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Merge pull request #4 from emmanuel-marty/master

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Re-sync with the main
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introspec 2019-10-22 20:09:00 +01:00 committed by GitHub
commit e1e1276c96
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14 changed files with 359 additions and 319 deletions
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1
Makefile
View File

@ -18,7 +18,6 @@ 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

3
README.md
View File

@ -69,7 +69,8 @@ License:
External links:
* [i8080 decompressors](https://gitlab.com/ivagor) by Ivan Gorodetsky
* [i8080 decompressors](https://gitlab.com/ivagor/lzsa8080/tree/master) by Ivan Gorodetsky
* [PDP-11 decompressors](https://gitlab.com/ivagor/lzsa8080/tree/master/PDP11) also by Ivan Gorodetsky
* LZSA's page on [Pouet](https://www.pouet.net/prod.php?which=81573)
# Compressed format

2
VS2017/lzsa.vcxproj
View File

@ -185,7 +185,6 @@
<ClInclude Include="..\src\format.h" />
<ClInclude Include="..\src\frame.h" />
<ClInclude Include="..\src\expand_inmem.h" />
<ClInclude Include="..\src\hashmap.h" />
<ClInclude Include="..\src\lib.h" />
<ClInclude Include="..\src\libdivsufsort\include\divsufsort_config.h" />
<ClInclude Include="..\src\libdivsufsort\include\divsufsort.h" />
@ -207,7 +206,6 @@
<ClCompile Include="..\src\expand_block_v2.c" />
<ClCompile Include="..\src\frame.c" />
<ClCompile Include="..\src\expand_inmem.c" />
<ClCompile Include="..\src\hashmap.c" />
<ClCompile Include="..\src\libdivsufsort\lib\divsufsort.c" />
<ClCompile Include="..\src\libdivsufsort\lib\sssort.c" />
<ClCompile Include="..\src\libdivsufsort\lib\trsort.c" />

6
VS2017/lzsa.vcxproj.filters
View File

@ -84,9 +84,6 @@
<ClInclude Include="..\src\libdivsufsort\include\divsufsort_config.h">
<Filter>Fichiers sources\libdivsufsort\include</Filter>
</ClInclude>
<ClInclude Include="..\src\hashmap.h">
<Filter>Fichiers sources</Filter>
</ClInclude>
</ItemGroup>
<ItemGroup>
<ClCompile Include="..\src\libdivsufsort\lib\divsufsort.c">
@ -146,8 +143,5 @@
<ClCompile Include="..\src\libdivsufsort\lib\divsufsort_utils.c">
<Filter>Fichiers sources\libdivsufsort\lib</Filter>
</ClCompile>
<ClCompile Include="..\src\hashmap.c">
<Filter>Fichiers sources</Filter>
</ClCompile>
</ItemGroup>
</Project>

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

@ -26,7 +26,6 @@
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 */
@ -81,8 +80,6 @@
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 */
@ -130,8 +127,6 @@
0CADC62422AAD8EB003E9821 /* format.h */,
0CADC5F322AAD8EB003E9821 /* frame.c */,
0CADC62C22AAD8EB003E9821 /* frame.h */,
0CADC69522C8A41F003E9821 /* hashmap.c */,
0CADC69422C8A41F003E9821 /* hashmap.h */,
0CADC5F222AAD8EB003E9821 /* lib.h */,
0CADC5FC22AAD8EB003E9821 /* libdivsufsort */,
0CADC62222AAD8EB003E9821 /* lzsa.c */,
@ -240,7 +235,6 @@
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
View File

@ -1,138 +0,0 @@
/*
* 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
View File

@ -1,99 +0,0 @@
/*
* 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 */

3
src/lzsa.c
View File

@ -48,7 +48,7 @@
#define OPT_RAW_BACKWARD 8
#define OPT_STATS 16
#define TOOL_VERSION "1.1.0"
#define TOOL_VERSION "1.1.2"
/*---------------------------------------------------------------------------*/
@ -1073,6 +1073,7 @@ int main(int argc, char **argv) {
fprintf(stderr, " -cbench: benchmark in-memory compression\n");
fprintf(stderr, " -dbench: benchmark in-memory decompression\n");
fprintf(stderr, " -test: run automated self-tests\n");
fprintf(stderr, " -stats: show compressed data stats\n");
fprintf(stderr, " -v: be verbose\n");
fprintf(stderr, " -f <value>: LZSA compression format (1-2)\n");
fprintf(stderr, " -r: raw block format (max. 64 Kb files)\n");

