| package org.apache.helix.messaging.handling; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.List; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import com.google.common.collect.ImmutableList; |
| import org.apache.helix.HelixException; |
| import org.apache.helix.NotificationContext; |
| import org.apache.helix.messaging.AsyncCallback; |
| import org.apache.helix.model.Message; |
| import org.apache.helix.model.Message.MessageType; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class AsyncCallbackService implements MultiTypeMessageHandlerFactory { |
| private final ConcurrentHashMap<String, AsyncCallback> _callbackMap = |
| new ConcurrentHashMap<String, AsyncCallback>(); |
| private static Logger _logger = LoggerFactory.getLogger(AsyncCallbackService.class); |
| |
| public AsyncCallbackService() { |
| } |
| |
| public void registerAsyncCallback(String correlationId, AsyncCallback callback) { |
| if (_callbackMap.containsKey(correlationId)) { |
| _logger.warn("correlation id " + correlationId + " already registered"); |
| } |
| _logger.info("registering correlation id " + correlationId); |
| _callbackMap.put(correlationId, callback); |
| } |
| |
| void verifyMessage(Message message) { |
| if (!message.getMsgType().toString().equalsIgnoreCase(MessageType.TASK_REPLY.name())) { |
| String errorMsg = |
| "Unexpected msg type for message " + message.getMsgId() + " type:" + message.getMsgType() |
| + " Expected : " + MessageType.TASK_REPLY; |
| _logger.error(errorMsg); |
| throw new HelixException(errorMsg); |
| } |
| String correlationId = message.getCorrelationId(); |
| if (correlationId == null) { |
| String errorMsg = "Message " + message.getMsgId() + " does not have correlation id"; |
| _logger.error(errorMsg); |
| throw new HelixException(errorMsg); |
| } |
| |
| if (!_callbackMap.containsKey(correlationId)) { |
| String errorMsg = |
| "Message " |
| + message.getMsgId() |
| + " does not have correponding callback. Probably timed out already. Correlation id: " |
| + correlationId; |
| _logger.error(errorMsg); |
| throw new HelixException(errorMsg, false); |
| } |
| _logger.info("Verified reply message " + message.getMsgId() + " correlation:" + correlationId); |
| } |
| |
| @Override |
| public MessageHandler createHandler(Message message, NotificationContext context) { |
| verifyMessage(message); |
| return new AsyncCallbackMessageHandler(message.getCorrelationId(), message, context); |
| } |
| |
| @Override |
| public String getMessageType() { |
| return MessageType.TASK_REPLY.name(); |
| } |
| |
| @Override |
| public List<String> getMessageTypes() { |
| return ImmutableList.of(MessageType.TASK_REPLY.name()); |
| } |
| |
| @Override |
| public void reset() { |
| |
| } |
| |
| public class AsyncCallbackMessageHandler extends MessageHandler { |
| private final String _correlationId; |
| |
| public AsyncCallbackMessageHandler(String correlationId, Message message, |
| NotificationContext context) { |
| super(message, context); |
| _correlationId = correlationId; |
| } |
| |
| @Override |
| public HelixTaskResult handleMessage() throws InterruptedException { |
| verifyMessage(_message); |
| HelixTaskResult result = new HelixTaskResult(); |
| assert (_correlationId.equalsIgnoreCase(_message.getCorrelationId())); |
| _logger.info("invoking reply message " + _message.getMsgId() + ", correlationid:" |
| + _correlationId); |
| |
| AsyncCallback callback = _callbackMap.get(_correlationId); |
| synchronized (callback) { |
| callback.onReply(_message); |
| if (callback.isDone()) { |
| _logger.info("Removing finished callback, correlationid:" + _correlationId); |
| _callbackMap.remove(_correlationId); |
| } |
| } |
| result.setSuccess(true); |
| return result; |
| } |
| |
| @Override |
| public void onError(Exception e, ErrorCode code, ErrorType type) { |
| _logger.error("Message handling pipeline get an exception. MsgId:" + _message.getMsgId(), e); |
| } |
| } |
| } |