CClientTCPSocket.h

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/* +---------------------------------------------------------------------------+
   |          The Mobile Robot Programming Toolkit (MRPT) C++ library          |
   |                                                                           |
   |                   http://mrpt.sourceforge.net/                            |
   |                                                                           |
   |   Copyright (C) 2005-2010  University of Malaga                           |
   |                                                                           |
   |    This software was written by the Machine Perception and Intelligent    |
   |      Robotics Lab, University of Malaga (Spain).                          |
   |    Contact: Jose-Luis Blanco  <jlblanco@ctima.uma.es>                     |
   |                                                                           |
   |  This file is part of the MRPT project.                                   |
   |                                                                           |
   |     MRPT is free software: you can redistribute it and/or modify          |
   |     it under the terms of the GNU General Public License as published by  |
   |     the Free Software Foundation, either version 3 of the License, or     |
   |     (at your option) any later version.                                   |
   |                                                                           |
   |   MRPT is distributed in the hope that it will be useful,                 |
   |     but WITHOUT ANY WARRANTY; without even the implied warranty of        |
   |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         |
   |     GNU General Public License for more details.                          |
   |                                                                           |
   |     You should have received a copy of the GNU General Public License     |
   |     along with MRPT.  If not, see <http://www.gnu.org/licenses/>.         |
   |                                                                           |
   +---------------------------------------------------------------------------+ */
#ifndef  CClientTCPSocket_H
#define  CClientTCPSocket_H

#include <mrpt/config.h>
#include <mrpt/system/os.h>
#include <mrpt/utils/utils_defs.h>
#include <mrpt/utils/CStream.h>

namespace mrpt
{
namespace utils
{
        class CServerTCPSocket;
        class CMessage;

        /** A TCP socket that can be connected to a TCP server, implementing MRPT's CStream interface for passing objects as well as generic read/write methods.
          *  Unless otherwise noticed, operations are blocking.
          *
          *  Note that for convenience, DNS lookup is performed with a timeout (default=3000ms), which can be changed by the static member CClientTCPSocket::DNS_LOOKUP_TIMEOUT_MS
          */
        class MRPTDLLIMPEXP CClientTCPSocket : public CStream
        {
                friend class CServerTCPSocket;

        public:
                /** See description of CClientTCPSocket */
                static unsigned int DNS_LOOKUP_TIMEOUT_MS;

        protected:

#ifdef MRPT_OS_WINDOWS
                /** The handle for the connected TCP socket, or INVALID_SOCKET
                  */
                unsigned int    m_hSock;
#else

                /** The handle for the connected TCP socket, or -1
                  */
                int                             m_hSock;
#endif

                /** The IP address of the remote part of the connection.
                  */
                std::string             m_remotePartIP;

                /** The TCP port of the remote part of the connection.
                  */
                unsigned short  m_remotePartPort;


                /** Introduces a virtual method responsible for reading from the stream (This method BLOCKS)
                  * This method is implemented as a call to "readAsync" with infinite timeouts.
                  * \sa readAsync
                  */
                size_t  Read(void *Buffer, size_t Count);

                /** Introduces a virtual method responsible for writing to the stream.
                  *  Write attempts to write up to Count bytes to Buffer, and returns the number of bytes actually written.
                  *  This method is implemented as a call to "writeAsync" with infinite timeouts.
                  * \sa writeAsync
                 */
                size_t  Write(const void *Buffer, size_t Count);

                /** Returns a description of the last error */
                std::string  getLastErrorStr();

        public:
                /** Default constructor
                  * \sa connect
                  */
                CClientTCPSocket( );

                /** Destructor
                 */
                ~CClientTCPSocket( );

