00001
00002 /***************************************************************************
00003  *  fuse_transceiver.cpp - Fuse transceiver
00004  *
00005  *  Created: Wed Nov 14 13:30:34 2007
00006  *  Copyright  2006-2007  Tim Niemueller [www.niemueller.de]
00007  *
00008  ****************************************************************************/
00009
00010 /*  This program is free software; you can redistribute it and/or modify
00011  *  it under the terms of the GNU General Public License as published by
00012  *  the Free Software Foundation; either version 2 of the License, or
00013  *  (at your option) any later version. A runtime exception applies to
00014  *  this software (see LICENSE.GPL_WRE file mentioned below for details).
00015  *
00016  *  This program is distributed in the hope that it will be useful,
00017  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  *  GNU Library General Public License for more details.
00020  *
00021  *  Read the full text in the LICENSE.GPL_WRE file in the doc directory.
00022  */
00023
00024 #include <fvutils/net/fuse_transceiver.h>
00025 #include <fvutils/net/fuse_message_queue.h>
00026 #include <fvutils/net/fuse_message.h>
00027 #include <netcomm/socket/stream.h>
00028 #include <netcomm/utils/exceptions.h>
00029
00030 #include <netinet/in.h>
00031 #include <cstdlib>
00032
00033 using namespace fawkes;
00034 
00035 /** @class FuseNetworkTransceiver <fvutils/net/fuse_transceiver.h>
00036  * FUSE Network Transceiver.
00037  * Utility class that provides methods to send and receive messages via
00038  * the network. Operates on message queues and a given socket.
00039  *
00040  * @ingroup FUSE
00041  * @ingroup FireVision
00042  * @author Tim Niemueller
00043  */
00044 
00045 /** Send messages.
00046  * @param s socket over which the data shall be transmitted.
00047  * @param msgq message queue that contains the messages that have to be sent
00048  * @exception ConnectionDiedException Thrown if any error occurs during the
00049  * operation since for any error the conncetion is considered dead.
00050  */
00051 void
00052 FuseNetworkTransceiver::send(StreamSocket *s, FuseNetworkMessageQueue *msgq)
00053 {
00054   msgq->lock();
00055   try {
00056     while ( ! msgq->empty() ) {
00057       FuseNetworkMessage *m = msgq->front();
00058       m->pack();
00059       const FUSE_message_t &f = m->fmsg();
00060       unsigned int payload_size = m->payload_size();
00061       s->write(&(f.header), sizeof(f.header));
00062       s->write(f.payload, payload_size);
00063       m->unref();
00064       msgq->pop();
00065     }
00066   } catch (SocketException &e) {
00067     msgq->unlock();
00068     throw ConnectionDiedException("Write failed");
00069   }
00070   msgq->unlock();
00071 }
00072
00073 
00074 /** Receive data.
00075  * This method receives all messages currently available from the network, or
00076  * a limited number depending on max_num_msgs. If max_num_msgs is 0 then all
00077  * messages are read. Note that on a busy connection this may cause recv() to
00078  * never return! The default is to return after 8 messages.
00079  * The messages are stored in the supplied message queue.
00080  * @param s socket to gather messages from
00081  * @param msgq message queue to store received messages in
00082  * @param max_num_msgs maximum number of messages to read from stream in one go.
00083  * @exception ConnectionDiedException Thrown if any error occurs during the
00084  * operation since for any error the conncetion is considered dead.
00085  */
00086 void
00087 FuseNetworkTransceiver::recv(StreamSocket *s, FuseNetworkMessageQueue *msgq,
00088                              unsigned int max_num_msgs)
00089 {
00090   msgq->lock();
00091
00092   try {
00093     unsigned int num_msgs = 0;
00094     do {
00095       FUSE_message_t msg;
00096       s->read(&(msg.header), sizeof(msg.header));
00097
00098       unsigned int payload_size = ntohl(msg.header.payload_size);
00099
00100       if ( payload_size > 0 ) {
00101
00102         msg.payload = malloc(payload_size);
00103         s->read(msg.payload, payload_size);
00104       } else {
00105         msg.payload = NULL;
00106       }
00107
00108       FuseNetworkMessage *m = new FuseNetworkMessage(&msg);
00109       msgq->push(m);
00110
00111       ++num_msgs;
00112     } while ( s->available() && (num_msgs < max_num_msgs) );
00113   } catch (SocketException &e) {
00114     msgq->unlock();
00115     throw ConnectionDiedException("Read failed");
00116   }
00117   msgq->unlock();
00118 }