xapian-core/net/remotetcpclient.h

   1 /** @file
   2  *  @brief TCP/IP socket based RemoteDatabase implementation
   3  */
   4 /* Copyright (C) 2007,2008,2010,2011,2014,2024 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 #include "socket_utils.h"
  26
  27 #include <string>
  28 #include <string_view>
  29
  30 #ifdef __WIN32__
  31 # define SOCKET_INITIALIZER_MIXIN private WinsockInitializer,
  32 #else
  33 # define SOCKET_INITIALIZER_MIXIN
  34 #endif
  35
  36 /** TCP/IP socket based RemoteDatabase implementation.
  37  *
  38  *  Connects via TCP/IP to an instance of xapian-tcpsrv.
  39  */
  40 class RemoteTcpClient : SOCKET_INITIALIZER_MIXIN public RemoteDatabase {
  41     /// Don't allow assignment.
  42     void operator=(const RemoteTcpClient &);
  43
  44     /// Don't allow copying.
  45     RemoteTcpClient(const RemoteTcpClient &);
  46
  47     /** Attempt to open a TCP/IP socket connection to xapian-tcpsrv.
  48      *
  49      *  Connect to xapian-tcpsrv running on port @a port of host @a hostname.
  50      *  Give up trying to connect after @a timeout_connect seconds.
  51      *
  52      *  @return A std::pair containing the file descriptor for the connection
  53      *          to the child process and a context string to return with any
  54      *          error messages.
  55      *
  56      *  Note: this method is called early on during class construction before
  57      *  any member variables or even the base class have been initialised.
  58      *  To help avoid accidentally trying to use member variables or call other
  59      *  methods which do, this method has been deliberately made "static".
  60      */
  61     static std::pair<int, std::string> open_socket(std::string_view hostname,
  62                                                    int port,
  63                                                    double timeout_connect);
  64
  65   public:
  66     /** Constructor.
  67      *
  68      *  Attempts to open a TCP/IP connection to xapian-tcpsrv running on port
  69      *  @a port of host @a hostname.
  70      *
  71      *  @param timeout_connect  Timeout for trying to connect (in seconds).
  72      *  @param timeout          Timeout during communication after successfully
  73      *                          connecting (in seconds).
  74      *  @param writable         Is this a WritableDatabase?
  75      *  @param flags            Xapian::DB_RETRY_LOCK or 0.
  76      */
  77     RemoteTcpClient(std::string_view hostname, int port,
  78                     double timeout_, double timeout_connect, bool writable,
  79                     int flags)
  80         : RemoteDatabase(open_socket(hostname, port, timeout_connect),
  81                          timeout_, writable, flags) { }
  82
  83     /** Destructor. */
  84     ~RemoteTcpClient();
  85 };
  86
  87 #endif  // XAPIAN_INCLUDED_REMOTETCPCLIENT_H