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.adapters;
023    
024    import java.util.concurrent.ConcurrentHashMap;
025    import java.util.concurrent.ConcurrentMap;
026    
027    import org.granite.gravity.Channel;
028    import org.granite.gravity.Subscription;
029    
030    import flex.messaging.messages.AsyncMessage;
031    
032    /**
033     * Adapted from Greg Wilkins code (Jetty).
034     * 
035     * @author William DRAI
036     */
037    public class Topic {
038    
039        private final TopicId id;
040        private final SimpleServiceAdapter serviceAdapter;
041    
042        private ConcurrentMap<String, Subscription> subscriptions = new ConcurrentHashMap<String, Subscription>();
043        private ConcurrentMap<String, Topic> children = new ConcurrentHashMap<String, Topic>();
044        private Topic wild;
045        private Topic wildWild;
046    
047    
048        public Topic(String topicId, SimpleServiceAdapter serviceAdapter) {
049            this.id = new TopicId(topicId);
050            this.serviceAdapter = serviceAdapter;
051        }
052    
053        public String getId() {
054            return id.toString();
055        }
056    
057        public TopicId getTopicId() {
058            return id;
059        }
060    
061        public Topic getChild(TopicId topicId) {
062            String next = topicId.getSegment(id.depth());
063            if (next == null)
064                return null;
065    
066            Topic topic = children.get(next);
067    
068            if (topic == null || topic.getTopicId().depth() == topicId.depth()) {
069                return topic;
070            }
071            return topic.getChild(topicId);
072        }
073    
074        public void addChild(Topic topic) {
075            TopicId child = topic.getTopicId();
076            if (!id.isParentOf(child))
077                throw new IllegalArgumentException(id + " not parent of " + child);
078    
079            String next = child.getSegment(id.depth());
080    
081            if ((child.depth() - id.depth()) == 1) {
082                // add the topic to this topics
083                Topic old = children.putIfAbsent(next, topic);
084    
085                if (old != null)
086                    throw new IllegalArgumentException("Already Exists");
087    
088                if (TopicId.WILD.equals(next))
089                    wild = topic;
090                else if (TopicId.WILDWILD.equals(next))
091                    wildWild = topic;
092            }
093            else {
094                Topic branch = serviceAdapter.getTopic((id.depth() == 0 ? "/" : (id.toString() + "/")) + next, true);
095                branch.addChild(topic);
096            }
097        }
098    
099        public void subscribe(Channel channel, String destination, String subscriptionId, String selector, boolean noLocal) {
100            synchronized (this) {
101                Subscription subscription = channel.addSubscription(destination, getId(), subscriptionId, noLocal);
102                subscription.setSelector(selector);
103                subscriptions.putIfAbsent(subscriptionId, subscription);
104            }
105        }
106    
107        public void unsubscribe(Channel channel, String subscriptionId) {
108            synchronized(this) {
109                    subscriptions.remove(subscriptionId);
110                channel.removeSubscription(subscriptionId);
111            }
112        }
113    
114    
115        public void publish(TopicId to, Channel fromChannel, AsyncMessage msg) {
116            int tail = to.depth()-id.depth();
117    
118            switch(tail) {
119                case 0:
120                    for (Subscription subscription : subscriptions.values()) {
121                        AsyncMessage m = msg.clone();
122                        subscription.deliver(fromChannel, m);
123                    }
124    
125                    break;
126    
127                case 1:
128                    if (wild != null) {
129                        for (Subscription subscription : wild.subscriptions.values()) {
130                            AsyncMessage m = msg.clone();
131                            subscription.deliver(fromChannel, m);
132                        }
133                    }
134    
135                default: {
136                    if (wildWild != null) {
137                        for (Subscription subscription : wildWild.subscriptions.values()) {
138                            AsyncMessage m = msg.clone();
139                            subscription.deliver(fromChannel, m);
140                        }
141                    }
142                    String next = to.getSegment(id.depth());
143                    Topic topic = children.get(next);
144                    if (topic != null)
145                        topic.publish(to, fromChannel, msg);
146                }
147            }
148        }
149    
150        @Override
151        public String toString() {
152            return id.toString() + " {" + children.values() + "}";
153        }
154    }