1 /* 2 * Copyright 2016 The gRPC Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.grpc.stub; 18 19 import io.grpc.ExperimentalApi; 20 21 /** 22 * Specialization of {@link StreamObserver} implemented by clients in order to interact with the 23 * advanced features of a call such as flow-control. 24 */ 25 @ExperimentalApi("https://github.com/grpc/grpc-java/issues/4693") 26 public interface ClientResponseObserver<ReqT, RespT> extends StreamObserver<RespT> { 27 /** 28 * Called by the runtime priot to the start of a call to provide a reference to the 29 * {@link ClientCallStreamObserver} for the outbound stream. This can be used to listen to 30 * onReady events, disable auto inbound flow and perform other advanced functions. 31 * 32 * <p>Only the methods {@link ClientCallStreamObserver#setOnReadyHandler(Runnable)} and 33 * {@link ClientCallStreamObserver#disableAutoInboundFlowControl()} may be called within this 34 * callback 35 * 36 * <pre> 37 * // Copy an iterator to the request stream under flow-control 38 * someStub.fullDuplexCall(new ClientResponseObserver<ReqT, RespT>() { 39 * public void beforeStart(final ClientCallStreamObserver<Req> requestStream) { 40 * StreamObservers.copyWithFlowControl(someIterator, requestStream); 41 * }); 42 * </pre> 43 */ beforeStart(final ClientCallStreamObserver<ReqT> requestStream)44 void beforeStart(final ClientCallStreamObserver<ReqT> requestStream); 45 } 46