25
src/matchfinder.c
View File

@ -285,3 +285,28 @@ void lzsa_skip_matches(lzsa_compressor *pCompressor, const int nStartOffset, con
lzsa_find_matches_at(pCompressor, i, &match, 0);
}
}
/**
* Find all matches for the data to be compressed
*
* @param pCompressor compression context
* @param nMatchesPerOffset maximum number of matches to store for each offset
* @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
*/
void lzsa_find_all_matches(lzsa_compressor *pCompressor, const int nMatchesPerOffset, const int nStartOffset, const int nEndOffset) {
lzsa_match *pMatch = pCompressor->match + (nStartOffset * nMatchesPerOffset);
int i;
for (i = nStartOffset; i < nEndOffset; i++) {
int nMatches = lzsa_find_matches_at(pCompressor, i, pMatch, nMatchesPerOffset);
while (nMatches < nMatchesPerOffset) {
pMatch[nMatches].length = 0;
pMatch[nMatches].offset = 0;
nMatches++;
}
pMatch += nMatchesPerOffset;
}
}

10
src/matchfinder.h
View File

@ -73,6 +73,16 @@ int lzsa_find_matches_at(lzsa_compressor *pCompressor, const int nOffset, lzsa_m
*/
void lzsa_skip_matches(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset);
/**
* Find all matches for the data to be compressed
*
* @param pCompressor compression context
* @param nMatchesPerOffset maximum number of matches to store for each offset
* @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
*/
void lzsa_find_all_matches(lzsa_compressor *pCompressor, const int nMatchesPerOffset, const int nStartOffset, const int nEndOffset);
#ifdef __cplusplus
}
#endif