                /** Establishes a connection with a remote part.
                  * \param remotePartAddress This string can be a host name, like "server" or "www.mydomain.org", or an IP address "11.22.33.44".
                  * \param remotePartTCPPort The port on the remote machine to connect to.
                  * \param timeout_ms  The timeout to wait for the connection (0: NO TIMEOUT)
                  * \exception This method raises an exception if an error is found with a textual description of the error.
                  */
                void connect(
                        const std::string       &remotePartAddress,
                        unsigned short          remotePartTCPPort,
                        unsigned int            timeout_ms = 0 );

                /** Returns true if this objects represents a successfully connected socket.
                  */
                bool  isConnected();

                /** Closes the connection.
                  */
                void  close();

                /** Writes a string to the socket.
                  * \exception std::exception On communication errors
                  */
                void  sendString( const std::string &str );

                /** This virtual method has no effect in this implementation over a TCP socket, and its use raises an exception
                 */
                size_t Seek(long Offset, CStream::TSeekOrigin Origin = sFromBeginning)
                {
                    MRPT_START
                        MRPT_UNUSED_PARAM(Offset); MRPT_UNUSED_PARAM(Origin);
                        THROW_EXCEPTION("This method has no effect in this class!");
                    MRPT_END
                }

                /** This virtual method has no effect in this implementation over a TCP socket, and its use raises an exception
                 */
                size_t getTotalBytesCount()
                {
                    MRPT_START
                        THROW_EXCEPTION("This method has no effect in this class!");
                    MRPT_END
                }

                /** This virtual method has no effect in this implementation over a TCP socket, and its use raises an exception
                 */
                size_t getPosition()
                {
                    MRPT_START
                        THROW_EXCEPTION("This method has no effect in this class!");
                    MRPT_END
                }

                /** A method for reading from the socket with an optional timeout.
                  * \param Buffer The destination of data.
                  * \param Cound The number of bytes to read.
                  * \param timeoutStart_ms The maximum timeout (in milliseconds) to wait for the starting of data from the other side.
                  * \param timeoutBetween_ms The maximum timeout (in milliseconds) to wait for a chunk of data after a previous one.
                  *  Set timeout's to -1 to block until the desired number of bytes are read, or an error happens.
                  *  \return The number of actually read bytes.
                  */
                size_t  readAsync(
                        void    *Buffer,
                        const size_t    Count,
                        const int       timeoutStart_ms = -1,
                        const int       timeoutBetween_ms = -1);

                /** A method for writing to the socket with optional timeouts.
                  *  The method supports writing block by block as the socket allows us to write more data.
                  * \param Buffer The data.
                  * \param Cound The number of bytes to write.
                  * \param timeout_ms The maximum timeout (in milliseconds) to wait for the socket to be available for writing (for each block).
                  *  Set timeout's to -1 to block until the desired number of bytes are written, or an error happens.
                  *  \return The number of actually written bytes.
                  */
                size_t  writeAsync(
                        const void      *Buffer,
                        const size_t Count,
                        const int       timeout_ms = -1 );

                /** Send a message through the TCP stream.
                  * \param outMsg The message to be shown.
                  * \param timeout_ms The maximum timeout (in milliseconds) to wait for the socket in each write operation.
                  * \return Returns false on any error, or true if everything goes fine.
                  */
                bool  sendMessage(
                        const CMessage& outMsg,
                        const int timeout_ms = -1
                        );

                /** Waits for an incoming message through the TCP stream.
                  * \param inMsg The received message is placed here.
                  * \param timeoutStart_ms The maximum timeout (in milliseconds) to wait for the starting of data from the other side.
                  * \param timeoutBetween_ms The maximum timeout (in milliseconds) to wait for a chunk of data after a previous one.
                  * \return Returns false on any error (or timeout), or true if everything goes fine.
                  */
                bool  receiveMessage(
                        CMessage&                       inMsg,
                        const unsigned int      timeoutStart_ms = 100,
                        const unsigned int      timeoutBetween_ms = 1000
                        );

        }; // End of class def.

        } // End of namespace
} // end of namespace
#endif