org.ow2.carol.cmi.ha.TOHashTable Maven / Gradle / Ivy

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/**
 * High Availability Service (HA) for JOnAS
 *
 * Copyright (C) 2006 Distributed Systems Lab.
 * Universidad Polit??cnica de Madrid (Spain)
 * Contact: http://lsd.ls.fi.upm.es/lsd
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * --------------------------------------------------------------------------
 * $Id: TOHashTable.java 1293 2007-10-07 09:52:15Z loris $
 * --------------------------------------------------------------------------
 */

package org.ow2.carol.cmi.ha;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import org.ow2.util.log.Log;
import org.ow2.util.log.LogFactory;


public class TOHashTable implements Map {

    /**
     * Logger.
     */
    private static Log logger = LogFactory.getLog(TOHashTable.class);

    private int timeout = 600000;

    private final ProcessThread processThread;

    private final Map map;

    public TOHashTable(final int timeout){
        map = new ConcurrentHashMap();
        this.timeout = timeout*1000;
        processThread = new ProcessThread(map);
        processThread.setDaemon(true);
        processThread.start();
    }

    public int getTimeout() {
        return timeout;
    }

    public void setTimeout(final int timeout) {
        this.timeout = timeout;
    }

    public V put(final K key, final V o) {
        Info i = new Info(o, System.currentTimeMillis() + timeout);
        Info previous = map.put(key, i);
        if (previous != null) {
            return previous.o;
        } else {
            return null;
        }
    }

    public V get(final Object key) {
        Info i = map.get(key);
        if (i != null) {
            return i.o;
        } else {
            return null;
        }
    }

    public V remove(final Object key) {
        Info i = map.remove(key);
        if (i != null) {
            return i.o;
        } else {
            return null;
        }
    }

    public void clear() {
        map.clear();
    }

    public boolean containsKey(final Object key) {
        return map.containsKey(key);
    }

    public boolean containsValue(final Object value) {
        throw new UnsupportedOperationException();
    }

    public Set> entrySet() {
        throw new UnsupportedOperationException();
    }

    public boolean isEmpty() {
        return map.isEmpty();
    }

    public Set keySet() {
        return map.keySet();
    }

    public void putAll(final Map t) {
        throw new UnsupportedOperationException();
    }

    public int size() {
        return map.size();
    }

    public Collection values() {
        throw new UnsupportedOperationException();
    }

    private class Info  {
        /**
         * The timer
         */
        V o;
        long timeoutMoment = 0;

        /**
         * Constructor
         * @param key
         * @param o
         * @param toht
         */
         Info(final V o, final long timeoutMoment) {
            this.o = o;
            this.timeoutMoment = timeoutMoment;
         }
    }

    /**
     * This Thread process object in table.
     * @author Francisco Perez-Sorrosal (fpsorrosal@[email protected])
     * @author Alberto Paz-Jimenez (apaz@[email protected])
     */
    class ProcessThread extends Thread {
        private volatile Thread test;
        private final Map table;

        public ProcessThread(final Map table) {
            this.table = table;
        }

        @Override
        public void run() {
            logger.debug("ProcessMessage thread started");

            test = Thread.currentThread();
            long currentTime = System.currentTimeMillis();
            while (test == Thread.currentThread()) {
                int removed = 0;
                Iterator i = table.values().iterator();
                while(i.hasNext()) {
                    Info info = i.next();
                    if (info.timeoutMoment <= currentTime) {
                        i.remove();
                        if (logger.isDebugEnabled()) {
                            removed++;
                        }
                    }
                }
                if (removed > 0) {
                    logger.debug("Removed: {0} objects from TOHashTable.", removed);
                }
                // Execute every 60 seconds
                synchronized (this) {
                    try {
                        wait(60000);
                    } catch (InterruptedException e) {
                        test = null;
                    }
                }
            }
        }

        public void stopExecution() {
            logger.debug("ProcessMessage thread stoped");

            synchronized (this) {
                test = null;
                notify();
            }
        }
    }
}