168
src/shrink_block_v1.c
View File

@ -35,7 +35,6 @@
#include "lib.h"
#include "shrink_block_v1.h"
#include "format.h"
#include "matchfinder.h"
/**
* Get the number of extra bits required to represent a literals length
@ -157,23 +156,24 @@ static inline int lzsa_get_offset_cost_v1(const unsigned int nMatchOffset) {
* @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_v1(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce) {
lzsa_arrival *arrival = pCompressor->arrival;
const int nMinMatchSize = pCompressor->min_match_size;
const int nFavorRatio = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 1 : 0;
const int nDisableScore = nReduce ? 0 : (2 * BLOCK_SIZE);
int i, j, n;
lzsa_match match[8];
memset(arrival + (nStartOffset << MATCHES_PER_OFFSET_SHIFT), 0, sizeof(lzsa_arrival) * ((nEndOffset - nStartOffset) << MATCHES_PER_OFFSET_SHIFT));
arrival[nStartOffset << MATCHES_PER_OFFSET_SHIFT].from_slot = -1;
for (i = nStartOffset; i != (nEndOffset - 1); i++) {
int m, nMatches;
int m;
for (j = 0; j < NMATCHES_PER_OFFSET && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].from_slot; j++) {
int nPrevCost = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].cost;
int nCodingChoiceCost = nPrevCost + 8 /* literal */;
int nScore = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].score + 1;
int nNumLiterals = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].num_literals + 1;
if (nNumLiterals == LITERALS_RUN_LEN_V1 || nNumLiterals == 256 || nNumLiterals == 512) {
@ -183,27 +183,32 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
if (!nFavorRatio && nNumLiterals == 1)
nCodingChoiceCost += MODESWITCH_PENALTY;
lzsa_arrival *pDestArrival = &arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT)];
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost <= pDestArrival->cost) {
for (n = 0; n < NMATCHES_PER_OFFSET /* we only need the literals + short match cost + long match cost cases */; n++) {
lzsa_arrival *pDestArrival = &arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n];
memmove(&arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + 1],
&arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT)],
sizeof(lzsa_arrival) * (NMATCHES_PER_OFFSET - 1));
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost < pDestArrival->cost ||
(nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
memmove(&arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n + 1],
&arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n],
sizeof(lzsa_arrival) * (NMATCHES_PER_OFFSET - n - 1));
pDestArrival->cost = nCodingChoiceCost;
pDestArrival->from_pos = i;
pDestArrival->from_slot = j + 1;
pDestArrival->match_offset = 0;
pDestArrival->match_len = 0;
pDestArrival->num_literals = nNumLiterals;
pDestArrival->rep_offset = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset;
pDestArrival->cost = nCodingChoiceCost;
pDestArrival->from_pos = i;
pDestArrival->from_slot = j + 1;
pDestArrival->match_offset = 0;
pDestArrival->match_len = 0;
pDestArrival->num_literals = nNumLiterals;
pDestArrival->score = nScore;
pDestArrival->rep_offset = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset;
break;
}
}
}
nMatches = lzsa_find_matches_at(pCompressor, i, match, 8);
const lzsa_match *match = pCompressor->match + (i << 3);
for (m = 0; m < nMatches; m++) {
for (m = 0; m < 8 && match[m].length; m++) {
int nMatchLen = match[m].length;
int nMatchOffsetCost = lzsa_get_offset_cost_v1(match[m].offset);
int nStartingMatchLen, k;
@ -221,13 +226,14 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
for (j = 0; j < NMATCHES_PER_OFFSET && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].from_slot; j++) {
int nPrevCost = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].cost;
int nCodingChoiceCost = nPrevCost + 8 /* token */ /* the actual cost of the literals themselves accumulates up the chain */ + nMatchOffsetCost + nMatchLenCost;
int nScore = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].score + 5;
int exists = 0;
if (!nFavorRatio && !arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].num_literals)
nCodingChoiceCost += MODESWITCH_PENALTY;
for (n = 0;
n < 3 && arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].from_slot && arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].cost <= nCodingChoiceCost;
n < NMATCHES_PER_OFFSET && arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].from_slot && arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].cost <= nCodingChoiceCost;
n++) {
if (lzsa_get_offset_cost_v1(arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].rep_offset) == lzsa_get_offset_cost_v1(match[m].offset)) {
exists = 1;
@ -235,11 +241,12 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
}
}
for (n = 0; !exists && n < 3 /* we only need the literals + short match cost + long match cost cases */; n++) {
for (n = 0; !exists && n < NMATCHES_PER_OFFSET /* we only need the literals + short match cost + long match cost cases */; n++) {
lzsa_arrival *pDestArrival = &arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n];
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost <= pDestArrival->cost) {
nCodingChoiceCost < pDestArrival->cost ||
(nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
memmove(&arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n + 1],
&arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n],
sizeof(lzsa_arrival) * (NMATCHES_PER_OFFSET - n - 1));
@ -250,6 +257,7 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
pDestArrival->match_offset = match[m].offset;
pDestArrival->match_len = k;
pDestArrival->num_literals = 0;
pDestArrival->score = nScore;
