DatabaseTCPServerExample

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    // -------- Start of File -------- //
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    // C++ Source Code File Name: server.cpp
    // C++ Compiler Used: MSVC, BCC32, GCC, HPUX aCC, SOLARIS CC
    // Produced By: DataReel Software Development Team
    // File Creation Date: 09/20/1999
    // Date Last Modified: 06/17/2016
    // Copyright (c) 2001-2016 DataReel Software Development
    // ----------------------------------------------------------- //
    // ------------- Program Description and Details ------------- //
    // ----------------------------------------------------------- //
    /*
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
    USA

    This program is used to the gxStream class.
    */
    // ----------------------------------------------------------- //
    #include "gxdlcode.h"

    #if defined (__USE_ANSI_CPP__) // Use the ANSI Standard C++ library
    #include <iostream>
    using namespace std; // Use unqualified names for Standard C++ library
    #else // Use the old iostream library by default
    #include <iostream.h>
    #endif // __USE_ANSI_CPP__

    #include <string.h>
    #include <stdlib.h>
    #include "gxstream.h"

    int ReadBlock(gxStream *server, gxBlockHeader &gx)
    {
      cout << "Reading a raw block of data" << "\n" << flush;
      __ULWORD__ block_size = (__ULWORD__)gx.block_length;

      char *buf = new char[block_size];
      if(server->ReadRemoteBlock(buf, gx) != 0) {
        delete[] buf;
        return 1;
      }

      cout.write(buf, block_size);
      cout << server->BytesRead() << " bytes received." << "\n" << flush;

      delete[] buf;
      return 0;
    }

    int AnswerRequest(gxStream *server, gxBlockHeader &gx)
    {
      cout << "Client has requested a block" << "\n" << flush;

      char *test_block = "The quick brown fox jumps over the lazy dog \
    0123456789\n";

      __ULWORD__ block_size = (__ULWORD__)gx.block_length;

      char *buf = new char[block_size];
      if(server->ReadRemoteBlock(buf, gx) != 0) {
        delete[] buf;
        return 1;
      }

      cout << "Client has requested block: ";
      cout.write(buf, block_size);
      cout << "\n" << flush;
      delete[] buf;

      cout << "Answering request" << "\n" << flush;

      if(server->WriteRemoteBlock((char *)test_block, strlen(test_block))
    			      != 0) return 1;
      return 0;
    }

    int ChangeBlock(gxStream *server, gxBlockHeader &gx)
    {
      cout << "Received a change block request" << "\n" << flush;
      __ULWORD__ block_size = (__ULWORD__)gx.block_length;

      char *buf = new char[block_size];
      if(server->ReadRemoteBlock(buf, gx) != 0) {
        delete[] buf;
        return 1;
      }

      cout << "Client requested that block \"";
      cout.write(buf, block_size);
      cout << "\" be changed to:" << "\n" << flush;
      delete[] buf;

      gxBlockHeader block_header;
      if(server->ReadClientHeader(block_header) != 0) return 1;

      char *block = new char[(__ULWORD__)block_header.block_length];
      if(server->ReadRemoteBlock((char *)block, block_header) != 0) {
        delete[] block;
        return 1;
      }

      cout.write(block, (__ULWORD__)block_header.block_length);
      cout.flush();

      delete[] block;
      return 0;
    }

    int AddBlock(gxStream *server, gxBlockHeader &gx)
    {
      cout << "Received an add block request" << "\n" << flush;
      __ULWORD__ block_size = (__ULWORD__)gx.block_length;

      char *block = new char[block_size];
      if(server->ReadRemoteBlock(block, gx) != 0) {
        delete[] block;
        return 1;
      }

      cout << "Client has requested the following block be added:" << "\n"
           << flush;
      cout.write(block, block_size);
      cout.flush();
      delete[] block;

      return 0;
    }

    int DeleteBlock(gxStream *server, gxBlockHeader &gx)
    {
      cout << "Received a delete block request" << "\n" << flush;
      __ULWORD__ block_size = (__ULWORD__)gx.block_length;

      char *buf = new char[block_size];
      if(server->ReadRemoteBlock(buf, gx) != 0) {
        delete[] buf;
        return 1;
      }

      cout << "Client has requested block \"";
      cout.write(buf, block_size);
      cout << "\" be deleted" << "\n" << flush;
      delete[] buf;
      return 0;
    }

    int main(int argc, char **argv)
    {
      // Check arguments. Should be only one: the port number to bind to.
      if(argc != 2) {
        cerr << "Usage: " << argv[0] << " port" << "\n" << flush;
        return 1;
      }

      gxStream server;
      gxsSocket_t remote_socket;
      unsigned short port = (unsigned short) atoi(argv[1]);

      cout << "Initializing the GX stream server..." << "\n" << flush;
      if(server.StreamServer(port) != 0) {
        cout << server.SocketExceptionMessage() << "\n" << flush;
        return 1;
      }

      // Get the host name assigned to this machine
      char hostname[gxsMAX_NAME_LEN];
      if(server.HostName(hostname) != 0) {
        cout << server.SocketExceptionMessage() << "\n" << flush;
        return 1;
      }
      cout << "Opening stream server on host " << hostname << "\n" << flush;

      while(1) { // Block until the next read.
        cout << "Listening on port " << port << "\n" << flush;
        remote_socket = server.Accept();

        if(remote_socket < 0) {
          cout << server.SocketExceptionMessage() << "\n" << flush;
          return 1;
        }

        // Read the block following a client connection
        gxBlockHeader gx;
        if(server.ReadClientHeader(gx) != 0) {
          cout << server.SocketExceptionMessage() << "\n" << flush;
          return 1;
        }

        // Get the client info
        char client_name[gxsMAX_NAME_LEN]; int r_port = -1;
        server.GetClientInfo(client_name, r_port);
        cout << client_name << " connecting on port " << r_port << "\n" << flush;

        // Read the status byte to determine what to do with this block
        __ULWORD__ block_status = gx.block_status;
        __SBYTE__ status = (__SBYTE__)((block_status & 0xFF00)>>8);

        switch(status) {
          // Process each block of data
          case gxAcknowledgeBlock:
    	cout << "Received an acknowledge block command" << "\n" << flush;
    	cout << "Sending acknowledgment" << "\n" << flush;
    	if(server.WriteRemoteAckBlock() != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxAddRemoteBlock:
    	if(AddBlock(&server, gx) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxChangeRemoteBlock:
    	if(ChangeBlock(&server, gx) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxRequestBlock:
    	if(AnswerRequest(&server, gx) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxDeleteRemoteBlock:
    	if(DeleteBlock(&server, gx) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxSendBlock :
    	if(ReadBlock(&server, gx) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxCloseConnection :
    	cout << "Client sent a close connection command" << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

          case gxKillServer:
    	cout << "Client shutdown the server" << "\n" << flush;
    	server.Close();
    	return 0;

          default:
    	cout << "Received bad block command from client" << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;
        }
      }

      cout << "Exiting..." << "\n" << flush;
      return 0;
    }
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