001    /**
002     *   GRANITE DATA SERVICES
003     *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004     *
005     *   This file is part of the Granite Data Services Platform.
006     *
007     *   Granite Data Services is free software; you can redistribute it and/or
008     *   modify it under the terms of the GNU Lesser General Public
009     *   License as published by the Free Software Foundation; either
010     *   version 2.1 of the License, or (at your option) any later version.
011     *
012     *   Granite Data Services is distributed in the hope that it will be useful,
013     *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014     *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015     *   General Public License for more details.
016     *
017     *   You should have received a copy of the GNU Lesser General Public
018     *   License along with this library; if not, write to the Free Software
019     *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020     *   USA, or see <http://www.gnu.org/licenses/>.
021     */
022    package org.granite.gravity.jetty;
023    
024    import org.granite.gravity.AbstractChannel;
025    import org.granite.gravity.AsyncHttpContext;
026    import org.granite.gravity.Gravity;
027    import org.granite.gravity.GravityConfig;
028    import org.granite.gravity.MessageReceivingException;
029    import org.granite.logging.Logger;
030    import org.mortbay.util.ajax.Continuation;
031    
032    import flex.messaging.messages.AsyncMessage;
033    
034    /**
035     * @author William DRAI
036     */
037    public class ContinuationChannel extends AbstractChannel {
038    
039        private static final Logger log = Logger.getLogger(ContinuationChannel.class);
040    
041        private Continuation continuation = null;
042    
043        public ContinuationChannel(Gravity gravity, String id, ContinuationChannelFactory factory, String clientType) {
044            super(gravity, id, factory, clientType);
045        }
046    
047        public void setContinuation(Continuation continuation) {
048            log.debug("Setting continuation %s for client: %s", continuation, getId());
049            try {
050                if (this.continuation != null && this.continuation.isPending()) {
051                    log.debug("Resuming previous continuation %s for client: %s", this.continuation, getId());
052                    this.continuation.resume();
053                }
054            }
055            finally {
056                this.continuation = continuation;
057            }
058        }
059        
060        public void close() {
061            try {
062                if (this.continuation != null)
063                    this.continuation.reset();
064            }
065            finally {
066                this.continuation = null;
067            }
068        }
069        
070    
071        public void resume() {
072            log.debug("Resuming pending continuation %s for client: %s", continuation, getId());
073            try {
074                if (this.continuation != null && this.continuation.isPending())
075                    this.continuation.resume();
076            }
077            finally {
078                this.continuation = null;
079            }
080        }
081        
082        @Override
083            public void receive(AsyncMessage message) throws MessageReceivingException {
084                    if (message == null)
085                            throw new NullPointerException("message cannot be null");
086    
087                    GravityConfig gravityConfig = gravity.getGravityConfig();
088                    
089                    receivedQueueLock.lock();
090                    try {
091                            if (receivedQueue.size() + 1 > gravityConfig.getMaxMessagesQueuedPerChannel())
092                                    throw new MessageReceivingException(message, "Could not queue message (channel's queue is full) for channel: " + this);
093                            
094                            receivedQueue.add(message);
095                    }
096                    finally {
097                            receivedQueueLock.unlock();
098                    }
099                    
100                    synchronized (this) {
101                            resume();
102                    }
103            }
104    
105            @Override
106            protected boolean hasAsyncHttpContext() {
107                    return false;
108            }
109    
110            @Override
111            protected void releaseAsyncHttpContext(AsyncHttpContext context) {
112            }
113    
114            @Override
115            protected AsyncHttpContext acquireAsyncHttpContext() {
116            return null;
117        }
118    
119        public boolean isLocal() {
120            return true;
121        }
122    
123            @Override
124            public void destroy() {
125                    try {
126                            super.destroy();
127                    }
128                    finally {
129                            synchronized (this) {
130                                    close();
131                            }
132                    }
133            }
134    }