy(Ordering.property('name')); const ret = await query.execute(); const res = await ret.allResults(); return res.map(t => ({ id: t._id, name: t.name, description: t.description })); }
TeaCategoryEditorPage: Retrieve Results
The
TeaCategoryEditorPage page just needs to await the results of the query.
async ngOnInit() { this.categories = await this.teaCategories.getAll(); }
Updating Tea Category Documents
In order to update the tea category documents, the
TeaCategoryEditorPage needs to obtain the document to edit then needs to save the changes back to the database.
TeaCategoryService: Get Document
The
get routine retrieves the document based on
id and unpacks the document into the model we are using to represent the data.
async get(id: string): Promise<TeaCategory> { await this.readyPromise; const d = await this.database.getDocument(id); const dict = d.toDictionary(); return { id: d.getId(), name: dict.name, description: dict.description }; }
We do not want developers that are using the
TeaCategoryService to worry about whether they are performing an insert or an update. They can just pass along a
TeaCategory object that needs to be saved and the service can figure out if the operation is an “add” or an “update” based on whether or not the object has an ID.
async save(category: TeaCategory): Promise<void> { return category.id ? this.update(category) : this.add(category); } private async add(category: TeaCategory): Promise<void> { await this.readyPromise; const doc = new MutableDocument() .setString('name', category.name) .setString('description', category.description); return this.database.save(doc); } private async update(category: TeaCategory): Promise<void> { await this.readyPromise; const d = await this.database.getDocument(category.id); const md = new MutableDocument(d.getId(), d.getSequence(), d.getData()); md.setString('name', category.name); md.setString('description', category.description); return this.database.teaCatgories.save(md); }
TeaCategoryEditorPage: Making Changes
Next, the
TeaCategoryEditorPage can easily handle both adding new tea categories and making changes to existing tea categories:
async ngOnInit() { const id = this.route.snapshot.paramMap.get('id'); if (id) { this.title = 'Edit Tea Category'; const category = await this.teaCategories.get(id); this.id = category.id; this.name = category.name; this.description = category.description; } else { this.title = 'Add New Tea Category'; } } async save() { await this.teaCategories.save({ id: this.id, name: this.name, description: this.description }); this.navController.back(); }
Responding to Changes
Our users can now add, update, and view tea categories, but the
HomePage does not show the changes right away. Instead, it only shows the changes after the user closes the application and starts it up again.
Furthermore, if the application had a process that would get new tea categories from a cloud-based service then update the database accordingly, we would not see those changes either.
So, we need a way for the application to respond to changes in the database.
TeaCategoryService: Respond to Data Changes
The database allows us to add change listeners in order to respond to changes to tea category data. We will again use our
TeaCategoryService to create an abstraction layer between the database and the rest of our code.
onChange(cb: () => void) { this.readyPromise .then(() => this.database.addChangeListener(cb)); }
HomePage: Detecting Database Changes
In the
HomePage, we still need to fetch the tea categories on entry, but we will also fetch the tea categories each time that a change to the database is detected.
Move ngOnInit() logic to a private method
private async fetchCategories(): Promise<void> { this.categories = await this.teaCategories.getAll(); }
In ngOnInit(), call the method and then set it up to be called with each database change:
ngOnInit() { this.fetchCategories(); this.teaCategories.onChange(() => this.fetchCategories()); }
Deleting a Document
The final CRUD operation is the deletion of documents.
TeaCategoryService:
In order to delete a document, we first get the document using the ID and then tell the database to delete the document.
async delete(id: string): Promise<void>{ await this.readyPromise; const d = await this.database.getDocument(id); return this.database.deleteDocument(d); }
HomePage: Delete UI
The
HomePage page’s responsibility here is to confirm that the user does intend to delete the category. If so, it hands the ID off to the service to do the actual work.
async removeTeaCategory(id: string): Promise<void> { const alert = await this.alertController.create({ header: 'Confirm Delete', message: 'Are you sure you want to permanently remove this category?', buttons: [ { text: 'Yes', handler: () => this.teaCategories.delete(id) }, { text: 'No', role: 'cancel' } ] }); alert.present(); }
After the user confirms the deletion, Android Oil is removed from the Tea Category list:
Conclusion
In this article, we explored the Ionic Native Offline Storage plugin’s complete offline experience by implementing the full set of CRUD operations available. We also explored best practices by architecting our application to separate data storage concerns into a separate service class. This shields the rest of our application from being concerned with details about how the data is stored and will allow us to easily expand our application in the future to use features such as synchronizing our offline data with a cloud-based data service. These are just some of the scenarios that can be supported in your application using the Offline Storage plugin.
If you are interested in exploring how Ionic Native can benefit your application development and aid you in delivering the best experience to your users, please contact one of our Solutions Architects (like me!) to schedule a demonstration. | https://ionicframework.com/blog/build-secure-offline-apps-with-ionic-couchbase-lite/ | CC-MAIN-2022-21 | en | refinedweb |
Step by step example how to add Redux to Create React App
In a previous article I wrote about how to use React state by building a simple cat application.
When the application is small its relatively easy to maintain React state.
But as the application grows the React state tree gets messier, unmanageable, and more complicated.
And this even more true when your app state starts to hold server responses, cache and UI state data.
UI state data may include routes information, whether to show a loading spinner, pagination, tabs, etc.
At some point your app will have so much going on that you’ve lost control over your app state, and how it works.
Why should you use redux?
Redux is a tiny state management library.
It’s meant to make your state management more predictable, and centralize your React state data, and state logic.
Redux solves these problems by implementing 3 core principals.
Principal 1: Single source of truth
Your entire app state data is in one object tree.
This tree may also be known as a store.
By maintaining a single store it allows you to be debug or inspect your application much easier.
Principal 2: State is read-only
Your store data gets passed down as React props. Which React doesn’t allow you to modify the props object directly.
This will help keep consistency through out the app.
Redux only allows you to update your store data through a functions called dispatch which you must defined the action to trigger.
These actions, describe what will be changing or happening to the store.
Principal 3: Changes are made with pure functions
These function are also known as reducers, which are attached to an action.
The job of a reducer is to get the current state and an action and return the next state.
So when you make a call to an action such as,
ADD_CAT.
Redux will take that action request, check if it exists, and if it has a reducer attached to it.
It will then execute that reducer function to update the store data.
P.S. Redux doesn’t just run on React, it may be used on any view JavaScript library, and even vanilla JS as well!
Adding Redux to React
For the sake of simplicity, I’m going to modify the cat list application that was built previously to showcase how to use Redux in React.
I know it’s another list app, but it’s simple and it’s easy to follow.
Also if you’d like to follow along with the actual code, scroll to the bottom for the Github source link.
The first step I need to take is to create the package.json file.
{ "name": "with-redux", "private": true, "dependencies": { "react": "^16.8.4", "react-dom": "^16.8.4", "react-redux": "^7.0.2", "react-scripts": "^3.2.0", "redux": "^4.0.1", "redux-thunk": "^2.3.0" }, "scripts": { "start": "react-scripts start" }, "browserslist": [ ">0.2%", "not dead", "not ie <= 11", "not op_mini all" ] }
This project is going to require the following React libraries
React - The UI library.
React DOM - The tool that let's us attache our React app to the DOM.
Redux - The state management library.
React Redux - The Redux React library that let's us attach the Redux store to the React application.
Redux Thunk - This library is a bit of an overkill for this example but it's popular, and wanted to demonstrate some of it's pros.
Redux Thunk let's us split our reducers in smaller pieces when the application grows to enormous, and it let's us run
dispatch() inside our actions.
Once your package.json file is ready, run
npm install inside your terminal.
Structuring the React redux structure folder
Here is the structure of the application.
As you may see, I have my public directory that holds the initial index.html file.
I also have a src directory that holds a few important files for this application to work.
index.js - It's responsible for making Redux available in the React application, as well as grabbing the React application and dumping it onto the HTML.
App.js - The main source application file. It allows you add cat names, and display them in a list format.
store.js - Is the glue that grabs the reducers and creates a Redux store out of it.
reducers/cats.js - Responsible for describing what the cat reducer looks like, naming the action, and attaching the action to a function that modifies the cat reducer data.
Now that you know the app structure, let's start going through the code.
Creating a Redux reducer
First I'll build my cat Redux reducer.
const initialState = { list: [], }; const actions = { 'ADD_CAT': addCat, }; function addCat(state, action) { return { list: [...state.list, action.payload], } } export default { initialState, actions }
The first thing thing I will create is a variable named
initialState.
initialState will hold a property named
list, which is an array of cat names.
initialState also defines what the initial state looks like for the cat state.
The next variable to create is called
actions.
actions is a key value pair object.
The key is the name of the action and the value is the reducer to be executed.
Right below the
actions variable, I defined a simple function called
addCat().
The name is pretty self explanatory. The function adds the cat name onto the
state.list property in the state.
Creating the Redux store file
This file may look scary but it's not that bad. I'll go over it step by step.
import { createStore, combineReducers, applyMiddleware } from 'redux'; import thunk from 'redux-thunk' import catStoreConfig from './reducers/cats'; const createReducer = (initialState, handlers) => { return (state = initialState, action) => { return (handlers[action.type] && handlers[action.type](state, action)) || state; }; }; const catReducers = createReducer(catStoreConfig.initialState, catStoreConfig.actions) const rootReducer = combineReducers({ cats: catReducers, }); export default createStore(rootReducer, {}, applyMiddleware(thunk));
First, I'm importing Redux libraries, and also the cat reducer file that was created above.
Second, I'm creating a function called
createReducer(), that glues together the initial state, and the actions, thus creating a reducer.
I used it to create my cat reducer, and then inject into a variable called
rootReducer.
I then exported a new store by using the
createStore() function and supplying it the root reducer with some middleware.
Using
Redux combineReducers may be another overkill in this app example but it shows you how to split and add reducers to your Redux store.
How to connect React component to Redux store
The next file to work on is the App.js file. This file will be responsible to display the UI, allow the user to enter a new cat name, and add it to the Redux store.
import React, { useState } from 'react'; import { connect } from 'react-redux'; const App = (props) => { const [catName, setCatName] = useState(''); return ( <> <div> <input placeholder="New cat name" value={catName} onChange={e => setCatName(e.target.value)}/> </div> <div> <button onClick={() => { if (catName.length) { props.dispatch({ type: 'ADD_CAT', payload: catName.trim(), }); setCatName(''); } else { alert('Cat name cannot be empty!') } }}> Add </button> </div> <ul> {props.cats.list.map((cat, i) => ( <li key={i}>{cat}</li> ))} </ul> </> ); } export default connect(state => state)(App);
If you're not familiar with React hooks, I highly recommend you read this article that teaches you how they work and how they're used: React useState.
Moving on, this file is huge. Step by step time again.
The first step here is to import
React useState, and the
connect() function from React Redux library.
Then I'll create the React component called
<App />.
I'm then exporting the
<App /> React component inside the
connect() function as a HOC (higher order component).
You might be asking, "what does connect do?"
Good question, the
connect() function let's a React component latch itself onto the Redux store.
The
connect function does not modify the component, but it creates a new component around to pass any state data from the Redux store, and it provides a function called
dispatch().
Here's a kid illustration to visually see how it works.
Redux connect accepts a handful of parameters but I'll go over the 2 most important ones.
In the example above I'm passing in only the first parameter which Redux calls,
mapStateToProps.
mapStateToProps is a function that allows you to pick and choose what Redux store data you want.
In the App.js file, I decided to get all, but you don't have to.
If the first parameter is provided, then the wrapper component will subscribe to the Redux store.
It acts like a listener to always provide the latest data to the component you've created.
If you'd like your app to not subscribe to the store just pass
null or
undefined as the first parameter.
The second parameter in
Redux connect is
mapDispatchToProps.
mapDispatchToProps allows you to create custom dispatch functions and pass them to the React component.
Let's take a look at the input and button section of the React component.
Inside the React component and before the return statement, I've create a new
useState hook for the cat name.
I've also attached
setCatName() inside the input HTML element for the
onChange event.
So whenever a user is typing the new cat name,
setCatName() will trigger, and update the value of
catName.
I've also added a button to submit the new cat name on the
onClick event.
Inside the
onClick event, I'm saying to check if the cat name is empty or not. If it is empty return an
alert() saying "Cat name cannot be empty!"
If there is a name, I want to trigger the
ADD_CAT Redux action by using
dispatch(), and supply the new cat name value in a property called
payload.
payload is a common practice when passing data through
dispatch().
It doesn't have to be called payload, you can call it whatever you want. But the property
type, must exist.
Right after the
dispatch() function, I'm resetting the cat name value to an empty string.
What does
dispatch() do again??
Yes,
dispatch() is a function that you only get from
Redux connect.
Dispatch allows you trigger actions defined in your reducer files, and it's the only way to modify the Redux store.
Think of dispatch as the
this.setState() of Redux.
The final part to go over in the App.js file is displaying the cat names that I've fetch from my Redux store.
Adding Redux store provider component
Finally, the final part to this masterpiece.
In our index.js file I'm going to add the
<Provider /> component to the React application, and supply the created store from the store.js file.
import React from 'react'; import ReactDOM from 'react-dom'; import { Provider } from 'react-redux'; import store from './store'; import App from './App'; ReactDOM.render(
, document.getElementById('root')); if (module.hot) module.hot.accept();, document.getElementById('root')); if (module.hot) module.hot.accept();
The
Provider component makes the Redux store available to any nested components that have been wrapped in the
connect() function.
It's good practice to make your
Provider at the top level, that way your entire React application has access to the Redux store data.
Conclusion
Redux has a lot of boilerplate and moving parts, but once you start understanding it; it just makes more sense on how this state management tool helps manage large projects.
If you have any questions feel free to ask me on Twitter.
Github source link: React with Redux
Related articles:
I like to tweet about Redux and post helpful code snippets. Follow me there if you would like some too! | https://linguinecode.com/post/step-by-step-example-how-to-add-redux-to-create-react-app | CC-MAIN-2022-21 | en | refinedweb |
MASM32 Downloads
interesting...(2^N-1)&X = Mod(X/2^N)
I was looking for a method in which I could use - Bidirectional-Associative-memory -
Quote from: LiaoMi on January 10, 2022, 09:06:21 PMI was looking for a method in which I could use - Bidirectional-Associative-memory - A.I. with Hopfield? To restore damaged images?
Ok, I've started working on my own version of h2incn - a program that will parse C header files and convert them into Nasm compatible .inc files. After creating the initial program outline I am now ready to begin adding in the preprocessing support.One of the things that I need is a fast way of performing lookups of defines and typedefs. I've settled on using hash maps and the hash function algorithm FNV-1 which, according to the authors, provides for a nice dispersion across a hash map. Thus I begin by defining a hash map to contain the key/value pairs and develop the hashing function.I want the hashing function and the hash map to be capable of holding arbitrary types and data sizes. Thus the routines being developed do not depend on simple character strings (although you can indeed supply them to the functions). That way, the routines may be used to hold objects of all types for any purpose ( token processing, game world objects, in-memory databases, caching, etc. ).The following is my Nasm modified version of the FNV-1 hash algorithm for use in both 32-bit and 64-bit systems. Note that the 32-bit version uses the standard C calling convention while the 64-bit version uses either Windows or Linux fastcall calling conventions. It may be optimized further (an exersize left for the reader) but I'm quite happy with it. I would love to know if others find use for it and what their collision findings are...
