jasenautoupdatemanager.java

spam source codejasen-0.9jASEN - java Anti Spam ENgine.zip 如标题所示

/*
 * @(#)JasenAutoUpdateManager.java	5/01/2005
 *
 * Copyright (c) 2005 jASEN.org
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in
 *      the documentation and/or other materials provided with the distribution.
 *
 *   3. The names of the authors may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *   4. Any modification or additions to the software must be contributed back
 *      to the project.
 *
 *   5. Any investigation or reverse engineering of source code or binary to
 *      enable emails to bypass the filters, and hence inflict spam and or viruses
 *      onto users who use or do not use jASEN could subject the perpetrator to
 *      criminal and or civil liability.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JASEN.ORG,
 * OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
package org.jasen.update;

import org.apache.log4j.Logger;
import org.jasen.JasenScanner;
import org.jasen.error.JasenException;
import org.jasen.interfaces.JasenErrorHandler;
import org.jasen.io.StreamReaderListener;
import org.jasen.util.ThreadUtils;

/**
 * <p>
 * The auto update manager is responsible for starting, stoping and scheduling the AutoUpdate thread.
 * </p>
 * <p>
 * All access to the auto update system should be via this class.  DO NOT access any other update class directly
 * </p>
 * @author Jason Polites
 */
public final class JasenAutoUpdateManager implements StreamReaderListener {

    static final Logger logger = Logger.getLogger(JasenAutoUpdateManager.class);

    private static JasenAutoUpdateManager instance;
    private static final Object lock = new Object();

    private JasenAutoUpdater updater;
    private JasenAutoUpdateReaper reaper;
    private JasenAutoUpdateNotifier notifier;

    private JasenAutoUpdateConfiguration configuration;

    private boolean initialized = false;
    private volatile boolean updating = false;

    private JasenErrorHandler errorHandler;
    private boolean destroyed;

    /**
     *
     */
    private JasenAutoUpdateManager() {
        super();
    }

    public static final JasenAutoUpdateManager getInstance() {
        if(instance == null) {
            synchronized(lock) {

                if(instance == null) {
                    instance = new JasenAutoUpdateManager();
                }

                lock.notifyAll();
            }
        }

        return instance;
    }

    void assertInitialised() throws JasenException {
        if(!initialized) {
            throw new JasenException("Cannot perform requested operation on uninitialized AutoUpdate manager.  Please ensure the auto update engine is enabled");
        }
    }

    /**
     * Initialises the manager with the given configuration object
     * @param configuration
     * @throws JasenException
     */
    public synchronized void init(JasenAutoUpdateConfiguration configuration) throws JasenException {

        logger.debug("Initialising auto update manager");

        if(!initialized) {

            this.configuration = configuration;

            errorHandler = configuration.getErrorHandler();

            // Create the update thread
            updater = new JasenAutoUpdater(this, "JasenAutoUpdater");

            // Create the reaper
            reaper = new JasenAutoUpdateReaper(updater, this, "JasenAutoUpdateReaper");
            
            // Create the notifier
            notifier = new JasenAutoUpdateNotifier(this, "JasenAutoUpdateNotifier");

            // Start the updater
            logger.debug("Starting auto updater");
            updater.start();

            // Start the reaper
            logger.debug("Starting auto updater reaper");
            reaper.start();
            
            // Start the notifyier
            logger.debug("Starting auto updater notifier");
            notifier.start();            

            initialized = true;
            destroyed = false;
        }

    }

    public synchronized void destroy() {
        if(!destroyed) {

            logger.debug("Stopping the updater");

            // Stop the updater...
            logger.debug("Waiting for auto updater to finish");

            // Wait for the updater to finish...
            if(!ThreadUtils.forceFinish(updater, JasenAutoUpdateReaper.killTimeout)) {
                logger.warn("Auto Updater did not finish within the given timeout of " + JasenAutoUpdateReaper.killTimeout + " milliseconds and will be interrupted");
            }

            // Stop the reaper...
            if(!ThreadUtils.forceFinish(reaper, JasenAutoUpdateReaper.killTimeout)) {
                logger.warn("Auto Updater Reaper did not finish within the given timeout of " + JasenAutoUpdateReaper.killTimeout + " milliseconds and will be interrupted");
            }   
            
            // Stop the notifier...
            if(!ThreadUtils.forceFinish(notifier, JasenAutoUpdateReaper.killTimeout)) {
                logger.warn("Auto Updater Notifier did not finish within the given timeout of " + JasenAutoUpdateReaper.killTimeout + " milliseconds and will be interrupted");
            }                

            destroyed = true;
            initialized = false;
        }
    }

    public JasenAutoUpdateConfiguration getConfiguration() {
        return configuration;
    }

    public JasenErrorHandler getErrorHandler() {
        return errorHandler;
    }

    public synchronized boolean isInitialized() {
        return initialized;
    }

    public boolean isIdle() {
        return updater.isIdle();
    }

    public boolean forceUpdate() throws JasenException {
        assertInitialised();
        return updater.forceUpdate();
    }

    /**
     * Called by the updater to signal that an update has occurred
     * @param report A report of the results of the update
     */
    void notifyUpdateComplete(JasenAutoUpdateReport report) {
        logger.debug("Received update complete notification, notifying scanner");
        notifier.notifyUpdateComplete(report);
        updating = false;

    }

    /**
     * Called by the updater to signal that an update is required
     *
     */
    void notifyUpdateRequired(JasenAutoUpdateParcel parcel) {

        updating = true;

        if(JasenScanner.getInstance().isAlive()) {
            JasenScanner.getInstance().notifyPendingUpdate(parcel);
        }
    }

    public void notifyBytesRead(long bytes) {
        if(JasenScanner.getInstance().isAlive()) {
            JasenScanner.getInstance().notifyUpdateDownload(bytes);
        }
    }
    
    /**
     * Indicates whether the auto update thread has signaled an update task underway
     * @return true if the auto updater is updating, false otherwise
     */
    public boolean isUpdating() {
        return updating;
    }
}