m-trieu commented on code in PR #32774: URL: https://github.com/apache/beam/pull/32774#discussion_r1837625329
########## runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/windmill/client/ResettableThrowingStreamObserver.java: ########## @@ -0,0 +1,158 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.beam.runners.dataflow.worker.windmill.client; + +import java.util.function.Supplier; +import javax.annotation.Nullable; +import javax.annotation.concurrent.GuardedBy; +import javax.annotation.concurrent.ThreadSafe; +import org.apache.beam.runners.dataflow.worker.windmill.client.grpc.observers.StreamObserverCancelledException; +import org.apache.beam.runners.dataflow.worker.windmill.client.grpc.observers.TerminatingStreamObserver; +import org.apache.beam.sdk.annotations.Internal; +import org.apache.beam.vendor.grpc.v1p60p1.io.grpc.stub.StreamObserver; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions; +import org.slf4j.Logger; + +/** + * Request observer that allows resetting its internal delegate using the given {@link + * #streamObserverFactory}. + * + * @implNote {@link StreamObserver}s generated by {@link #streamObserverFactory} are expected to be + * {@link ThreadSafe}. Has same methods declared in {@link StreamObserver}, but they throw + * {@link StreamClosedException} and {@link WindmillStreamShutdownException}, which much be + * handled by callers. + */ +@ThreadSafe +@Internal +final class ResettableThrowingStreamObserver<T> { + private final Supplier<TerminatingStreamObserver<T>> streamObserverFactory; + private final Logger logger; + + @GuardedBy("this") + private @Nullable TerminatingStreamObserver<T> delegateStreamObserver; + + @GuardedBy("this") + private boolean isPoisoned = false; + + /** + * Indicates that the current delegate is closed via {@link #poison() or {@link #onCompleted()}}. + * If not poisoned, a call to {@link #reset()} is required to perform future operations on the + * StreamObserver. + */ + @GuardedBy("this") + private boolean isCurrentStreamClosed = false; + + ResettableThrowingStreamObserver( + Supplier<TerminatingStreamObserver<T>> streamObserverFactory, Logger logger) { + this.streamObserverFactory = streamObserverFactory; + this.logger = logger; + this.delegateStreamObserver = null; + } + + private synchronized StreamObserver<T> delegate() + throws WindmillStreamShutdownException, StreamClosedException { + if (isPoisoned) { + throw new WindmillStreamShutdownException("Stream is already shutdown."); + } + + if (isCurrentStreamClosed) { + throw new StreamClosedException( + "Current stream is closed, requires reset for future stream operations."); + } + + return Preconditions.checkNotNull( + delegateStreamObserver, + "requestObserver cannot be null. Missing a call to startStream() to initialize."); Review Comment: done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
