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 */
022package org.granite.gravity.jetty;
023
024import org.granite.gravity.AbstractChannel;
025import org.granite.gravity.AsyncHttpContext;
026import org.granite.gravity.Gravity;
027import org.granite.gravity.GravityConfig;
028import org.granite.gravity.MessageReceivingException;
029import org.granite.logging.Logger;
030import org.mortbay.util.ajax.Continuation;
031
032import flex.messaging.messages.AsyncMessage;
033
034/**
035 * @author William DRAI
036 */
037public 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}