| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| |
|
| | """DEPRECATED: Declares the RPC service interfaces. |
| | |
| | This module declares the abstract interfaces underlying proto2 RPC |
| | services. These are intended to be independent of any particular RPC |
| | implementation, so that proto2 services can be used on top of a variety |
| | of implementations. Starting with version 2.3.0, RPC implementations should |
| | not try to build on these, but should instead provide code generator plugins |
| | which generate code specific to the particular RPC implementation. This way |
| | the generated code can be more appropriate for the implementation in use |
| | and can avoid unnecessary layers of indirection. |
| | """ |
| |
|
| | __author__ = 'petar@google.com (Petar Petrov)' |
| |
|
| |
|
| | class RpcException(Exception): |
| | """Exception raised on failed blocking RPC method call.""" |
| | pass |
| |
|
| |
|
| | class Service(object): |
| |
|
| | """Abstract base interface for protocol-buffer-based RPC services. |
| | |
| | Services themselves are abstract classes (implemented either by servers or as |
| | stubs), but they subclass this base interface. The methods of this |
| | interface can be used to call the methods of the service without knowing |
| | its exact type at compile time (analogous to the Message interface). |
| | """ |
| |
|
| | def GetDescriptor(): |
| | """Retrieves this service's descriptor.""" |
| | raise NotImplementedError |
| |
|
| | def CallMethod(self, method_descriptor, rpc_controller, |
| | request, done): |
| | """Calls a method of the service specified by method_descriptor. |
| | |
| | If "done" is None then the call is blocking and the response |
| | message will be returned directly. Otherwise the call is asynchronous |
| | and "done" will later be called with the response value. |
| | |
| | In the blocking case, RpcException will be raised on error. |
| | |
| | Preconditions: |
| | |
| | * method_descriptor.service == GetDescriptor |
| | * request is of the exact same classes as returned by |
| | GetRequestClass(method). |
| | * After the call has started, the request must not be modified. |
| | * "rpc_controller" is of the correct type for the RPC implementation being |
| | used by this Service. For stubs, the "correct type" depends on the |
| | RpcChannel which the stub is using. |
| | |
| | Postconditions: |
| | |
| | * "done" will be called when the method is complete. This may be |
| | before CallMethod() returns or it may be at some point in the future. |
| | * If the RPC failed, the response value passed to "done" will be None. |
| | Further details about the failure can be found by querying the |
| | RpcController. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def GetRequestClass(self, method_descriptor): |
| | """Returns the class of the request message for the specified method. |
| | |
| | CallMethod() requires that the request is of a particular subclass of |
| | Message. GetRequestClass() gets the default instance of this required |
| | type. |
| | |
| | Example: |
| | method = service.GetDescriptor().FindMethodByName("Foo") |
| | request = stub.GetRequestClass(method)() |
| | request.ParseFromString(input) |
| | service.CallMethod(method, request, callback) |
| | """ |
| | raise NotImplementedError |
| |
|
| | def GetResponseClass(self, method_descriptor): |
| | """Returns the class of the response message for the specified method. |
| | |
| | This method isn't really needed, as the RpcChannel's CallMethod constructs |
| | the response protocol message. It's provided anyway in case it is useful |
| | for the caller to know the response type in advance. |
| | """ |
| | raise NotImplementedError |
| |
|
| |
|
| | class RpcController(object): |
| |
|
| | """An RpcController mediates a single method call. |
| | |
| | The primary purpose of the controller is to provide a way to manipulate |
| | settings specific to the RPC implementation and to find out about RPC-level |
| | errors. The methods provided by the RpcController interface are intended |
| | to be a "least common denominator" set of features which we expect all |
| | implementations to support. Specific implementations may provide more |
| | advanced features (e.g. deadline propagation). |
| | """ |
| |
|
| | |
| |
|
| | def Reset(self): |
| | """Resets the RpcController to its initial state. |
| | |
| | After the RpcController has been reset, it may be reused in |
| | a new call. Must not be called while an RPC is in progress. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def Failed(self): |
| | """Returns true if the call failed. |
| | |
| | After a call has finished, returns true if the call failed. The possible |
| | reasons for failure depend on the RPC implementation. Failed() must not |
| | be called before a call has finished. If Failed() returns true, the |
| | contents of the response message are undefined. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def ErrorText(self): |
| | """If Failed is true, returns a human-readable description of the error.""" |
| | raise NotImplementedError |
| |
|
| | def StartCancel(self): |
| | """Initiate cancellation. |
| | |
| | Advises the RPC system that the caller desires that the RPC call be |
| | canceled. The RPC system may cancel it immediately, may wait awhile and |
| | then cancel it, or may not even cancel the call at all. If the call is |
| | canceled, the "done" callback will still be called and the RpcController |
| | will indicate that the call failed at that time. |
| | """ |
| | raise NotImplementedError |
| |
|
| | |
| |
|
| | def SetFailed(self, reason): |
| | """Sets a failure reason. |
| | |
| | Causes Failed() to return true on the client side. "reason" will be |
| | incorporated into the message returned by ErrorText(). If you find |
| | you need to return machine-readable information about failures, you |
| | should incorporate it into your response protocol buffer and should |
| | NOT call SetFailed(). |
| | """ |
| | raise NotImplementedError |
| |
|
| | def IsCanceled(self): |
| | """Checks if the client cancelled the RPC. |
| | |
| | If true, indicates that the client canceled the RPC, so the server may |
| | as well give up on replying to it. The server should still call the |
| | final "done" callback. |
| | """ |
| | raise NotImplementedError |
| |
|
| | def NotifyOnCancel(self, callback): |
| | """Sets a callback to invoke on cancel. |
| | |
| | Asks that the given callback be called when the RPC is canceled. The |
| | callback will always be called exactly once. If the RPC completes without |
| | being canceled, the callback will be called after completion. If the RPC |
| | has already been canceled when NotifyOnCancel() is called, the callback |
| | will be called immediately. |
| | |
| | NotifyOnCancel() must be called no more than once per request. |
| | """ |
| | raise NotImplementedError |
| |
|
| |
|
| | class RpcChannel(object): |
| |
|
| | """Abstract interface for an RPC channel. |
| | |
| | An RpcChannel represents a communication line to a service which can be used |
| | to call that service's methods. The service may be running on another |
| | machine. Normally, you should not use an RpcChannel directly, but instead |
| | construct a stub {@link Service} wrapping it. Example: |
| | |
| | Example: |
| | RpcChannel channel = rpcImpl.Channel("remotehost.example.com:1234") |
| | RpcController controller = rpcImpl.Controller() |
| | MyService service = MyService_Stub(channel) |
| | service.MyMethod(controller, request, callback) |
| | """ |
| |
|
| | def CallMethod(self, method_descriptor, rpc_controller, |
| | request, response_class, done): |
| | """Calls the method identified by the descriptor. |
| | |
| | Call the given method of the remote service. The signature of this |
| | procedure looks the same as Service.CallMethod(), but the requirements |
| | are less strict in one important way: the request object doesn't have to |
| | be of any specific class as long as its descriptor is method.input_type. |
| | """ |
| | raise NotImplementedError |
| |
|