// ------------------------------- // // -------- Start of File -------- // // ------------------------------- // // ----------------------------------------------------------- // // C++ Source Code File Name: dbobject.cpp // Compiler Used: MSVC, BCC32, GCC, HPUX aCC, SOLARIS CC // Produced By: glNET Software // File Creation Date: 09/18/1997 // Date Last Modified: 06/12/2001 // Copyright (c) 2001 glNET Software // ----------------------------------------------------------- // // ------------- 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 Database object class used with the client/server example. */ // ----------------------------------------------------------- // #include "dbobject.h" #include <iostream.h> DatabaseObjectData::DatabaseObjectData() { oid = (OID)0; cid = (CID)0; for(unsigned i = 0; i < gxMaxNameLength; i++) name[i] = 0; } FAU DatabaseObject::WriteObject() { FAU addr = Alloc(sizeof(DatabaseObjectData)); if(!addr) return 0; Write(p, sizeof(DatabaseObjectData)); // Write a 32-bit CRC checksum for the object WriteObjectChecksum(addr); return addr; } void DatabaseObject::ReadObject(FAU Address) { // Optimize seeks during intervening reads SeekTo(Address); Read((char *)this->p, sizeof(DatabaseObjectData)); // Test the objects checksum int rv = ReadObjectChecksum(Address); if(!rv) #ifdef __CPP_EXCEPTIONS__ throw CChecksumError(); #else cout << DatabaseExceptionMessage() << endl; #endif } FAU DatabaseObject::FindObject() { int rv; // Return value // If not using index file or entry not found, search the data file DatabaseObjectData dbobject; FAU oa; // Object Address gxBlockHeader blk; // Block Header FAU gxdfileEOF = GetEOF(); FAU addr = 0; addr = FindFirstBlock(addr); // Search the entire file if(addr == (FAU)0) return 0; // No database blocks found in file dbobject.oid = p->oid; dbobject.cid = p->cid; strcpy(dbobject.name, p->name); while(1) { if(addr >= gxdfileEOF) break; Read(&blk, sizeof(gxBlockHeader), addr); if(blk.block_check_word == gxCheckWord) { if((__SBYTE__)blk.block_status == gxNormalBlock) { oa = addr + BlockHeaderSize(); ReadObject(oa); if(strcmp(p->name, dbobject.name) == 0) { return oa; // Found unique data member } } addr = addr + blk.block_length; // Goto the next database block } else { addr = FindFirstBlock(addr); if(!addr) break; } } // Reset the objects data p->oid = dbobject.oid; p->cid = dbobject.cid; strcpy(p->name, dbobject.name); return 0; // Could not find } FAU DatabaseObject::ChangeObject(const DatabaseObjectData &new_dbobject_info) { FAU addr = FindObject(); if(!addr) return 0; // Object does not exist Write(&new_dbobject_info, sizeof(new_dbobject_info), addr); // Write a 32-bit CRC checksum for the object WriteObjectChecksum(addr); strcpy(p->name, new_dbobject_info.name); p->oid = new_dbobject_info.oid; p->cid = new_dbobject_info.cid; return addr; } FAU DatabaseObject::DeleteObject() { FAU addr = FindObject(); if(!addr) return 0; // Object does not exist Delete(addr); return addr; } FAU DatabaseObject::RemoveObject() { FAU addr = FindObject(); if(!addr) return 0; // Object does not exist Remove(addr); return addr; } // ----------------------------------------------------------- // // ------------------------------- // // --------- End of File --------- // // ------------------------------- //