// ------------------------------- //
// -------- 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 --------- //
// ------------------------------- //