nl.topicus.jdbc.shaded.com.google.api.gax.rpc.ApiStreamObserver Maven / Gradle / Ivy
/*
* Copyright 2017, Google LLC All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google LLC nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package nl.topicus.jdbc.shaded.com.google.api.gax.rpc;
import nl.topicus.jdbc.shaded.com.google.api.core.BetaApi;
/**
* Receives notifications from an observable stream of messages.
*
* It is used for sending messages in bidi (bidirectional) or client-streaming calls, or for
* receiving messages in bidi or server-streaming calls.
*
*
For outgoing messages, an {@code ApiStreamObserver} is provided by GAX to the application, and
* the application then provides the messages to send. For incoming messages, the application
* implements the {@code ApiStreamObserver} and passes it to GAX, which then calls the observer with
* the messages for the application to receive them.
*
*
Implementations are expected to be thread-compatible. Separate
* {@code ApiStreamObserver}s do not need to be synchronized together; incoming and outgoing
* directions are independent. Since individual {@code ApiStreamObserver}s are not thread-safe, if
* multiple threads will be writing to a {@code ApiStreamObserver} concurrently, the application
* must synchronize calls.
*
*
This interface is a fork of nl.topicus.jdbc.shaded.io.grpc.stub.StreamObserver to enable shadowing of Guava, and also
* to allow for a transport-agnostic interface that doesn't depend on gRPC.
*/
@BetaApi("The surface for streaming is not stable yet and may change in the future.")
public interface ApiStreamObserver {
/**
* Receives a value from the stream.
*
* Can be called many times but is never called after {@link #onError(Throwable)} or {@link
* #onCompleted()} are called.
*
*
Clients may invoke onNext at most once for server streaming calls, but may receive many
* onNext callbacks. Servers may invoke onNext at most once for client streaming calls, but may
* receive many onNext callbacks.
*
*
If an exception is thrown by an implementation the caller is expected to terminate the
* stream by calling {@link #onError(Throwable)} with the caught exception prior to propagating
* it.
*
* @param value the value passed to the stream
*/
void onNext(V value);
/**
* Receives a terminating error from the stream.
*
*
May only be called once and if called, it must be the last method called. In particular if
* an exception is thrown by an implementation of {@code onError}, no further calls to any method
* are allowed.
*
* @param t the error occurred on the stream
*/
void onError(Throwable t);
/**
* Receives a notification of successful stream completion.
*
*
May only be called once, and if called it must be the last method called. In particular if
* an exception is thrown by an implementation of {@code onCompleted}, no further calls to any
* method are allowed.
*/
void onCompleted();
}