;; FNV1HASH.ASM;; Copyright (C)2010 Rob Neff; Source code is licensed under the new/simplified 2-clause BSD OSI license.;; This function implements the FNV-1 hash algorithm.; This source file is formatted for Nasm compatibility although it; is small enough to be easily converted into another assembler format.;; Example C/C++ call:;; #ifdef __cplusplus; extern "C" {; #endif;; unsigned int FNV1Hash(char *buffer, unsigned int len, unsigned int offset_basis);;; #ifdef __cplusplus; }; #endif;; int hash;;; /* obtain 32-bit FNV1 hash */; hash = FNV1Hash(buffer, len, 2166136261);;; /* if desired - convert from a 32-bit to 16-bit hash */; hash = ((hash >> 16) ^ (hash & 0xFFFF));;%ifidni __BITS__,32;; 32-bit C calling convention;%define buffer%define len%define offset_basisglobal _FNV1Hash_FNV1Hash: push ebp ; set up stack frame mov ebp, esp push esi ; save registers used push edi push ebx push ecx push edx mov esi, buffer ;esi = ptr to buffer mov ecx, len ;ecx = length of buffer (counter) mov eax, offset_basis ;set to 2166136261 for FNV-1 mov edi, 1000193h ;FNV_32_PRIME = 16777619 xor ebx, ebx ;ebx = 0nextbyte: mul edi ;eax = eax * FNV_32_PRIME mov bl, ;bl = byte from esi xor eax, ebx ;al = al xor bl inc esi ;esi = esi + 1 (buffer pos) dec ecx ;ecx = ecx - 1 (counter) jnz nextbyte ;if ecx != 0, jmp to NextByte pop edx ; restore registers pop ecx pop ebx pop edi pop esi mov esp, ebp ; restore stack frame pop ebp ret ; eax = fnv1 hash%elifidni __BITS__,64;; 64-bit function;%ifidni __OUTPUT_FORMAT__,win64;; 64-bit Windows fastcall convention:; ints/longs/ptrs: RCX, RDX, R8, R9; floats/doubles: XMM0 to XMM3;global FNV1HashFNV1Hash: xchg rcx, rdx ;rcx = length of buffer xchg r8, rdx ;r8 = ptr to buffer%elifidni __OUTPUT_FORMAT__,elf64;; 64-bit Linux fastcall convention; ints/longs/ptrs: RDI, RSI, RDX, RCX, R8, R9; floats/doubles: XMM0 to XMM7;global _FNV1Hash_FNV1Hash: mov rcx, rsi mov r8, rdi%endif mov rax, rdx ;rax = offset_basis - set to 14695981039346656037 for FNV-1 mov r9, 100000001B3h ;r9 = FNV_64_PRIME = 1099511628211 mov r10, rbx ;r10 = saved copy of rbx xor rbx, rbx ;rbx = 0nextbyte: mul r9 ;rax = rax * FNV_64_PRIME mov bl, ;bl = byte from r8 xor rax, rbx ;al = al xor bl inc r8 ;inc buffer pos dec rcx ;rcx = rcx - 1 (counter) jnz nextbyte ;if rcx != 0, jmp to nextbyte mov rbx, r10 ;restore rbx ret ;rax = fnv1 hash%endif | https://masm32.com/board/index.php?topic=9754.0 | CC-MAIN-2022-21 | en | refinedweb |
Floating Point Support
You may ask yourself "Why should an RTOS care about floating point?" Indeed, the Nut/OS kernel doesn't use any floating point operations. And as long as the supported CPUs don't provide any floating point hardware, the kernel is not involved. However, Nut/OS is more than just a kernel and offers a rich set of standard I/O routines. Applications may want to use these routines to read floating point values from a TCP socket or display them on an LCD.
Be aware that dealing with floating point values will significantly blow up your code. When programming for tiny embedded devices it is recommended to avoid them. Thus, floating point support in Nut/OS is disabled by default. You have to start the Configurator, enable it, re-create the build tree and re-build the system.
Enabling Floating Point Support
Start the Nut/OS Configurator and load the configuration of your board. Make sure that all settings are OK (press Crtl+T) and that the right compiler is selected in the Tools section of the component tree. If unsure, consult the Nut/OS Software Manual.
To enable floating point I/O, check the option Floating Point below C Runtime (Target Specific) -> File Streams in the module tree on the left side of the Configurator's main window.
After selecting Generate Build Tree from the build menu, the Configurator will create or re-write a header file named crt.h in the subdirectory include/cfg of your build tree.
#ifndef _INCLUDE_CFG_CRT_H_ #define _INCLUDE_CFG_CRT_H_ /* * Do not edit! Automatically generated on Mon May 09 19:34:19 2005 */ #ifndef STDIO_FLOATING_POINT #define STDIO_FLOATING_POINT #endif #endif
When rebuilding Nut/OS by selecting Build Nut/OS from the build menu, then this header file will be used instead of the original one in the source tree.
If you prefer to build Nut/OS on the command line within the source tree, then you need to edit the original file before running make install.
Sample Application
The sample code in app/uart, which is included in the Ethernut distribution, demonstrates floating point output, if floating point support had been enabled in the Configurator. The following code fragments show the relevant parts:
#include <cfg/crt.h> #include <stdio.h> ... #ifdef STDIO_FLOATING_POINT double dval = 0.0; #endif ... int main(void) { ... for (;;) { ... #ifdef STDIO_FLOATING_POINT dval += 1.0125; fprintf(uart, "FP %f\n", dval); #endif ... } }
Floating Point Internals
Nut/OS supports floating point input and output, which means, that it is able to convert ASCII representations of floating point values to their binary representations for input and vice versa for output. In other words, the Nut/OS standard I/O functions can read ASCII digits to store them in floating point variables or they can be used to print out the values of floating point numbers in ASCII digits.
Nut/OS does not provide floating point routines by itself, but depends on external floating point libraries. The ImageCraft AVR Compiler comes with build in libraries, while avrlibc provides this support for GCCAVR. Just recently (June 2008), floating point support had been added for ARM targets using newlib.
Reading floating point values is done inside the internal function
int _getf(int _getb(int, void *, size_t), int fd, CONST char *fmt, va_list ap)
Printing floating point values is a different story. It is actually done in function
int _putf(int _putb(int, CONST void *, size_t), int fd, CONST char *fmt, va_list ap)
The newlib library, used for building Nut/OS applications running on ARM CPUs, offers the function _dtoa_r to convert the binary representation to ASCII strings. However, things are more complicated here, because the fuction uses unique internal routines to allocate heap memory. These routines are not provided by Nut/OS and, even worse, the newlib memory management conficts with the one provided by Nut/OS. TO solve this issue, a new function _sbrk had been added to the Nut/OS libraries, which is used by newlib to request heap space. This way, a part of the Nut/OS heap is assigned to the newlib memory management. Since newlib calls _sbrk every time it wants to increase its heap space and because it expects a continous memory area for the total heap memory, a hard coded number of bytes will be allocated by Nut/OS on the first call. This value is specified in crt/sbrk.c:
#ifndef LIB_HEAPSIZE #define LIB_HEAPSIZE 16384 #endif
Currently you can't change this value in the Configurator. Instead you may add the following line to the file UserConf.mk in the build tree prior to building the Nut/OS libraries:
HWDEF += -DLIB_HEAPSIZE=8192
Note, that floating point I/O for ARM targets is still experimental and may not work as expected.
Not much additional code is added by Nut/OS, but the amount of code added by the external libraries will be significant. If you are using the GNU compiler, do not forget to add -lm to the LIBS= entry in your application's Makefile.
Runtime Libraries and stdio
Today's C libraries for embedded systems are distributed with a rich set of stdio function, which partly may be more advanced than those provided by Nut/OS. Typically they offer full floating point support. So why not use them?
The main reason is, that they are less well connected to the hardware. Typically they pass output or expect input on a character by character base, which is slow. Further, they are not fully compatible among each other, which transfers the burden of porting from one platform to another to the application programmer. In opposite to desktop computers, embedded systems do not come with predefined standard devices. C libraries for embedded systems handle this in different ways. Another problem is network support. Some libraries even provide rich file system access, but not much is offered when it comes to networking. On the other hand, Nut/OS provides almost all stdio functions on all platforms for almost all I/O devices including TCP streams in a consistent way.
Both, Nut/OS and the C runtime library, offer a large number of stdio functions with equal names. Sometimes this results in conflicts while linking application codes, or worse, while the application code is running. If an application with stdio calls acts strange, you should inspect the cross reference list in the linker map file first. Make sure, that all stdio calls are linked to Nut/OS libraries.
The following extract from a GCC linker map file shows, that fprintf is located in the Nut/OS library libnutcrt.a and referenced in the application object file uart.o.
Cross Reference Table Symbol File fprintf ../../nutbld-enut30d-gcc/lib\libnutcrt.a(fprintf.o) uart.o
When removing -lnutcrt from the LIBS entry in the application's Makefile, the linker will take fprintf from C library instead. In this specific case, using newlib for ARM, it will additionally result in several linker errors.
Cross Reference Table Symbol File fprintf c:/programme/yagarto/bin/../lib/gcc/arm-elf/4.2.2/../../../../arm-elf/lib\libc.a uart.o
If you are using YAGARTO, which includes newlib, another problem appears. Actually the same problem exists with all libraries, which had been build with syscall support. You will end up with a number of undefined references.
To remove the syscalls module from YAGARTO's newlib, change to arm-elf/lib within the YAGARTO installation directory and run
arm-elf-ar -d libc.a lib_a-syscalls.o
This had been tested with newlib 1.16 in YAGARTO 20080408. For previous releases try
arm-elf-ar -d libc.a syscalls.o
Some History
In early releases Nut/OS simply ignored floating point values. Until today the author never needed it and is almost sure, that he will never need it. Unless you have to handle very large ranges, everything can be done with integers. Keep in mind, that floating point calculations are slow, consume a lot of CPU power and worse, they may result in significant rounding errors.
Anyway, it had been added. Early releases of Nut/OS offered two libraries, nutcrtf and nutcrt. The first one included floating point I/O while the latter didn't. These libraries were build by compiling either getff.c and putff.c for the floating point version or getf.c and putf.c for the library without floating point support. Internally the first two simply include the latter two source files after defining STDIO_FLOATING_POINT. What a crap! :-)
If an application required floating point I/O, the default library nutcrt had been replaced by nutcrtf in the list of libraries to be linked to the application code. This way the user wasn't forced to change any original source code. After the introduction of the Configurator, customizing and rebuilding Nut/OS became much more simple. Furthermore, by separating the build directory from the source tree, several differently configured systems can easily coexist. Thus, there is no specific floating point version of any library required any more.
Floating point I/O for ARM targets is available in Nut/OS version 4.5.5 and above.
Harald Kipp
Castrop-Rauxel, June 28th, 2008. | http://www.ethernut.de/en/documents/ntn-4_floats.html | CC-MAIN-2022-21 | en | refinedweb |
Code splitting routers with React Lazy and Suspense
Are you wondering if you should lazy load React components? Does it improve your application performance?
React is fast. But before it becomes fast, your browser has to do a lot of work before it serves your fast React application.
One of the bottlenecks for React is the bundle size.
The problem with a huge bundle file size is that it increase in TTI (time to interactive).
The longer the TTI (time to interactive) is, the more angry users you get.
What is TTI (time to interactive)?
TTI is the result of how long does it take for the user to actually be able to interact with the application or site.
This is measured in time (milliseconds, seconds, minutes, etc).
Let’s take a look at CNN.com and throttle the network to a slow 3G.
In each row you can see the JavaScript file being downloaded and executed.
You can also see the compressed size, the uncompressed size, and how long it took to be completed.
If we open on their cnn-footer-lib.min.js file, you’ll see that there is nothing minified about it.
And it looks like it contains a lot of the logic for the site in that 1 file.
That’s why it’s taking them more than 10 seconds to download the JS files and execute the code.
React + Webpack = 1 big bundle file
99% of the time when you’re developing in React, you’re going to be using Webpack to help you bundle up everything into a nice package.
Webpack at it’s core, is meant to help hot reload during development, and bundle all your JavaScript files into 1 or multiple JS files.
But if you’re developing React, you’re typically aiming for a single page application, which you’ll typically have 1 JavaScript bundle file.
Your React files aren’t big, it’s actually some of the smallest. But as you install React core, and other third party libraries that bundle output gets bigger.
And loading a 500kb file size isn’t a pretty user experience.
To give a better user experience, you can do a technique called dynamic importing, also known as lazy loading.
Benefits of Lazy loading React components
The concept of lazy loading our React components is really simple.
Load the minimal code to the browser that will render a page.
Load additional small chunks of code when needed.
By loading less JavaScript code to the browser, that will default to better performance and better TTI results.
The concept of lazy loading may apply to any JavaScript application, but for the sake of simplicity will keep it to React talk.
Code splitting routes with React
In today’s example, I will be starting off from a previous article that explains how to get started with React router.
One thing to note, is that the previous work is using Create React App.
And Create React App has already enabled Webpack to perform code splitting.
The goal now is to utilize the code splitting capabilities, and lazy loading technique, and apply it to the React app.
Another reason I want to use a previous example is because I’m going to demonstrate how to do route base code splitting with React.
I only want to load the JavaScript code that is needed to render a page, at that given time.
And I will be using React lazy and Suspense to load other React files as a user navigates through the application.
Lazy loading with React Suspense and React lazy
Before we jump into implementing the lazy load code, let’s do a quick recap of the current app.
Here are the current pages the cat application has.
I have 3 pages:
- A list of cats
- A form to add a cat name
- A single view for a cat
Let’s take a quick look at the current code.
The file above is a route configuration that just attaches a path to a page.
The next file is the App.js file that grabs the route configuration file and creates routes out of it.
Look at lines 31-44.
It goes through a
Array.map loop to create a React route component.
Now let’s take a quick look at the React developer tools and see how it looks at initial render.
React renders every page route. Even when you don’t need it at that moment.
Let’s take a quick look at the network tab for JS files.
The main.[name].chunk.js file is basic Webpack initial code. The big file size is the React cat application.
Our goal is to make our initial load smaller and load in chunks when needed.
Let’s start adding the code!
How to add lazy loading to React router
The first step I took, was to remove route.js file.
The second step was to modify the App.js file. Take a look at the highlighted areas only.
The highlighted areas shows where the code has changed a bit. Don’t worry I’ll break it down.
Step 1: Import React router Switch component
The first step I took to update the App.js file was in line 5.
I imported the
Switch component from
react-router-dom.
<Switch> // ... routes </Switch>
The
Switch component job is to only render a single route component.
You will never see more than one.
In the React developer tool image above, you might have seen 3 routes. Let’s take a look at the developer tool again to see how many routes will render.
And as you navigate through the application, only 1 route component will ever show.
This is helpful because there is no need to have additional code that doesn’t get used at that given time.
Step 2: Create React lazy Components
In line 8 to 10, I created a React lazy components for each page.
// Dynamically import a React component and convert // it to a React component. const CatList = React.lazy(() => import('./pages/CatList'));
React lazy let’s you import dynamically a file and covert it into a regular React component.
Step 3: Use React Suspense component
Before I use my React lazy components, I’m going to add the
React.Suspense component as a wrapper.
React.Suspense is another component provided from the React library.
The
React.Suspense component helps as a fallback option, to let your users know it’s loading.
This is due to how dynamic importing works.
So what is dynamic importing?
// Static importing import React from 'react'; // Dynamic importing import('./path/to/component');
If we take a look at the code example above, I’ve given 2 different examples of using the keyword
import.
Even though it looks like the same, it’s not.
The first
import statement can only happen at the top of the file, and only accepts a literal string.
This is good for importing modules that you’ll need in your code file.
The second
import example, uses parenthesis, as you would use in a function.
This lets JavaScript know that this will be treated asynchronously, and will return a promise.
Since dynamic importing is asynchronous, that’s where
React.Suspense comes into play.
