6502/lzsa
1
0
Fork 0
mirror of https://github.com/emmanuel-marty/lzsa.git synced 2024-11-29 05:49:20 +00:00
Code Issues Projects Releases Wiki Activity

Speed LZSA2 compression up; tiny ratio increase

Browse Source
This commit is contained in:
Emmanuel Marty 2019-09-19 00:11:26 +02:00 committed by GitHub
parent 8b7d0ab04d
commit e4076e4090
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 52 additions and 53 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
src/shrink_block_v2.c
View File

@ -36,8 +36,7 @@
#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))
#include "matchfinder.h"
/**
* Write 4-bit nibble to output (compressed) buffer
@ -188,14 +187,14 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const int nSt
lzsa_arrival *arrival = pCompressor->arrival;
int nMinMatchSize = pCompressor->min_match_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));
arrival[nStartOffset << MATCHES_PER_OFFSET_SHIFT].from_slot = -1;
for (i = nStartOffset; i != (nEndOffset - 1); i++) {
const lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
int m;
int m, nMatches;
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;
@ -212,21 +211,20 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const int nSt
nCodingChoiceCost += 16;
}
for (n = 0; n < NMATCHES_PER_OFFSET; n++) {
int exists = 0;
for (n = 0;
n < NMATCHES_PER_OFFSET && arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n].from_slot && arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n].cost <= nCodingChoiceCost;
n++) {
if (arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n].rep_offset == arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset) {
exists = 1;
}
}
for (n = 0; !exists && n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + n];
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost <= pDestArrival->cost) {
int exists = 0;
for (int l = n; l < NMATCHES_PER_OFFSET && arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + l].from_slot &&
arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + l].cost == nCodingChoiceCost; l++) {
if (arrival[((i + 1) << MATCHES_PER_OFFSET_SHIFT) + l].rep_offset == arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset) {
exists = 1;
break;
}
}
if (!exists) {
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));
@ -238,15 +236,16 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const int nSt
pDestArrival->match_len = 0;
pDestArrival->num_literals = nNumLiterals;
pDestArrival->rep_offset = arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset;
}
break;
}
}
}
for (m = 0; m < NMATCHES_PER_OFFSET && pMatch[m].length >= nMinMatchSize; m++) {
int nMatchLen = pMatch[m].length;
int nNoRepMatchOffsetCost = (pMatch[m].offset <= 32) ? 4 : ((pMatch[m].offset <= 512) ? 8 : ((pMatch[m].offset <= (8192 + 512)) ? 12 : 16));
nMatches = lzsa_find_matches_at(pCompressor, i, match, 32);
for (m = 0; m < nMatches; m++) {
int nMatchLen = match[m].length;
int nNoRe_matchOffsetCost = (match[m].offset <= 32) ? 4 : ((match[m].offset <= 512) ? 8 : ((match[m].offset <= (8192 + 512)) ? 12 : 16));
int nStartingMatchLen, k;
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
@ -260,26 +259,26 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const int nSt
int nMatchLenCost = lzsa_get_match_varlen_size_v2(k - MIN_MATCH_SIZE_V2);
for (j = 0; j < NMATCHES_PER_OFFSET && arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].from_slot; j++) {
int nMatchOffsetCost = (pMatch[m].offset == arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset) ? 0 : nNoRepMatchOffsetCost;
int nMatchOffsetCost = (match[m].offset == arrival[(i << MATCHES_PER_OFFSET_SHIFT) + j].rep_offset) ? 0 : nNoRe_matchOffsetCost;
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;
for (n = 0; n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n];
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost <= pDestArrival->cost) {
int exists = 0;
for (int l = n; l < NMATCHES_PER_OFFSET && arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + l].from_slot &&
arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + l].cost == nCodingChoiceCost; l++) {
if (arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + l].rep_offset == pMatch[m].offset) {
for (n = 0;
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 (arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n].rep_offset == match[m].offset) {
exists = 1;
break;
}
}
if (!exists) {
for (n = 0; !exists && n < NMATCHES_PER_OFFSET; n++) {
lzsa_arrival *pDestArrival = &arrival[((i + k) << MATCHES_PER_OFFSET_SHIFT) + n];
if (pDestArrival->from_slot == 0 ||
nCodingChoiceCost <= pDestArrival->cost) {
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));
@ -287,11 +286,10 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const int nSt
pDestArrival->cost = nCodingChoiceCost;
pDestArrival->from_pos = i;
pDestArrival->from_slot = j + 1;
pDestArrival->match_offset = pMatch[m].offset;
pDestArrival->match_offset = match[m].offset;
pDestArrival->match_len = k;
pDestArrival->num_literals = 0;
pDestArrival->rep_offset = pMatch[m].offset;
}
pDestArrival->rep_offset = match[m].offset;
break;
}
}

1
src/shrink_context.c
View File

@ -202,6 +202,7 @@ int lzsa_compressor_shrink_block(lzsa_compressor *pCompressor, unsigned char *pI
if (nPreviousBlockSize) {
lzsa_skip_matches(pCompressor, 0, nPreviousBlockSize);
}
if ((pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) == 0 || pCompressor->format_version < 2)
lzsa_find_all_matches(pCompressor, nPreviousBlockSize, nPreviousBlockSize + nInDataSize);
if (pCompressor->format_version == 1) {