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Improve LZSA2 compression ratio further and allow incompressible raw blocks

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Emmanuel Marty 2019-07-01 09:25:19 +02:00 committed by GitHub
parent 8d8f50a509
commit 59eb891394
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GPG Key ID: 4AEE18F83AFDEB23
11 changed files with 760 additions and 46 deletions
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1
Makefile
View File

@ -18,6 +18,7 @@ OBJS += $(OBJDIR)/src/expand_context.o
OBJS += $(OBJDIR)/src/expand_inmem.o
OBJS += $(OBJDIR)/src/expand_streaming.o
OBJS += $(OBJDIR)/src/frame.o
OBJS += $(OBJDIR)/src/hashmap.o
OBJS += $(OBJDIR)/src/matchfinder.o
OBJS += $(OBJDIR)/src/shrink_block_v1.o
OBJS += $(OBJDIR)/src/shrink_block_v2.o

6
Xcode/lzsa.xcodeproj/project.pbxproj
View File

@ -26,6 +26,7 @@
0CADC64722AAD8EB003E9821 /* expand_context.c in Sources */ = {isa = PBXBuildFile; fileRef = 0CADC62F22AAD8EB003E9821 /* expand_context.c */; };
0CADC64822AAD8EB003E9821 /* shrink_block_v2.c in Sources */ = {isa = PBXBuildFile; fileRef = 0CADC63022AAD8EB003E9821 /* shrink_block_v2.c */; };
0CADC64A22AB8DAD003E9821 /* divsufsort_utils.c in Sources */ = {isa = PBXBuildFile; fileRef = 0CADC64922AB8DAD003E9821 /* divsufsort_utils.c */; };
0CADC69622C8A420003E9821 /* hashmap.c in Sources */ = {isa = PBXBuildFile; fileRef = 0CADC69522C8A41F003E9821 /* hashmap.c */; };
/* End PBXBuildFile section */
/* Begin PBXCopyFilesBuildPhase section */
@ -80,6 +81,8 @@
0CADC63022AAD8EB003E9821 /* shrink_block_v2.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = shrink_block_v2.c; path = ../../src/shrink_block_v2.c; sourceTree = "<group>"; };
0CADC64922AB8DAD003E9821 /* divsufsort_utils.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = divsufsort_utils.c; sourceTree = "<group>"; };
0CADC64B22AB8DC3003E9821 /* divsufsort_config.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = divsufsort_config.h; sourceTree = "<group>"; };
0CADC69422C8A41F003E9821 /* hashmap.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = hashmap.h; path = ../../src/hashmap.h; sourceTree = "<group>"; };
0CADC69522C8A41F003E9821 /* hashmap.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = hashmap.c; path = ../../src/hashmap.c; sourceTree = "<group>"; };
/* End PBXFileReference section */
/* Begin PBXFrameworksBuildPhase section */
@ -127,6 +130,8 @@
0CADC62422AAD8EB003E9821 /* format.h */,
0CADC5F322AAD8EB003E9821 /* frame.c */,
0CADC62C22AAD8EB003E9821 /* frame.h */,
0CADC69522C8A41F003E9821 /* hashmap.c */,
0CADC69422C8A41F003E9821 /* hashmap.h */,
0CADC5F222AAD8EB003E9821 /* lib.h */,
0CADC5FC22AAD8EB003E9821 /* libdivsufsort */,
0CADC62222AAD8EB003E9821 /* lzsa.c */,
@ -235,6 +240,7 @@
isa = PBXSourcesBuildPhase;
buildActionMask = 2147483647;
files = (
0CADC69622C8A420003E9821 /* hashmap.c in Sources */,
0CADC64822AAD8EB003E9821 /* shrink_block_v2.c in Sources */,
0CADC63D22AAD8EB003E9821 /* sssort.c in Sources */,
0CADC64322AAD8EB003E9821 /* expand_block_v2.c in Sources */,