Suspense will display the fallback option until the promise has completed.
The promise in this case, is that a React file has been loaded and executed by the browser.
This will happen as the user goes to each new page.
Step 4: Add our React lazy component to a route
<Route exact path="/" render={() => <CatList cats={cats}/>} /> <Route path="/add" render={props => { return <AddCat onSubmit={cat => { setCats([...cats, cat]) props.history.push('/') }} /> }} /> <Route exact path="/cat/:name" render={() => <SingleCat cats={cats} />} />
This is a fairly simple step.
Inside my
Switch component I’m defining my routes, with a path, and the
React.lazy component that I want to use.
And I’m also passing properties down to each
React.lazy component, such my list of cats or a
onSubmit() handler function.
The result
What I’ve managed to do is grab the entire app and split them into smaller chunks.
There is always going to be a main bundle JS file. But only 1 small chunk file will be downloaded.
As the user navigates through the app and discovers new pages, other small chunks will be downloaded.
This method makes it easy for the browser to process, and execute quickly.
Smaller chunks of code equals faster TTI results (time to interactive).
Conclusion
Code splitting your React application will bring better performance, because it will only load the minimal code it needs to render a page.
Thus bringing a better user experience, and making your users happy.
Github code: React router with lazy loading
I like to tweet about React and post helpful code snippets. Follow me there if you would like some too! | https://linguinecode.com/post/code-splitting-react-router-with-react-lazy-and-react-suspense | CC-MAIN-2022-21 | en | refinedweb |
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Try this: sudo apt-get update --fix-missing
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echo "deb kali-rolling main non-free contrib" | sudo tee /etc/apt/sources.list echo "deb kali-last-snapshot main non-free contrib" | sudo tee /etc/apt/sources.list echo "deb kali-experimental main non-free contrib" | sudo tee -a /etc/apt/sources.list
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Starting Apache...fail.
ubuntu XAMPP Starting Apache...fail
Please install the gcc make perl packages from your distribution.
pip install django storages
No module named 'storages'
Address already in use - bind(2) for "127.0.0.1" port 3000 (Errno::EADDRINUSE)
error gyp ERR! stack Error: not found: make
gyp ERR! stack Error: not found: make
Error: You must install at least one postgresql-client-<version> package
pip upgrade
how to upgrade pip
what is --use-feature=2020-resolver
unable to create process using ' ' virtualenv
E: The repository ' hirsute Release' does not have a Release file.
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).
[ERROR] Error while getting Capacitor CLI version. Is Capacitor installed?
ps not found
bash: ps: command not found
ps command not found debian
Module not found: Can't resolve 'axios' in 'C:\Users\
laravel mix ERROR in ./resources/js/bootstrap.js 8:15-31 Module not found: Error: Can't resolve 'axios'
Error starting daemon: error while opening volume store metadata database: timeout
Unit mongodb.service could not be found ubuntu
ModuleNotFoundError: No module named 'libs.resources'
Invalid command 'ProxyPass', perhaps misspelled or defined by a module not included in the server configuratio
Wrong permissions on configuration file, should not be world writable!
00h00m00s 0/0: : ERROR: [Errno 2] No such file or directory: 'install'
XAMPP: Starting Apache...fail.
Please install all available updates for your release before upgrading.
bash: gedit: command not found
nonexistentpath data directory /data/db not found
dotnet ef not found
Could not install packages due to an OSError: [WinError 5] Access is denied:
mac error that port is already in use
ERROR:uvicorn.error:[Errno 98] Address already in use
vue-cli-service not found ubuntu
how to fix /opt/lampp/bin/mysql.server: 264: kill: no such process
cannot find lock /var/lib/dpkg/lock-frontend
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem
sudo: yum: command not found
ModuleNotFoundError: No module named 'gin'
The command could not be located because '/snap/bin' is not included in the PATH environment variable.
Permissions 0644 for '/root/.ssh/id_rsa' are too open.
ssh permissions too open
permissions too open.
nginx.service is not active, cannot reload.
Data path ".builders['app-shell']" should have required property 'class'.
Failed at the node-sass@4.10.0 postinstall script.
Failed at the node-sass@4.14.1 postinstall script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
The requested apache plugin does not appear to be installed
jango.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module
error loading mysqldb module.
magento 2 file permission
magento 2 version file permissions
Invalid command 'Header', perhaps misspelled or
Err:1 focal-secur Temporary failure resolving 'security.ubuntu.com'
W: Failed to fetch Temporary failure resolving 'security.ubuntu.com' W: Some index files failed to download. They have been ignored, or old ones used instead.
sudo: unzip: command not found
error: failed to synchronize all databases (invalid or corrupted database (PGP signature))
apt-add-repository command not found
arduino permission denied
(node:14140) UnhandledPromiseRejectionWarning: Error: FFmpeg/avconv not found!
unable to resolve 'react-native-gesture-handler'
curl not found
Invalid command 'SSLEngine', perhaps misspelled or defined by a module not included
Failed to start gunicorn daemon ubuntu
permission denied running shell script
ubuntu install imagemagick
docker remove child images
unable to delete (cannot be forced) - image has dependent child images)
docker remove images without tag
ERROR 1698 (28000): Access denied for user 'root'@'localhost'
lsb_release: command not found
An error occurred while uploading the sketch avrdude: ser_open(): can't open device "/dev/ttyUSB0": Permission denied
'json-server' is not recognized as an internal or external command, operable program or batch file.
Shell/Bash answers related to “'json-server' is not recognized as an internal or external command, operable program or batch file.
command not found: lvim
zsh: command not found: gatsby
nginx: [alert] could not open error log file: open() "/var/log/nginx/error.log" failed (13: Permission denied)
error: cannot open .git/FETCH_HEAD: Permission denied
Class 'Doctrine\DBAL\Driver\PDOPgSql\Driver' not found
ERROR: Could not install packages due to an OSError: [WinError 5] Access is deni ied: 'C:\\Users\\ok\\AppData\\Local\\Temp\\pip-uninstall-vl2o0dwn\\pip.exe' Consider using the `--user` option or check the permissions.
Failed to download metadata for repo ‘AppStream’
'vue-cli-service' is not recognized as an internal or external command, operable program or batch file.
install snap on kalicannot communicate with server: Post " dial unix /run/snapd.socket: connect: no such file or directory
psycopg2-binary install
how to install psql python in ubuntu
psycopg2 mac
pip install pyscopg2
install psycopg2 ubuntu 20.04
could not find a version that satisfies the requirement psycopg2
install rclone
rclone ubuntu install guide tutorial
zsh compinit: insecure directories, run compaudit for list.
digitally signed react native
fixing powershell error
ps1 file not digitally signed
powershell execution-policy bypass
file is not digitally signed
not digitally signed. you cannot run this script on the current system
is not digitally signed. you cannot run this script on the current system
ionic.ps1 is not digitally signed.
cannot be loaded because running scripts is disabled on this system.
npm ERR! cb() never called!
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY
docker: Error response from daemon: dial unix docker.raw.sock: connect: no such file or directory
error pip install psycopg2-binary ld: library not found for -lssl
bash: pip: command not found
storage/logs/laravel.log" could not be opened: failed to open stream: Permission denied
ModuleNotFoundError: No module named 'django.db.migrations.migration'
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
libgthread-2.0.so.0: cannot open shared object file: No such file or directory
command ng not foudn
command ng not found
Firebase tools
install firebase npm globally
install firebase tools
npm firebase -g
How do I export data from firebase authentication?
(‘08001’, ‘[08001] [Microsoft][ODBC Driver 17 for SQL Server]Client unable to establish connection (0) (SQLDriverConnect)’)
Error: Cannot find module '@truffle/hdwallet-provider'
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
how to install gulp
bash: gulp: command not found
fix failed to fetch in apt-get update
Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
OSError: [Errno 24] inotify instance limit reached
Failed to restart mongodb.service: Unit mongodb.service is masked.
winehq-stable : Depends: wine-stable (= 5.0.1~bionic)
Failed to restart apache2.service: Unit not found.
/bin/bash^M: bad interpreter: No such file or directory
could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
bash: cmake: command not found
NotImplementedError: OpenSSH keys only supported if ED25519 is available net-ssh requires the following gems for ed25519 suppor
ifconfig command not found
the remote end hung up unexpectedly fatal:
valet install command not found
subprocess.CalledProcessError: Command '('lsb_release', '-a')' returned non-zero exit status 1.
Something went wrong installing the "sharp" module
zsh: command not found: react-native
ng : File C:\Program Files\nodejs\ng.ps1 cannot be loaded because running scripts is disabled on this system.
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
'gh-pages' is not recognized as an internal or external command
install wheel
invalid command bdist_wheel
Column count of mysql.proc is wrong. Expected 21, found 20. Created with MariaDB 100145, now running 100415. Please use mysql_upgrade to fix this error
git@bitbucket.org: Permission denied (publickey).
ubuntu error: EACCES: permission denied, symlink '../lib/node_modules/yarn/bin/yarn.js' -> '/usr/local/bin/yarn'
could not connect to development server
"gcc": executable file not found in $PATH
make: g++: Command not found
bash: make: command not found
errors were encountered while processing: mysql-server-5.7 mysql-server e: sub-process /usr/bin/dpkg returned an error code (1)
run.sh: line 39: $'\r': command not found
ERROR: Could not build wheels for numpy which use PEP 517 and cannot be installed directly
ImportError: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.22' not found
Could not install from "Hussain\AppData\Roaming\npm-cache\_npx\15208" as it does not contain a package.json file.
Cannot retrieve metalink for repository: epel/i386. Please verify its path and try again
Error running '__rvm_make -j1'
apache2 does not start xampp mac
command failed: npm install --loglevel error --legacy-peer-deps
Failed to start redis-server.service: Unit redis-server.service is masked.
Could not find OpenSSL. Install an OpenSSL development package or
Kernel driver not installed (rc=-1908) Make sure the kernel module has been loaded successfully. where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.
Although GNOME Shell integration extension is running, native host connector is not detected.
This requires the 'non-nullable' language feature to be enabled.
Key path "" does not exist or is not readable
chmod 777 ubuntu xampp
'cypress' is not recognized as an internal or external command, operable program or batch file.
Invalid command 'ProxyPass',
error failed to launch the browser process puppeteer
adb failed to connect to '192.168.0.9:5555': Connection refused
macos install yarn
bash: yarn: command not found
nginx E: Sub-process /usr/bin/dpkg returned an error code (1)
Unable to correct problems, you have held broken packages
git cannot spawn gpg no such file or directory
Writing login information to the keychain failed with error 'The name org.freedesktop.secrets was not provided by
Skipping acquire of configured file 'main/binary-i386/Packages' as repository ' bionic InRelease' doesn't support architecture 'i386'
error: Not a valid ref: refs/remotes/origin/master fatal: ambiguous argument 'refs/remotes/origin/master': unknown revision or path not in the working tree.
'Cordova/CDVUserAgentUtil.h' file not found
locate command not found
Error: ENOSPC: System limit for number of file watchers reached
avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied ioctl("TIOCMGET"):
undefined reference to `sem_init'
npm ERR! Maximum call stack size exceeded ubuntu
git error: cannot lock ref 'refs/remotes/origin/master': unable to resolve reference 'refs/remotes/origin/master': reference broken
Error response from daemon: open \\.\pipe\docker_engine_linux: The system cannot find the file specified.
wsl ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
Command 'ng' not found, but can be installed with:
bash: lsb_release: command not found
The command 'docker' could not be found in this WSL 1 distro
steam is not in the sudoers file.
sudo: /etc/sudoers is owned by uid 1001, should be 0 sudo: no valid sudoers sources found, quitting
xampp the installer requires root privileges
remote: HTTP Basic: Access denied fatal: Authentication failed for
fatal: unable to access
Load key ".pem": bad permissions
git error invalid path
Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed
windows npm install permission denied
code UNABLE_TO_GET_ISSUER_CERT_LOCALLY
error: failed to push some refs to
Package 'php7.4-curl' has no installation candidate
nginx: [error] open() "/run/nginx.pid" failed (2: No such file or directory)
could not find driver (SQL: select * from information_schema.table
sudo command not found
unable to start ssh-agent service, error :1058
vue-cli-service not found
install gunicorn
gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>
E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
NoPermissions (FileSystemError): Error: EACCES: permission denied, open '/var/www/html/index.html'
source.list kali linux
w: some index files failed to download kali linux
Cipher algorithm 'AES-256-GCM' not found (OpenSSL)
conda command not found linux
Unrecognized command "eject"
Failed to start cron.service: Unit not found. in centos7
E: Sub-process /usr/bin/dpkg returned an error code (1)
crt secure no warnings
packages required to install psycopg2
ModuleNotFoundError: No module named 'psycopg2'
no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
Jwt Authentication error Argument 3 passed to Lcobucci\JWT\Signer\Hmac::doVerify()
pip install psycopg2 error fedora
There are no commands defined in the "ide-helper" namespace
There are no commands defined in the "ide-helper"
connection failed blueman.bluez.errors.dbusfailederror protocol not available
ubuntu no bluetooth found
mongodb log directory missing ubuntu
Installation failed: Download failed. Destination directory for file streaming does not exist or is not writable.
psycopg2 error install
setremotelogin: Turning Remote Login on or off requires Full Disk Access privileges.
ssh-add could not open a connection to your authentication agent centos
Homebrew PHP appears not to be linked. Please run [valet use php@X.Y]
'sanity' is not recognized as an internal or external command
No known instance method for selector 'userAgent'
permission denied: ./deploy.sh
could not open file "postmaster.pid": No such file or directory
[ErrorException] file_put_contents(./composer.json): failed to open stream: Permission denie d
could not read .composer/auth.json permission denied
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?
fatal error: portaudio.h: No such file or directory
cannot connect to daemon at tcp:5037: Connection refused
an apparmor policy prevents this sender
Your connection attempt failed for user 'root' to the MySQL server at localhost:3306: An AppArmor policy prevents this sender from sending this message to this recipient
could not store passwrod mysqkl workbench
could not store password an apparmor policy
no build file in linux headers
rrors were encountered while processing: /var/cache/apt/archives/libpython3.10-stdlib_3.10.4-1+focal2_amd64.deb
Error: GPG check FAILED fedora mysql
forever command not found
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
create react app with npm not yarn
react
"/src/reportWebVitals.js Module not found: Can't resolve 'web-vitals' in 'E:\ReactResources\RectProjects\test-app\src'"
pip install fails with connection error ssl
Failed to start nginx.service: Unit nginx.service not found.
windows fatal: unable to access SSL certificate problem: unable to get local issuer certificate
fatal: unable to access ' SSL certificate problem: unable to get local issuer certificate
Error initializing network controller: Error creating default "bridge" network: Failed to program NAT chain: ZONE_CONFLICT: 'docker0' already bound to a zone
No module named SimpleHTTPServer
Sub-process /usr/bin/dpkg returned an error code
'typ "{}"not recognised (need to install plug-in?)'.format(self.typ) NotImplementedError: typ "['safe', 'rt']"not recognised (need to install plug-in?)
npm WARN deprecated tar@2.2.2: This version of tar is no longer supported, and will not receive security updates. Please upgrade asap.
mongodb did not start
pipenv an error occurred while installing psycopg2==2.8.4
pipenv an error psycopg2
Could not install packages due to an EnvironmentError: [WinError 32] The process cannot access the file because it is being used by another process
Error: Let's Encrypt validation status 400.
