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