138
src/hashmap.c Normal file
View File

@ -0,0 +1,138 @@
/*
* hashmap.c - integer hashmap 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 "hashmap.h"
/**
* Generate key hash by mixing
*
* @param key key to get hash for
*
* @return hash
*/
static unsigned int lzsa_hashmap_get_hash(unsigned long long key) {
key = (~key) + (key << 21);
key = key ^ (key >> 24);
key = (key + (key << 3)) + (key << 8);
key = key ^ (key >> 14);
key = (key + (key << 2)) + (key << 4);
key = key ^ (key >> 28);
key = key + (key << 31);
return key & (LZSA_HASH_NBUCKETS - 1);
}
/**
* Initialize hashmap
*
* @param pHashMap hashmap
*/
void lzsa_hashmap_init(lzsa_hashmap_t *pHashMap) {
pHashMap->pBuffer = NULL;
memset(pHashMap->pBucket, 0, sizeof(lzsa_hashvalue_t *) * LZSA_HASH_NBUCKETS);
}
/**
* Set value for key
*
* @param pHashMap hashmap
* @param key key to set value for
* @param value new value
*/
void lzsa_hashmap_insert(lzsa_hashmap_t *pHashMap, unsigned long long key, unsigned int value) {
unsigned int hash = lzsa_hashmap_get_hash(key);
lzsa_hashvalue_t **pBucket = &pHashMap->pBucket[hash];
while (*pBucket) {
if ((*pBucket)->key == key) {
(*pBucket)->value = value;
return;
}
pBucket = &((*pBucket)->pNext);
}
if (!pHashMap->pBuffer || pHashMap->pBuffer->nFreeEntryIdx >= 255) {
lzsa_hashbuffer_t *pNewBuffer = (lzsa_hashbuffer_t *)malloc(sizeof(lzsa_hashbuffer_t));
if (!pNewBuffer) return;
pNewBuffer->pNext = pHashMap->pBuffer;
pNewBuffer->nFreeEntryIdx = 0;
pHashMap->pBuffer = pNewBuffer;
}
*pBucket = &pHashMap->pBuffer->value[pHashMap->pBuffer->nFreeEntryIdx++];
(*pBucket)->pNext = NULL;
(*pBucket)->key = key;
(*pBucket)->value = value;
}
/**
* Get value for key
*
* @param pHashMap hashmap
* @param key key to get value for
* @param pValue pointer to where to store value if found
*
* @return 0 if found, nonzero if not found
*/
int lzsa_hashmap_find(lzsa_hashmap_t *pHashMap, unsigned long long key, unsigned int *pValue) {
unsigned int hash = lzsa_hashmap_get_hash(key);
lzsa_hashvalue_t **pBucket = &pHashMap->pBucket[hash];
while (*pBucket) {
if ((*pBucket)->key == key) {
*pValue = (*pBucket)->value;
return 0;
}
pBucket = &((*pBucket)->pNext);
}
return -1;
}
/**
* Clear hashmap
*
* @param pHashMap hashmap
*/
void lzsa_hashmap_clear(lzsa_hashmap_t *pHashMap) {
while (pHashMap->pBuffer) {
lzsa_hashbuffer_t *pCurBuffer = pHashMap->pBuffer;
pHashMap->pBuffer = pCurBuffer->pNext;
free(pCurBuffer);
pCurBuffer = NULL;
}
memset(pHashMap->pBucket, 0, sizeof(lzsa_hashvalue_t *) * LZSA_HASH_NBUCKETS);
}

99
src/hashmap.h Normal file
View File

@ -0,0 +1,99 @@
/*
* hashmap.h - integer hashmap definitions
*
* 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/
*
*/
#ifndef _HASHMAP_H
#define _HASHMAP_H
#include <stdlib.h>
/** Number of hashmap buckets */
#define LZSA_HASH_NBUCKETS 256
/* Forward definitions */
typedef struct _lzsa_hashvalue_t lzsa_hashvalue_t;
typedef struct _lzsa_hashbuffer_t lzsa_hashbuffer_t;
/** One hashmap bucket entry */
typedef struct _lzsa_hashvalue_t {
lzsa_hashvalue_t *pNext;
unsigned long long key;
unsigned int value;
} lzsa_hashvalue_t;
/** One buffer storing hashmap bucket entries */
typedef struct _lzsa_hashbuffer_t {
lzsa_hashbuffer_t *pNext;
int nFreeEntryIdx;
lzsa_hashvalue_t value[255];
} lzsa_hashbuffer_t;
/** Hashmap */
typedef struct {
lzsa_hashbuffer_t *pBuffer;
lzsa_hashvalue_t *pBucket[LZSA_HASH_NBUCKETS];
} lzsa_hashmap_t;
/**
* Initialize hashmap
*
* @param pHashMap hashmap
*/
void lzsa_hashmap_init(lzsa_hashmap_t *pHashMap);
/**
* Set value for key
*
* @param pHashMap hashmap
* @param key key to set value for
* @param value new value
*/
void lzsa_hashmap_insert(lzsa_hashmap_t *pHashMap, unsigned long long key, unsigned int value);
/**
* Get value for key
*
* @param pHashMap hashmap
* @param key key to get value for
* @param pValue pointer to where to store value if found
*
* @return 0 if found, nonzero if not found
*/
int lzsa_hashmap_find(lzsa_hashmap_t *pHashMap, unsigned long long key, unsigned int *pValue);
/**
* Clear hashmap
*
* @param pHashMap hashmap
*/
void lzsa_hashmap_clear(lzsa_hashmap_t *pHashMap);
#endif /* _HASHMAP_H */

4
src/lzsa.c
View File

@ -46,7 +46,7 @@
#define OPT_RAW 2
#define OPT_FAVOR_RATIO 4
#define TOOL_VERSION "1.0.2"
#define TOOL_VERSION "1.0.3"
/*---------------------------------------------------------------------------*/
@ -127,7 +127,7 @@ static int do_compress(const char *pszInFilename, const char *pszOutFilename, co
case LZSA_ERROR_MEMORY: fprintf(stderr, "out of memory\n"); break;
case LZSA_ERROR_COMPRESSION: fprintf(stderr, "internal compression error\n"); break;
case LZSA_ERROR_RAW_TOOLARGE: fprintf(stderr, "error: raw blocks can only be used with files <= 64 Kb\n"); break;
case LZSA_ERROR_RAW_UNCOMPRESSED: fprintf(stderr, "error: data is incompressible, raw blocks only support compressed data\n"); break;
case LZSA_ERROR_RAW_UNCOMPRESSED: fprintf(stderr, "error: incompressible data needs to be <= 64 Kb in raw blocks\n"); break;
case LZSA_OK: break;
default: fprintf(stderr, "unknown compression error %d\n", nStatus); break;
}

