mirror of
https://github.com/emmanuel-marty/lzsa.git
synced 2024-12-23 22:29:27 +00:00
Remove file after restructuring
This commit is contained in:
Emmanuel Marty
GitHub
parent
124adf8ade
commit
998714d714
460
src/shrink_v1.c
460
src/shrink_v1.c
@ -1,460 +0,0 @@
|
|||||||
/*
|
|
||||||
* shrink_v1.c - LZSA1 block compressor 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 <stdio.h>
|
|
||||||
#include <stdlib.h>
|
|
||||||
#include <string.h>
|
|
||||||
#include "lib.h"
|
|
||||||
#include "shrink_v1.h"
|
|
||||||
#include "format.h"
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Get the number of extra bits required to represent a literals length
|
|
||||||
*
|
|
||||||
* @param nLength literals length
|
|
||||||
*
|
|
||||||
* @return number of extra bits required
|
|
||||||
*/
|
|
||||||
static inline int lzsa_get_literals_varlen_size_v1(const int nLength) {
|
|
||||||
if (nLength < LITERALS_RUN_LEN_V1) {
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
if (nLength < 256)
|
|
||||||
return 8;
|
|
||||||
else {
|
|
||||||
if (nLength < 512)
|
|
||||||
return 16;
|
|
||||||
else
|
|
||||||
return 24;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Write extra literals length bytes to output (compressed) buffer. The caller must first check that there is enough
|
|
||||||
* room to write the bytes.
|
|
||||||
*
|
|
||||||
* @param pOutData pointer to output buffer
|
|
||||||
* @param nOutOffset current write index into output buffer
|
|
||||||
* @param nLength literals length
|
|
||||||
*/
|
|
||||||
static inline int lzsa_write_literals_varlen_v1(unsigned char *pOutData, int nOutOffset, int nLength) {
|
|
||||||
if (nLength >= LITERALS_RUN_LEN_V1) {
|
|
||||||
if (nLength < 256)
|
|
||||||
pOutData[nOutOffset++] = nLength - LITERALS_RUN_LEN_V1;
|
|
||||||
else {
|
|
||||||
if (nLength < 512) {
|
|
||||||
pOutData[nOutOffset++] = 250;
|
|
||||||
pOutData[nOutOffset++] = nLength - 256;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
pOutData[nOutOffset++] = 249;
|
|
||||||
pOutData[nOutOffset++] = nLength & 0xff;
|
|
||||||
pOutData[nOutOffset++] = (nLength >> 8) & 0xff;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
return nOutOffset;
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Get the number of extra bits required to represent an encoded match length
|
|
||||||
*
|
|
||||||
* @param nLength encoded match length (actual match length - MIN_MATCH_SIZE_V1)
|
|
||||||
*
|
|
||||||
* @return number of extra bits required
|
|
||||||
*/
|
|
||||||
static inline int lzsa_get_match_varlen_size_v1(const int nLength) {
|
|
||||||
if (nLength < MATCH_RUN_LEN_V1) {
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
if ((nLength + MIN_MATCH_SIZE_V1) < 256)
|
|
||||||
return 8;
|
|
||||||
else {
|
|
||||||
if ((nLength + MIN_MATCH_SIZE_V1) < 512)
|
|
||||||
return 16;
|
|
||||||
else
|
|
||||||
return 24;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Write extra encoded match length bytes to output (compressed) buffer. The caller must first check that there is enough
|
|
||||||
* room to write the bytes.
