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.gae;
023
024import org.granite.config.GraniteConfig;
025import org.granite.config.flex.ServicesConfig;
026import org.granite.gravity.Channel;
027import org.granite.gravity.ChannelFactory;
028import org.granite.gravity.DefaultGravity;
029import org.granite.gravity.GravityConfig;
030import org.granite.gravity.Subscription;
031import org.granite.messaging.jmf.SharedContext;
032import org.granite.util.UUIDUtil;
033
034import com.google.appengine.api.memcache.Expiration;
035import com.google.appengine.api.memcache.MemcacheService;
036import com.google.appengine.api.memcache.MemcacheServiceFactory;
037
038import flex.messaging.messages.Message;
039
040/**
041 * @author William DRAI
042 * @author Franck WOLFF
043 */
044public class GAEGravity extends DefaultGravity {
045
046    ///////////////////////////////////////////////////////////////////////////
047    // Fields.
048    
049    static final String CHANNEL_PREFIX = "org.granite.gravity.gae.channel.";
050    
051    private static MemcacheService gaeCache = MemcacheServiceFactory.getMemcacheService();
052    
053    ///////////////////////////////////////////////////////////////////////////
054    // Constructor.
055
056    public GAEGravity(GravityConfig gravityConfig, ServicesConfig servicesConfig, GraniteConfig graniteConfig, SharedContext sharedContext) {
057        super(gravityConfig, servicesConfig, graniteConfig, sharedContext);
058    }
059    
060
061    ///////////////////////////////////////////////////////////////////////////
062    // Channel's operations.
063
064    @Override
065    protected <C extends Channel> C createChannel(ChannelFactory<C> channelFactory, String channelId) {
066        C channel = null;
067        if (channelId != null) {
068                channel = getChannel(channelFactory, channelId);
069                if (channel != null)
070                        return channel;
071        }
072        
073        channel = channelFactory.newChannel(UUIDUtil.randomUUID(), null);
074        Expiration expiration = Expiration.byDeltaMillis((int)getGravityConfig().getChannelIdleTimeoutMillis());
075        gaeCache.put(CHANNEL_PREFIX + channel.getId(), channel, expiration);
076        gaeCache.put(GAEChannel.MSG_COUNT_PREFIX + channel.getId(), 0L, expiration);
077        return channel;
078    }
079
080    @SuppressWarnings("unchecked")
081        @Override
082    public <C extends Channel> C getChannel(ChannelFactory<C> channelFactory, String channelId) {
083        if (channelId == null)
084            return null;
085
086        return (C)gaeCache.get(CHANNEL_PREFIX + channelId);
087    }
088
089
090    @Override
091    public Channel removeChannel(String channelId, boolean timeout) {
092        if (channelId == null)
093            return null;
094
095        Channel channel = (Channel)gaeCache.get(CHANNEL_PREFIX + channelId);
096        if (channel != null) {
097            for (Subscription subscription : channel.getSubscriptions()) {
098                Message message = subscription.getUnsubscribeMessage();
099                handleMessage(channel.getFactory(), message, true);
100            }
101
102            channel.destroy(timeout);
103            gaeCache.delete(CHANNEL_PREFIX + channelId);
104                gaeCache.delete(GAEChannel.MSG_COUNT_PREFIX + channelId);
105        }
106
107        return channel;
108    }
109
110    @Override
111    public boolean access(String channelId) {
112        return true;
113    }
114    
115    
116    @Override
117    public void internalStart() {
118        // Avoid starting thread pool
119    }
120
121    
122    @Override
123    protected void postManage(Channel channel) {
124        Expiration expiration = Expiration.byDeltaMillis((int)getGravityConfig().getChannelIdleTimeoutMillis());
125        gaeCache.put(CHANNEL_PREFIX + channel.getId(), channel, expiration);
126    }
127}