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/*
* expand_inmem.c - in-memory decompression implementation
*
* Copyright (C) 2019 Emmanuel Marty
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
/*
* Uses the libdivsufsort library Copyright (c) 2003-2008 Yuta Mori
*
* Inspired by LZ4 by Yann Collet. https://github.com/lz4/lz4
* With help, ideas, optimizations and speed measurements by spke <zxintrospec@gmail.com>
* With ideas from Lizard by Przemyslaw Skibinski and Yann Collet. https://github.com/inikep/lizard
* Also with ideas from smallz4 by Stephan Brumme. https://create.stephan-brumme.com/smallz4/
*
*/
#include <stdlib.h>
#include <string.h>
#include "expand_inmem.h"
#include "lib.h"
#include "frame.h"
#define BLOCK_SIZE 65536
/**
* Get maximum decompressed size of compressed data
*
* @param pFileData compressed data
* @param nFileSize compressed size in bytes
*
* @return maximum decompressed size
*/
size_t lzsa_get_max_decompressed_size_inmem(const unsigned char *pFileData, size_t nFileSize) {
const unsigned char *pCurFileData = pFileData;
const unsigned char *pEndFileData = pCurFileData + nFileSize;
int nFormatVersion = 0;
size_t nMaxDecompressedSize = 0;
const int nHeaderSize = lzsa_get_header_size();
/* Check header */
if ((pCurFileData + nHeaderSize) > pEndFileData ||
lzsa_decode_header(pCurFileData, nHeaderSize, &nFormatVersion) != 0)
return -1;
pCurFileData += nHeaderSize;
while (pCurFileData < pEndFileData) {
unsigned int nBlockDataSize = 0;
int nIsUncompressed = 0;
const int nFrameSize = lzsa_get_frame_size();
/* Decode frame header */
if ((pCurFileData + nFrameSize) > pEndFileData ||
lzsa_decode_frame(pCurFileData, nFrameSize, &nBlockDataSize, &nIsUncompressed) != 0)
return -1;
pCurFileData += nFrameSize;
if (!nBlockDataSize)
break;
/* Add one potentially full block to the decompressed size */
nMaxDecompressedSize += BLOCK_SIZE;
if ((pCurFileData + nBlockDataSize) > pEndFileData)
return -1;
pCurFileData += nBlockDataSize;
}
return nMaxDecompressedSize;
}
/**
* Decompress data in memory
*
* @param pFileData compressed data
* @param pOutBuffer buffer for decompressed data
* @param nFileSize compressed size in bytes
* @param nMaxOutBufferSize maximum capacity of decompression buffer
* @param nFlags compression flags (LZSA_FLAG_xxx)
* @param pFormatVersion pointer to format version, updated if this function is successful
*
* @return actual decompressed size, or -1 for error
*/
size_t lzsa_decompress_inmem(unsigned char *pFileData, unsigned char *pOutBuffer, size_t nFileSize, size_t nMaxOutBufferSize, const unsigned int nFlags, int *pFormatVersion) {
unsigned char *pCurFileData = pFileData;
const unsigned char *pEndFileData = pCurFileData + nFileSize;
unsigned char *pCurOutBuffer = pOutBuffer;
const unsigned char *pEndOutBuffer = pCurOutBuffer + nMaxOutBufferSize;
int nPreviousBlockSize;
const int nHeaderSize = lzsa_get_header_size();
if (nFlags & LZSA_FLAG_RAW_BLOCK) {
return (size_t)lzsa_decompressor_expand_block(pFileData, (int)nFileSize, pOutBuffer, 0, (int)nMaxOutBufferSize, *pFormatVersion, nFlags);
}
/* Check header */
if ((pCurFileData + nHeaderSize) > pEndFileData ||
lzsa_decode_header(pCurFileData, nHeaderSize, pFormatVersion) != 0)
return -1;
pCurFileData += nHeaderSize;
nPreviousBlockSize = 0;
while (pCurFileData < pEndFileData) {
unsigned int nBlockDataSize = 0;
int nIsUncompressed = 0;
const int nFrameSize = lzsa_get_frame_size();
/* Decode frame header */
if ((pCurFileData + nFrameSize) > pEndFileData ||
lzsa_decode_frame(pCurFileData, nFrameSize, &nBlockDataSize, &nIsUncompressed) != 0)
return -1;
pCurFileData += nFrameSize;
if (!nBlockDataSize)
break;
if (!nIsUncompressed) {
int nDecompressedSize;
/* Decompress block */
if ((pCurFileData + nBlockDataSize) > pEndFileData)
return -1;
nDecompressedSize = lzsa_decompressor_expand_block(pCurFileData, nBlockDataSize, pCurOutBuffer - nPreviousBlockSize, nPreviousBlockSize, (int)(pEndOutBuffer - pCurOutBuffer + nPreviousBlockSize), *pFormatVersion, nFlags);
if (nDecompressedSize < 0)
return -1;
pCurOutBuffer += nDecompressedSize;
nPreviousBlockSize = nDecompressedSize;
}
else {
/* Copy uncompressed block */
if ((pCurFileData + nBlockDataSize) > pEndFileData)
return -1;
if ((pCurOutBuffer + nBlockDataSize) > pEndOutBuffer)
return -1;
memcpy(pCurOutBuffer, pCurFileData, nBlockDataSize);
pCurOutBuffer += nBlockDataSize;
}
pCurFileData += nBlockDataSize;
}
return (int)(pCurOutBuffer - pOutBuffer);
}
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