|
|
||||||
*
|
|
||||||
* @param pOutData pointer to output buffer
|
|
||||||
* @param nOutOffset current write index into output buffer
|
|
||||||
* @param nLength encoded match length (actual match length - MIN_MATCH_SIZE_V1)
|
|
||||||
*/
|
|
||||||
static inline int lzsa_write_match_varlen_v1(unsigned char *pOutData, int nOutOffset, int nLength) {
|
|
||||||
if (nLength >= MATCH_RUN_LEN_V1) {
|
|
||||||
if ((nLength + MIN_MATCH_SIZE_V1) < 256)
|
|
||||||
pOutData[nOutOffset++] = nLength - MATCH_RUN_LEN_V1;
|
|
||||||
else {
|
|
||||||
if ((nLength + MIN_MATCH_SIZE_V1) < 512) {
|
|
||||||
pOutData[nOutOffset++] = 239;
|
|
||||||
pOutData[nOutOffset++] = nLength + MIN_MATCH_SIZE_V1 - 256;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
pOutData[nOutOffset++] = 238;
|
|
||||||
pOutData[nOutOffset++] = (nLength + MIN_MATCH_SIZE_V1) & 0xff;
|
|
||||||
pOutData[nOutOffset++] = ((nLength + MIN_MATCH_SIZE_V1) >> 8) & 0xff;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
return nOutOffset;
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Attempt to pick optimal matches, so as to produce the smallest possible output that decompresses to the same input
|
|
||||||
*
|
|
||||||
* @param pCompressor compression context
|
|
||||||
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
|
|
||||||
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
|
|
||||||
*/
|
|
||||||
static void lzsa_optimize_matches_v1(lsza_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
|
|
||||||
int *cost = (int*)pCompressor->pos_data; /* Reuse */
|
|
||||||
int nLastLiteralsOffset;
|
|
||||||
int nMinMatchSize = pCompressor->min_match_size;
|
|
||||||
const int nFavorRatio = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 1 : 0;
|
|
||||||
int i;
|
|
||||||
|
|
||||||
cost[nEndOffset - 1] = 8;
|
|
||||||
nLastLiteralsOffset = nEndOffset;
|
|
||||||
|
|
||||||
for (i = nEndOffset - 2; i != (nStartOffset - 1); i--) {
|
|
||||||
int nBestCost, nBestMatchLen, nBestMatchOffset;
|
|
||||||
|
|
||||||
int nLiteralsLen = nLastLiteralsOffset - i;
|
|
||||||
nBestCost = 8 + cost[i + 1];
|
|
||||||
if (nLiteralsLen == LITERALS_RUN_LEN_V1 || nLiteralsLen == 256 || nLiteralsLen == 512) {
|
|
||||||
/* Add to the cost of encoding literals as their number crosses a variable length encoding boundary.
|
|
||||||
* The cost automatically accumulates down the chain. */
|
|
||||||
nBestCost += 8;
|
|
||||||
}
|
|
||||||
if (pCompressor->match[(i + 1) << MATCHES_PER_OFFSET_SHIFT].length >= MIN_MATCH_SIZE_V1)
|
|
||||||
nBestCost += MODESWITCH_PENALTY;
|
|
||||||
nBestMatchLen = 0;
|
|
||||||
nBestMatchOffset = 0;
|
|
||||||
|
|
||||||
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
|
|
||||||
int m;
|
|
||||||
|
|
||||||
for (m = 0; m < NMATCHES_PER_OFFSET && pMatch[m].length >= nMinMatchSize; m++) {
|
|
||||||
int nMatchOffsetSize = (pMatch[m].offset <= 256) ? 8 : 16;
|
|
||||||
|
|
||||||
if (pMatch[m].length >= LEAVE_ALONE_MATCH_SIZE) {
|
|
||||||
int nCurCost;
|
|
||||||
int nMatchLen = pMatch[m].length;
|
|
||||||
|
|
||||||
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
|
|
||||||
nMatchLen = nEndOffset - LAST_LITERALS - i;
|
|
||||||
|
|
||||||
nCurCost = 8 + nMatchOffsetSize + lzsa_get_match_varlen_size_v1(nMatchLen - MIN_MATCH_SIZE_V1);
|
|
||||||
nCurCost += cost[i + nMatchLen];
|
|
||||||
if (pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].length >= MIN_MATCH_SIZE_V1)
|
|
||||||
nCurCost += MODESWITCH_PENALTY;
|
|
||||||
|
|
||||||
if (nBestCost > (nCurCost - nFavorRatio)) {
|
|
||||||
nBestCost = nCurCost;
|
|
||||||
nBestMatchLen = nMatchLen;
|
|
||||||
nBestMatchOffset = pMatch[m].offset;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
int nMatchLen = pMatch[m].length;
|
|
||||||
int k, nMatchRunLen;
|
|
||||||
|
