developer.intra2net.com Git - libt2n/blob - src/connection.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Gerd v. Egidy                                   *
   3  *   gve@intra2net.com                                                     *
   4  *                                                                         *
   5  *   This library is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU Lesser General Public License version   *
   7  *   2.1 as published by the Free Software Foundation.                     *
   8  *                                                                         *
   9  *   This library is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU Lesser General Public License for more details.                   *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU Lesser General Public      *
  15  *   License along with this program; if not, write to the                 *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  18  ***************************************************************************/
  19
  20 #include <string>
  21 #include <sstream>
  22 #include <iostream>
  23
  24 #include <netinet/in.h>
  25
  26 #include "connection.hxx"
  27
  28 namespace libt2n
  29 {
  30
  31 connection::packet_size_indicator connection::bytes_available()
  32 {
  33     // no size information -> no packet
  34     if (buffer.size() < sizeof(packet_size_indicator))
  35         return 0;
  36
  37     packet_size_indicator psize=ntohl(*((packet_size_indicator*)(buffer.data())));
  38
  39     // enough data for one packet in buffer?
  40     if (buffer.size() < sizeof(packet_size_indicator)+psize)
  41         return 0;
  42
  43     // ok, full packet there
  44     return psize;
  45 }
  46
  47 /** @brief read a complete data packet from the buffer. The packet is removed from the
  48             connection buffer.
  49     @param[out] data the data package
  50     @retval true if packet found
  51 */
  52 bool connection::get_packet(std::string& data)
  53 {
  54     packet_size_indicator psize;
  55
  56     if ((psize=bytes_available()))
  57     {
  58         data.assign(buffer,sizeof(packet_size_indicator),psize);
  59         buffer.erase(0,sizeof(packet_size_indicator)+psize);
  60         return true;
  61     }
  62     else
  63         return false;
  64 }
  65
  66 /** @brief get (maybe incomplete) data of the next packet from the buffer. Does not remove the data
  67             from the connection buffer.
  68     @param[out] data the data package
  69     @retval full size of the packet when it will be complete
  70 */
  71 unsigned int connection::peek_packet(std::string& data)
  72 {
  73     // no size information -> no packet
  74     if (buffer.size() < sizeof(packet_size_indicator))
  75         return 0;
  76
  77     packet_size_indicator psize=ntohl(*((packet_size_indicator*)(buffer.data())));
  78
  79     // not the full data available?
  80     packet_size_indicator currsize=psize;
  81     if (buffer.size() < currsize+sizeof(packet_size_indicator))
  82         currsize=buffer.size()-sizeof(packet_size_indicator);
  83
  84     data.assign(buffer,sizeof(packet_size_indicator),currsize);
  85
  86     return psize;
  87 }
  88
  89 /// send a blob to the peer
  90 void connection::write(const std::string& data)
  91 {
  92     // prepend packet size to data
  93     packet_size_indicator psize=htonl(data.size());
  94     std::string send_data(data);
  95     send_data.insert(0,(char*)&psize,sizeof(packet_size_indicator));
  96
  97     real_write(send_data);
  98 }
  99
 100 }