Please make sure, that MariaDB Connector/C is installed on your system.
django runserver no reload
E: Unable to locate package libboost-signals-dev
apache2.service is not active cannot reload. ubuntu
bash: bin/activate: No such file or directory
remote: Repository not found. fatal: repository ' not found
fatal: unable to access Could not resolve host wsl
An unhandled exception occurred: Collection "@nativescript/schematics" cannot be resolved
Error: Cannot find module 'resolve'
No module named 'psycopg2'
Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied)
gumlet/php-image-resize 1.9.2 requires ext-gd *
unix:///var/run/supervisor.sock no such file
find skip permission denied messages
truffle.ps1 is not digitally signed
zsh: no matches found: autoprefixer@^9
htaccess all requests goes to index.php
install expo cli windows
install expo
how to check expo cli version
expo cli
npx react-native
start react native app
Error: Problem validating fields in app.json. See • should NOT have additional property 'nodeModulesPath'.
exec user process caused: exec format error
Failed to load module "appmenu-gtk-module"
cuda_home environment variable is not set. please set it to your cuda install root.
Fix the upstream dependency conflict, or retry this command with --force, or --legacy-peer-deps to accept an incorrect (and potentially broken) dependency resolution.
Module not found: Can't resolve ' in
insufficient permission for adding an object to repository database .git/objects
evillimiter: command not found
nginx cors only one is allowed
error ppa.launchpad.net/certbot/certbot/ubuntu focal Release
Error: Node Sass does not yet support your current environment: Linux 64-bit with Unsupported runtime (83)
cannot find module 'sass' vue
mocha zsh: command not found: mocha
linux failed to save insufficient permissions vscode
ConfigurationError: The "dnspython" module must be installed to use mongodb+srv:// URIs
installation of package ‘openssl’ had non-zero exit status
fatal: the remote end hung up unexpectedly
Fatal error in launcher:
libespeak.so.1: cannot open shared object file: No such file or directory
error: pcap library not found!
Cannot find module '@angular/fire/messaging' or its corresponding type declarations
Cannot find module '@angular/fire/firestore' or its corresponding type declarations
warning: unable to access '/Users/me/.config/git/attributes': Permission denied
The repository ' bionic Release' does not have a Release file.
psycopg2.OperationalError: could not connect to server: Connection refused Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5432?
npm install Cannot read property 'match' of undefined
vscode Module 'cv2' has no 'imshow' member
cpanel error fatal: bad config value for 'receive.denycurrentbranch' in config
adonis Cannot find module 'phc-argon2'
ERROR: While executing gem ... (Gem::FilePermissionError)
Brew was unable to install [php@7.1].
error: RPC failed; curl 56 LibreSSL SSL_read: Connection reset by peer, errno 54
You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.
ifconfig not found ubuntu 20.04
ifconfig not found ubuntu
-bash: : Permission denied
error Command failed with exit code 3221225477
EACCES: permission denied, unlink '/home/ericgit/.cache/yarn/v6/np
Failed to save 'go.mod': Insufficient permissions. Select 'Retry as Sudo' to retry as superuser.
bash firebase command not found
device or resource busy
error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory"
react-devtools agent got no connection
Failed to fetch HttpError404
suid privilege escalation systemctl
vmplayer kernel headers not found
"xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory
Error relocating /usr/bin/curl
bash errors: syntax error - ambiguous - file
Got an error creating the test database: ERREUR: droit refusé pour créer une base de données
Using the 'memory' GSettings backend. Your settings will not be saved or shared with other applications.
mkdir: `hdfs://127.0.0.1:9000/user/hadoop': No such file or directory
docker container could not open port /dev/ttyUSB0
No such file or directory: '/tmp/pip-build-sllmC0/jsonschema/setup.py'
23:in `system!': failed to run on-target -u root apt-get update >> var/install.log 2>&1
gcsfuse allow_other
code: 'ERR_OSSL_EVP_UNSUPPORTED'
fatal: repository ' not found
bash: /usr/bin/ng: No such file or directory
pip's dependency resolver does not currently take into account all the packages that are installed
adb shell error: more than one device/emulator
ubuntu mongodb not starting
Verificação de acesso de escrita [/srv/moodle/lib/editor/atto/plugins] Instalação abortada devido a falha de validação
WSL2 trying to launch VSCode with code . results in error "Please install missing certificates."
notify once a job is completed
errno 2 no such file or directory less
tried accessing the FileTransfer plugin but it's not installed.
database already registered
fatal: unknown date format format-local:%f %t ./bin/gbuild:167:in `block (2 levels) in build_one_configuration': error looking up author date in antimony (runtimeerror)
remote: The project you were looking for could not be found. fatal: repository ' not found
$'\r': command not found
Usually this happens when watchman isn't running. Create an empty `.watchmanconfig` file in your project's root folder or initialize a git or hg repository in your project
Could not create service of type FileHasher using BuildSessionServices.createFileHasher()
error timed out while waiting for handshake digitalocean
unable to correct problems you have held broken packages npm
no module named psycopg2
ArgumentError: Malformed version number string 0.32+git
laravel: command not found
error while loading shared libraries: libasound.so.2: cannot open shared object file: No such file or directory
Permissions 0664 for '/home/kapua/keys/dev11' are too open.
private key is too open
Permissions 0644 for are too open. It is required that your private key files are NOT accessible by others. This private key will be ignored
this text file seems to be executable script
linux adress is already in use
target lcobucci jwt parser is not instantiable while building laravel passport
The nearest package directory doesn't seem to be part of the projec
lxde desktop shortcut not runable
pip install django-heroku error
GVfs metadata is not supported. Fallback to Tell Metadata Manager. Either GVfs is not correctly installed or GVfs metadata are not supported on this platform. In the latter case, you should configure Tepl with --disable-gvfs-metadata.
Got error: 1698: Access denied for user 'root'@'localhost' when trying to connect
serve : File C:\Users\MY PC\AppData\Roaming\npm\serve.ps1 cannot be loaded because running scripts is disabled on this system
how to fix could not fix var lock /var/lib/dpkg/lock ubuntu
E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)
Peer's Certificate issuer is not recognized
gpg: WARNING: unsafe permissions on homedir
firebase npm install "Enter authorization code"
An error occurred while running subprocess capacitor.
Module '"@angular/fire"' has no exported member 'AngularFireModule'
ImportError: cannot import name 'task' from 'celery'
You don't have permission to access this resource.
how to restart apache2 in ubuntu 20.04
mkdir: /data/db: Read-only file system
echo /etc/hosts permission denied
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
mkdir create if not exists
error: ‘thread’ is not a member of std
unix:///tmp/supervisor.sock refused connection
E: Package 'pgadmin4' has no installation candidate
Call to undefined function factory() in Psy Shell code on line 1
This system is not registered with an entitlement server. You can use subscription-manager to register.
nginx control process exited with error code
OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443
fatal: unable to access ' OpenSSL SSL_read: Connection was reset, errno 10054 code example
django.core.exceptions.ImproperlyConfigured: The SECRET_KEY setting must not be empty
An error occurred (UnrecognizedClientException) when calling the GetAuthorizationToken operation: The security token included in the request is invalid.
laravel remote: error: unable to unlink old 'public/.htaccess': Permission denied
could not connect to server: Connection refused Is the server running on host and accepting TCP/IP connections on port 5432?
Failed to start The Apache HTTP Server.
error: src refspec master does not match any error: failed to push some refs to android studio
react native git error: src refspec main does not match
failed to clear cache. make sure you have the appropriate permissions. laravel
dyld: lazy symbol binding failed: Symbol not found: _ffi_prep_closure_loc
zsh: no matches found: with *
Package opencv was not found in the pkg-config search path. Perhaps you should add the directory containing `opencv.pc' to the PKG_CONFIG_PATH environment variable
listen EADDRINUSE: address already in use :::8081
kill a port windows
npm install Unable to authenticate, need: Bearer authorization_uri
pacman 404
fatal: unable to auto-detect email address (got 'root@LaptopName.(none)')
Error: EACCES: permission denied, mkdir '/Users/f5238390/Sites/pyramid-ui/node_modules/node-sass/build
Class 'ZipArchive' not found
the remote end hung up unexpectedly
firebase : File C:\Users\Abrar Mahi\AppData\Roaming\npm\firebase.ps1 cannot be loaded because running scripts is disabled on this system. For more information, see about_Execution_Policies at
libGL.so.1: cannot open shared object file: No such file or directory
ImportError: libGL.so.1: cannot open shared object file: No such file or directory
ineffective mark-compacts near heap limit allocation failed - javascript heap out of memory angular
nginx php log
php log server
server php log
nginx php-fpm log
php-fpm log
ubuntu php error log
php error log
Error: .ini file does not include supervisorctl section
apache server not starting in xampp ubuntu
apache is not starting in xampp ubuntu 20
xampp apache not starting
cd: permission denied:
react/rctbridge.h' file not found
has_add_permission() takes 2 positional arguments but 3 were given
Failed to execute child process “python” (No such file or directory)
npm ERR! fatal: not a git repository: /home/node/app/../../.git/modules/
install nodemon
sh: 1: nodemon: not found
ubuntu The following signatures couldn't be verified because the public key is not available: NO_PUBKEY
it is required that your private key files are not accessible by others
javax.net.ssl.SSLException MESSAGE: closing inbound before receiving peer's close_notify
unable to access : Could not resolve host: github.com
bash script: permission denied
InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.
Unknown collation: 'utf8mb4_0900_ai_ci'
Fix Unknown collation: 'utf8mb4_0900_ai_ci' error
view index not found. laravel
npm ERR! path /usr/local/lib/nodejs/node-v10.15.3-linux-x64/lib/node_modules while installing angular cli
Client does not support authentication protocol requested by server; consider upgrading MySQL client
matplotlib install
Error loading module: No module named 'matplotlib'
ews address already in use :::9000
Error: listen EADDRINUSE: address already in use :::9000
failed to open stream: Permission denied in path on mac
psycopg2 error
ll command not found
ERROR: Could not install packages due to an EnvironmentError: [WinError 5] Access is denied: 'd:\\anaconda3\\scripts\\pip.exe' Consider using the `--user` option or check the permissions.
no such file or directory scandir node-sass/vendor
bash: tree: command not found... centos7
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
pkg-config: not found
E: Package 'mysql-server' has no installation candidate
bind failed address already in use mac
typeerror: __init__() got an unexpected keyword argument 'column'
docker: error response from daemon: pull access denied for getting-started, repository does not exist or may require 'docker login': denied: requested access to the resource is denied.
install bootstrap in angular 9
how to install bootstrap in angular 11
Module not found: Error: Can't resolve
scp connection refused
ngular JIT compilation failed: '@angular/compiler' not loaded!
CommandNotFoundError: Your shell has not been properly
bash: fork: Cannot allocate memory
Stack found this candidate but arguments dont match
bloquear /var/lib/apt/lists
the input device is not a TTY. If you are using mintty, try prefixing the command with 'winpty'
ffmpeg not installed
dev/kvm not found
Error starting domain: Requested operation is not valid: network 'default' is not active
how to install imagemagick in linux
error: insufficient permission for adding an object to repository database .git/objects
cannot be loaded because running scripts is disabled on this system
tsc: command not found on arch
docker.service: Unit entered failed state.
docker.service: Failed with result 'exit-code'
error: Not a valid ref: refs/remotes/origin/master
error while loading shared libraries: libx11-xcb.so.1:
error Invalid plugin options for "gatsby-plugin-manifest":
debuild: command not found
v-restore-user command not found
Verify that the 'libvirtd' daemon is running
valet: command not found
Unable to create directory wp-content/uploads/. Is its parent directory writable by the server?
mongodb active failed (result exit-code)
conn = _connect(dsn, connection_factory=connection_factory, **kwasync) psycopg2.OperationalError: could not connect to server: Connection refused Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5432?
YumRepo Error: All mirror URLs are not using ftp, or file. Eg. Invalid release/repo/arch combination/
gnutls_handshake() failed: an unexpected tls packet was received.
permission denied /dev/kvm
Error: EACCES: permission denied, mkdtemp linux ubuntu
subl command not found
ifconfig not foound
Err:1 focal InRelease Temporary failure resolving 'archive.ubuntu.com' wsl
Failed to set up listener: SocketException: Address already in use
INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package com.*.version signatures do not match previously installed version; ignoring!
INSTALL_FAILED_USER_RESTRICTED: Install canceled by user
netlify build command
netlify Command failed with exit code 1: yarn build
error permission to .git denied to deploy key
GPG error: hirsute InRelease
no_pubkey
Warning: Homebrew's sbin was not found in your PATH but you have installed formulae that put executables in /usr/local/sbin.
upgrade pip error
download pip
pip not able to upgrade
ERROR: Could not install packages due to an EnvironmentError: [WinError 5] Access is denied: 'd:\\geeklone technology\\brandprotection\\brandprotection\\env\\scripts\\pip.exe' Consider using the `--user` option or check the permissions.
fatal: remote origin already exists.
Tell CMake where to find the compiler by setting either the environment variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path to the compiler, or to the compiler name if it is in the PATH.
bash: /proc/sys/vm/drop_caches: Permission denied
Required Windows feature(s) not enabled : Hyper-V and Containers
host key verification failed
error: src refspec master does not match any error: failed to push some refs to '
Unable to find a valid SQLite command
ifconfig not found
zsh: command not found
error pg_config executable not found. ubuntu
pushed into the wrong repo
Please make sure you have the correct access rights and the repository exists.
failed to restart mysql.service: unit mysql.service not found.
pod install not working bad interpreter: No such file or directory
linux sudo /opt/lampp/lampp start command not found
crontab command not found
the unit apache2.service has entered the 'failed' state with result 'exit-code'
bash: $'\302\226git': command not found
E: Unable to locate package mongodb-org
after checkout fatal: You are not currently on a branch.
bin/sh sam: not found
error: src refspec master does not match any.
fatal: Not possible to fast-forward, aborting.
libnss3.so: cannot open shared object file: No such file or directory
The terminal process failed to launch: Path to shell executable "/bin/zsh" does not exist.
Failure while executing; `/bin/launchctl bootstrap gui/501 /Users/singh/Library/LaunchAgents/homebrew.mxcl. exited with 5. singh@Singhs-Air ~ % sudo apachectl start
Unable to connect to libvirt qemu:///system.
launch bash script from application mac without opening terminal
shebang line
bash "[[: not found"
standard_init_linux.go:178: exec user process caused "exec format error"
Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/pgdg.list:1 and /etc/apt/sources.list.d/pgdg.list:2
ERROR: Could not install packages due to an EnvironmentError: HTTPSConnectionPool(host='files.pythonhosted.org'
Error: listen EADDRINUSE: address already in use
fatal: unable to access ' The requested URL returned error: 403
Module not found: Error: Can't resolve 'hammerjs'
aws folder permission denied
# Check failed: allocator->SetPermissions(reinterpret_cast<void*>(region.begin()), region.size(), PageAllocator::kNoAccess).
Package 'php-imagick' has no installation candidate
echo to file permission denied
laravel could not find driver
ng command not found
alpine add user
/bin/sh useradd not found alpine
vue command not found
uvicorn ERROR: [Errno 98] Address already in use
ERROR: There are no scenarios; must have at least one.
Failed to install the following Android SDK packages as some licences have not been accepted.
solving environment failed with initial frozen solve
/usr/bin/env: ‘bash\r’: No such file or directory
unable to connect my bluetooth devices to kali linux
Error: pg_config executable not found."fedora"
-bash: expo: command not found
rc.local not running
discord unexpected token =
error during global initialization mongodb
pkgAcquire::Run (13: Permission denied)
couldn't be accessed by user '_apt'. - pkgAcquire::Run
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
depmod: not found
Illuminate\Http\Exceptions\PostTooLargeException Ubuntu
fatal: unable to access ' Could not resolve host: github.com
address already in use 0.0.0.0:8080
The authenticity of host 'github.com (140.82.121.3)' can't be established. RSA key fingerprint is SHA256
clone with ssh gitlab fatal: Could not read from remote repository.