53
src/shrink_block_v1.c
View File

@ -433,6 +433,50 @@ static int lzsa_write_block_v1(lzsa_compressor *pCompressor, const unsigned char
return nOutOffset;
}
/**
* Emit raw block of uncompressible 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_raw_uncompressed_block_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
int nNumLiterals = nEndOffset - nStartOffset;
int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V1) ? LITERALS_RUN_LEN_V1 : nNumLiterals;
int nOutOffset = 0;
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v1(nNumLiterals) + (nNumLiterals << 3) + 4;
if ((nOutOffset + (nCommandSize >> 3)) > nMaxOutDataSize)
return -1;
pCompressor->num_commands = 0;
pOutData[nOutOffset++] = (nTokenLiteralsLen << 4) | 0x0f;
nOutOffset = lzsa_write_literals_varlen_v1(pOutData, nOutOffset, nNumLiterals);
if (nNumLiterals != 0) {
memcpy(pOutData + nOutOffset, pInWindow + nStartOffset, nNumLiterals);
nOutOffset += nNumLiterals;
nNumLiterals = 0;
}
pCompressor->num_commands++;
/* Emit EOD marker for raw block */
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
*
@ -446,6 +490,8 @@ static int lzsa_write_block_v1(lzsa_compressor *pCompressor, const unsigned char
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
*/
int lzsa_optimize_and_write_block_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
int nResult;
lzsa_optimize_matches_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
int nDidReduce;
@ -455,5 +501,10 @@ int lzsa_optimize_and_write_block_v1(lzsa_compressor *pCompressor, const unsigne
nPasses++;
} while (nDidReduce && nPasses < 20);
return lzsa_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nResult = lzsa_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
if (nResult < 0 && pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
nResult = lzsa_write_raw_uncompressed_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
}
return nResult;
}

