io.grpc.stub

Class ClientCallStreamObserver<ReqT>

java.lang.Object

io.grpc.stub.CallStreamObserver<ReqT>

io.grpc.stub.ClientCallStreamObserver<ReqT>

All Implemented Interfaces:

StreamObserver<ReqT>

public abstract class ClientCallStreamObserver<ReqT>
extends CallStreamObserver<ReqT>

A refinement of CallStreamObserver that allows for lower-level interaction with client calls. An instance of this class is obtained via ClientResponseObserver, or by manually casting the StreamObserver returned by a stub.

Like StreamObserver, implementations are not required to be thread-safe; if multiple threads will be writing to an instance concurrently, the application must synchronize its calls.

DO NOT MOCK: The API is too complex to reliably mock. Use InProcessChannelBuilder to create "real" RPCs suitable for testing and make a fake for the server-side.

Constructor Summary

Constructors

Constructor and Description
ClientCallStreamObserver()

Method Summary

Modifier and Type	Method and Description
abstract void	cancel(String message, Throwable cause) Prevent any further processing for this ClientCallStreamObserver.
void	disableAutoRequestWithInitial(int request) Swaps to manual flow control where no message will be delivered to StreamObserver.onNext(Object) unless it is request()ed.
abstract boolean	isReady() If true, indicates that the observer is capable of sending additional messages without requiring excessive buffering internally.
abstract void	request(int count) Requests the peer to produce count more messages to be delivered to the 'inbound' StreamObserver.
abstract void	setMessageCompression(boolean enable) Sets message compression for subsequent calls to StreamObserver.onNext(V).
abstract void	setOnReadyHandler(Runnable onReadyHandler) Set a Runnable that will be executed every time the stream isReady() state changes from false to true.

Methods inherited from class io.grpc.stub.CallStreamObserver

disableAutoInboundFlowControl

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.grpc.stub.StreamObserver

onCompleted, onError, onNext

Constructor Detail

ClientCallStreamObserver

public ClientCallStreamObserver()

Method Detail

cancel

public abstract void cancel(@Nullable
                            String message,
                            @Nullable
                            Throwable cause)

Prevent any further processing for this ClientCallStreamObserver. No further messages will be received. The server is informed of cancellations, but may not stop processing the call. Cancelling an already cancel()ed ClientCallStreamObserver has no effect.

No other methods on this class can be called after this method has been called.

It is recommended that at least one of the arguments to be non-null, to provide useful debug information. Both argument being null may log warnings and result in suboptimal performance. Also note that the provided information will not be sent to the server.

Parameters:

message - if not null, will appear as the description of the CANCELLED status

cause - if not null, will appear as the cause of the CANCELLED status

disableAutoRequestWithInitial

public void disableAutoRequestWithInitial(int request)

Swaps to manual flow control where no message will be delivered to StreamObserver.onNext(Object) unless it is request()ed. Since request() may not be called before the call is started, a number of initial requests may be specified.

This method may only be called during ClientResponseObserver.beforeStart().

isReady

public abstract boolean isReady()

If true, indicates that the observer is capable of sending additional messages without requiring excessive buffering internally. This value is just a suggestion and the application is free to ignore it, however doing so may result in excessive buffering within the observer.

If false, the runnable passed to setOnReadyHandler(java.lang.Runnable) will be called after isReady() transitions to true.

Specified by:

isReady in class CallStreamObserver<ReqT>

setOnReadyHandler

public abstract void setOnReadyHandler(Runnable onReadyHandler)

Set a Runnable that will be executed every time the stream isReady() state changes from false to true. While it is not guaranteed that the same thread will always be used to execute the Runnable, it is guaranteed that executions are serialized with calls to the 'inbound' StreamObserver.

May only be called during ClientResponseObserver.beforeStart(io.grpc.stub.ClientCallStreamObserver<ReqT>).

Because there is a processing delay to deliver this notification, it is possible for concurrent writes to cause isReady() == false within this callback. Handle "spurious" notifications by checking isReady()'s current value instead of assuming it is now true. If isReady() == false the normal expectations apply, so there would be another onReadyHandler callback.

Specified by:

setOnReadyHandler in class CallStreamObserver<ReqT>

Parameters:

onReadyHandler - to call when peer is ready to receive more messages.

request

public abstract void request(int count)

Requests the peer to produce count more messages to be delivered to the 'inbound' StreamObserver.

This method is safe to call from multiple threads without external synchronization.

Specified by:

request in class CallStreamObserver<ReqT>

Parameters:

count - more messages

setMessageCompression

public abstract void setMessageCompression(boolean enable)

Sets message compression for subsequent calls to StreamObserver.onNext(V).

Specified by:

setMessageCompression in class CallStreamObserver<ReqT>

Parameters:

enable - whether to enable compression.