Permission denied (publickey,keyboard-interactive).
error: src refspec main does not match any error: failed to push some refs to '
*** WARNING : deprecated key derivation used
Writing login information to the keychain failed with error 'GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.secrets was not provided by any .service files'.
error failed to commit transaction (failed to retrieve some files)
uid : unable to do port forwarding: socat not found
ERR_NO_CERTIFICATES: Encountered adb error: NoCertificates. ionic
django.core.exceptions.ImproperlyConfigured: Requested setting ROOT_URLCONF, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.
postgres users can login with any or no password
"GH001: Large files detected. You may want to try Git Large File Storage" error fix
remote error large files detected
[INS-30131] Initial setup required for the execution of installer validations failed.
chmod: Unable to change file mode Operation not permitted
Error: Couldn't find the 'yo' binary. Make sure it's installed and in your $PATH
command not found
Host key verification failed. fatal: Could not read from remote repository.
error: src refspec main does not match any error: failed to push some refs to
pymongo.errors.ServerSelectionTimeoutError: localhost:27017
vscode Error: EACCES: permission denied
htaccess deny all but
zsh: command not found: nslookup
npm err_socket_timeout
zsh: permission denied
Unable to boot device due to insufficient system resources.
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sudo apt-get ignore warning
sudo apt-get ignore errors
The 'Install-Module' command was found in the module 'PowerShellGet', but the module could not be loaded. For more information, run 'Import-Module PowerShellGet'.
Cannot make for rpm, the following external binaries need to be installed: rpmbuild
Module not found: Can't resolve 'notistack' in 'C:\Users\
there are insecure directories /usr/local/share/zsh
command not found: strings
adb command not found zsh
apache2 .htaccess not writable
libcuda.so.1: cannot open shared object file: No such file or directory
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock:
Package signatures do not match previously installed version; ignoring!
The following packages have unmet dependencies: nginx : Depends: libssl1.0.0 (>= 1.0.2~beta3)
su: failed to execute /bin/bash: Resource temporarily unavailable
#40 22.05 ERROR: Cannot uninstall 'PyYAML'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.
access-control-allow-origin htaccess
: Failed to start A high performance web server and a reverse proxy server. -- Subject: A start job for unit nginx.service has failed
error Cannot find module 'metro-config'
No receipt for 'com.apple.pkg.CLTools_Executables' found at '/'
gh --version Command 'gh' not found,
Accessors are only available when targeting ECMAScript 5 and higher.
error TS1056
remote origin already exist error
add pg_config to path
configuration file is group-readable. This is insecure linux
unknown error after kill: runc did not terminate sucessfully: container_linux.go:392: signaling init process caused "permission denied"
The terminal process failed to launch: Path to shell executable "cmd.exe" does not exist. vscode
The repository ' bionic InRelease' is not signed.
FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
'image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8)
The application could not be installed: INSTALL_FAILED_CONFLICTING_PROVIDER
zsh: command not found: wine-stable
wine command not found
env: sh\r: No such file or directory
remote: Support for password authentication was removed on August 13, 2021. Please use a personal access token instead.
error cleaning log files [Error: EACCES: permission denied, scandir '/root/.npm/_logs']
npm Error: EACCES: permission denied, scandir
sudo: command not found
Warning: Homebrew's "sbin" was not found in your PATH but you have installed
Postman Collection Format v1 is no longer supported and can not be imported directly. You may convert your collection to Format v2 and try importing again.
gp policy force update
windows refresh group policy
port 80 in use by "unable to open process" with pid 4!
wsl user has not been granted the requested logon type at this computer
xcrun: error: invalid active developer path
bash: conda: command not found
It is required that your private key files are NOT accessible by others ubuntu
ubuntu errors were encountered while processing libc-bin
libc-bin error
script to install cf cli in linux
Can't open C:\ci\openssl_1581353098519\_h_env\Library/openssl.cnf for reading, No such file or directory
! [rejected] master -> master (fetch first) error: failed to push some refs to '
Fatal error in launcher: Unable to create process using getting this error while installing pip
* daemon not running; starting now at tcp:5037
BUILD FAILED (Ubuntu 20.04 using python-build 20180424)
TclError('no display name and no $DISPLAY environment variable'
error: refname refs/heads/master not found fatal: Branch rename failed
[Thu Nov 5 15:20:23 2020] Failed to listen on localhost:3200 (reason: Address already in use)
error: command failed: adb shell am start -n
vue-cli-service not found linux
git push heroku master error: src refspec master does not match any '
how to avoid nginx not found 404 error ubuntu react app
[error] The installed version of the /Database Logging/ module is too old to update
debian libc-client.a). Please check your c-client installation
allow-unauthenticated not working
react/rctbridgemodule.h' file not found xcode
ubuntu 18.04 jenkins The following signatures couldn't be verified because the public key is not available:
crontab is not running my shell script
dpkg: error processing archive /var/cache/apt/archives/atftpd_0.7.git20210915-
xrandr configure crtc 2 failed ubuntu
Skipping acquire of configured file 'multiverse/binary-1386/Packages' as repository ' focal-security InRelease' doesn't support architecture '1386'
E: Package 'tesseract-ocr-dev' has no installation candidate
curl : Depends: libcurl3-gnutls
Could not find an NgModule. Use the skip-import option to skip importing in NgModule.
why is my db.sqlite3 is not gitignore
The platform "win32" is incompatible with this module.
Usage Error: The nearest package directory
symfony Unable to write in the "logs" directory (/var/www/html/var/log).
Invalid base64 sqs
distutils.sysconfig install
The configuration file now needs a secret passphrase (blowfish_secret).
php mysqli_connect: authentication method unknown to the client [caching_sha2_password]
Could not execute 'apt-key' to verify signature (is gnupg installed?)
pyaudio windows fail
TypeError: Could not load reporter "mochawesome"
Please ensure that the SDK and/or project is installed in a location that has read/write permissions for the current user.
error: insufficient permissions for device
npm install not workjing behind proxy
Error: Unable to find a match: centos-release-openstack-queens
Cannot validate since a PHP installation could not be found. Use the setting 'php.validate.executablePath' to configure the PHP executable. mac
unknown collation 'utf8mb4_0900_ai_ci'
mysql issue unknown collation 'utf8mb4_0900_ai_ci'
zsh problem: compinit:503: no such file or directory
gvm not generated password
redis: command not found
error: resource android:attr/lStar not found.
how to silence operation not permitted
Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted
Could not find or parse valid build output file.
curl without progress
job name getprojectmetadata does not exist
docker fatal: Not a git repository (or any of the parent directories): .git
Support for password authentication was removed. Please use a personal access token instead
ubuntu 14 Some index files failed to download. They have been ignored, or old ones used instead.
Error mounting: mount: unknown filesystem type 'ntfs'
Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details
gitlab server certificate verification failed
sourcetree permission denied (publickey) github mac
Start rc.local manually
docker NoRouteToHostException: No route to host (Host unreachable)
height not divisible by 2 (3308x1975) Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
Could not open /dev/vmmon: No such file or directory. Please make sure that the kernel module `vmmon' is loaded.
emporary failure resolving
The file \AppData\Roaming\npm\yarn.ps1 is not digitally signed.
mongodb database not connected docker
docker sh: react-scripts: not found
Unable to init server: Could not connect: Connection refused
failed (Result: start-limit-hit)
ubuntu psql: error: FATAL: Peer authentication failed for user
Treating warnings as errors because process.env.CI = true. github
pyinstaller “failed to execute script” error with --noconsole option
linux guzzle
Couldn't join realm: Necessary packages are not installed: oddjob, oddjob-mkhomedir, sssd, adcli
refusing to exec crouton from noexec mount
No package 'gcr-3' found
remote: Permission to asfand005/test.git denied to asfand87.
W: GPG error: xenial InRelease: The following signatures were invalid: KEYEXPIRED 1622248854
libqt5core5a is not installed.
windows build support installation failed unity linux
The switch --no-outline, is not support using unpatched qt, and will be ignored.QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-w
conda install throws ssl error
Unsupported upgrade request.
attributeerror module 'platform' has no attribute 'linux_distribution' ubuntu 20.04 docker-compose
Delta compression using up to 4 threads error: RPC failed; curl 92 HTTP/2 stream 0 was not closed cleanly: CANCEL (err 8) send-pack: unexpected disconnect while reading sideband packet
Target DEP-11-icons-small (stable/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list.d/archive_uri- and /etc/apt/sources.list.d/docker-ce.list:1
install pillow error alpine linux
openssl error with ruby 2.3.4 in ubuntu
v4l2 not found
install ksd command
Trying to bind fd 26 to <0.0.0.0:443>: errno=13
ksd command not found
Access denied for user ''@'localhost' (using password: YES)
bash cake command not found
libsound2-dev missing
patch: command not found
Test validator does not look started.
XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
unable to start test validator. check .anchor/test-ledger/test-ledger-log.txt for errors.
migrate has no installation candidate
where are php errors logged
node installation error authenticated user is not valid
Failed to build logging Installing collected packages: logging Running setup.py install for logging ... error
A snapshot operation for 'Pixel_4_API_30' is pending and timeout has expired. Exiting...
CMake: unsupported GNU version -- gcc versions later than 8 are not supported
fatal: Authentication failed for '
QSslSocket: cannot resolve CRYPTO_set_id_callback QSslSocket: cannot resolve CRYPTO_set_locking_callback QSslSocket: cannot resolve sk_free QSslSocket
REMOTE HOST IDENTIFICATION HAS CHANGED! how to fix in ubuntu
iwconfig command not found
Error generated. /dvs/git/dirty/git-master_linux/multimedia/nvgstreamer/gst-nvarguscamera/gstnvarguscamerasrc.cpp, execute:783 (propagating)
how to make apache2 not autorestat when startup
shell script no such file or directory
chmod: cannot access 'adb':
failed to push some refs to
cannot find module inquirer
Grant Htaccess to all directory
[22668] Error loading Python lib '/tmp/_MEIxdmlWe/libpython3.7m.so.1.0': dlopen: libcrypt.so.1: cannot open shared object file: No such file or directory
docker wget not found
Execution failed for task ':react-native-firebase_auth:generateDebugRFile'
dpkg-buildpackage: error: fakeroot debian/rules clean subprocess returned exit status 2
ModuleNotFoundError: No module named 'win32event'
env: ‘/etc/init.d/tomcat’: No such file or directory
error: eaccess: permission denied ionic
mariadb references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
invalid signature for kali linux repositories
*15856 connect() to unix:/var/run/php/php8.0-fpm.sock failed (11: Resource temporarily unavailable)
linux "Error: Timeout was reached"
To permanently fix this problem, please run: npm ERR! sudo chown -R 1000:1000
Timeout waiting to lock daemon addresses registry. It is currently in use by another Gradle instance.
200 response .htaccess
dokcer not working
get virtual display linux
[pid=9008][err] Error: no DISPLAY environment variable specified
NGINX: connect() to unix:/var/run/php7.2-fpm.sock failed (2: No such file or directory)
Runtime.ImportModuleError: Unable to import module 'lambda_function': libGL.so.1: cannot open shared object file: No such file or directory
fenicsproject no active host found
`path` for shell provisioner does not exist on the host system:
laravel routes return not found after setting virtual host on localhost linux
zsh: command not found: adb
fatal: failed to install gitlab-runner: service gitlab-runner already exists
cordova: command not found
You don't have write permissions for the rvm
budo is not recognized as an internal or external command
The capture session could not be initiated on capture device "en0"
ansible Permission denied (publickey,password).
error: required key missing from keyring
chsh pam authentication failure
the 'apxs' command appears not to be installed or is not executable shell
enable vault autocomplete
homestead.yaml adding provisions
cat: /var/jenkins_home/secrets/initialAdminPassword: No such file or directory
-bash: bin/startup.sh: Permission denied
Library not loaded: /opt/homebrew/opt/icu4c/lib/libicui18n.69.dylib
is installed in '/home/agent1409/.local/bin' which is not on PATH
fix is installed in '/home/incredible/.local/bin' which is not on PATH
Error: serverless-domain-manager: Plugin configuration is missing.
[ERROR] An error occurred while running subprocess capacitor.
failed to open stream: No space left on device linode
rec: command not found
error: snap "gimp" has "install-snap" change in progress
docker.credentials.errors.StoreError: Credentials store docker-credential-desktop.exe exited with ""
powershell pip CERTIFICATE_VERIFY_FAILED
apache you don't have access to this resource
Starting ssh-agent on Windows 10 fails: "unable to start ssh-agent service, error :1058"
problem detected port 80 in use by unable to open process with pid 4
CMake Error: Could not find CMAKE_ROOT !!!
command not found: django-admin
TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x22
no matching manifest for linux/arm64/v8 in the manifest list entries
export to path linux (pipenv)
command not found pipenv zsh
A two digit month could not be found Data missing
heroku error: src refspec master does not match any
ImportError: /lib64/libstdc++.so.6: version `CXXABI_1.3.9' not found
wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error+dd image
error: pathspec 'origin/main-dev' did not match any file(s) known to git
fatal: 'origin/main-dev' is not a commit and a branch 'base' cannot be created from it
git basic access denied
bash: syntax error near unexpected token 'do'
not a git repository after clone
not a git repository fatal error
hide permission denied ~/.bash
Module not found: Can't resolve ''
fatal: 'heroku' does not appear to be a git repository
ubuntu camera not longer found
"Start-bitstransfer cannot find path because it does not exist"
ERROR `/directory/' not found. jekyll
dpkg: error processing archive /var/cache/apt/archives/influxdb_1.8.10-1_amd64.deb (--unpack):
GPG error: buster InRelease:
git unable to connect to cache daemon: Permission denied
zsh: permission denied: ./manage.py for django projects
error: cannot find module '/usr/src/app/ng' Docker
McFly: Upgrading McFly DB to version 3, please wait...thread 'main' panicked at 'McFly error: Unable to add cmd_tpl to commands (duplicate column name: cmd_tpl)', src/history/schema.rs:41:17
no matches found: *.dmg
fatal: [node1]: FAILED! => {"attempts": 4, "changed": false, "msg": "No package matching 'python-apt' is available"}
laravel nginx 404 not found
is needed to run `file_system` for your system
Error: error modifying EC2 Volume "vol-04e2b1a2d03860650": InvalidParameterValue: New size cannot be smaller than existing size
What does mv: cannot stat not_here: No such file or directory mean in Ubuntu 20.04?
sigin failed for rsa github signing
node-pre-gyp ERR! install response status 404 Not Found
var/lib/dpkg/info/ubuntu-advantage-tools.prerm:%20py3clean:%20not%20found
error: failed to init transaction
Invalid response body while trying to fetch
def_daemon[19685]: segfault at 7f4d6811b7f0 ip 00007f4d6811b7f0 sp 00007f4d65bcc808 error 15
storage/logs" and it could not be created: Permission denied
Error uncompressing archive : Unable to created directory /var/jenkins_home_restore
dconf command not found
Permission denied (publickey). /usr/local/bin/mosh: Did not find mosh server startup message. (Have you installed mosh on your server?)
custom notification with powershell
gcloud.ps1 cannot be loaded
zmq.hpp not found
heroku The 'composer install' process failed with an error
Cannot not find '/run/user/1001/snap.remmina/../pulse/native'
Err:9 focal Release 404 Not Found [IP: 91.189.95.85 80]
Unable to correct problems, you have held broken packages installing cuda
System.DllNotFoundException: Unable to load DLL 'System.Security.Cryptography.Native': The specified module could not be found.