pDestArrival->rep_offset = match[m].offset;
break;
}
@ -260,12 +268,12 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
}
lzsa_arrival *end_arrival = &arrival[(i << MATCHES_PER_OFFSET_SHIFT) + 0];
pCompressor->best_match[i].length = 0;
pCompressor->best_match[i].offset = 0;
pBestMatch[i].length = 0;
pBestMatch[i].offset = 0;
while (end_arrival->from_slot > 0 && end_arrival->from_pos >= 0) {
pCompressor->best_match[end_arrival->from_pos].length = end_arrival->match_len;
pCompressor->best_match[end_arrival->from_pos].offset = end_arrival->match_offset;
pBestMatch[end_arrival->from_pos].length = end_arrival->match_len;
pBestMatch[end_arrival->from_pos].offset = end_arrival->match_offset;
end_arrival = &arrival[(end_arrival->from_pos << MATCHES_PER_OFFSET_SHIFT) + (end_arrival->from_slot - 1)];
}
@ -276,18 +284,19 @@ static void lzsa_optimize_forward_v1(lzsa_compressor *pCompressor, const int nSt
* impacting the compression ratio
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @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(lzsa_compressor *pCompressor, const int nStartOffset, const int nEndOffset) {
static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nDidReduce = 0;
for (i = nStartOffset; i < nEndOffset; ) {
lzsa_match *pMatch = pCompressor->best_match + i;
lzsa_match *pMatch = pBestMatch + i;
if (pMatch->length >= MIN_MATCH_SIZE_V1) {
if (pMatch->length <= 9 /* Don't waste time considering large matches, they will always win over literals */ &&
@ -295,7 +304,7 @@ static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const in
int nNextIndex = i + pMatch->length;
int nNextLiterals = 0;
while (nNextIndex < nEndOffset && pCompressor->best_match[nNextIndex].length < MIN_MATCH_SIZE_V1) {
while (nNextIndex < nEndOffset && pBestMatch[nNextIndex].length < MIN_MATCH_SIZE_V1) {
nNextLiterals++;
nNextIndex++;
}
@ -309,7 +318,7 @@ static int lzsa_optimize_command_count_v1(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;
}
nDidReduce = 1;
@ -318,15 +327,15 @@ static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const in
}
if ((i + pMatch->length) < nEndOffset && pMatch->length >= LCP_MAX &&
pMatch->offset && pMatch->offset <= 32 && pCompressor->best_match[i + pMatch->length].offset == pMatch->offset && (pMatch->length % pMatch->offset) == 0 &&
(pMatch->length + pCompressor->best_match[i + pMatch->length].length) <= MAX_VARLEN) {
pMatch->offset && pMatch->offset <= 32 && pBestMatch[i + pMatch->length].offset == pMatch->offset && (pMatch->length % pMatch->offset) == 0 &&
(pMatch->length + pBestMatch[i + pMatch->length].length) <= MAX_VARLEN) {
int nMatchLen = pMatch->length;
/* 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;
}
@ -342,10 +351,63 @@ static int lzsa_optimize_command_count_v1(lzsa_compressor *pCompressor, const in
return nDidReduce;
}
/**
* Get compressed data block size
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @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 size of compressed data that will be written to output buffer
*/
static int lzsa_get_compressed_size_v1(lzsa_compressor *pCompressor, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset) {
int i;
int nNumLiterals = 0;
int nCompressedSize = 0;
for (i = nStartOffset; i < nEndOffset; ) {
const lzsa_match *pMatch = pBestMatch + i;
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);
nCompressedSize += nCommandSize;
nNumLiterals = 0;
i += nMatchLen;
}
else {
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);
nCompressedSize += nCommandSize;
nNumLiterals = 0;
}
if (pCompressor->flags & LZSA_FLAG_RAW_BLOCK) {
nCompressedSize += 8 * 4;
}
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
@ -354,14 +416,14 @@ static int lzsa_optimize_command_count_v1(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_v1(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset, unsigned char *pOutData, const int nMaxOutDataSize) {
static int lzsa_write_block_v1(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;
int nOutOffset = 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_V1) {
int nMatchOffset = pMatch->offset;
@ -554,18 +616,42 @@ static int lzsa_write_raw_uncompressed_block_v1(lzsa_compressor *pCompressor, co
* @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;
int nResult, nBaseCompressedSize;
lzsa_optimize_forward_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
/* Compress optimally without breaking ties in favor of less tokens */
lzsa_optimize_forward_v1(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */);
int nDidReduce;
int nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
nResult = lzsa_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nBaseCompressedSize = lzsa_get_compressed_size_v1(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
lzsa_match *pBestMatch = pCompressor->best_match;
if (nBaseCompressedSize > 0 && nInDataSize < 65536) {
int nReducedCompressedSize;
/* Compress optimally and do break ties in favor of less tokens */
lzsa_optimize_forward_v1(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */);
nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v1(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
nReducedCompressedSize = lzsa_get_compressed_size_v1(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (nReducedCompressedSize > 0 && nReducedCompressedSize <= nBaseCompressedSize) {
/* Pick the parse with the reduced number of tokens as it didn't negatively affect the size */
pBestMatch = pCompressor->improved_match;
}
}
nResult = lzsa_write_block_v1(pCompressor, pBestMatch, 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);
}

