com.cisco.oss.foundation.message.AbstractMessageDispatcher.java Source code

Introduction

Here is the source code for com.cisco.oss.foundation.message.AbstractMessageDispatcher.java

Source

/*
 * Copyright 2015 Cisco Systems, Inc.
 *
 *  Licensed 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 com.cisco.oss.foundation.message;

import com.cisco.oss.foundation.configuration.ConfigurationFactory;
import org.apache.commons.configuration.Configuration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

abstract class AbstractMessageDispatcher implements MessageDispatcher {

    private static final Logger LOGGER = LoggerFactory.getLogger(MessageDispatcher.class);

    private List<Message> waitingList;
    private ConcurrentMessageHandler concurrentMessageHandler;
    private ExecutorService executorService;
    private CapacityEnsurableLinkedBlockingQueue<Runnable> blockingWaitingQueue;

    public AbstractMessageDispatcher(ConcurrentMessageHandler concurrentMessageHandler) {
        this.concurrentMessageHandler = concurrentMessageHandler;

        Configuration configuration = ConfigurationFactory.getConfiguration();
        int maxThreadPoolSize = configuration.getInt(MessageConstants.QUEUE_SIZE_PROPERTY);
        int waitingQueueSize = configuration.getInt(MessageConstants.WAITING_QUEUE_SIZE_PROPERTY);

        waitingList = new CopyOnWriteArrayList<Message>();
        try {
            if (waitingQueueSize > 0) {
                blockingWaitingQueue = new CapacityEnsurableLinkedBlockingQueue<Runnable>(waitingQueueSize);
            } else {
                blockingWaitingQueue = new CapacityEnsurableLinkedBlockingQueue<Runnable>();
            }
        } catch (Exception ex) {
            LOGGER.error("Failed to create message dispatcher", ex);
        }
        executorService = new ThreadPoolExecutor(maxThreadPoolSize, maxThreadPoolSize, 0L, TimeUnit.MILLISECONDS,
                blockingWaitingQueue); //Executors.newFixedThreadPool(maxThreadPoolSize);
    }

    public ConcurrentMessageHandler getConcurrentMessageHandler() {
        return concurrentMessageHandler;
    }

    public ExecutorService getExecutorService() {
        return executorService;
    }

    public List<Message> getWaitingList() {
        return waitingList;
    }

    protected abstract boolean checkAndDispatchEvent(Message message, boolean alreadyOnWaitingList);

    protected abstract void pushNextEvent();

    public void handleMessage(Message message) {
        // Do eventRecive method on lifecyclePhases
        getConcurrentMessageHandler().onRecieveMessage(message);
        // Try to dispatch the event
        checkAndDispatchEvent(message, false);
    }

    protected void dispatchMessage(Message message) {
        MessageProcessorRunnable workerRunnable = new MessageProcessorRunnable(concurrentMessageHandler, message);

        try {
            LOGGER.trace("On ensure capacity");
            blockingWaitingQueue.ensureCapacity();
            LOGGER.trace("Finish ensure capacity, going to execute");
            executorService.execute(workerRunnable);
            return;
        } catch (Exception ex) {
            LOGGER.error("Failed to dispatch message", ex);
        }
    }

    private void completeProcessing(Message message, Throwable throwable) {
        try {
            if (null != throwable) {
                getConcurrentMessageHandler().onException(message, throwable);
            } else {
                getConcurrentMessageHandler().onCompleteMessage(message);
            }
        } finally {
            pushNextEvent();
        }
    }

    class MessageProcessorRunnable implements Runnable {

        private Message message;
        private ConcurrentMessageHandler concurrentMessageHandler;

        public MessageProcessorRunnable(ConcurrentMessageHandler concurrentMessageHandler, Message message) {
            this.message = message;
            this.concurrentMessageHandler = concurrentMessageHandler;
        }

        @Override
        public void run() {
            try {
                LOGGER.trace("Start running run method");
                concurrentMessageHandler.process(message);
                concurrentMessageHandler = null;
                completeProcessing(message, null);
                LOGGER.trace("Finish running run method with success");
            } catch (Throwable throwable) {
                LOGGER.error("Problem occurred when processing message '{}'. Error is: {}",
                        new Object[] { message, throwable, throwable });
                completeProcessing(message, throwable);
                LOGGER.trace("Finish running run method with exception");
            }
        }
    }
}