|
||||||
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
|
|
||||||
nMatchLen = nEndOffset - LAST_LITERALS - i;
|
|
||||||
|
|
||||||
nMatchRunLen = nMatchLen;
|
|
||||||
if (nMatchRunLen > MATCH_RUN_LEN_V1)
|
|
||||||
nMatchRunLen = MATCH_RUN_LEN_V1;
|
|
||||||
|
|
||||||
for (k = nMinMatchSize; k < nMatchRunLen; k++) {
|
|
||||||
int nCurCost;
|
|
||||||
|
|
||||||
nCurCost = 8 + nMatchOffsetSize /* no extra match len bytes */;
|
|
||||||
nCurCost += cost[i + k];
|
|
||||||
if (pCompressor->match[(i + k) << MATCHES_PER_OFFSET_SHIFT].length >= MIN_MATCH_SIZE_V1)
|
|
||||||
nCurCost += MODESWITCH_PENALTY;
|
|
||||||
|
|
||||||
if (nBestCost > (nCurCost - nFavorRatio)) {
|
|
||||||
nBestCost = nCurCost;
|
|
||||||
nBestMatchLen = k;
|
|
||||||
nBestMatchOffset = pMatch[m].offset;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
for (; k <= nMatchLen; k++) {
|
|
||||||
int nCurCost;
|
|
||||||
|
|
||||||
nCurCost = 8 + nMatchOffsetSize + lzsa_get_match_varlen_size_v1(k - MIN_MATCH_SIZE_V1);
|
|
||||||
nCurCost += cost[i + k];
|
|
||||||
if (pCompressor->match[(i + k) << MATCHES_PER_OFFSET_SHIFT].length >= MIN_MATCH_SIZE_V1)
|
|
||||||
nCurCost += MODESWITCH_PENALTY;
|
|
||||||
|
|
||||||
if (nBestCost > (nCurCost - nFavorRatio)) {
|
|
||||||
nBestCost = nCurCost;
|
|
||||||
nBestMatchLen = k;
|
|
||||||
nBestMatchOffset = pMatch[m].offset;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
if (nBestMatchLen >= MIN_MATCH_SIZE_V1)
|
|
||||||
nLastLiteralsOffset = i;
|
|
||||||
|
|
||||||
cost[i] = nBestCost;
|
|
||||||
pMatch->length = nBestMatchLen;
|
|
||||||
pMatch->offset = nBestMatchOffset;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Attempt to minimize the number of commands issued in the compressed data block, in order to speed up decompression without
|
|
||||||
* impacting the compression ratio
|
|
||||||
*
|
|
||||||
* @param pCompressor compression context
|
|
||||||
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
|
|
||||||
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
|
|
||||||
*
|
|
||||||
* @return non-zero if the number of tokens was reduced, 0 if it wasn't
|
|
||||||
*/
|
|
||||||
static int lzsa_optimize_command_count_v1(lsza_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
|
|
||||||
int i;
|
|
||||||
int nNumLiterals = 0;
|
|
||||||
int nDidReduce = 0;
|
|
||||||
|
|
||||||
for (i = nStartOffset; i < nEndOffset; ) {
|
|
||||||
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
|
|
||||||
|
|
||||||
if (pMatch->length >= MIN_MATCH_SIZE_V1) {
|
|
||||||
int nMatchLen = pMatch->length;
|
|
||||||
int nReduce = 0;
|
|
||||||
|
|
||||||
if (nMatchLen <= 9 && (i + nMatchLen) < nEndOffset) /* max reducable command size: <token> <EE> <ll> <ll> <offset> <offset> <EE> <mm> <mm> */ {
|
|
||||||
int nMatchOffset = pMatch->offset;
|
|
||||||
int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V1;
|
|
||||||
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + ((nMatchOffset <= 256) ? 8 : 16) /* match offset */ + lzsa_get_match_varlen_size_v1(nEncodedMatchLen);
|
|
||||||
|
|
||||||
if (pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].length >= MIN_MATCH_SIZE_V1) {
|
|
||||||
if (nCommandSize >= ((nMatchLen << 3) + lzsa_get_literals_varlen_size_v1(nNumLiterals + nMatchLen))) {
|
|
||||||
/* This command is a match; the next command is also a match. The next command currently has no literals; replacing this command by literals will
|
|
||||||
* make the next command eat the cost of encoding the current number of literals, + nMatchLen extra literals. The size of the current match command is
|
|
||||||
* at least as much as the number of literal bytes + the extra cost of encoding them in the next match command, so we can safely replace the current
|
|
||||||
