org.wso2.andes.server.util.AlreadyProcessedMessageTracker.java Source code

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Here is the source code for org.wso2.andes.server.util.AlreadyProcessedMessageTracker.java

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/*
 * Copyright (c) 2005-2014, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. 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.wso2.andes.server.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.SortedMap;
import java.util.concurrent.*;

public class AlreadyProcessedMessageTracker {

    private static Log log = LogFactory.getLog(AlreadyProcessedMessageTracker.class);

    private ConcurrentHashMap<Long, Object> trackingMessageIDs = new ConcurrentHashMap<Long, Object>();
    private SortedMap<Long, Long> trackingMessagesRemovalTasks = new ConcurrentSkipListMap<Long, Long>();
    private static final ScheduledExecutorService alreadyProcessedMessageIDsRemovingScheduler = Executors
            .newSingleThreadScheduledExecutor();
    private long timeOutPerMessage = 15000000000L;
    private long trackingMessagesRemovalTaskIntervalInSec = 10;
    private String identifier = "";

    /**
     * Wrapper class for tracking messages. This will remove timed out messages when a new
     * message comes in.
     *
     * @param identifier Name of the message tracker.
     * @param trackingTimeOut  How long message should remain in the tracker.
     * @param trackingMessagesRemovalTaskIntervalInSec  task interval which checks the messages
     *                                                  to remove.
     */
    public AlreadyProcessedMessageTracker(String identifier, long trackingTimeOut,
            long trackingMessagesRemovalTaskIntervalInSec) {
        this.identifier = identifier;
        this.timeOutPerMessage = trackingTimeOut;
        this.trackingMessagesRemovalTaskIntervalInSec = trackingMessagesRemovalTaskIntervalInSec;
        startRemovingProcessedMessageIDS();
    }

    public void insertMessageForTracking(long messageID, Object value) {
        log.debug("inserting message id " + messageID + " for tracking. identifier=" + identifier);
        trackingMessageIDs.put(messageID, value);
    }

    public boolean checkIfAlreadyTracked(long messageID) {
        boolean result;
        if (trackingMessageIDs.get(messageID) != null) {
            result = true;
        } else {
            result = false;
        }
        log.debug("checking if already tracked message ID: " + messageID + " result = " + result + "identifier="
                + identifier);
        return result;
    }

    public Object removeMessageFromTracking(long messageID) {
        log.debug("removing message id " + messageID + " from tracking. identifier=" + identifier);
        return trackingMessageIDs.remove(messageID);
    }

    public void clearAllMessagesFromTracking() {
        log.debug("clearing all messages from tracking. identifier=" + identifier);
        trackingMessageIDs.clear();
    }

    public void addTaskToRemoveMessageFromTracking(long messageID) {
        trackingMessagesRemovalTasks.put(System.nanoTime(), messageID);
    }

    public void shutDownMessageTracker() {
        log.debug("shutting down message tracker. identifier=" + identifier);
        trackingMessageIDs.clear();
        alreadyProcessedMessageIDsRemovingScheduler.shutdown();
    }

    private void startRemovingProcessedMessageIDS() {
        alreadyProcessedMessageIDsRemovingScheduler.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                while (!trackingMessagesRemovalTasks.isEmpty()) {
                    long currentTime = System.nanoTime();
                    SortedMap<Long, Long> timedOutContentList = trackingMessagesRemovalTasks
                            .headMap(currentTime - timeOutPerMessage);
                    for (Long key : timedOutContentList.keySet()) {
                        long msgid = trackingMessagesRemovalTasks.get(key);
                        trackingMessageIDs.remove(msgid);
                        log.debug("cleared message from tracking message id " + msgid + "identifier=" + identifier);
                        trackingMessagesRemovalTasks.remove(key);
                    }
                }
            }
        }, 5, trackingMessagesRemovalTaskIntervalInSec, TimeUnit.SECONDS);
    }
}