/*
** Command & Conquer Red Alert(tm)
** Copyright 2025 Electronic Arts Inc.
**
** This program 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.
**
** This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* $Header: /CounterStrike/LZOSTRAW.CPP 1 3/03/97 10:25a Joe_bostic $ */
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : Command & Conquer *
* *
* File Name : LZOSTRAW.CPP *
* *
* Programmer : Joe L. Bostic *
* *
* Start Date : 07/02/96 *
* *
* Last Update : July 4, 1996 [JLB] *
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* LZOStraw::Get -- Fetch data through the LZO processor. *
* LZOStraw::LZOStraw -- Constructor for LZO straw object. *
* LZOStraw::~LZOStraw -- Destructor for the LZO straw. *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#include "lzostraw.h"
#include "lzo.h"
#include <string.h>
#include <assert.h>
/***********************************************************************************************
* LZOStraw::LZOStraw -- Constructor for LZO straw object. *
* *
* This will initialize the LZO straw object. Whether the object is to compress or *
* decompress and the block size to use is specified. The data is compressed in blocks *
* that are sized to be quick to compress and yet still yield good compression ratios. *
* *
* INPUT: decrypt -- Should the data be decompressed? *
* *
* blocksize-- The size of the blocks to process. *
* *
* OUTPUT: none *
* *
* WARNINGS: It takes two buffers of the blocksize specified if compression is to be *
* performed. *
* *
* HISTORY: *
* 07/04/1996 JLB : Created. *
*=============================================================================================*/
LZOStraw::LZOStraw(CompControl control, int blocksize) :
Control(control),
Counter(0),
Buffer(NULL),
Buffer2(NULL),
BlockSize(blocksize)
{
SafetyMargin = BlockSize;
Buffer = new char[BlockSize+SafetyMargin];
if (control == COMPRESS) {
Buffer2 = new char[BlockSize+SafetyMargin];
}
}
/***********************************************************************************************
* LZOStraw::~LZOStraw -- Destructor for the LZO straw. *
* *
* The destructor will free up the allocated buffers that it allocated in the constructor. *
* *
* INPUT: none *
* *
* OUTPUT: none *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 07/04/1996 JLB : Created. *
*=============================================================================================*/
LZOStraw::~LZOStraw(void)
{
delete [] Buffer;
Buffer = NULL;
delete [] Buffer2;
Buffer2 = NULL;
}
/***********************************************************************************************
* LZOStraw::Get -- Fetch data through the LZO processor. *
* *
* This routine will fetch the data bytes specified. It does this by first accumulating *
* a full block of data and then compressing or decompressing it as indicated. Subsequent *
* requests for data will draw from this buffer of processed data until it is exhausted *
* and another block must be fetched. *
* *
* INPUT: destbuf -- Pointer to the buffer to hold the data requested. *
* *
* length -- The number of data bytes requested. *
* *
* OUTPUT: Returns with the actual number of bytes stored into the buffer. If this number *
* is less than that requested, then this indicates that the data source has been *
* exhausted. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 07/04/1996 JLB : Created. *
*=============================================================================================*/
int LZOStraw::Get(void * destbuf, int slen)
{
assert(Buffer != NULL);
int total = 0;
/*
** Verify parameters for legality.
*/
if (destbuf == NULL || slen < 1) {
return(0);
}
while (slen > 0) {
/*
** Copy as much data is requested and available into the desired
** destination buffer.
*/
if (Counter) {
int len = (slen < Counter) ? slen : Counter;
if (Control == DECOMPRESS) {
memmove(destbuf, &Buffer[BlockHeader.UncompCount-Counter], len);
} else {
memmove(destbuf, &Buffer2[(BlockHeader.CompCount+sizeof(BlockHeader))-Counter], len);
}
destbuf = ((char *)destbuf) + len;
slen -= len;
Counter -= len;
total += len;
}
if (slen == 0) break;
if (Control == DECOMPRESS) {
int incount = Straw::Get(&BlockHeader, sizeof(BlockHeader));
if (incount != sizeof(BlockHeader)) break;
char *staging_buffer = new char [BlockHeader.CompCount];
incount = Straw::Get(staging_buffer, BlockHeader.CompCount);
if (incount != BlockHeader.CompCount) break;
unsigned int length = sizeof(Buffer);
lzo1x_decompress ((unsigned char*)staging_buffer, BlockHeader.CompCount, (unsigned char*)Buffer, &length, NULL);
delete [] staging_buffer;
Counter = BlockHeader.UncompCount;
} else {
BlockHeader.UncompCount = (unsigned short)Straw::Get(Buffer, BlockSize);
if (BlockHeader.UncompCount == 0) break;
char *dictionary = new char [64*1024];
unsigned int length = sizeof (Buffer2) - sizeof (BlockHeader);
lzo1x_1_compress ((unsigned char*)Buffer, BlockHeader.UncompCount, (unsigned char*)(&Buffer2[sizeof(BlockHeader)]), &length, dictionary);
BlockHeader.CompCount = (unsigned short)length;
delete [] dictionary;
memmove(Buffer2, &BlockHeader, sizeof(BlockHeader));
Counter = BlockHeader.CompCount+sizeof(BlockHeader);
}
}
return(total);
}