org.glassfish.grizzly.comet.DefaultNotificationHandler Maven / Gradle / Ivy

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2007-2011 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.glassfish.grizzly.comet;

import java.io.IOException;
import java.util.Iterator;
import java.util.concurrent.ExecutorService;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Default NotificationHandler that uses a thread pool dedicated to the CometEngine to execute the notification
 * process.

 *
 * @author Jeanfrancois Arcand
 * @author Gustav Trede
 */
public class DefaultNotificationHandler implements NotificationHandler {
    private final static Logger logger = Logger.getLogger(DefaultNotificationHandler.class.getName());
    private static final IllegalStateException ISEempty = new IllegalStateException();
    /**
     * The {@link ExecutorService} used to execute threaded notification.
     */
    protected ExecutorService threadPool;

    public DefaultNotificationHandler() {
    }

    /**
     * Set the {@link ExecutorService} used for notifying the CometHandler.
     */
    protected void setThreadPool(ExecutorService threadPool) {
        this.threadPool = threadPool;
    }

    /**
     * Notify all {@link CometHandler}.
     *
     * @param cometEvent the CometEvent used to notify CometHandler
     * @param iteratorHandlers An iterator over a list of CometHandler
     */
    public void notify(final CometEvent cometEvent, final Iterator iteratorHandlers)
        throws IOException {
        while (iteratorHandlers.hasNext()) {
            notify(cometEvent, iteratorHandlers.next());
        }
    }

    /**
     * Notify the {@link CometHandler}.
     *
     * @param cometEvent cometEvent the CometEvent used to notify CometHandler
     */
    public void notify(final CometEvent cometEvent, final CometHandler cometHandler) throws IOException {
        notify0(cometEvent, cometHandler);
    }

    /**
     * Notify a {@link CometHandler}.
     * 
     * CometEvent.INTERRUPT -> CometHandler.onInterrupt CometEvent.NOTIFY ->
     * CometHandler.onEvent CometEvent.INITIALIZE -> CometHandler.onInitialize
     * CometEvent.TERMINATE -> CometHandler.onTerminate CometEvent.READ ->
     * CometHandler.onEvent CometEvent.WRITE -> CometHandler.onEvent
     *
     * @param cometEvent An object shared amongst {@link CometHandler}.
     * @param cometHandler The CometHandler to invoke.
     */
    protected void notify0(CometEvent cometEvent, CometHandler cometHandler) {
        try {
            switch (cometEvent.getType()) {
                case INTERRUPT:
                    cometHandler.onInterrupt(cometEvent);
                    break;
                case NOTIFY:
                case READ:
                case WRITE:
                    if (cometEvent.getCometContext().isActive(cometHandler)) {
                        cometHandler.onEvent(cometEvent);
                    }
                    break;
                case INITIALIZE:
                    cometHandler.onInitialize(cometEvent);
                    break;
                case TERMINATE:
                    cometHandler.onTerminate(cometEvent);
                    break;
                default:
                    throw ISEempty;
            }
        } catch (Throwable ex) {
            logger.log(Level.FINE, "Notification failed: ", ex);
            try {
                cometEvent.getCometContext().resumeCometHandler(cometHandler);
            } catch (Throwable t) {
                logger.log(Level.FINE, "Resume phase failed: ", t);
            }
        }
    }


}