xapian-core/net/remotetcpclient.h

   1 /** @file remotetcpclient.h
   2  *  @brief TCP/IP socket based RemoteDatabase implementation
   3  */
   4 /* Copyright (C) 2007,2008,2010,2011,2014 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_REMOTETCPCLIENT_H
  22 #define XAPIAN_INCLUDED_REMOTETCPCLIENT_H
  23
  24 #include "backends/remote/remote-database.h"
  25
  26 #ifdef __WIN32__
  27 # define SOCKET_INITIALIZER_MIXIN private WinsockInitializer,
  28 #else
  29 # define SOCKET_INITIALIZER_MIXIN
  30 #endif
  31
  32 /** TCP/IP socket based RemoteDatabase implementation.
  33  *
  34  *  Connects via TCP/IP to an instance of xapian-tcpsrv.
  35  */
  36 class RemoteTcpClient : SOCKET_INITIALIZER_MIXIN public RemoteDatabase {
  37     /// Don't allow assignment.
  38     void operator=(const RemoteTcpClient &);
  39
  40     /// Don't allow copying.
  41     RemoteTcpClient(const RemoteTcpClient &);
  42
  43     /** Attempt to open a TCP/IP socket connection to xapian-tcpsrv.
  44      *
  45      *  Connect to xapian-tcpsrv running on port @a port of host @a hostname.
  46      *  Give up trying to connect after @a timeout_connect seconds.
  47      *
  48      *  Note: this method is called early on during class construction before
  49      *  any member variables or even the base class have been initialised.
  50      *  To help avoid accidentally trying to use member variables or call other
  51      *  methods which do, this method has been deliberately made "static".
  52      */
  53     static int open_socket(const std::string & hostname, int port,
  54                            double timeout_connect);
  55
  56     /** Get a context string for use when constructing Xapian::NetworkError.
  57      *
  58      *  Note: this method is used from constructors so has been made static to
  59      *  avoid problems with trying to use uninitialised member variables.  In
  60      *  particular, it can't be made a virtual method of the base class.
  61      */
  62     static std::string get_tcpcontext(const std::string & hostname, int port);
  63
  64   public:
  65     /** Constructor.
  66      *
  67      *  Attempts to open a TCP/IP connection to xapian-tcpsrv running on port
  68      *  @a port of host @a hostname.
  69      *
  70      *  @param timeout_connect  Timeout for trying to connect (in seconds).
  71      *  @param timeout          Timeout during communication after successfully
  72      *                          connecting (in seconds).
  73      *  @param writable         Is this a WritableDatabase?
  74      *  @param flags            Xapian::DB_RETRY_LOCK or 0.
  75      */
  76     RemoteTcpClient(const std::string & hostname, int port,
  77                     double timeout_, double timeout_connect, bool writable,
  78                     int flags)
  79         : RemoteDatabase(open_socket(hostname, port, timeout_connect),
  80                          timeout_, get_tcpcontext(hostname, port),
  81                          writable, flags) { }
  82
  83     /** Destructor. */
  84     ~RemoteTcpClient();
  85 };
  86
  87 #endif  // XAPIAN_INCLUDED_REMOTETCPCLIENT_H