The repository ' buster-updates InRelease' is not signed
rm: cannot remove 'wk_base_survey': Permission denied wsl
scp: /home//pass.csv: Permission denied
set the environment path variable for ffmpeg by running the following command:
ibus-daemon is not running
if file not exists
Trying to register Bundler::GemfileError for status code 4 but Bundler::GemfileError is already registered
Exception: No Linux desktop project configured. See
fork/exec /bin/bash: resource temporarily unavailable
Command 'mpirun' not found
lxc command not found
pe: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
could not get batched bridge
cannot import name 'AnsibleCollectionLoader'
ImportError: lxml not found, please install it
C:\Ruby30-x64\bin\ruby.exe: Is a directory -- . (LoadError)
sudo: code: command not found
O arquivo C:\Users\jukin\AppData\Roaming\npm\yarn.ps1
dev/ktm not found
dpkg: error processing package libc-bin (--configure): installed libc-bin package post-installation script subprocess returned error exit status 134
remote: ! You are trying to install ruby-2.7.0 on heroku-20.
PrestaShop installation needs to write critical files in the folder var/cache
yarn <pre>00h00m00s 0/0: : ERROR: There are no scenarios; must have at least one. </pre>
Err:15 bionic Release 404 Not Found [IP: 91.189.95.83 80]
Git failed with a fatal error. could not read Password for
codeception environnement variable not found
"osx" please install the libcurl development files or specify --curl-config
splunk error can not create trial
how to sudo pip permission denied
Error response from daemon: Get " dial tcp: lookup registry-1.docker.io: device or resource busy
linux check how many open files are allowed
invariant violation: requirenativecomponent: "rctpdf" was not found in the uimanager.
Calling Non-checksummed download of pup formula file from an arbitrary URL is disabled!
failed to start service utility VM (createreadwrite): kernel 'C:\Program Files\Linux Containers\kernel' not found
permission denied while doing set-executionpolicy
command lxd not found - linux
add-apt-repository universe invalid
an audio or video streams is not handled due to missing codec)
package 'ffmpeg' has no installation candidate ubuntu 18.04
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missing mysql_config
Error: Account is not an upgradeable program or already in use
fatal: cannot lock ref 'HEAD': unable to resolve reference 'refs/heads/master':
Execution failed for task ':app:compressDebugAssets'.
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bash: ng: command not found yarn
Command 'root' not found
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could not open lock file "/tmp/.s.PGSQL.5432.lock": Permission denied
open files limit
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error: <class 'xmlrpclib.Fault'>, <Fault 6: 'SHUTDOWN_STATE'>: file: /usr/lib/python2.7/xmlrpclib.py line: 800
configure: error: "curses not found"
Authentication failed for tfs git
Err:5 focal/main amd64 libgif7 amd64 5.1.9-1 Temporary failure resolving 'archive.ubuntu.com'
Unable to connect to server: connection to server at "localhost" (127.0.0.1), port 5432 failed: Connection refused Is the server running on that host and accepting TCP/IP connections?
error: Setup script exited with error: libhdf5.so: cannot open shared object file: No such file or directory
14 bionic InRelease The following signatures were invalid: EXPKEYSIG F42ED6FBAB17C654 Open Robotics <info@osrfoundation.org> Fetched 4,680 B in 3s (1,803 B/s)
Postgres - FATAL: database files are incompatible with server
Got error 'PHP message: PHP Fatal error: Uncaught Error: Call to undefined function json_decode()
protonup no such file or directory
filetype exfat not configured in kernel
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The repository ' groovy Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default.
git config --system core.longpaths true premission denied
bash: $'\302\203 git': command not found
il pacchetto non è valido oppure è corrotto (firma PGP):
canonicalgrouplimited.ubuntu on windows parameter is incorrect
Ubuntu Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 15551 (apt)
busca de ficheiro em linux sem access denied e com data
DISABLE_DATABASE_ENVIRONMENT_CHECK=1
Show error message and exit if $FOO is unset (or null)
ubuntu show RLIMIT_NOFILE
NameError: name 'msno' is not defined
libthai0:i386 depends on libdatrie1 (>= 0.2.0); however: Package libdatrie1:i386 is not configured yet.
How to create a hash digest for an encrypted file and how to verify it's authenticity
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. | https://www.codegrepper.com/code-examples/shell/source.list+kali+linux | CC-MAIN-2022-21 | en | refinedweb |
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I took a look at the laser. It is probably the LD TEC (DTEC) failure.
As the temperature of the LD (DTMP) gradually deviated from 25degCish,
the DTEC voltage also went up from 2Vish to 2.1, 2.2...
When DTEC reaches 3V, it stopped lasing. This cools the diode a bit, and
it start lasing but repeat the above process.
I am not sure which of the head and controller has the issue.
The situation did not improve much by reducing the pumping current (ADJ: -15).
BTW, Turning on/off the noise eater did not change the situation.
I think the head/controller set should be sent out to JDSU and find how they will say.
I turned the laser back on around 1am. This is still happening, although right now it is turning off more often than before, maybe every 15 seconds or so. I am going to turn off the laser for the night.
The measured laser temperature is about 45C (I have a 25,000 count offset in the Y ALS Slow control right now....higher offset, lower temp), although the measured laser temp drops to ~43.5C when the power goes down.
Jamie and I discovered a problem with Matlab/Simulink earlier today.
In the end suspension models, there is a subblock (with top_names) for ALS stuff. Inside there, we use a library part called "ALS_END". When the model was created, it included the part ...../userapps/release/isc/c1/models/ALS_END.mdl . However, if you open up the c1scy diagram and look in the ALS block for this part, you see the part that is in ..../userapps/release/isc/common/models/ALS_END.mdl . Note the difference - the one we want is in the c1 directory, while the one that was created (by Jamie) for the LHO One Arm Test is in the common directory.
If you compile the c1scy model, the RCG is using the correct library part, so the information regarding which part we want is still in there.
However, if you delete the ALS_END part from the model, put the correct one in, save, close, then reopen the model, it once again displays the wrong model. The right click "go to library part" option brings you to the library part that is displayed, which is currently the wrong one. THIS IS BAD, since we could start modifying the wrong things. You do get a warning by Matlab about the file being "shadowed", so we should take heed when we see that warning, and make sure we are getting the file we want.
We are currently running Matlab version 7.11.0.584, which is r2010b. Step 1 will be to update Matlab to the latest version, in hopes that this fixes things. We also should change the name of our c1 part, so that it does not have the same name as the one for the sites. This is not a great solution since we can't guarantee that we will never choose the same names as other sites, but it will at least fix this one case. Again, if you see the warning about "shadowed" filenames, pay attention.
This work earlier today had required moving the harmonic separator back closer to its original position, so that the green could get through without clipping. I locked the Xarm (overriding the trigger) and realigned TRX to the PD and camera..
Manasa has done some work to get the Xgreen aligned, so I'll switch to trying to find that beatnote for now.
[Jenne, Manasa].
Jamie and I were doing some locking, and we found that the Yarm green wasn't locking. It would flash, but not really stay locked for more than a few seconds, and sometimes the green light would totally disappear. If the end shutter is open, you can always see some green light on the arm transmission cameras. So if the shutter is open but there is nothing on the camera, that means something is wrong.
I went down to the end, and indeed, sometimes the green light completely disappears from the end table. At those times, the LED on the front of the laser goes off, then it comes back on, and the green light is back. This also corresponds to the POWER display on the lcd on the laser driver going to ~0 (usually it reads ~680mW, but then it goes to ~40mW). The laser stays off for 1-2 seconds, then comes back and stays on for 1-2 minutes, before turning off for a few seconds again.
Koji suggested turning the laser off for an hour or so to see if letting it cool down helps (I just turned it off ~10min ago), otherwise we may have to ship it somewhere for repairs :(
This is happening again to the Yend laser. It's been fine for the afternoon, and I've been playing with the temperature. First I have been making big sweeps, to figure out what offset values do to the actual temperature, and more recently was starting to do a finer sweep. Using the 'max hold' function on the 8591, I have seen the beat appear during my big sweeps. Currently, the laser temperature measurement is at the Yend, and the RF analyzer is here in the control room, so I don't know what temp it was at when the peaks appeared.
Anyhow, while trying to reaquire lock of the TEM00 mode after changing the temperature, I find that it is very difficult (the green seems misaligned in pitch), and every minute or so the light disappears, and I can no longer see the straight-through beam on the camera. I went down to the end, and the same symptoms of LED on the laser head turning off, power out display goes to ~40mW, are happening. I have turned off the laser as was the solution last time, in hopes that that will fix things.
I ran a cable to the GTRX camera. It is now input #2. The videoswitch script input naming is modified to match this: Input 2 used to be "IFOPO", and is now "GTRX". Input 28 used to be "GRNT", and is now "GTRY". Both green trans cameras are available from the video screen.
I pulled the beatbox from the 1X2 rack so that I could try to hack in some output whitening filters. These are shamefully absent because of my mis-manufacturing of the power on the board.
Right now we're just using the MON output. The MON output buffer (U10) is the only chip in the output section that's stuffed:
The power problem is that all the AD829s were drawn with their power lines reversed. We fixed this by flipping the +15 and -15 power planes and not stuffing the differential output drivers (AD8672).
It's possible to hack in some resistors/capacitors around U10 to get us some filtering there. It's also possible to just stuff U9, which is where the whitening is supposed to be, then just jump it's output over to the MON output jack. That might be the cleanest solution, with the least amount of hacking on the board.
I modified the beatbox according to this plan. I stuffed the whitening filter stage (U9) as indicated in the schematic (I left out the C26 compensation cap which, according to the AD829 datasheet, is not actually needed for our application). I also didn't have any 301 ohm resistors so I stuffed R18 with 332 ohm, which I think should be fine.
Instead of messing with the working monitor output that we have in place, I stuffed the J5 SMA connector and wired U9 output to it in a single-ended fashion (ie. I grounded the shield pins of J5 to the board since we're not driving it differentially). I then connected J5 to the I/Q MON outputs on the front panel. If there's a problem we can just rewire those back to the J4 MON outputs and recover exactly where we were last week.
It all checks out: 0 dB of gain at DC, 1 Hz zero, 10 Hz pole, with 20 dB of gain at high frequencies.
I installed it back in the rack, and reconnected X/Y ARM ALS beatnote inputs and the delay lines. The I/Q outputs are now connected directly to the DAQ without going through any SR560s (so we recover four SR560s).
I dedicated my evening to trying to get the Ygreen beatnote (the idea being to then get the Xgreen beatnote).
First up was tweaking up the green alignment. Per Yuta's suggestion, elog 8283, I increased the refl PD gain by 2 clicks (20dB) to keep the lock super stable while improving the alignment. After I finished, I turned it back to its nominal value. I discovered that I need lenses in front of the DC PD (for Ygreen, and I'm sure Xgreen will be the same). The beam is just barely taking up the whole 2mm diode, so beam jitter translates directly to DC power change measured by the diode. I ended up going just by the green transmission camera for the night, and achieved 225uW of Ygreen on the PSL table. This was ~2,000 counts, but some of the beam is always falling off the diode, so my actual counts value should be higher after installing a lens.
I then opened up the PSL green shutter, which is controlled by the button labeled "SPS" on the shutter screen - I will fix the label during some coffee break tomorrow. Using my convenient new PSL green setup, removing the DC PD allows the beam to reflect all the way to the fuse box on the wall, so you can check beam overlap between the PSL green and the arm green at a range of distances. I did this for Ygreen, and overlapped the Ygreen and PSL green.
I checked the situation of the beat cabling, since Jamie has the beatbox out for whitening filter modifications tonight. In order to get some signal into the control room, I connected the output of the BBPD amplifier (mounted on the front of the 1X2 rack) directly to the cable that goes to the control room. (As part of my cleanup, I put all the cables back the way I found them, so that Jamie can hook everything back up like normal when he finishes the beatbox.)
I then started watching the signal on the 8591E analyzer, but didn't magically see a peak (one can always hope....).
I decided that I should put the offset in the Y AUX laser slow servo back to the value that we had been using for a long time, ~29,000 counts. This is where things started going south. After letting that go for a minute or two, I thought to go check the actual temperature of the laser head. The "T+" temperature on the controller read something like 42C, but the voltmeter which reads a voltage proportional to the temp (10C/V) was reading 5.6V. I immediately turned off the offset, but it's going to take a while for it to cool down, so I'll come back in the morning. I want the AUX laser to be something like 34C, so I just have to wait. Ooops.
Still to do (for the short-term FPMI):
* Find Y beatnote.
* Align Xgreen to the arm - it's still off in pitch.
* Align Xgreen and PSL green to be overlapped, hitting the BBPD.
* Find the X beatnote.
* Reinstall the beatbox.
* Use ALS to stabilize both arms' lengths.
* Lock MICH with AS.
* Look at the noise spectrum of AS - is there more noise than we expect (Yuta and Koji saw extra noise last summer), and if so, where does it come from? Yuta calculated (elog 6931) that the noise is much more than expected from just residual arm motion.
* Write a talk.
Both X and Y green are aligned such that the arm beams hit the broadband PD. Also, the 4th port of the combining BS for each arm was used to put a camera and DC PD for each arm. So, ALS-TRX and ALS-TRY are both active right now. The camera currently labeled "GRNT" is the Ygreen transmission. I have a camera installed for Xgreen transmission, but I have not run a cable to the video matrix. For now, to speed things up, I'll just use the GRNT cable and move it back and forth between the cameras.
-
Jamie has informed me of numpy's numpy.savetxt() method, which is exactly what I want for this situation (human-readable text storage of an array). So, I will now be using:
# outfile is the name of the .png graph. data is the array with our desired data.
numpy.savetxt(outfile + '.dat', data)
to save the data. I can later retrieve it with numpy.loadtxt()
The.
- I took the shutter from AS table to use it for the PSL green. It was sitting near MC REFL path unused (elog #8259).
-.
-.
[Jenne, Manasa]
2 colors 2 arms realized!
1. Spot centering:
We spot centered the IR in both arms.
- Use TT1 and TT2 to center in Y arm (I visually center the spots on the ITM and ETM and then use TTs iteratively)
- Use BS-ETM to center in X arm
Spot positions after centering
X arm Y arm
itmx etmx itmy etmy
pitch -0.86 0.37 1.51 0.05
yaw 0.01 -0.1 0.08 0.10.
3. ALS - green alignment
We then moved on to Ygreen. We used the out of vac steering mirrors to center the beam on the 2 irises that are in place on the table, which was a good starting place. After doing that, and tweaking a small amount to overlap the incident and reflected beams on the green steering mirrors, we saw some mode lock. We adjusted the end table steering mirrors until the Ygreen locked on TEM00. We then followed Rana's suggestion of locking the IR to keep the cavity rigid while we optimized the green transmission. Yuta, while adjusting ITMY and ETMY (rather than the out of vac mirrors) had been able to achieve a green transmission for the Yarm of ~2700 counts using the GTRX DC PD that's on the table. We were only able to get ~2200, with brief flashes up to 2500.
After that, we moved on to the X arm. Since there are no irises on the table, we used the shutter as a reference, and the ETM optic itself. Jenne looked through the viewport at the back of the ETM, while Manasa steered mirrors such that we were on the center of the ETM and the shutter. After some tweaking, we saw some higher order modes lock. We had a very hard time getting TEM00 to stay locked for more than ~1 second, even if the IR beam was locked. It looks like we need to translate the beam up in pitch. The leakage of the locked cavity mode is not overlapped with the incident beam or the promptly reflected beam. This indicates that we're pretty far from optimally aligned. Manasa was able to get up to ~2000 counts using the same GTRX PD though (with the Ygreen shutter closed, to avoid confusion). Tomorrow we will get the Xarm resonating green in the 00 mode.
