Fawkes API  Fawkes Development Version
transceiver.cpp
00001 
00002 /***************************************************************************
00003  *  transceiver.cpp - Fawkes transceiver
00004  *
00005  *  Created: Tue Nov 21 23:46:13 2006
00006  *  Copyright  2006  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 <netcomm/fawkes/transceiver.h>
00025 #include <netcomm/fawkes/message.h>
00026 #include <netcomm/fawkes/message_queue.h>
00027 #include <netcomm/socket/stream.h>
00028 #include <netcomm/utils/exceptions.h>
00029 
00030 #include <netinet/in.h>
00031 #include <cstdlib>
00032 
00033 namespace fawkes {
00034 
00035 /** @class FawkesNetworkTransceiver transceiver.h <netcomm/fawkes/transceiver.h>
00036  * Fawkes 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 NetComm
00041  * @author Tim Niemueller
00042  */
00043 
00044 /** Send messages.
00045  * @param s socket over which the data shall be transmitted.
00046  * @param msgq message queue that contains the messages that have to be sent
00047  * @exception ConnectionDiedException Thrown if any error occurs during the
00048  * operation since for any error the conncetion is considered dead.
00049  */
00050 void
00051 FawkesNetworkTransceiver::send(StreamSocket *s, FawkesNetworkMessageQueue *msgq)
00052 {
00053   msgq->lock();
00054   try {
00055     while ( ! msgq->empty() ) {
00056       FawkesNetworkMessage *m = msgq->front();
00057       m->pack();
00058       const fawkes_message_t &f = m->fmsg();
00059       unsigned int payload_size = m->payload_size();
00060       s->write(&(f.header), sizeof(f.header));
00061       s->write(f.payload, payload_size);
00062       m->unref();
00063       msgq->pop();
00064     }
00065   } catch (SocketException &e) {
00066     msgq->unlock();
00067     throw ConnectionDiedException("Write failed");
00068   }
00069   msgq->unlock();
00070 }
00071 
00072 
00073 /** Receive data.
00074  * This method receives all messages currently available from the network, or
00075  * a limited number depending on max_num_msgs. If max_num_msgs is 0 then all
00076  * messages are read. Note that on a busy connection this may cause recv() to
00077  * never return! The default is to return after 8 messages.
00078  * The messages are stored in the supplied message queue.
00079  * @param s socket to gather messages from
00080  * @param msgq message queue to store received messages in
00081  * @param max_num_msgs maximum number of messages to read from stream in one go.
00082  * @exception ConnectionDiedException Thrown if any error occurs during the
00083  * operation since for any error the conncetion is considered dead.
00084  */
00085 void
00086 FawkesNetworkTransceiver::recv(StreamSocket *s, FawkesNetworkMessageQueue *msgq,
00087                                unsigned int max_num_msgs)
00088 {
00089   msgq->lock();
00090 
00091   try {
00092     unsigned int num_msgs = 0;
00093     while ( s->available() && (num_msgs++ < max_num_msgs) ) {
00094       fawkes_message_t msg;
00095       s->read(&(msg.header), sizeof(msg.header));
00096 
00097       unsigned int payload_size = ntohl(msg.header.payload_size);
00098 
00099       if ( payload_size > 0 ) {
00100         msg.payload = malloc(payload_size);
00101         s->read(msg.payload, payload_size);
00102       } else {
00103         msg.payload = NULL;
00104       }
00105 
00106       FawkesNetworkMessage *m = new FawkesNetworkMessage(msg);
00107       msgq->push(m);
00108     }
00109   } catch (SocketException &e) {
00110     msgq->unlock();
00111     throw ConnectionDiedException("Read failed");
00112   }
00113   msgq->unlock();
00114 }
00115 
00116 } // end namespace fawkes