184
src/shrink_block_v2.c
View File

@ -35,8 +35,6 @@
#include "lib.h"
#include "shrink_block_v2.h"
#include "format.h"
#include "hashmap.h"
#include "matchfinder.h"
/**
* Write 4-bit nibble to output (compressed) buffer
@ -182,13 +180,14 @@ static inline int lzsa_write_match_varlen_v2(unsigned char *pOutData, int nOutOf
* @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
* @param nInsertForwardReps non-zero to insert forward repmatch candidates, zero to use the previously inserted candidates
*/
static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, const int nStartOffset, const int nEndOffset) {
static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce, const int nInsertForwardReps) {
lzsa_arrival *arrival = pCompressor->arrival;
const int nFavorRatio = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 1 : 0;
const int nMinMatchSize = pCompressor->min_match_size;
const int nDisableScore = nReduce ? 0 : (2 * BLOCK_SIZE);
int i, j, n;
lzsa_match match[32];
memset(arrival + (nStartOffset << MATCHES_PER_OFFSET_SHIFT), 0, sizeof(lzsa_arrival) * ((nEndOffset - nStartOffset) << MATCHES_PER_OFFSET_SHIFT));
@ -199,7 +198,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
arrival[nStartOffset << MATCHES_PER_OFFSET_SHIFT].from_slot = -1;
for (i = nStartOffset; i != (nEndOffset - 1); i++) {
int m, nMatches;
int m;
for (j = 0; j < NMATCHES_PER_OFFSET && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].from_slot; j++) {
const int nPrevCost = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].cost & 0x3fffffff;
@ -232,9 +231,11 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
if (!exists) {
int nScore = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].score + 1;
for (n = 0; n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &pDestSlots[n];
if (nCodingChoiceCost <= pDestArrival->cost) {
if (nCodingChoiceCost < pDestArrival->cost ||
(nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
if (pDestArrival->from_slot) {
memmove(&pDestSlots[n + 1],
@ -248,7 +249,10 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
pDestArrival->match_offset = 0;
pDestArrival->match_len = 0;
pDestArrival->num_literals = nNumLiterals;
pDestArrival->score = nScore;
pDestArrival->rep_offset = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset;
pDestArrival->rep_pos = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_pos;
pDestArrival->rep_len = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_len;
break;
}
}
@ -256,9 +260,9 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
}
nMatches = lzsa_find_matches_at(pCompressor, i, match, 32);
lzsa_match *match = pCompressor->match + (i << 5);
for (m = 0; m < nMatches; m++) {
for (m = 0; m < 32 && match[m].length; m++) {
int nMatchLen = match[m].length;
int nMatchOffset = match[m].offset;
int nNoRepmatchOffsetCost = (nMatchOffset <= 32) ? 4 : ((nMatchOffset <= 512) ? 8 : ((nMatchOffset <= (8192 + 512)) ? 12 : 16));
@ -274,7 +278,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
if (nMatchOffset != nRepOffset &&
nRepOffset &&
i >= nRepOffset &&
i > nRepOffset &&
(i - nRepOffset + nMatchLen) <= (nEndOffset - LAST_LITERALS)) {
while (nCurMaxRepLen < nMatchLen && pInWindow[i - nRepOffset + nCurMaxRepLen] == pInWindow[i - nMatchOffset + nCurMaxRepLen])
nCurMaxRepLen++;
@ -285,6 +289,36 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
while (j < NMATCHES_PER_OFFSET)
nMaxRepLen[j++] = 0;
for (j = 0; j < NMATCHES_PER_OFFSET && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].from_slot; j++) {
int nRepOffset = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset;
if (nMatchOffset != nRepOffset && nRepOffset && nInsertForwardReps && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_len >= MIN_MATCH_SIZE_V2) {
int nRepPos = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_pos;
int nRepLen = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_len;