396
src/shrink_block_v2.c
View File

@ -35,6 +35,9 @@
#include "lib.h"
#include "shrink_block_v2.h"
#include "format.h"
#include "hashmap.h"
#define HASH_KEY(__nRepMatchOffset,__nNumLiterals,__i) (((unsigned long long)(__nRepMatchOffset)) | (((unsigned long long)(__i)) << 17) | (((unsigned long long)(__nNumLiterals)) << 34))
/**
* Write 4-bit nibble to output (compressed) buffer
@ -222,7 +225,7 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
if (pCompressor->best_match[i + 1].length >= MIN_MATCH_SIZE_V2)
nLiteralsCost += MODESWITCH_PENALTY;
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
const lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
int *pSlotCost = pCompressor->slot_cost + (i << MATCHES_PER_OFFSET_SHIFT);
int m;
@ -309,8 +312,8 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
if (nMatchOffsetSize && nCurIndex < nEndOffset && pCompressor->best_match[nCurIndex].length >= MIN_MATCH_SIZE_V2 && !repmatch_opt[nCurIndex].expected_repmatch) {
int r;
for (r = 0; r < NMATCHES_PER_OFFSET && pCompressor->match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].length >= MIN_MATCH_SIZE_V2; r++) {
if (pCompressor->match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].offset == pMatch[m].offset) {
for (r = 0; r < NMATCHES_PER_OFFSET && pCompressor->selected_match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].length >= MIN_MATCH_SIZE_V2; r++) {
if (pCompressor->selected_match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].offset == pMatch[m].offset) {
int nAltCost = nCurCost - nMatchOffsetSize + pCompressor->slot_cost[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r] - cost[nCurIndex];
if (nAltCost <= nCurCost) {
@ -356,8 +359,8 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
if (nMatchOffsetSize && nCurIndex < nEndOffset && pCompressor->best_match[nCurIndex].length >= MIN_MATCH_SIZE_V2 && !repmatch_opt[nCurIndex].expected_repmatch) {
int r;
for (r = 0; r < NMATCHES_PER_OFFSET && pCompressor->match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].length >= MIN_MATCH_SIZE_V2; r++) {
if (pCompressor->match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].offset == pMatch[m].offset) {
for (r = 0; r < NMATCHES_PER_OFFSET && pCompressor->selected_match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].length >= MIN_MATCH_SIZE_V2; r++) {
if (pCompressor->selected_match[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r].offset == pMatch[m].offset) {
int nAltCost = nCurCost - nMatchOffsetSize + pCompressor->slot_cost[(nCurIndex << MATCHES_PER_OFFSET_SHIFT) + r] - cost[nCurIndex];
if (nAltCost <= nCurCost) {
@ -382,8 +385,8 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
}
pSlotCost[m] = nBestCost;
pMatch[m].length = nBestMatchLen;
pMatch[m].offset = nBestMatchOffset; /* not necessary */
pCompressor->selected_match[(i << MATCHES_PER_OFFSET_SHIFT) + m].length = nBestMatchLen;
pCompressor->selected_match[(i << MATCHES_PER_OFFSET_SHIFT) + m].offset = nBestMatchOffset;
if (m == 0 || (nBestMatchLen && cost[i] >= nBestCost)) {
cost[i] = nBestCost;
@ -400,6 +403,7 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
}
for (; m < NMATCHES_PER_OFFSET; m++) {
pSlotCost[m] = 0;
pCompressor->selected_match[(i << MATCHES_PER_OFFSET_SHIFT) + m] = pMatch[m];
}
if (pCompressor->best_match[i].length >= MIN_MATCH_SIZE_V2)
@ -412,7 +416,7 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
for (i = nStartOffset; i < nEndOffset; ) {
if (pCompressor->best_match[i].length >= MIN_MATCH_SIZE_V2) {
if (nIncomingOffset >= 0 && repmatch_opt[i].incoming_offset == nIncomingOffset && repmatch_opt[i].best_slot_for_incoming >= 0) {
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT) + repmatch_opt[i].best_slot_for_incoming;
lzsa_match *pMatch = pCompressor->selected_match + (i << MATCHES_PER_OFFSET_SHIFT) + repmatch_opt[i].best_slot_for_incoming;
int *pSlotCost = pCompressor->slot_cost + (i << MATCHES_PER_OFFSET_SHIFT) + repmatch_opt[i].best_slot_for_incoming;
pCompressor->best_match[i].length = pMatch->length;
@ -446,7 +450,7 @@ static void lzsa_optimize_matches_v2(lzsa_compressor *pCompressor, const int nSt
*
* @return non-zero if the number of tokens was reduced, 0 if it wasn't
*/
static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nDidReduce = 0;
@ -455,7 +459,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
lzsa_repmatch_opt *repmatch_opt = pCompressor->repmatch_opt;
for (i = nStartOffset; i < nEndOffset; ) {
lzsa_match *pMatch = pCompressor->best_match + i;
lzsa_match *pMatch = pBestMatch + i;
if (pMatch->length >= MIN_MATCH_SIZE_V2) {
int nMatchLen = pMatch->length;
@ -468,10 +472,10 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
int nRepMatchSize = (nRepMatchOffset <= 32) ? 4 : ((nRepMatchOffset <= 512) ? 8 : ((nRepMatchOffset <= (8192 + 512)) ? 12 : 16)) /* match offset */;
int nUndoRepMatchCost = (nPreviousMatchOffset < 0 || !repmatch_opt[nPreviousMatchOffset].expected_repmatch) ? 0 : nRepMatchSize;
if (pCompressor->best_match[i + nMatchLen].length >= MIN_MATCH_SIZE_V2) {
if (pBestMatch[i + nMatchLen].length >= MIN_MATCH_SIZE_V2) {
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + lzsa_get_match_varlen_size_v2(nEncodedMatchLen) - nUndoRepMatchCost;
if (pCompressor->best_match[i + nMatchLen].offset != nMatchOffset) {
if (pBestMatch[i + nMatchLen].offset != nMatchOffset) {
nCommandSize += (nMatchOffset <= 32) ? 4 : ((nMatchOffset <= 512) ? 8 : ((nMatchOffset <= (8192 + 512)) ? 12 : 16)) /* match offset */;
}
@ -484,7 +488,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
}
else {
if (nMatchOffset != nRepMatchOffset &&
pCompressor->best_match[i + nMatchLen].offset == nRepMatchOffset) {
pBestMatch[i + nMatchLen].offset == nRepMatchOffset) {
if (nCommandSize > ((nMatchLen << 3) + lzsa_get_literals_varlen_size_v2(nNumLiterals + nMatchLen) - nRepMatchSize)) {
/* Same case, replacing this command by literals alone isn't enough on its own to have savings, however this match command is inbetween two matches with
@ -503,10 +507,10 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
do {
nCurIndex++;
nNextNumLiterals++;
} while (nCurIndex < nEndOffset && pCompressor->best_match[nCurIndex].length < MIN_MATCH_SIZE_V2);
} while (nCurIndex < nEndOffset && pBestMatch[nCurIndex].length < MIN_MATCH_SIZE_V2);
if (nCurIndex >= nEndOffset || pCompressor->best_match[nCurIndex].length < MIN_MATCH_SIZE_V2 ||