* match command by literals, the output size will not increase and it will remove one command. */
|
|
||||||
nReduce = 1;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
int nCurIndex = i + nMatchLen;
|
|
||||||
int nNextNumLiterals = 0;
|
|
||||||
|
|
||||||
do {
|
|
||||||
nCurIndex++;
|
|
||||||
nNextNumLiterals++;
|
|
||||||
} while (nCurIndex < nEndOffset && pCompressor->match[nCurIndex << MATCHES_PER_OFFSET_SHIFT].length < MIN_MATCH_SIZE_V1);
|
|
||||||
|
|
||||||
if (nCommandSize >= ((nMatchLen << 3) + lzsa_get_literals_varlen_size_v1(nNumLiterals + nNextNumLiterals + nMatchLen) - lzsa_get_literals_varlen_size_v1(nNextNumLiterals))) {
|
|
||||||
/* This command is a match, and is followed by literals, and then another match or the end of the input data. If encoding this match as literals doesn't take
|
|
||||||
* more room than the match, and doesn't grow the next match command's literals encoding, go ahead and remove the command. */
|
|
||||||
nReduce = 1;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
if (nReduce) {
|
|
||||||
int j;
|
|
||||||
|
|
||||||
for (j = 0; j < nMatchLen; j++) {
|
|
||||||
pCompressor->match[(i + j) << MATCHES_PER_OFFSET_SHIFT].length = 0;
|
|
||||||
}
|
|
||||||
nNumLiterals += nMatchLen;
|
|
||||||
i += nMatchLen;
|
|
||||||
|
|
||||||
nDidReduce = 1;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
if ((i + nMatchLen) < nEndOffset && nMatchLen >= LCP_MAX &&
|
|
||||||
pMatch->offset && pMatch->offset <= 32 && pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].offset == pMatch->offset && (nMatchLen % pMatch->offset) == 0 &&
|
|
||||||
(nMatchLen + pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].length) <= MAX_VARLEN) {
|
|
||||||
/* Join */
|
|
||||||
|
|
||||||
pMatch->length += pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].length;
|
|
||||||
pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].offset = 0;
|
|
||||||
pCompressor->match[(i + nMatchLen) << MATCHES_PER_OFFSET_SHIFT].length = -1;
|
|
||||||
continue;
|
|
||||||
}
|
|
||||||
|
|
||||||
nNumLiterals = 0;
|
|
||||||
i += nMatchLen;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
nNumLiterals++;
|
|
||||||
i++;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
return nDidReduce;
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Emit block of compressed data
|
|
||||||
*
|
|
||||||
* @param pCompressor compression context
|
|
||||||
* @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
|
|
||||||
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
|
|
||||||
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
|
|
||||||
* @param pOutData pointer to output buffer
|
|
||||||
* @param nMaxOutDataSize maximum size of output buffer, in bytes
|
|
||||||
*
|
|
||||||
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
|
|
||||||
*/
|
|
||||||
static int lzsa_write_block_v1(lsza_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
|
|
||||||
int i;
|
|
||||||
int nNumLiterals = 0;
|
|
||||||
int nInFirstLiteralOffset = 0;
|
|
||||||
int nOutOffset = 0;
|
|
||||||
|
|
||||||
for (i = nStartOffset; i < nEndOffset; ) {
|
|
||||||
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
|
|
||||||
|
|
||||||
if (pMatch->length >= MIN_MATCH_SIZE_V1) {
|
|
||||||
int nMatchOffset = pMatch->offset;
|
|
||||||
int nMatchLen = pMatch->length;
|
|
||||||
int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V1;
|
|
||||||
int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
|
|
||||||
int nTokenMatchLen = (nEncodedMatchLen >= MATCH_RUN_LEN_V1) ? MATCH_RUN_LEN_V1 : nEncodedMatchLen;
|
|
||||||
int nTokenLongOffset = (nMatchOffset <= 256) ? 0x00 : 0x80;
|
|
||||||
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3) + (nTokenLongOffset ? 16 : 8) /* match offset */ + lzsa_get_match_varlen_size_v1(nEncodedMatchLen);