We need to do a little cleanup on the PSL green setup. Yuta installed a shutter (I forget which unused one he took, but it was already connected to the computers.), so we can use it to block the PSL green beam. The idea here is to use the 4th port of the combining beam splitters that are just before each beat PD, and place a PD and camera for each arm. We already have 2 PDs on the table connected to channels, and one camera, so we're almost there. Jenne will work on this tommorrow during the day, so that we can try to get some beat signals and do some handoffs in the evening.
Koji reminded me (again....this is probably the 2nd or 3rd time I've "discovered" this, at least) that the script
..../scripts/MC/WFS/WFS_FilterBank_offsets
exists, and that we should use it sometimes. See his elog 7452 for details.
2
Notes about using this script:
* Only use it after MC has been very well aligned. MC REFL DC should be less than 0.5 when the MC is locked (with the DC value ~4.5 with the MC unlocked, as usual). This is hard to achieve, but important. Also, check the MC spot centering.
* With the WFS servo off, but the MC locked and light on the WFS diodes, run the script..
Steve just told those of us in the control room that the custodian who goes into the IFO room regularly steps on the blue support beams to reach the top of the chambers to clean them. Since we have seen in the past that stepping on the blue tubes can give the tables a bit of a kick, this could help explain some of the drift, particularly if it was mostly coming from TT2. The custodian has promised Steve that he won't step on the blue beams anymore.
This doesn't explain any of the ~1 hour timescale drift that we see in the afternoons/evenings, so that's still mysterious..
[Manasa, Annalisa, Jenne]
The MC wasn't locking on TEM00 this morning, and the WFS kept pulling the MC out of alignment. The MC was realigned, and the WFS spots are back to being roughly centered (all of this only touching the MC sliders), but the WFS keep doing bad things. They're okay, and improve the alignment slightly at first, but as soon as the FM1 integrator comes on, the MC alignment immediately starts going bad, and within a second or so the MC has unlocked.
The WFS are off right now, and we'll keep investigating after LIGOX.).
~20 minutes ago, maybe right around the time the fb's RAID died (elog 8274) the mode cleaner started behaving weirdly again. The reflected value is very high, even with the WFS on. Earlier this evening, I saw that with the WFS off, the MC reflection was high, but the WFS brought it back down to ~0.7 or 0.8. But now it's ~1.3. With the WFS off, the reflected value is ~1.1. I don't really understand.
Also, the PMC has been drifting in alignment in pitch all day, but a lot more later in the day. The PMC trans is 0.800 right now, but it was as high as 0.825 today, and spent most of the day in the high 0.81xxx range today.
I would provide plots, but as mentioned in elog 8274, we can't get data right now.
[Manasa, Jenne].
Quick Note on Multiprocessing: The multiprocessing was plugged into the codebase on March 4. Since then, the various pages that appear when you click on certain tabs (such as the page found here: from clicking the 'IFO' tab) don't display graphs. But, the graphs are being generated (if you click here or here, you will find the two graphs that are supposed to be displayed). So, for some reason, the multiprocessing is preventing these graphs from appearing, even though they are being generated. I rolled back the multiprocessing changes temporarily, so that the newly generated pages look correct until I find the cause of this.
Fixing Plot Limits: The plots generated by the summary_pages.py script have a few problems, one of which is: the graphs don't choose their boundaries in a very useful way. For example, in these pressure plots, the dropout 0 values 'ruin' the graph in the sense that they cause the plot to be scaled from 0 to 760, instead of a more useful range like 740 to 760 (which would allow us to see details better).
The call to the plotting functions begins in process_data() of summary_pages.py, around line 972, with a call to plot_data(). This function takes in a data list (which represents the x-y data values, as well as a few other fields such as axes labels). The easiest way to fix the plots would be to "cleanse" the data list before calling plot_data(). In doing so, we would remove dropout values and obtain a more meaningful plot.
To observe the data list that is passed to plot_data(), I added the following code:
# outfile is a string that represents the name of the .png file that will be generated by the code.
print_verbose("Saving data into a file.")
print_verbose(outfile)
outfile_mch = open(outfile + '.dat', 'w')
# at this point in process_data(), data is an array that should contain the desired data values.
if (data == []):
print_verbose("Empty data!")
print >> outfile_mch, data
outfile_mch.close()
When I ran this in the code midday, it gave a human-readable array of values that appeared to match the plots of pressure (i.e. values between 740 and 760, with a few dropout 0 values). However, when I let the code run overnight, instead of observing a nice list in 'outfile.dat', I observed:
[('Pressure', array([ 1.04667840e+09, 1.04667846e+09, 1.04667852e+09, ...,
1.04674284e+09, 1.04674290e+09, 1.04674296e+09]), masked_array(data = [ 744.11076965 744.14254761 744.14889221 ..., 742.01931356 742.05930208
742.03433228],
mask = False,
fill_value = 1e+20)
)]
I.e. there was an ellipsis (...) instead of actual data, for some reason. Python does this when printing lists in a few specific situations. The most common of which is that the list is recursively defined. For example:
INPUT:
a = [5]
a.append(a)
print a
OUTPUT:
[5, [...]]
It doesn't seem possible that the definitions for the data array become recursive (especially since the test worked midday). Perhaps the list becomes too long, and python doesn't want to print it all because of some setting.
Instead, I will use cPickle to save the data. The disadvantage is that the output is not human readable. But cPickle is very simple to use. I added the lines:
import cPickle
cPickle.dump(data, open(outfile + 'pickle.dat', 'w'))
This should save the 'data' array into a file, from which it can be later retrieved by cPickle.load().
There are other modules I can use that will produce human-readable output, but I'll stick with cPickle for now since it's well supported. Once I verify this works, I will be able to do two things:
1) Cut out the dropout data values to make better plots.
2) When the process_data() function is run in its current form, it reprocesses all the data every time. Instead, I will be able to draw the existing data out of the cPickle file I create. So, I can load the existing data, and only add new values. This will help the program run faster.
This is my interpretation of where Steve is proposing to place the seismometers (he wrote ITMX southwest, but I'm pretty sure from the photo he means southeast).
I think his point is that these locations are on the less-used side of the beam tube, so they will not be in the way. Also, they are not underneath the tube, so we will not have any problems putting the covers on/taking them off..
Granite base 20" x 20" x 5" locations are on the CES side of our IFO arms: as shown ETMY_ south-west, ETMX_north-east, ITMX_south-east . No height limitation. This side of the tube has no traffic.
SS cover McMaster# 41815T4 (H) SS container cov.
How to calculate the accumulated round-trip Gouy phase (and namely the transverse mode spacing) of a general cavity
only from the round-trip ABCD matrix
T1300189
I'm working on getting the input beam centered on the Yarm optics. To do this, I measured the spot positions, move the tip tilts, realign the cavity, then measure the new spot positions. While doing this, I am also moving the BS and Xarm optics to keep the Xarm aligned, so that I don't have to do hard beam-finding later.
Here is the plot of spot measurements today. The last measurement was taken with no moving, or realigning, just several hours later after speaking with our Indian visitors. I'm closer than I was, but there is more work to do.
Re: POY beam reduction.
We are able to lock the Yarm with the beam / gain as it is. I had thought we might need to increase the DC gain in the whitening board by a factor of 2, but so far it's fine. | http://nodus.ligo.caltech.edu:8080/40m/?id=8259 | CC-MAIN-2022-21 | en | refinedweb |
ToasterToaster
Android-like toast with very simple interface. (formerly JLToast)
ScreenshotsScreenshots
FeaturesFeatures
- Queueing: Centralized toast center manages the toast queue.
- Customizable: See the Appearance section.
- String or AttributedString: Both supported.
- UIAccessibility: VoiceOver support.
At a GlanceAt a Glance
import Toaster Toast(text: "Hello, world!").show()
InstallationInstallation
For iOS 8+ projects with CocoaPods:
pod 'Toaster'
For iOS 8+ projects with Carthage:
github "devxoul/Toaster"
Getting StartedGetting Started
Setting Duration and DelaySetting Duration and Delay
Toast(text: "Hello, world!", duration: Delay.long) Toast(text: "Hello, world!", delay: Delay.short, duration: Delay.long)
Removing ToastsRemoving Toasts
Removing toast with reference:
let toast = Toast(text: "Hello") toast.show() toast.cancel() // remove toast immediately
Removing current toast:
if let currentToast = ToastCenter.default.currentToast { currentToast.cancel() }
Removing all toasts:
ToastCenter.default.cancelAll()
AppearanceAppearance
Since Toaster 2.0.0, you can use
UIAppearance to set default appearance. This is an short example to set default background color to red.
ToastView.appearance().backgroundColor = .red
Supported appearance properties are:
Attributed stringAttributed string
Since Toaster 2.3.0, you can also set an attributed string:
Toast(attributedText: NSAttributedString(string: "AttributedString Toast", attributes: [NSAttributedString.Key.backgroundColor: UIColor.yellow]))
AccessibilityAccessibility
By default, VoiceOver with UIAccessibility is enabled since Toaster 2.3.0. To disable it:
ToastCenter.default.isSupportAccessibility = false
LicenseLicense
Toaster is under WTFPL. You can do what the fuck you want with Toast. See LICENSE file for more info. | https://cocoapods.org/pods/Toaster | CC-MAIN-2022-21 | en | refinedweb |
LED blink
Now it’s time for your first project! Let’s start by learning how to use the most basic and commonly used component: the LED. It’s everywhere in life, for lighting, indication, or decoration...
For those coming from the software programming world, you may be familiar with the traditional “hello world” program. In the world of electronics, we have a similar starter project: blinking an LED!
Learning goals
- Understand how the digital output signal works.
- Get to know ohm's law and figure out the relations between current, voltage, and resistance.
- Start to write code and learn some Swift programming knowledge.
🔸Background
What is digital output?
In electronics and telecommunication, electronic signals carry data from one device to another to send and receive all kinds of information. They are always time-varying, which means the voltage changes as time goes on. Different voltages can convey infos and be decoded to a specified message. Depending on the ways the voltage changes, the signals are divided into two types: digital signal and analog signal. You'll take a look at the digital signal in this tutorial.
In most cases, a digital signal has two states: on or off. It is suitable to work with some components, such LED (which is either turned on or off), the button (which will be only pressed or released) ...
Here are different expressions to represent two voltage states:
note
For our board, 3.3V represent true and 0V represent false. Of course, there are many other possibilities, like 5V for true.
GPIO (general-purpose input/output) pins can handle digital output and input signals. You’ll set it as output in your code.
You can use a digital output to control the LED both built onto the board or external LEDs (not included). For the LED module on your kit, when you apply a high signal to the LED, it will turn on, and if you apply a low signal, it will be off.
🔸New component
Diode
The diode is a polarized component. It has a positive side (anode) and a negative side (cathode). In the circuit, the current can only flow in a single direction, from anode to cathode. If you connect it in an opposite direction, the current will not be allowed to pass through.
Symbol:
LED
LED (Light-emitting diode) is a type of diode that will emit light when there is a current. Only when you connect it in the right direction – connect the anode to power and the cathode to ground - is the current allowed to flow, lighting up the LED.
Symbol:
info
How to identify the two legs of LED?
- Typically the long leg is positive and the short leg is negative.
- Alternatively, sometimes you will find a notch on the negative side.
The LED allows a limited range of current, normally no more than 20mA. So you should add a resistor when connecting it to your circuit. Or the LED might burn out when driving too much current.
When you connect the LED in the circuit, there are two cases to control the LED:
- Connect the anode to a digital output pin and cathode to ground. When connected this way, the LED turns on when the pin outputs a high signal. This is how the LED is connected on the Feather board.
Pin is the digital output pin, R is a resistor, is an LED, and GND is ground
- Another method is to connect the anode to a power source and connect the cathode to a digital output pin. When the digital output signal is high, there is no voltage difference between two ends of the LED, but when the digital signal is low, current is allowed to flow, causing the LED to turn on.
Vcc is a power source, R is a resistor, is an LED, and pin is a digital output pin
There are many types of LEDs. The LED on your SwiftIO Circuit Playgrounds is a small variant designed to be convenient for mass production.
Resistor
The resistor functions as a current-limiting component which, just as its name suggests, can resist the current in the circuit. It has two legs. You can connect it in either direction as it is not polarized. Its ability to resist the current, called resistance, is measured in ohm (Ω).
Symbol: (international), (US)
info
How can you tell how much resistance a resistor provides?
Each resistor has a specific resistance. Note the colored bands in the diagram. Each band corresponds to a certain number. Here is an online guide and calculator to determine how to total the value of all the bands together.
Challenge
What’s the resistance of the sample resistor R1 pictured above, as well as the resistors R2 and R3 below? See below for the answer!
Answer
- R1: 10KΩ with a tolerance of ± 5%
- R2: 330Ω with a tolerance of ± 5%
- R3: 470KΩ with a tolerance of ± 1%
This kind of resistor is useful primarily when you DIY some stuff. However, the SwiftIO Feather board and the rest of the kit uses surface mount resistors as they are smaller and more suitable for mass production.
🔸New concept
Ohm’s law
When starting with electronics, you must get familiar with these three concepts: voltage, current, and resistance:
- Voltage measures potential energy between two points.
- Current describes the rate of flow of electric charges that flow through the circuit.
- And resistance is the capability to resist the flow of current.
An intuitive and common analogy is water pressure in a tank. Imagine a water tank with water inside and an opening at the bottom.
In this scenario, the water pressure (water level) is like voltage, the opening is like resistance, and the amount of water spilling out is like current.
- Looking at the first figure, very little water will come out (current) because there isn’t much pressure (voltage) and the opening is small (resistance).
- In the second example, we’ve increased the water level (voltage), but kept the same sized opening (resistance), which results in an increase in the flow of the water (current).
- Finally, in the last one, we’ve also increased the size of the opening (reduced resistance), keeping the water level (voltage) the same, resulting in another increase in flow (current).
Ohm’s law describes how voltage, current and resistance interact with each other and works similar to the water tank above. The formula is:
V = I * R
V: voltage (unit: volts or V)
I: current (unit: amps or A)
R: resistance (unit: ohm or Ω)
Using some simple algebra, we can also put forward the following formulas:
R = V / I
and
I = V / R
As stated previously, all digital pins on the SwiftIO Feather board output a high signal of 3.3V. If the resistance in the circuit is 330Ω, the current would be 0.01A.
Exercise
Given an LED with the following characteristics, how many ohm resistor should you use to complete the circuit, using the 3.3V digital out pin source?
- Forward current: 15mA max
- Forward voltage: 3.0V
Here is the equation:
R = (V-Vled) / Iled
- V: supply voltage
- Vled: forward voltage for the LED, that is, voltage drop as the current across the LED.
- Iled: forward current for the LED (usually 10-20mA). It’s the maximum current. If you don’t have the specs about LED, you could normally suppose it to be 20mA.
The resistor needed for the LED is:
R = (3.3 - 3.0) / 0.015 = 20Ω
Btw, the resistance of the LED itself is little so you could ingnore it.
Frequently you will be unable to find a resistor that matches the exact theoretical value. When this happens, you can use a resistor that has a slightly greater resistance.
In general, the resistance calculated is a minimum requirement. You can also choose a resistor with much larger resistance. Doing so will cause the LED’s brightness to change with it. (Greater resistance will cause the LED to be dimmer)
Serial circuit and parallel circuit
Serial and parallel circuits are the ways to connect more than two devices in the circuit.
In a serial circuit, devices are connected end-to-end in a chain, like R1 and R2. The current flows through them in one direction from positive to negative. And the current flowing through each device is the same.
