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

   1 /***************************************************************************
   2  *   Copyright (C) 2008 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 <functional>
  21 #include <string>
  22
  23 #include <socket_wrapper.hxx>
  24
  25 namespace libt2n
  26 {
  27
  28 /// return active connection, create new tcp or unix connection if not existing
  29 client_connection* BasicSocketWrapper::get_connection(void)
  30 {
  31     if (c.get() == NULL)
  32     {
  33         if (socket_type == tcp_s)
  34             c=std::auto_ptr<socket_client_connection>
  35                 (new socket_client_connection(port,server,connect_timeout_usec,max_retries,logstream,log_level));
  36         else if (socket_type == unix_s)
  37             c=std::auto_ptr<socket_client_connection>
  38                 (new socket_client_connection(path,connect_timeout_usec,max_retries,logstream,log_level));
  39     }
  40
  41     return c.get();
  42 }
  43
  44 /// try to reconnect max_retries time if we encounter a t2n_communication_error
  45 /// during execution of the command
  46 bool ReconnectSocketWrapper::handle(command_client* stubBase, boost::function< void() > f)
  47 {
  48     int tries=0;
  49
  50     while(true)
  51     {
  52         try
  53         {
  54             // we always reconnect if something went wrong before:
  55             // makes sure the buffers are clean of half-sent packets etc.
  56             if (tries > 0)
  57                 c->reconnect();
  58
  59             f();
  60             // we were successful
  61             return true;
  62         }
  63         catch(t2n_connect_error &e)
  64         {
  65             // reconnect already tries max_tries times to reconnect: we are done if that failed
  66             throw(e);
  67         }
  68         catch(t2n_communication_error &e)
  69         {
  70             // aborts the loop with an exception after max_retries iterations
  71             // retries means that the first try doesn't count: use >
  72             if (tries > max_retries)
  73                 throw(e);
  74
  75             // otherwise ignore the exception and reconnect in the next iteration
  76         }
  77         catch(...)
  78         {
  79             throw;
  80         }
  81
  82         tries++;
  83     }
  84
  85     return false;
  86 }
  87
  88 /// return active connection, return a dummy-connection if we can't establish one
  89 client_connection* ReconnectIgnoreFailureSocketWrapper::get_connection(void)
  90 {
  91     client_connection* tmp=BasicSocketWrapper::get_connection();
  92
  93     if (tmp->is_closed())
  94     {
  95         // throw away the closed connection...
  96         c.reset();
  97         // ...return the dummy one instead
  98         tmp=&dc;
  99     }
 100
 101     return tmp;
 102 }
 103
 104 /// try to execute the command, may ignore the command if server not available
 105 bool ReconnectIgnoreFailureSocketWrapper::handle(command_client* stubBase, boost::function< void() > f)
 106 {
 107     if (!connection_established())
 108     {
 109         // dummy connection is in place: try to establish a real one
 110         client_connection* tmp=get_connection();
 111
 112         if (tmp != &dc)
 113         {
 114             // success! we've got a real connection
 115             stubBase->replace_connection(tmp);
 116         }
 117     }
 118
 119     // only try to handle the call if we've got a real connection
 120     if (connection_established())
 121     {
 122         try
 123         {
 124             ReconnectSocketWrapper::handle(stubBase,f);
 125             return true;
 126         }
 127         catch(t2n_communication_error &e)
 128         {
 129             // ignore
 130         }
 131         catch(...)
 132         {
 133             throw;
 134         }
 135     }
 136
 137     return false;
 138 }
 139
 140 }