pCompressor->best_match[nCurIndex].offset != nMatchOffset) {
if (nCurIndex >= nEndOffset || pBestMatch[nCurIndex].length < MIN_MATCH_SIZE_V2 ||
pBestMatch[nCurIndex].offset != nMatchOffset) {
nCommandSize += (nMatchOffset <= 32) ? 4 : ((nMatchOffset <= 512) ? 8 : ((nMatchOffset <= (8192 + 512)) ? 12 : 16)) /* match offset */;
}
@ -516,9 +520,9 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
nReduce = 1;
}
else {
if (nCurIndex < nEndOffset && pCompressor->best_match[nCurIndex].length >= MIN_MATCH_SIZE_V2 &&
pCompressor->best_match[nCurIndex].offset != nMatchOffset &&
pCompressor->best_match[nCurIndex].offset == nRepMatchOffset) {
if (nCurIndex < nEndOffset && pBestMatch[nCurIndex].length >= MIN_MATCH_SIZE_V2 &&
pBestMatch[nCurIndex].offset != nMatchOffset &&
pBestMatch[nCurIndex].offset == nRepMatchOffset) {
if (nCommandSize > ((nMatchLen << 3) + lzsa_get_literals_varlen_size_v2(nNumLiterals + nNextNumLiterals + nMatchLen) - lzsa_get_literals_varlen_size_v2(nNextNumLiterals) - nRepMatchSize)) {
/* Same case, but now replacing this command allows to use a rep-match and get savings, so do it */
nReduce = 1;
@ -532,7 +536,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
int j;
for (j = 0; j < nMatchLen; j++) {
pCompressor->best_match[i + j].length = 0;
pBestMatch[i + j].length = 0;
}
nNumLiterals += nMatchLen;
i += nMatchLen;
@ -549,13 +553,13 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
nRepMatchOffset = pMatch->offset;
if ((i + nMatchLen) < nEndOffset && nMatchLen >= LCP_MAX &&
pMatch->offset && pMatch->offset <= 32 && pCompressor->best_match[i + nMatchLen].offset == pMatch->offset && (nMatchLen % pMatch->offset) == 0 &&
(nMatchLen + pCompressor->best_match[i + nMatchLen].length) <= MAX_VARLEN) {
pMatch->offset && pMatch->offset <= 32 && pBestMatch[i + nMatchLen].offset == pMatch->offset && (nMatchLen % pMatch->offset) == 0 &&
(nMatchLen + pBestMatch[i + nMatchLen].length) <= MAX_VARLEN) {
/* Join */
pMatch->length += pCompressor->best_match[i + nMatchLen].length;
pCompressor->best_match[i + nMatchLen].offset = 0;
pCompressor->best_match[i + nMatchLen].length = -1;
pMatch->length += pBestMatch[i + nMatchLen].length;
pBestMatch[i + nMatchLen].offset = 0;
pBestMatch[i + nMatchLen].length = -1;
continue;
}
@ -574,10 +578,252 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
return nDidReduce;
}
/**
* Get cost of the best encoding choice at a given offset, going forward
*
* @param pCompressor compression context
* @param i offset in input window
* @param nEndOffset offset to end finding matches at (typically the size of the total input window in bytes)
* @param nNumLiterals current pending number of literals to be encoded with the next token
* @param nRepMatchOffset current rep-match offset
* @param nDepth current recursion depth
* @param pBestMatchLen pointer to returned best match length for the position (0 for no match)
* @param pBestMatchOffset pointer to returned best match offset for the position (if there is a match)
*
* @return cost of best encoding choice for offset
*/
static int lzsa_get_forward_cost_v2(lzsa_compressor *pCompressor, const int i, const int nEndOffset, const int nNumLiterals, const int nRepMatchOffset, int nDepth, int *pBestMatchLen, int *pBestMatchOffset) {
if (i >= nEndOffset)
return 0;
int *cost = (int*)pCompressor->pos_data; /* Reuse */
if (nDepth >= pCompressor->max_forward_depth)
return cost[i];
if (nDepth >= 1) {
unsigned int nValue = 0;
if (!lzsa_hashmap_find(&pCompressor->cost_map, HASH_KEY(nRepMatchOffset, nNumLiterals, i), &nValue))
return nValue;
}
int nMinMatchSize = pCompressor->min_match_size;
int m;
const lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
int nBestCost, nBestMatchLen, nBestMatchOffset, nTmpMatchLen, nTmpMatchOffset;
int nLiteralsCost;
nBestCost = 8 + lzsa_get_forward_cost_v2(pCompressor, i + 1, nEndOffset, nNumLiterals + 1, nRepMatchOffset, nDepth + 1, &nTmpMatchLen, &nTmpMatchOffset);
nBestMatchLen = 0;
nBestMatchOffset = 0;
nLiteralsCost = lzsa_get_literals_varlen_size_v2(nNumLiterals);
for (m = 0; m < NMATCHES_PER_OFFSET && pMatch[m].length >= nMinMatchSize; m++) {
if (pMatch[m].length > 30) {
int nCurCost;
int nMatchLen = pMatch[m].length;
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
nMatchLen = nEndOffset - LAST_LITERALS - i;
int nMatchOffsetSize;
if (nRepMatchOffset == pMatch[m].offset)
nMatchOffsetSize = 0;
else {
nMatchOffsetSize = (pMatch[m].offset <= 32) ? 4 : ((pMatch[m].offset <= 512) ? 8 : ((pMatch[m].offset <= (8192 + 512)) ? 12 : 16));
}
nCurCost = 8 + nLiteralsCost + nMatchOffsetSize + lzsa_get_match_varlen_size_v2(nMatchLen - MIN_MATCH_SIZE_V2);
nCurCost += lzsa_get_forward_cost_v2(pCompressor, i + nMatchLen, nEndOffset, 0, pMatch[m].offset, nDepth + 1, &nTmpMatchLen, &nTmpMatchOffset);
if (nBestCost >= nCurCost) {
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_V2)
nMatchRunLen = MATCH_RUN_LEN_V2;
for (k = nMinMatchSize; k < nMatchRunLen; k++) {
int nCurCost;
int nMatchOffsetSize;
if (nRepMatchOffset == pMatch[m].offset)
nMatchOffsetSize = 0;
else {
nMatchOffsetSize = (pMatch[m].offset <= 32) ? 4 : ((pMatch[m].offset <= 512) ? 8 : ((pMatch[m].offset <= (8192 + 512)) ? 12 : 16));
}
nCurCost = 8 + nLiteralsCost + nMatchOffsetSize /* no extra match len bytes */;
nCurCost += lzsa_get_forward_cost_v2(pCompressor, i + k, nEndOffset, 0, pMatch[m].offset, nDepth + 1, &nTmpMatchLen, &nTmpMatchOffset);
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
}
for (; k <= nMatchLen; k++) {
int nCurCost;
int nMatchOffsetSize;
if (nRepMatchOffset == pMatch[m].offset)
nMatchOffsetSize = 0;
else {
nMatchOffsetSize = (pMatch[m].offset <= 32) ? 4 : ((pMatch[m].offset <= 512) ? 8 : ((pMatch[m].offset <= (8192 + 512)) ? 12 : 16));
}
nCurCost = 8 + nLiteralsCost + nMatchOffsetSize + lzsa_get_match_varlen_size_v2(k - MIN_MATCH_SIZE_V2);
nCurCost += lzsa_get_forward_cost_v2(pCompressor, i + k, nEndOffset, 0, pMatch[m].offset, nDepth + 1, &nTmpMatchLen, &nTmpMatchOffset);
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
}
}
}
*pBestMatchLen = nBestMatchLen;
*pBestMatchOffset = nBestMatchOffset;
lzsa_hashmap_insert(&pCompressor->cost_map, HASH_KEY(nRepMatchOffset, nNumLiterals, i), nBestCost);
return nBestCost;
}
/**
* Attempt to further improve the selected optimal matches with a chain-N forward parser pass
*
* @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_forward_v2(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nRepMatchOffset = 0;