if (nRepPos > nMatchOffset &&
(nRepPos - nMatchOffset + nRepLen) <= (nEndOffset - LAST_LITERALS) &&
!memcmp(pInWindow + nRepPos - nRepOffset, pInWindow + nRepPos - nMatchOffset, nRepLen)) {
lzsa_match *fwd_match = pCompressor->match + (nRepPos << 5);
int exists = 0;
int r;
for (r = 0; r < 32 && fwd_match[r].length >= MIN_MATCH_SIZE_V2; r++) {
if (fwd_match[r].offset == nMatchOffset) {
exists = 1;
break;
}
}
if (!exists && r < 32) {
fwd_match[r].offset = nMatchOffset;
fwd_match[r].length = nRepLen;
}
}
}
}
if (nMatchLen >= LEAVE_ALONE_MATCH_SIZE)
nStartingMatchLen = nMatchLen;
else
@ -319,10 +353,13 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
if (!exists) {
int nScore = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].score + ((nMatchOffset == nRepOffset) ? 2 : 3);
for (n = 0; n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &pDestSlots[n];
if (nCodingChoiceCost <= pDestArrival->cost) {
if (nCodingChoiceCost < pDestArrival->cost ||
(nCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
if (pDestArrival->from_slot) {
memmove(&pDestSlots[n + 1],
&pDestSlots[n],
@ -335,7 +372,10 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
pDestArrival->match_offset = nMatchOffset;
pDestArrival->match_len = k;
pDestArrival->num_literals = 0;
pDestArrival->score = nScore;
pDestArrival->rep_offset = nMatchOffset;
pDestArrival->rep_pos = i;
pDestArrival->rep_len = k;
break;
}
}
@ -361,10 +401,13 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
if (!exists) {
int nScore = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].score + 2;
for (n = 0; n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &pDestSlots[n];
if (nRepCodingChoiceCost <= pDestArrival->cost) {
if (nRepCodingChoiceCost < pDestArrival->cost ||
(nRepCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
if (pDestArrival->from_slot) {
memmove(&pDestSlots[n + 1],
&pDestSlots[n],
@ -377,7 +420,10 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
pDestArrival->match_offset = nRepOffset;
pDestArrival->match_len = k;
pDestArrival->num_literals = 0;
pDestArrival->score = nScore;
pDestArrival->rep_offset = nRepOffset;
pDestArrival->rep_pos = i;
pDestArrival->rep_len = k;
break;
}
}
@ -390,12 +436,12 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
lzsa_arrival *end_arrival = &arrival[(i << MATCHES_PER_OFFSET_SHIFT) + 0];
pCompressor->best_match[i].length = 0;
pCompressor->best_match[i].offset = 0;
pBestMatch[i].length = 0;
pBestMatch[i].offset = 0;
while (end_arrival->from_slot > 0 && end_arrival->from_pos >= 0) {
pCompressor->best_match[end_arrival->from_pos].length = end_arrival->match_len;
pCompressor->best_match[end_arrival->from_pos].offset = end_arrival->match_offset;
pBestMatch[end_arrival->from_pos].length = end_arrival->match_len;
pBestMatch[end_arrival->from_pos].offset = end_arrival->match_offset;
end_arrival = &arrival[(end_arrival->from_pos << MATCHES_PER_OFFSET_SHIFT) + (end_arrival->from_slot - 1)];
}
}
@ -443,7 +489,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
/* Check if we can change the current match's offset to be the same as the previous match's offset, and get an extra repmatch. This will occur when
* matching large regions of identical bytes for instance, where there are too many offsets to be considered by the parser, and when not compressing to favor the
* ratio (the forward arrivals parser already has this covered). */
if (i >= nRepMatchOffset &&
if (i > nRepMatchOffset &&
(i - nRepMatchOffset + pMatch->length) <= (nEndOffset - LAST_LITERALS) &&
!memcmp(pInWindow + i - nRepMatchOffset, pInWindow + i - pMatch->offset, pMatch->length)) {
pMatch->offset = nRepMatchOffset;
@ -453,7 +499,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
if (pBestMatch[nNextIndex].offset && pMatch->offset != pBestMatch[nNextIndex].offset && nRepMatchOffset != pBestMatch[nNextIndex].offset) {
