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
021 package org.granite.gravity.gae;
022
023 import org.granite.config.GraniteConfig;
024 import org.granite.config.flex.ServicesConfig;
025 import org.granite.gravity.Channel;
026 import org.granite.gravity.ChannelFactory;
027 import org.granite.gravity.DefaultGravity;
028 import org.granite.gravity.GravityConfig;
029 import org.granite.gravity.Subscription;
030 import org.granite.util.UUIDUtil;
031
032 import com.google.appengine.api.memcache.Expiration;
033 import com.google.appengine.api.memcache.MemcacheService;
034 import com.google.appengine.api.memcache.MemcacheServiceFactory;
035
036 import flex.messaging.messages.Message;
037
038 /**
039 * @author William DRAI
040 * @author Franck WOLFF
041 */
042 public class GAEGravity extends DefaultGravity {
043
044 ///////////////////////////////////////////////////////////////////////////
045 // Fields.
046
047 static final String CHANNEL_PREFIX = "org.granite.gravity.gae.channel.";
048
049 private static MemcacheService gaeCache = MemcacheServiceFactory.getMemcacheService();
050
051 ///////////////////////////////////////////////////////////////////////////
052 // Constructor.
053
054 public GAEGravity(GravityConfig gravityConfig, ServicesConfig servicesConfig, GraniteConfig graniteConfig) {
055 super(gravityConfig, servicesConfig, graniteConfig);
056 }
057
058
059 ///////////////////////////////////////////////////////////////////////////
060 // Channel's operations.
061
062 @Override
063 protected <C extends Channel> C createChannel(ChannelFactory<C> channelFactory, String channelId) {
064 C channel = null;
065 if (channelId != null) {
066 channel = getChannel(channelFactory, channelId);
067 if (channel != null)
068 return channel;
069 }
070
071 channel = channelFactory.newChannel(UUIDUtil.randomUUID(), null);
072 Expiration expiration = Expiration.byDeltaMillis((int)getGravityConfig().getChannelIdleTimeoutMillis());
073 gaeCache.put(CHANNEL_PREFIX + channel.getId(), channel, expiration);
074 gaeCache.put(GAEChannel.MSG_COUNT_PREFIX + channel.getId(), 0L, expiration);
075 return channel;
076 }
077
078 @SuppressWarnings("unchecked")
079 @Override
080 public <C extends Channel> C getChannel(ChannelFactory<C> channelFactory, String channelId) {
081 if (channelId == null)
082 return null;
083
084 return (C)gaeCache.get(CHANNEL_PREFIX + channelId);
085 }
086
087
088 @Override
089 public Channel removeChannel(String channelId) {
090 if (channelId == null)
091 return null;
092
093 Channel channel = (Channel)gaeCache.get(CHANNEL_PREFIX + channelId);
094 if (channel != null) {
095 for (Subscription subscription : channel.getSubscriptions()) {
096 Message message = subscription.getUnsubscribeMessage();
097 handleMessage(channel.getFactory(), message, true);
098 }
099
100 channel.destroy();
101 gaeCache.delete(CHANNEL_PREFIX + channelId);
102 gaeCache.delete(GAEChannel.MSG_COUNT_PREFIX + channelId);
103 }
104
105 return channel;
106 }
107
108 @Override
109 public boolean access(String channelId) {
110 return true;
111 }
112
113
114 @Override
115 public void internalStart() {
116 // Avoid starting thread pool
117 }
118
119
120 @Override
121 protected void postManage(Channel channel) {
122 Expiration expiration = Expiration.byDeltaMillis((int)getGravityConfig().getChannelIdleTimeoutMillis());
123 gaeCache.put(CHANNEL_PREFIX + channel.getId(), channel, expiration);
124 }
125 }