DatabaseServerExample

    // ------------------------------- //
    // -------- Start of File -------- //
    // ------------------------------- //
    // ----------------------------------------------------------- //
    // 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 demonstrate how to stream database blocks
    across a network connection.
    */
    // ----------------------------------------------------------- //
    #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 <stdlib.h>
    #include "gxstream.h"
    #include "dbobject.h"

    int FindObject(gxStream *server, gxBlockHeader &blk,
    	       DatabaseObject *dbobjectdb)
    {
      cout << "Client has queried the database" << "\n" << flush;

      if(server->ReadRemoteBlock((char *)dbobjectdb->p, blk) != 0) return 1;
      cout << "Searching for: " << dbobjectdb->p->name << "\n" << flush;

      FAU_t addr = dbobjectdb->FindObject();
      if(addr == (FAU_t)0) {
        cout << "Did not find the object" << "\n" << flush;
        dbobjectdb->p->name[0] = 0;
        dbobjectdb->p->oid = (OID)0;
        dbobjectdb->p->cid = (CID)0;
      }
      else
        cout << "Found the requested object" << "\n" << flush;

      cout << "Sending search results to the client" << "\n" << flush;
      if(server->WriteRemoteBlock((char *)dbobjectdb->p,
    			      sizeof(DatabaseObjectData))
         != 0) return 1;

      return 0;
    }

    int ChangeObject(gxStream *server, gxBlockHeader &blk,
    		 DatabaseObject *dbobjectdb)
    {
      cout << "Received a change object request" << "\n" << flush;

      // Read the name of the object to be changed
      if(server->ReadRemoteBlock((char *)dbobjectdb->p, blk) != 0) return 1;

      cout << "Client requested a change to object: " <<
        dbobjectdb->p->name << "\n" << flush;

      DatabaseObjectData new_dbobject_info;
      gxBlockHeader block_header;

      // Get the object's new info from the client
      if(server->ReadClientHeader(block_header) != 0) return 1;
      if(server->ReadRemoteBlock((char *)&new_dbobject_info, block_header) != 0)
        return 1;

      FAU_t addr = dbobjectdb->ChangeObject(new_dbobject_info);
      if(addr == (FAU_t)0) {
        cout << "Change request denied: Did not find object in the database"
    	 << "\n" << flush;
        dbobjectdb->p->name[0] = 0;
        dbobjectdb->p->oid = (OID)0;
        dbobjectdb->p->cid = (CID)0;
      }
      else {
        cout << "Object changed to: " << dbobjectdb->p->name << ", "
    	 << dbobjectdb->p->oid
    	 << ", " << dbobjectdb->p->cid << "\n" << flush;
      }
      return 0;
    }

    int AddObject(gxStream *server, gxBlockHeader &blk,
    	      DatabaseObject *dbobjectdb)
    {
      cout << "Adding an object" << "\n" << flush;
      if(server->ReadRemoteBlock(dbobjectdb->p, blk) != 0) return 1;
      dbobjectdb->WriteObject();
      cout << dbobjectdb->p->name << " added to the database" << "\n" << flush;
      return 0;
    }

    int DeleteObject(gxStream *server, gxBlockHeader &blk,
    		 DatabaseObject *dbobjectdb)
    {
      cout << "Deleting an object" << "\n" << flush;
      if(server->ReadRemoteBlock(dbobjectdb->p, blk) != 0) return 1;
      FAU_t addr = dbobjectdb->DeleteObject();
      if(addr == (FAU_t)0) {
        cout << "Could not find \"" << dbobjectdb->p->name << "\" in the database"
    	 << "\n" << flush;
      }
      else {
        cout << "Deleted: " << dbobjectdb->p->name << "\n" << flush;
      }
      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;
      }

      DatabaseObject *dbobjectdb = new DatabaseObject;
      cout << "Initializing the database..." << "\n" << flush;
      const char *fname = "dbobject.gxd";

      if(!gxDatabase::Exists(fname)) {
        cout << "Creating new file..." << "\n" << flush;
        dbobjectdb->Create(fname);
      }
      else {
        cout << "Opening existing file..." << "\n" << flush;
        dbobjectdb->Open(fname);
      }

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

      cout << "Initializing the database stream server..." << "\n" << flush;
      if(server.StreamServer(port) != 0) {
        cout << server.SocketExceptionMessage() << "\n" << flush;
        delete dbobjectdb;
        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;
        delete dbobjectdb;
        return 1;
      }
      cout << "Opening database stream server on host " << hostname
           << "\n" << flush;

      int server_up = 1;
      while(server_up) { // Loop until signaled to exit
        cout << "Listening on port " << port << "\n" << flush;
        remote_socket = server.Accept(); // Block until the next read.
        if(remote_socket < 0) {
          cout << server.SocketExceptionMessage() << "\n" << flush;
          delete dbobjectdb;
          return 1;
        }

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

        cout << flush;

        // 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 = blk.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(AddObject(&server, blk, dbobjectdb) != 0)
    	  cout << server.SocketExceptionMessage() << "\n" << flush;
    	server.CloseRemoteSocket();
    	break;

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

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

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

          case gxSendBlock :
    	cout << "Not excepting raw data blocks" << "\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_up = 0;
    	break;

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

      dbobjectdb->Close();
      delete dbobjectdb;

      server.Close();
      cout << "Exiting..." << "\n" << flush;
      return 0;
    }
    // ----------------------------------------------------------- //
    // ------------------------------- //
    // --------- End of File --------- //
    // ------------------------------- //