| /* |
| * 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.tinkerpop.gremlin.server; |
| |
| import org.apache.tinkerpop.gremlin.driver.message.ResponseMessage; |
| import org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode; |
| import org.apache.tinkerpop.gremlin.server.handler.Frame; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| /** |
| * A context for asynchronously writing response messages related to a particular request. |
| * <p>The "write" methods of this class ensure that at most one {@link ResponseStatusCode#isFinalResponse() final} |
| * response message is written to the underlying channel. Attempts to write more than one final response message will |
| * be ignored with a warning log message.</p> |
| * <p>Note: an object of this class should be used instead of writing to the channel directly when multiple threads |
| * are expected to produce final response messages concurrently. Callers must ensure that the same |
| * {@link ResponseHandlerContext} is used by all threads writing response messages for the same request.</p> |
| * |
| * @author Dmitri Bourlatchkov |
| * @deprecated As of release 3.3.8, replaced by {@link Context}. |
| */ |
| @Deprecated |
| public class ResponseHandlerContext { |
| private static final Logger logger = LoggerFactory.getLogger(ResponseHandlerContext.class); |
| |
| private final Context context; |
| private final AtomicBoolean finalResponseWritten = new AtomicBoolean(); |
| |
| public ResponseHandlerContext(final Context context) { |
| this.context = context; |
| } |
| |
| public Context getContext() { |
| return context; |
| } |
| |
| /** |
| * Writes a response message to the underlying channel while ensuring that at most one |
| * {@link ResponseStatusCode#isFinalResponse() final} response is written. |
| * <p>Note: this method should be used instead of writing to the channel directly when multiple threads |
| * are expected to produce response messages concurrently.</p> |
| * <p>Attempts to write more than one final response message will be ignored.</p> |
| * @see #writeAndFlush(ResponseStatusCode, Object) |
| */ |
| public void writeAndFlush(final ResponseMessage message) { |
| writeAndFlush(message.getStatus().getCode(), message); |
| } |
| |
| /** |
| * Writes a response message to the underlying channel while ensuring that at most one |
| * {@link ResponseStatusCode#isFinalResponse() final} response is written. |
| * <p>The caller must make sure that the provided response status code matches the content of the message.</p> |
| * <p>Note: this method should be used instead of writing to the channel directly when multiple threads |
| * are expected to produce response messages concurrently.</p> |
| * <p>Attempts to write more than one final response message will be ignored.</p> |
| * @see #writeAndFlush(ResponseMessage) |
| */ |
| public void writeAndFlush(final ResponseStatusCode code, final Object responseMessage) { |
| final boolean messageIsFinal = code.isFinalResponse(); |
| if(finalResponseWritten.compareAndSet(false, messageIsFinal)) { |
| context.getChannelHandlerContext().writeAndFlush(responseMessage); |
| } else { |
| if (responseMessage instanceof Frame) { |
| ((Frame) responseMessage).tryRelease(); |
| } |
| |
| final String logMessage = String.format("Another final response message was already written for request %s, ignoring response code: %s", |
| context.getRequestMessage().getRequestId(), code); |
| logger.warn(logMessage); |
| } |
| |
| } |
| } |