/* Otherwise, try to gain a match forward as well */
if (i >= pBestMatch[nNextIndex].offset && (i - pBestMatch[nNextIndex].offset + pMatch->length) <= (nEndOffset - LAST_LITERALS)) {
if (i > pBestMatch[nNextIndex].offset && (i - pBestMatch[nNextIndex].offset + pMatch->length) <= (nEndOffset - LAST_LITERALS)) {
int nMaxLen = 0;
while (nMaxLen < pMatch->length && pInWindow[i - pBestMatch[nNextIndex].offset + nMaxLen] == pInWindow[i - pMatch->offset + nMaxLen])
nMaxLen++;
@ -508,7 +554,7 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
nReducedCommandSize += (pBestMatch[nNextIndex].offset <= 32) ? 4 : ((pBestMatch[nNextIndex].offset <= 512) ? 8 : ((pBestMatch[nNextIndex].offset <= (8192 + 512)) ? 12 : 16));
int nReplaceRepOffset = 0;
if (nRepMatchOffset && nRepMatchOffset != nPrevRepMatchOffset && nRepMatchLen >= MIN_MATCH_SIZE_V2 && nRepMatchOffset != pBestMatch[nNextIndex].offset && nRepIndex >= pBestMatch[nNextIndex].offset &&
if (nRepMatchOffset && nRepMatchOffset != nPrevRepMatchOffset && nRepMatchLen >= MIN_MATCH_SIZE_V2 && nRepMatchOffset != pBestMatch[nNextIndex].offset && nRepIndex > pBestMatch[nNextIndex].offset &&
(nRepIndex - pBestMatch[nNextIndex].offset + nRepMatchLen) <= (nEndOffset - LAST_LITERALS) &&
!memcmp(pInWindow + nRepIndex - nRepMatchOffset, pInWindow + nRepIndex - pBestMatch[nNextIndex].offset, nRepMatchLen)) {
/* Replacing this match command by literals would let us create a repmatch */
@ -568,6 +614,78 @@ static int lzsa_optimize_command_count_v2(lzsa_compressor *pCompressor, const un
return nDidReduce;
}
/**
* Get compressed data block size
*
* @param pCompressor compression context
* @param pBestMatch optimal matches to emit
* @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 size of compressed data that will be written to output buffer
*/
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 nOutOffset = 0;
int nRepMatchOffset = 0;
int nCompressedSize = 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
*
@ -852,9 +970,11 @@ static int lzsa_write_raw_uncompressed_block_v2(lzsa_compressor *pCompressor, co
* @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;
int nResult, nBaseCompressedSize;
lzsa_optimize_forward_v2(pCompressor, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
/* Compress optimally without breaking ties in favor of less tokens */
lzsa_optimize_forward_v2(pCompressor, pInWindow, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */, (nInDataSize < 65536) ? 1 : 0 /* insert forward reps */);
int nDidReduce;
int nPasses = 0;
@ -863,7 +983,29 @@ int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigne
nPasses++;
} while (nDidReduce && nPasses < 20);
nResult = lzsa_write_block_v2(pCompressor, pCompressor->best_match, pInWindow, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, pOutData, nMaxOutDataSize);
nBaseCompressedSize = lzsa_get_compressed_size_v2(pCompressor, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
lzsa_match *pBestMatch = pCompressor->best_match;
if (nBaseCompressedSize > 0 && nInDataSize < 65536) {
int nReducedCompressedSize;
/* Compress optimally and do break ties in favor of less tokens */
lzsa_optimize_forward_v2(pCompressor, pInWindow, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 1 /* reduce */, 0 /* use forward reps */);
nPasses = 0;
do {
nDidReduce = lzsa_optimize_command_count_v2(pCompressor, pInWindow, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
nPasses++;
} while (nDidReduce && nPasses < 20);
nReducedCompressedSize = lzsa_get_compressed_size_v2(pCompressor, pCompressor->improved_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (nReducedCompressedSize > 0 && nReducedCompressedSize <= nBaseCompressedSize) {
/* Pick the parse with the reduced number of tokens as it didn't negatively affect the size */
pBestMatch = pCompressor->improved_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);
}