int *cost = (int*)pCompressor->pos_data; /* Reuse */
lzsa_hashmap_init(&pCompressor->cost_map);
for (i = nStartOffset; i < nEndOffset; ) {
int nBestMatchLen = 0, nBestMatchOffset = 0;
int nBestCost = lzsa_get_forward_cost_v2(pCompressor, i, nEndOffset, nNumLiterals, nRepMatchOffset, 0, &nBestMatchLen, &nBestMatchOffset);
lzsa_hashmap_clear(&pCompressor->cost_map);
lzsa_match *pMatch = pCompressor->improved_match + i;
if (nBestCost < cost[i]) {
pMatch->length = nBestMatchLen;
pMatch->offset = nBestMatchOffset;
}
if (pMatch->length >= MIN_MATCH_SIZE_V2) {
nNumLiterals = 0;
nRepMatchOffset = pMatch->offset;
i += pMatch->length;
}
else {
nNumLiterals++;
i++;
}
}
lzsa_hashmap_clear(&pCompressor->cost_map);
}
/**
* Calculate compressed size
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to evaluate
* @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 compressed size
*/
static int lzsa_get_compressed_size_v2(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nCompressedSize = 0;
int nCurNibbleOffset = -1, nCurFreeNibbles = 0;
int nRepMatchOffset = 0;
for (i = nStartOffset; i < nEndOffset; ) {
const lzsa_match *pMatch = pBestMatch + i;
if (pMatch->length >= MIN_MATCH_SIZE_V2) {
int nMatchOffset = pMatch->offset;
int nMatchLen = pMatch->length;
int nEncodedMatchLen = nMatchLen - MIN_MATCH_SIZE_V2;
int nOffsetSize;
if (nMatchOffset == nRepMatchOffset) {
nOffsetSize = 0;
}
else {
if (nMatchOffset <= 32) {
nOffsetSize = 4;
}
else if (nMatchOffset <= 512) {
nOffsetSize = 8;
}
else if (nMatchOffset <= (8192 + 512)) {
nOffsetSize = 12;
}
else {
nOffsetSize = 16;
}
}
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3) + nOffsetSize /* match offset */ + lzsa_get_match_varlen_size_v2(nEncodedMatchLen);
nCompressedSize += nCommandSize;
nNumLiterals = 0;
nRepMatchOffset = nMatchOffset;
i += nMatchLen;
}
else {
nNumLiterals++;
i++;
}
}
{
int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V2) ? LITERALS_RUN_LEN_V2 : nNumLiterals;
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3);
nCompressedSize += nCommandSize;
nNumLiterals = 0;
}
if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
nCompressedSize += 8 + 4 + 8;
}
return nCompressedSize;
}
/**
* Emit block of compressed data
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @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
@ -586,7 +832,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const in
*
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
*/
static int lzsa_write_block_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
static int lzsa_write_block_v2(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
int i;
int nNumLiterals = 0;
int nInFirstLiteralOffset = 0;
@ -595,7 +841,7 @@ static int lzsa_write_block_v2(lzsa_compressor *pCompressor, const unsigned char
int nRepMatchOffset = 0;
for (i = nStartOffset; i < nEndOffset; ) {
lzsa_match *pMatch = pCompressor->best_match + i;
const lzsa_match *pMatch = pBestMatch + i;
if (pMatch->length >= MIN_MATCH_SIZE_V2) {
int nMatchOffset = pMatch->offset;
@ -727,6 +973,63 @@ static int lzsa_write_block_v2(lzsa_compressor *pCompressor, const unsigned char
return nOutOffset;
}
/**
* Emit raw block of uncompressible 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_raw_uncompressed_block_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
int nCurNibbleOffset = -1, nCurFreeNibbles = 0;
int nNumLiterals = nEndOffset - nStartOffset;
int nTokenLiteralsLen = (nNumLiterals >= LITERALS_RUN_LEN_V2) ? LITERALS_RUN_LEN_V2 : nNumLiterals;
int nOutOffset = 0;
int nCommandSize = 8 /* token */ + lzsa_get_literals_varlen_size_v2(nNumLiterals) + (nNumLiterals << 3) + 8 + 4 + 8;
if ((nOutOffset + ((nCommandSize + 7) >> 3)) > nMaxOutDataSize)
return -1;
pCompressor->num_commands = 0;
pOutData[nOutOffset++] = (nTokenLiteralsLen << 3) | 0x47;
nOutOffset = lzsa_write_literals_varlen_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, &nCurFreeNibbles, nNumLiterals);
if (nOutOffset < 0) return -1;
if (nNumLiterals != 0) {
memcpy(pOutData + nOutOffset, pInWindow + nStartOffset, nNumLiterals);
nOutOffset += nNumLiterals;
nNumLiterals = 0;
}
/* Emit EOD marker for raw block */
pOutData[nOutOffset++] = 0; /* Match offset */
nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, &nCurFreeNibbles, 15); /* Extended match length nibble */
if (nOutOffset < 0) return -1;
if ((nOutOffset + 1) > nMaxOutDataSize)
return -1;
pOutData[nOutOffset++] = 232; /* EOD match length byte */
pCompressor->num_commands++;
if (nCurNibbleOffset != -1) {
nOutOffset = lzsa_write_nibble_v2(pOutData, nOutOffset, nMaxOutDataSize, &nCurNibbleOffset, &nCurFreeNibbles, 0);
if (nOutOffset < 0 || nCurNibbleOffset != -1)
return -1;
}
return nOutOffset;
}
/**
* Select the most optimal matches, reduce the token count if possible, and then emit a block of compressed LZSA2 data
*
@ -740,14 +1043,49 @@ static int lzsa_write_block_v2(lzsa_compressor *pCompressor, const unsigned char
* @return size of compressed data in output buffer, or -1 if the data is uncompressible
*/
int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nPreviousBlockSize, const int nInDataSize, unsigned char *pOutData, const int nMaxOutDataSize) {
int nResult;
lzsa_optimize_matches_v2(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
lzsa_match *pBestMatch;
if (pCompressor->max_forward_depth > 0) {
memcpy(pCompressor->improved_match, pCompressor->best_match, nInDataSize * sizeof(lzsa_match));
lzsa_optimize_forward_v2(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
int nDidReduce;
int nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
return lzsa_write_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
int nBestCost = lzsa_get_compressed_size_v2(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
int nImprovedCost = lzsa_get_compressed_size_v2(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (nBestCost > nImprovedCost)
pBestMatch = pCompressor->improved_match;
else
pBestMatch = pCompressor->best_match;
}
else {
int nDidReduce;
int nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
pBestMatch = pCompressor->best_match;
}
nResult = lzsa_write_block_v2(pCompressor, pBestMatch, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
if (nResult < 0 && pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
nResult = lzsa_write_raw_uncompressed_block_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
}
return nResult;
}

