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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
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 * Copyright (c) 2009-2012 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
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 * 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
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 * file and include the License file at packager/legal/LICENSE.txt.
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 *
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package com.sun.enterprise.web.connector.grizzly.comet;

/**
 * Main class allowing Comet support on top of Grizzly Asynchronous
 * Request Processing mechanism. This class is the entry point to any
 * component interested to execute Comet request style. Components can be
 * Servlets, JSP, JSF or pure Java class. A component interested to support
 * Comet request must do:
 *
 * (1) First, register the cometContext path on which Comet support will be applied:
 *     CometEngine cometEngine = CometEngine.getEngine()
 *     CometContext cometContext = cometEngine.register(contextPath)
 * (2) Second, add an instance of {@link CometHandler} to the
 *     {@link CometContext} returned by the register method:
 *     cometContext.addCometHandler(handler);
 * (3) Finally, you can invokeCometHandler other {@link CometHandler} by doing:
 *     cometContext.invokeCometHandler(Object)(handler);
 *
 * You can also select the stage where the request polling happens when
 * registering the cometContext path (see register(String,int);
 *
 *
 * @author Jeanfrancois Arcand
 * @deprecated - Use {@link CometEngine}
 */
public class CometEngine extends com.sun.grizzly.comet.CometEngine {
    
    protected final static CometEngine cometEngine = new CometEngine();

    
    /**
     * {@inheritDoc}
     */   
    public static CometEngine getEngine(){
        return cometEngine;
}
    
    
    /**
     * {@inheritDoc}
     */   
    @Override
    public CometContext register(String contextPath){
        return register(contextPath,AFTER_SERVLET_PROCESSING);
    }
    
    
    /**
     * {@inheritDoc}
     */   
    @Override
    public CometContext register(String topic, int type) {
        // Double checked locking used used to prevent the otherwise static/global 
        // locking, cause example code does heavy usage of register calls
        // for existing topics from http get calls etc.
        CometContext cometContext = (CometContext) activeContexts.get(topic);
        if (cometContext == null) {
            synchronized (activeContexts) {
                cometContext = (CometContext) activeContexts.get(topic);
                if (cometContext == null) {
                    cometContext = (CometContext) cometContextCache.poll();
                    if (cometContext != null) {
                        cometContext.setTopic(topic);
                    }
                    if (cometContext == null) {
                        cometContext = new CometContext(topic, type);
                        NotificationHandler notificationHandler = new DefaultNotificationHandler();
                        cometContext.setNotificationHandler(notificationHandler);
                        if (notificationHandler != null && (notificationHandler instanceof DefaultNotificationHandler)) {
                            ((DefaultNotificationHandler) notificationHandler).setThreadPool(threadPool);
                        }
                    }
                    activeContexts.put(topic, cometContext);
                }
            }
        }
        return cometContext;
    }
    
    
    /**
     * {@inheritDoc}
     */   
    @Override
    public CometContext getCometContext(String contextPath){
        return (CometContext)activeContexts.get(contextPath);
    }
}