26
src/shrink_context.c
View File

@ -58,7 +58,9 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->intervals = NULL;
pCompressor->pos_data = NULL;
pCompressor->open_intervals = NULL;
pCompressor->match = NULL;
pCompressor->best_match = NULL;
pCompressor->improved_match = NULL;
pCompressor->arrival = NULL;
pCompressor->min_match_size = nMinMatchSize;
if (pCompressor->min_match_size < nMinMatchSizeForFormat)
@ -74,6 +76,8 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->stats.min_literals = -1;
pCompressor->stats.min_match_len = -1;
pCompressor->stats.min_offset = -1;
pCompressor->stats.min_rle1_len = -1;
pCompressor->stats.min_rle2_len = -1;
if (!nResult) {
pCompressor->intervals = (unsigned int *)malloc(nMaxWindowSize * sizeof(unsigned int));
@ -91,7 +95,16 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
pCompressor->best_match = (lzsa_match *)malloc(nMaxWindowSize * sizeof(lzsa_match));
if (pCompressor->best_match) {
return 0;
pCompressor->improved_match = (lzsa_match *)malloc(nMaxWindowSize * sizeof(lzsa_match));
if (pCompressor->improved_match) {
if (pCompressor->format_version == 2)
pCompressor->match = (lzsa_match *)malloc(nMaxWindowSize * 32 * sizeof(lzsa_match));
else
pCompressor->match = (lzsa_match *)malloc(nMaxWindowSize * 8 * sizeof(lzsa_match));
if (pCompressor->match)
return 0;
}
}
}
}
@ -111,6 +124,16 @@ int lzsa_compressor_init(lzsa_compressor *pCompressor, const int nMaxWindowSize,
void lzsa_compressor_destroy(lzsa_compressor *pCompressor) {
divsufsort_destroy(&pCompressor->divsufsort_context);
if (pCompressor->match) {
free(pCompressor->match);
pCompressor->match = NULL;
}
if (pCompressor->improved_match) {
free(pCompressor->improved_match);
pCompressor->improved_match = NULL;
}
if (pCompressor->arrival) {
free(pCompressor->arrival);
pCompressor->arrival = NULL;
@ -162,6 +185,7 @@ int lzsa_compressor_shrink_block(lzsa_compressor *pCompressor, unsigned char *pI
if (nPreviousBlockSize) {
lzsa_skip_matches(pCompressor, 0, nPreviousBlockSize);
}
lzsa_find_all_matches(pCompressor, (pCompressor->format_version == 2) ? 32 : 8, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (pCompressor->format_version == 1) {
nCompressedSize = lzsa_optimize_and_write_block_v1(pCompressor, pInWindow, nPreviousBlockSize, nInDataSize, pOutData, nMaxOutDataSize);

7
src/shrink_context.h
View File

@ -34,7 +34,6 @@
#define _SHRINK_CONTEXT_H
#include "divsufsort.h"
#include "hashmap.h"
#ifdef __cplusplus
extern "C" {
@ -73,7 +72,10 @@ typedef struct {
short from_slot;
unsigned short rep_offset;
unsigned short rep_len;
int rep_pos;
int num_literals;
int score;
unsigned short match_offset;
unsigned short match_len;
@ -114,14 +116,15 @@ typedef struct _lzsa_compressor {
unsigned int *intervals;
unsigned int *pos_data;
unsigned int *open_intervals;
lzsa_match *match;
lzsa_match *best_match;
lzsa_match *improved_match;
lzsa_arrival *arrival;
int min_match_size;
int format_version;
int flags;
int safe_dist;
int num_commands;
lzsa_hashmap_t cost_map;
lzsa_stats stats;
} lzsa_compressor;