|
|
||||||
|
|
||||||
if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
|
|
||||||
return -1;
|
|
||||||
if (nMatchOffset < MIN_OFFSET || nMatchOffset > MAX_OFFSET)
|
|
||||||
return -1;
|
|
||||||
|
|
||||||
pOutData[nOutOffset++] = nTokenLongOffset | (nTokenLiteralsLen << 4) | nTokenMatchLen;
|
|
||||||
nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
|
|
||||||
|
|
||||||
if (nNumLiterals != 0) {
|
|
||||||
memcpy(pOutData + nOutOffset, pInWindow + nInFirstLiteralOffset, nNumLiterals);
|
|
||||||
nOutOffset += nNumLiterals;
|
|
||||||
nNumLiterals = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
pOutData[nOutOffset++] = (-nMatchOffset) & 0xff;
|
|
||||||
if (nTokenLongOffset) {
|
|
||||||
pOutData[nOutOffset++] = (-nMatchOffset) >> 8;
|
|
||||||
}
|
|
||||||
nOutOffset = lzsa_write_match_varlen_v1(pOutData, nOutOffset, nEncodedMatchLen);
|
|
||||||
i += nMatchLen;
|
|
||||||
|
|
||||||
pCompressor->num_commands++;
|
|
||||||
}
|
|
||||||
else {
|
|
||||||
if (nNumLiterals == 0)
|
|
||||||
nInFirstLiteralOffset = i;
|
|
||||||
nNumLiterals++;
|
|
||||||
i++;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
{
|
|
||||||
int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
|
|
||||||
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3);
|
|
||||||
|
|
||||||
if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
|
|
||||||
return -1;
|
|
||||||
|
|
||||||
if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK)
|
|
||||||
pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x0f;
|
|
||||||
else
|
|
||||||
pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x00;
|
|
||||||
nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
|
|
||||||
|
|
||||||
if (nNumLiterals != 0) {
|
|
||||||
memcpy(pOutData + nOutOffset, pInWindow + nInFirstLiteralOffset, nNumLiterals);
|
|
||||||
nOutOffset += nNumLiterals;
|
|
||||||
nNumLiterals = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
pCompressor->num_commands++;
|
|
||||||
}
|
|
||||||
|
|
||||||
if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
|
|
||||||
/* Emit EOD marker for raw block */
|
|
||||||
|
|
||||||
if ((nOutOffset + 4) > nMaxOutDataSize)
|
|
||||||
return -1;
|
|
||||||
|
|
||||||
pOutData[nOutOffset++] = 0;
|
|
||||||
pOutData[nOutOffset++] = 238;
|
|
||||||
pOutData[nOutOffset++] = 0;
|
|
||||||
pOutData[nOutOffset++] = 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
return nOutOffset;
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
|
||||||
* Select the most optimal matches, reduce the token count if possible, and then emit a block of compressed LZSA1 data
|
|
||||||
*
|
|
||||||
* @param pCompressor compression context
|
|
||||||
* @param pInWindow pointer to input data window (previously compressed bytes + bytes to compress)
|
|
||||||
* @param nStartOffset current offset in input window (typically the number of previously compressed bytes)
|
|
||||||
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes
|
|
||||||
* @param pOutData pointer to output buffer
|
|
||||||
* @param nMaxOutDataSize maximum size of output buffer, in bytes
|
|
||||||
*
|
|
||||||
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
|
|
||||||
*/
|
|
||||||
int lzsa_optimize_and_write_block_v1(lsza_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
|
|
||||||
lzsa_optimize_matches_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
|
|
||||||
|
|
||||||
int nDidReduce;
|
|
||||||
int nPasses = 0;
|
|
||||||
do {
|
|
||||||
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
|
|
||||||
nPasses++;
|
|
||||||
} while (nDidReduce && nPasses < 20);
|
|
||||||
|
|
||||||
return lzsa_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
|
|
||||||
}
|
|
||||||
Loading…
Reference in New Issue
Block a user