21
src/shrink_context.c
View File

@ -58,7 +58,9 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->pos_data = NULL;
pCompressor->open_intervals = NULL;
pCompressor->match = NULL;
pCompressor->selected_match = NULL;
pCompressor->best_match = NULL;
pCompressor->improved_match = NULL;
pCompressor->slot_cost = NULL;
pCompressor->repmatch_opt = NULL;
pCompressor->min_match_size = nMinMatchSize;
@ -66,6 +68,7 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->min_match_size = nMinMatchSizeForFormat;
else if (pCompressor->min_match_size > nMaxMinMatchForFormat)
pCompressor->min_match_size = nMaxMinMatchForFormat;
pCompressor->max_forward_depth = 0;
pCompressor->format_version = nFormatVersion;
pCompressor->flags = nFlags;
pCompressor->num_commands = 0;
@ -84,9 +87,15 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
if (pCompressor->match) {
if (pCompressor->format_version == 2) {
pCompressor->selected_match = (lzsa_match *)malloc(nMaxWindowSize * NMATCHES_PER_OFFSET * sizeof(lzsa_match));
if (pCompressor->selected_match) {
pCompressor->best_match = (lzsa_match *)malloc(nMaxWindowSize * sizeof(lzsa_match));
if (pCompressor->best_match) {
pCompressor->improved_match = (lzsa_match *)malloc(nMaxWindowSize * sizeof(lzsa_match));
if (pCompressor->improved_match) {
pCompressor->slot_cost = (int *)malloc(nMaxWindowSize * NMATCHES_PER_OFFSET * sizeof(int));
if (pCompressor->slot_cost) {
@ -97,6 +106,8 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
}
}
}
}
}
else {
return 0;
}
@ -128,11 +139,21 @@ void lzsa_compressor_destroy(lzsa_compressor *pCompressor) {
pCompressor->slot_cost = NULL;
}
if (pCompressor->improved_match) {
free(pCompressor->improved_match);
pCompressor->improved_match = NULL;
}
if (pCompressor->best_match) {
free(pCompressor->best_match);
pCompressor->best_match = NULL;
}
if (pCompressor->selected_match) {
free(pCompressor->selected_match);
pCompressor->selected_match = NULL;
}
if (pCompressor->match) {
free(pCompressor->match);
pCompressor->match = NULL;

