001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005  This file is part of Granite Data Services.
006
007  Granite Data Services is free software; you can redistribute it and/or modify
008  it under the terms of the GNU Library General Public License as published by
009  the Free Software Foundation; either version 2 of the License, or (at your
010  option) any later version.
011
012  Granite Data Services is distributed in the hope that it will be useful, but
013  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015  for more details.
016
017  You should have received a copy of the GNU Library General Public License
018  along with this library; if not, see <http://www.gnu.org/licenses/>.
019*/
020
021package org.granite.gravity.jetty;
022
023import org.granite.gravity.AbstractChannel;
024import org.granite.gravity.AsyncHttpContext;
025import org.granite.gravity.Gravity;
026import org.granite.gravity.GravityConfig;
027import org.granite.gravity.MessageReceivingException;
028import org.granite.logging.Logger;
029import org.mortbay.util.ajax.Continuation;
030
031import flex.messaging.messages.AsyncMessage;
032
033/**
034 * @author William DRAI
035 */
036public class ContinuationChannel extends AbstractChannel {
037
038    private static final Logger log = Logger.getLogger(ContinuationChannel.class);
039
040    private Continuation continuation = null;
041
042    public ContinuationChannel(Gravity gravity, String id, ContinuationChannelFactory factory, String clientType) {
043        super(gravity, id, factory, clientType);
044    }
045
046    public void setContinuation(Continuation continuation) {
047        log.debug("Setting continuation %s for client: %s", continuation, getId());
048        try {
049            if (this.continuation != null && this.continuation.isPending()) {
050                log.debug("Resuming previous continuation %s for client: %s", this.continuation, getId());
051                this.continuation.resume();
052            }
053        }
054        finally {
055            this.continuation = continuation;
056        }
057    }
058    
059    public void close() {
060        try {
061            if (this.continuation != null)
062                this.continuation.reset();
063        }
064        finally {
065            this.continuation = null;
066        }
067    }
068    
069
070    public void resume() {
071        log.debug("Resuming pending continuation %s for client: %s", continuation, getId());
072        try {
073            if (this.continuation != null && this.continuation.isPending())
074                this.continuation.resume();
075        }
076        finally {
077            this.continuation = null;
078        }
079    }
080    
081    @Override
082        public void receive(AsyncMessage message) throws MessageReceivingException {
083                if (message == null)
084                        throw new NullPointerException("message cannot be null");
085
086                GravityConfig gravityConfig = gravity.getGravityConfig();
087                
088                receivedQueueLock.lock();
089                try {
090                        if (receivedQueue.size() + 1 > gravityConfig.getMaxMessagesQueuedPerChannel())
091                                throw new MessageReceivingException(message, "Could not queue message (channel's queue is full) for channel: " + this);
092                        
093                        receivedQueue.add(message);
094                }
095                finally {
096                        receivedQueueLock.unlock();
097                }
098                
099                synchronized (this) {
100                        resume();
101                }
102        }
103
104        @Override
105        protected boolean hasAsyncHttpContext() {
106                return false;
107        }
108
109        @Override
110        protected void releaseAsyncHttpContext(AsyncHttpContext context) {
111        }
112
113        @Override
114        protected AsyncHttpContext acquireAsyncHttpContext() {
115        return null;
116    }
117
118    public boolean isLocal() {
119        return true;
120    }
121
122        @Override
123        public void destroy() {
124                try {
125                        super.destroy();
126                }
127                finally {
128                        synchronized (this) {
129                                close();
130                        }
131                }
132        }
133}