xapian-core/net/tcpserver.h

   1 /** @file tcpserver.h
   2  *  @brief Generic TCP/IP socket based server base class.
   3  */
   4 /* Copyright (C) 2007,2008 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_TCPSERVER_H
  22 #define XAPIAN_INCLUDED_TCPSERVER_H
  23
  24 #ifdef __WIN32__
  25 # include "remoteconnection.h"
  26 # define SOCKET_INITIALIZER_MIXIN : private WinsockInitializer
  27 #else
  28 # define SOCKET_INITIALIZER_MIXIN
  29 #endif
  30
  31 #if defined __CYGWIN__ || defined __WIN32__
  32 # include "safewindows.h" // Only for HANDLE!
  33 #endif
  34
  35 #include <xapian/visibility.h>
  36
  37 #include <string>
  38
  39 /** TCP/IP socket based server for RemoteDatabase.
  40  *
  41  *  This class implements the server used by xapian-tcpsrv.
  42  */
  43 class XAPIAN_VISIBILITY_DEFAULT TcpServer SOCKET_INITIALIZER_MIXIN {
  44     /// Don't allow assignment.
  45     void operator=(const TcpServer &);
  46
  47     /// Don't allow copying.
  48     TcpServer(const TcpServer &);
  49
  50 #if defined __CYGWIN__ || defined __WIN32__
  51     /// Mutex to stop two TcpServers running on the same port.
  52     HANDLE mutex;
  53 #endif
  54
  55     /** The socket we're listening on. */
  56     int listen_socket;
  57
  58     /** Create a listening socket ready to accept connections.
  59      *
  60      *  @param host     hostname or address to listen on or an empty string to
  61      *                  accept connections on any interface.
  62      *  @param port     TCP port to listen on.
  63      *  @param tcp_nodelay      If true, enable TCP_NODELAY option.
  64      */
  65     XAPIAN_VISIBILITY_INTERNAL
  66     static int get_listening_socket(const std::string & host, int port,
  67                                     bool tcp_nodelay
  68 #if defined __CYGWIN__ || defined __WIN32__
  69                                     , HANDLE &mutex
  70 #endif
  71             );
  72
  73   protected:
  74     /** Should we produce output when connections are made or lost? */
  75     bool verbose;
  76
  77     /** Accept a connection and return the filedescriptor for it. */
  78     XAPIAN_VISIBILITY_INTERNAL
  79     int accept_connection();
  80
  81   public:
  82     /** Construct a TcpServer and start listening for connections.
  83      *
  84      *  @param host     The hostname or address for the interface to listen on
  85      *                  (or "" to listen on all interfaces).
  86      *  @param port     The TCP port number to listen on.
  87      *  @param tcp_nodelay      If true, enable TCP_NODELAY option.
  88      *  @param verbose  Should we produce output when connections are
  89      *                  made or lost?
  90      */
  91     TcpServer(const std::string &host, int port, bool tcp_nodelay,
  92               bool verbose);
  93
  94     /** Destructor. */
  95     virtual ~TcpServer();
  96
  97     /** Accept connections and service requests indefinitely.
  98      *
  99      *  This method runs the TcpServer as a daemon which accepts a connection
 100      *  and forks itself (or creates a new thread under Windows) to serve the
 101      *  request while continuing to listen for more connections.
 102      */
 103     void run();
 104
 105     /** Accept a single connection, service requests on it, then stop.  */
 106     void run_once();
 107
 108     /// Handle a single connection on an already connected socket.
 109     virtual void handle_one_connection(int socket) = 0;
 110 };
 111
 112 #endif  // XAPIAN_INCLUDED_TCPSERVER_H