5
src/shrink_context.h
View File

@ -34,6 +34,7 @@
#define _SHRINK_CONTEXT_H
#include "divsufsort.h"
#include "hashmap.h"
#ifdef __cplusplus
extern "C" {
@ -77,13 +78,17 @@ typedef struct _lzsa_compressor {
unsigned int *pos_data;
unsigned int *open_intervals;
lzsa_match *match;
lzsa_match *selected_match;
lzsa_match *best_match;
lzsa_match *improved_match;
int *slot_cost;
lzsa_repmatch_opt *repmatch_opt;
int min_match_size;
int max_forward_depth;
int format_version;
int flags;
int num_commands;
lzsa_hashmap_t cost_map;
} lzsa_compressor;
/**

15
src/shrink_inmem.c
View File

@ -84,6 +84,21 @@ size_t lzsa_compress_inmem(const unsigned char *pInputData, unsigned char *pOutB
}
}
if ((compressor.flags & LZSA_FLAG_FAVOR_RATIO)) {
if (nInputSize < 16384)
compressor.max_forward_depth = 25;
else {
if (nInputSize < 32768)
compressor.max_forward_depth = 15;
else {
if (nInputSize < BLOCK_SIZE)
compressor.max_forward_depth = 10;
else
compressor.max_forward_depth = 0;
}
}
}
int nPreviousBlockSize = 0;
int nNumBlocks = 0;

42
src/shrink_streaming.c
View File

@ -36,6 +36,24 @@
#include "format.h"
#include "frame.h"
#include "lib.h"
#ifdef _WIN32
#include <windows.h>
#else
#include <stdio.h>
#endif
/**
* Delete file
*
* @param pszInFilename name of file to delete
*/
static void lzsa_delete_file(const char *pszInFilename) {
#ifdef _WIN32
DeleteFileA(pszInFilename);
#else
remove(pszInFilename);
#endif
}
/*-------------- File API -------------- */
@ -76,6 +94,7 @@ lzsa_status_t lzsa_compress_file(const char *pszInFilename, const char *pszOutFi
if (nStatus) {
outStream.close(&outStream);
inStream.close(&inStream);
lzsa_delete_file(pszOutFilename);
return nStatus;
}
@ -84,6 +103,11 @@ lzsa_status_t lzsa_compress_file(const char *pszInFilename, const char *pszOutFi
lzsa_dictionary_free(&pDictionaryData);
outStream.close(&outStream);
inStream.close(&inStream);
if (nStatus) {
lzsa_delete_file(pszOutFilename);
}
return nStatus;
}
@ -115,6 +139,7 @@ lzsa_status_t lzsa_compress_stream(lzsa_stream_t *pInStream, lzsa_stream_t *pOut
int nResult;
unsigned char cFrameData[16];
int nError = 0;
int nRawPadding = (nFlags & LZSA_FLAG_RAW_BLOCK) ? 8 : 0;
pInData = (unsigned char*)malloc(BLOCK_SIZE * 2);
if (!pInData) {
@ -175,9 +200,24 @@ lzsa_status_t lzsa_compress_stream(lzsa_stream_t *pInStream, lzsa_stream_t *pOut
}
nDictionaryDataSize = 0;
if (nNumBlocks == 0 && (compressor.flags & LZSA_FLAG_FAVOR_RATIO)) {
if (nInDataSize < 16384)
compressor.max_forward_depth = 25;
else {
if (nInDataSize < 32768)
compressor.max_forward_depth = 15;
else {
if (nInDataSize < BLOCK_SIZE)
compressor.max_forward_depth = 10;
else
compressor.max_forward_depth = 0;
}
}
}
int nOutDataSize;
nOutDataSize = lzsa_compressor_shrink_block(&compressor, pInData + BLOCK_SIZE - nPreviousBlockSize, nPreviousBlockSize, nInDataSize, pOutData, (nInDataSize >= BLOCK_SIZE) ? BLOCK_SIZE : nInDataSize);
nOutDataSize = lzsa_compressor_shrink_block(&compressor, pInData + BLOCK_SIZE - nPreviousBlockSize, nPreviousBlockSize, nInDataSize, pOutData, ((nInDataSize + nRawPadding) >= BLOCK_SIZE) ? BLOCK_SIZE : (nInDataSize + nRawPadding));
if (nOutDataSize >= 0) {
/* Write compressed block */