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Increase LZSA2 ratio

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Emmanuel Marty 2019-10-29 12:09:14 +01:00 committed by GitHub
parent 78f588a833
commit f249597dfd
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 8 additions and 14 deletions
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18
src/shrink_block_v2.c
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@ -222,15 +222,6 @@ static void lzsa_insert_forward_match_v2(lzsa_compressor *pCompressor, const uns
lzsa_insert_forward_match_v2(pCompressor, pInWindow, nRepPos, nMatchOffset, nEndOffset, nDepth + 1);
}
else if (!exists && r >= NMATCHES_PER_INDEX_V2) {
for (r = NMATCHES_PER_INDEX_V2 - 1; r >= 0; r--) {
if (fwd_match[r].length < nRepLen) {
fwd_match[r].offset = nMatchOffset;
fwd_match[r].length = nRepLen;
break;
}
}
}
}
}
}
@ -378,19 +369,20 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
if (nRepCodingChoiceCost <= pDestSlots[NMATCHES_PER_ARRIVAL - 1].cost) {
if (nCodingChoiceCost <= pDestSlots[NMATCHES_PER_ARRIVAL - 1].cost) {
int exists = 0;
int nScore = arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].score + ((nMatchOffset == nRepOffset) ? 2 : 3);
for (n = 0;
n < NMATCHES_PER_ARRIVAL && pDestSlots[n].cost <= nCodingChoiceCost;
n++) {
if (pDestSlots[n].rep_offset == nMatchOffset) {
if (pDestSlots[n].rep_offset == nMatchOffset &&
(!nInsertForwardReps || pDestSlots[n].cost != nCodingChoiceCost || pDestSlots[n].rep_pos >= i || nScore >= (pDestSlots[n].score + nDisableScore) ||
pDestSlots[NMATCHES_PER_ARRIVAL - 1].from_slot)) {
exists = 1;
break;
}
}
if (!exists) {
int nScore = arrival[(i << MATCHES_PER_ARRIVAL_SHIFT) + j].score + ((nMatchOffset == nRepOffset) ? 2 : 3);
for (n = 0; n < NMATCHES_PER_ARRIVAL; n++) {
lzsa_arrival *pDestArrival = &pDestSlots[n];
@ -1018,6 +1010,8 @@ int lzsa_optimize_and_write_block_v2(lzsa_compressor *pCompressor, const unsigne
/* 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 */);
if (nInDataSize < 65536)
lzsa_optimize_forward_v2(pCompressor, pInWindow, pCompressor->best_match, nPreviousBlockSize, nPreviousBlockSize + nInDataSize, 0 /* reduce */, 1 /* insert forward reps */);
int nDidReduce;
int nPasses = 0;

4
src/shrink_context.h
View File

@ -55,8 +55,8 @@ extern "C" {
#define NMATCHES_PER_INDEX_V1 8
#define MATCHES_PER_INDEX_SHIFT_V1 3
#define NMATCHES_PER_INDEX_V2 32
#define MATCHES_PER_INDEX_SHIFT_V2 5
#define NMATCHES_PER_INDEX_V2 64
#define MATCHES_PER_INDEX_SHIFT_V2 6
#define LEAVE_ALONE_MATCH_SIZE 1000