In a parallel circuit, the devices share two common nodes, like R3 and R4. Node (a) connects both two devices, so the current could flow through either of them. The voltage between two nodes (a and b) is the same, so the voltages spent on R3 and R4 are the same.
In your real situation, the circuit would not be that easy. The serial and parallel circuit would both be used when building the circuit.
Let’s look at an example. You will know better about two circuits.
- In the first circuit, the two lamps are connected in series, so the switch can control both of them. If any of the lamps breaks down, even if the switch is closed, the other lamp will not be lit.
- In the second circuit, the two lamps are connected in parallel, you can control any of them by using the corresponding switch that is connected to it in series: switch1 controls the lamp1, switch2 controls the lamp2. And the two lamps work separately.
Open, closed and short circuit
In addition to the previously mentioned types of circuits, there are three more you need to know about: open circuit, closed circuit, and short circuit.
- The first figure is a closed circuit. This allows current to flow freely from the positive terminal through a load that consumes electric power, finally returning back to the negative terminal.
- In an open circuit, there is a gap somewhere on the circuit, therefore disallowing any current to flow through it.
- Current tends to flow through the path with lower resistance, if you accidentally connect the positive to the negative terminal of the power supply, the current will flow directly through this path and bypass the other paths with higher resistance. The resistance of wires are so small that you could normally ignore it. This causes a short circuit. When the current reaches sufficiently high levels, this can cause serious damage.
Current safety
In a complete circuit, the current will always flow from the point of higher voltage (usually power) to the one of lower voltage (usually ground or GND). Consumed energy is turned into light, heat, sound and many other forms.
If you were to connect the power directly to the ground using a wire, this would cause a short circuit. It can (and usually do) cause damage to your circuit and board, and is also very possible to start a fire.
Another warning: if you’re not careful about selecting an appropriately strong resistor to resist the level of current flowing through the circuit, the devices can be burnt and damaged (and additionally cause a fire hazard).
🔸Circuit - LED module
The image below shows how the LED module is connected to the SwiftIO Feather board in a simplified way.
The LED is connected to D19. GND and 3V3 are connected respectively to the corresponding pin on the board.
info
On circuit diagrams, the red line is usually for power and the black line for ground.
The circuits are all built when designing the board, so you don’t need to connect any wires. And as mentioned before, the white sockets are used to build the circuit after the board is disassembled.
note
The circuits above are simplified for your reference.
🔸Preparation
Class
DigitalOut - as indicated by its name, this class is used to control digital output, to get high or low voltage.
Global function
sleep(ms:) - Make the microcontroller suspend its work for a certain time, measured in milliseconds.
🔸Projects
1. LED blink
In your first try, let’s make the LED blink - on for one second, then off for one second, and repeat it over and over again.
Example code
// First import the SwiftIO and MadBoard libraries into the project to use related functionalities.
import SwiftIO
import MadBoard
// Initialize the specified pin used for digital output.
let led = DigitalOut(Id.D19)
// The code in the loop will run over and over again.
while true {
//Output high voltage to turn on the LED.
led.write(true)
// Keep the LED on for 1 second.
sleep(ms: 1000)
// Turn off the LED and then keep that state for 1s.
led.write(false)
sleep(ms: 1000)
}
Code analysis
Here are some key statements for this program, make sure you understand them before you start to code.
// Comment
This is the comment for the code used to explain how the program works and also for future reference. It always starts with two slashes.
import SwiftIO
import MadBoard
These two libraries are necessary for all your projects with the boards. In short, a library contains a predefined collection of code and provides some specified functionalities. You can use the given commands directly without caring about how everything is realized.
SwiftIO is used to control input and output. It includes all the necessary commands to talk to your board easily.
MadBoard contains the ids of all types boards. The ids for different types of boards may be different since the numbers of pins are not same. Make sure the id used in your code later is correct.
let led = DigitalOut(Id.D19)
let is the keyword to declare a constant. A constant is like a container whose content will never change. But before using it, you need to declare it in advance. Its name could be whatever you like and it’s better to be descriptive, instead of a random name like abc. If the name of your constant consists of several words, then except the first word, the first letter of the rest words needs to be capitalized, like
ledPin. This is known as the camel case.
The class, in brief, is more like a mold that you could use to create different examples, known as instances, with similar characteristics. The class
DigitalOut provides ways to change digital output, so all its instances share the functionalities. The process of creating an instance is called initialization.
The constant
led is the instance of the
DigitalOut class. To initialize it,
- The pin id is required.
Idis an enumeration including the ids of all pins. As for enumeration, enum for short, it could group a set of related values. Just remember that the id needs to be written as
Id.D19.
- The
modeof the digital pin is pushPull in most cases and you will know more about it in the future.
- The
valuedecides the output state of the pin after it's initialized. By default, it outputs a low level. If you want the pin to output 3.3V by default, the statement should be
let led = DigitalOut(Id.D19, value: true).
In this way, the pin D19 would work as a digital output pin and get prepared for the following instructions.
while true {
}
It’s a dead loop in which the code will run over and over again unless you power off the board. The code block inside the brackets needs to be indented by 4 spaces.
note
Sometimes you find nothing that needs to run repeatedly, you could add
sleep in it to make the board sleep and keep in a known state.
led.write(true)
The
led instance has access to all the instance methods in the
DigitalOut.
write() is one of its methods. You’ll use dot syntax to access it: the instance name, followed by a dot, the method in the end. Then you decide the voltage level as its parameter,
true for high voltage,
false for low voltage. A value either
true or
false is of Boolean type.
sleep(ms: 1000)
An instance method needs dot syntax to invoke it, but a global function doesn’t. You can directly call it. The function
sleep(ms:) has a parameter name
ms and a parameter (the specified period). During sleep time, the microcontroller would suspend its processes.
info
Both methods and functions group a code block, and you could realize the same functionality by calling their name. Their difference is that a method belongs to a class while a function is separately declared.
Why add this statement? The microcontroller executes state change of digital pins extremely quickly. If you just change the output state between high and low, the LED will be on and off so quickly that you cannot notice it. So a short period of time is added here to slow the speed of change. If you want the LED to blink faster, you could reduce the sleep time.
info
When using methods or functions, why do some parameters need to add a name and others don't?
Let’s look at the source code below for example:
func write(_ value: Bool)
A function parameter has a argument label and a parameter name. The argument label is used when calling a function. While there is an underscore “_” before the parameter name
value, it means the label can be omitted when invoking the function:
led.write(true).
func sleep(ms: Int)
In this case,
ms serves as the argument label by default, so it's necessary:
sleep(ms: 1000).
2. LED morse code
Example code
Have you heard of Morse code? It encodes characters into a sequence of dashes and dots to send messages. To reproduce it, you could use long flash and short flash respectively. In morse code, s is represented by three dots, o is represented by three dashes. So the SOS signal needs three short flashes, three long flashes, and then three short flashes again.
// Import the libraries to use all their functionalities.
import SwiftIO
import MadBoard
// Initialize the digital output pin.
let led = DigitalOut(Id.D19)
// Define the LED states to represent the letter s and o.
let sSignal = [false, false, false]
let oSignal = [true, true ,true]
// Set the LED blink rate according to the values in the array.
func send(_ values: [Bool], to light: DigitalOut) {
// The duration of slow flash and quick flash.
let long = 1000
let short = 500
// Iterate all the values in the array.
// If the value is true, the LED will be on for 1s, which is a slow flash.
// And if it’s false, the LED will be on for 0.5s, which is a quick flash.
for value in values {
light.high()
if value {
sleep(ms: long)
} else {
sleep(ms: short)
}
light.low()
sleep(ms: short)
}
}
// Blink the LED.
// At first, the LED starts 3 fast blink to represent s, then 3 slow blink to represent o, and 3 fast blink again.
// Wait 1s before repeating again.
while true {
send(sSignal, to: led)
send(oSignal, to: led)
send(sSignal, to: led)
sleep(ms: 1000)
}
Code analysis
let sSignal = [false, false, false]
let oSignal = [true, true, true]
Here, two arrays are used to store the info of two letters. Since there are only two states: fast or slow flash, you could use boolean value to represent two states.
false corresponds to quick flash.
An array stores a series of ordered values of the same type in a pair of square brackets. The values above are all boolean values.
func send(_ values: [Bool], to light: DigitalOut) {
...
}
You will create a function to finish blinks for a single letter. It needs two parameters: the first is an array of boolean values that stores the info for a letter; the second is the digital pin that the LED is connected to.
This function is to make your code more organized and clear. Of course, you can use other ways of abstraction.
info
Usually, it's better not to use the variable or constants that are declared out of the function itself. All stuff needed is passed in as its parameters. As you invoke the function, you will then tell which pin is going to be used and what the values are. Thus you could use this piece of code in other project without modifying the code. This practice would be really helpful as you work on great projects in the future.
let long = 1000
let short = 500
Set the duration of LED on-time. The values are stored in two constants so it would be clearer as you use them later.
for value in values {
...
}
This is a for-in loop. It has two keywords:
for and
in. It’s used to repeat similar operations for each element and usually used with arrays. The code inside the curly brackets would repeat several times to iterate all elements in the array.
value represents the elements in the array
values. It doesn’t matter if you use
value or a, b, c to name it. But it’s better to use a descriptive name.
if condition {
task1
} else {
task2
}
This is a conditional statement. The if-else statement makes it possible to do different tasks according to the condition. The condition is always a boolean expression that will return either true or false. And it will use some comparison operators to evaluate the value as follows:
- Equal to:
a == b
- Not equal to:
a != b
- Greater than:
a > b
- Less than:
a < b
- Greater than or equal to:
a >= b
- Less than or equal to:
a <= b
If the condition evaluates true, task1 will be executed and task2 will be skipped. If the condition is false, task2 will be executed instead of task1.
In the code above, the
value is judged to know how long the LED should be on.
light.high()
light.low()
Set high or low voltage. This is similar to the method
write(), but it’s more straightforward. The statement
led.write(true) of course works.
🔸More info
If you would like to find out more about some details, please refer to the following link: | https://docs.madmachine.io/tutorials/swiftio-circuit-playgrounds/modules/led | CC-MAIN-2022-21 | en | refinedweb |
Slides of structure 2: Modern C++ for Computer Vision Lecture 2: C++ Basic Syntax (uni-bonn.de)
This part mainly introduces the keywords, entities, entity declarations and definitions, types, variables, naming rules of identifiers, expressions, if else structures, switch structures, while loops, for loops, arithmetic expressions, conditional expressions, self increasing and self decreasing in C + +
if(STATEMENT){ //... } else{ //... } switch(STATEMENT){ case 1: EXPRESIONS;break; case 2: EXPRESIONS;break; } while(STATEMENT){ //... } for(int i=0;i<10;i++){ //... }
Spooler alert (supplementary)
1. For loop in C + + 17 and python 3 Comparison of for loops in X
In the latest C++ 17 standard, the new writing method of for loop is compared with that in Python:
//Pythonic Implementation my_dict = {'a':27,'b':3} for key,value in my_dict.items(): print(key,"has value",value) // Implementaion in c++ 17 std::map<char,int> my_dict{{'a',27},{'b',3}} for (const auto&[key,value]:my_dict) { std::cout<<"has value"<<value<<std::endl; }
It can be seen that the new standard has Python taste, but the implementation of C + + is 15 times faster than Python:
2. Built-in types
For the "Out of the box" type in C + + (Out of the box), you can refer to Fundamental types - cppreference.com
int a = 10; auto b = 10.1f ; // Automatic type [float] auto c = 10; //Automatic type [int] auto d = 10.0 ; // Automatic type [double] std::array<int,3> arr={1,2,3}; // Array of intergers
The automatic type here is also a bit like Python.
3. C-style strings are evil
C + + can be programmed in C style like other types in C:
#include<cstring> #include<iostream> int main(){ const char source[] = "Copy this"; char dest[5]; std::cout<<source<<std::endl; std::strcpy(dest,source); std::cout<<dest<<std::endl; //Source is const, no problem right std::cout<<source<<std::endl; return 0; }
You may think that the source is const char type and should not be changed, but the result is unexpected. This is the so-called "C-style strings are evil", so it is more recommended to use Strings type. There is this
Several precautions:
- #std::string can be used after include < string >
- string type implements operator overloading and can be spliced with +;
- You can check whether STR is empty through str.empty();
- It can be combined with I/O streams to play tricks
For example, in the above example, we use the string type in C + +:
#include<iostream> #include<string> int main(){ const std::string source{"Copy this"}; std::string dest = source; std::cout << source << '\n'; std::cout<< dest <<'\n'; return 0; }
The result of this operation is completely expressed.
Add: why is there such a mistake in the first example? We found std::strcpy Official description , the signature of this function is:
char* strcpy( char* dest, const char* src );
Copies the character string pointed to by src, including the null terminator, to the character array whose first element is pointed to by dest.
The behavior is undefined if the dest array is not large enough. The behavior is undefined if the strings overlap.
Let's take a look at the function prototype of strcpy:
//C language standard library function strcpy is a typical industrial simplest implementation. //Return value: the address of the target string. //The ANSI-C99 standard does not define exceptions, so the return value is determined by the implementer, usually NULL. //Parameters: des is the target string and source is the original string. char* strcpy(char* des,const char* source) { char* r=des; assert((des != NULL) && (source != NULL)); while((*r++ = *source++)!='\0'); return des; } //while((*des++=*source++)); Explanation: the assignment expression returns the left operand, so the loop stops after assignment '\ 0'.
In fact, it's not a language problem here. Both source and dest are located in the stack area and adjacent to each other in memory. Therefore, DeST's memory overflows into source, overwriting the previous part of source and adding \ 0. The location information of both is as follows:
+--------+ ... +--------+ | src[2] | <--- -0x5 +--------+ | src[1] | <--- -0x6 +--------+ | src[0] | <--- -0x7 +--------+ | dest[3]| <--- -0x8 +--------+ | dest[2]| <--- -0x9 +--------+ | dest[1]| <--- -0xa +--------+ | dest[0]| <--- -0xb +--------+
How to avoid buffer Overflow caused by insufficient memory space pointed to by dest?
Here is an official example. In order to avoid unpredictable behavior caused by insufficient dest length, the length of src is adjusted according to the length of src:
#include <iostream> #include <cstring> #include <memory> int main() { const char* src = "Take the test."; // src[0] = 'M'; // can't modify string literal auto dst = std::make_unique<char[]>(std::strlen(src)+1); // +1 for the null terminator std::strcpy(dst.get(), src); dst[0] = 'M'; std::cout << src << '\n' << dst.get() << '\n'; }
Of course, you can also use more secure strncpy or strcpy_s.
4. Any variables can be const
It's worth noting that any type can be declared const as long as you're sure it won't change.
Google style names constants with camelCase and starts with the lowercase letter k, for example:
const float kImportantFloat = 20.0f; const int kSomeInt = 20; const std::string kHello = "Hello";
Add: Google style names variables in snake_case, and all of them are lowercase letters, such as some_var.
Variable reference is also a very common usage, which is faster and less code than copying data, but sometimes we use const to avoid unwanted changes.
5. I/O streams
#Include < iostream > to use I/O stream
Here are the commonly used String streams:
- Standard output cerr and cout
- Standard input cin
- File streams fsstream, i fstream and ofstream
- String stringstream can convert the combination of int, double, string and other types into string, or decompose strings into int, double, string, etc.
6. Program input parameters
C + + allows parameters to be passed to binary files. For example, the main function can receive parameters:
int main(int argc,cahr const *argv[])
Where argc represents the number of input parameters and argv is the array of input strings. By default, the former is equal to 1 and the latter is equal to "< binary_path >" | https://programmer.ink/think/modern_cpp_3-c-basic-syntax.html | CC-MAIN-2022-21 | en | refinedweb |
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