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 java.io.IOException;
024    import java.util.List;
025    
026    import javax.servlet.ServletConfig;
027    import javax.servlet.ServletException;
028    import javax.servlet.http.HttpServletRequest;
029    import javax.servlet.http.HttpServletResponse;
030    
031    import org.granite.gravity.AbstractGravityServlet;
032    import org.granite.gravity.Gravity;
033    import org.granite.gravity.GravityManager;
034    import org.granite.logging.Logger;
035    
036    import com.google.apphosting.api.DeadlineExceededException;
037    
038    import flex.messaging.messages.AsyncMessage;
039    import flex.messaging.messages.Message;
040    
041    
042    /**
043     * @author William DRAI
044     */
045    public class GravityGAEServlet extends AbstractGravityServlet {
046    
047        private static final long serialVersionUID = 1L;
048    
049        private static final Logger log = Logger.getLogger(GravityGAEServlet.class);
050    
051    
052        private static long GAE_TIMEOUT = 20000L;
053        private static long GAE_POLLING_INTERVAL = 500L;
054    
055    
056        @Override
057        public void init(ServletConfig config) throws ServletException {
058            super.init(config, new GAEChannelFactory());
059        }
060    
061    
062        @Override
063        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
064            doPost(req,resp);
065        }
066    
067        @Override
068        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
069    
070                    Gravity gravity = GravityManager.getGravity(getServletContext());
071                    
072                    try {
073                            // Setup context (thread local GraniteContext, etc.)
074                            initializeRequest(gravity, request, response);
075                            
076                            // New Request.
077                            Message[] amf3Requests = deserialize(gravity, request);
078    
079                log.debug(">> [AMF3 REQUESTS] %s", (Object)amf3Requests);
080    
081                Message[] amf3Responses = null;
082                
083                boolean accessed = false;
084                for (int i = 0; i < amf3Requests.length; i++) {
085                    Message amf3Request = amf3Requests[i];
086                    
087                    // Ask gravity to create a specific response (will be null for connect request from tunnel).
088                    Message amf3Response = gravity.handleMessage(amf3Request);
089                    String channelId = (String)amf3Request.getClientId();
090                    
091                    // Mark current channel (if any) as accessed.
092                    if (!accessed)
093                            accessed = gravity.access(channelId);
094                    
095                    // (Re)Connect message from tunnel.
096                    if (amf3Response == null) {
097                        if (amf3Requests.length > 1)
098                            throw new IllegalArgumentException("Only one request is allowed on tunnel.");
099    
100                            GAEChannel channel = (GAEChannel)gravity.getChannel(channelId);
101                            if (channel == null)
102                                    throw new NullPointerException("No channel on connect");
103                            
104                            long pollingInterval = gravity.getGravityConfig().getExtra().get("gae/@polling-interval", Long.TYPE, GAE_POLLING_INTERVAL);
105    
106                        long initialTime = System.currentTimeMillis();
107                        do {
108                            // Get messages or wait
109                            List<Message> messages = null;
110                            synchronized (channel) {
111                                // Get pending messages from client queue
112                                messages = channel.takeMessages();
113                            }
114            
115                            // Send the messages
116                            if (messages != null) {
117                                    amf3Responses = messages.toArray(new Message[0]);
118                                    ((AsyncMessage)amf3Responses[i]).setCorrelationId(amf3Requests[i].getMessageId());
119                                    break;
120                            }
121                            
122                            try {
123                                    Thread.sleep(pollingInterval);
124                            }
125                            catch (InterruptedException e) {
126                                    break;
127                            }
128                            catch (DeadlineExceededException e) {
129                                    break;
130                            }
131                        }
132                        while (System.currentTimeMillis()-initialTime < GAE_TIMEOUT);
133                        
134                        if (amf3Responses == null)
135                            amf3Responses = new Message[0];
136                    }
137                    else {
138                            if (amf3Responses == null)
139                                    amf3Responses = new Message[amf3Requests.length];
140                            amf3Responses[i] = amf3Response;
141                    }
142                }
143    
144                log.debug("<< [AMF3 RESPONSES] %s", (Object)amf3Responses);
145    
146                serialize(gravity, response, amf3Responses);
147                    }
148            catch (IOException e) {
149                log.error(e, "Gravity message error");
150                throw e;
151            }
152            catch (Exception e) {
153                log.error(e, "Gravity message error");
154                throw new ServletException(e);
155            }
156                    finally {
157                            // Cleanup context (thread local GraniteContext, etc.)
158                            cleanupRequest(request);
159                    }
160        }
161    }