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Faster LZSA2 compression

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Emmanuel Marty 2020-07-14 12:36:56 +02:00 committed by GitHub
parent c39158eea8
commit cf49af5cda
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 52 additions and 29 deletions
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81
src/shrink_block_v2.c
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@ -558,7 +558,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
int exists = 0;
for (n = 0;
n < nMatchesPerArrival && pDestSlots[n].cost <= nRepCodingChoiceCost;
n < nMatchesPerArrival && pDestSlots[n].cost < nRepCodingChoiceCost;
n++) {
if (pDestSlots[n].rep_offset == nRepOffset) {
exists = 1;
@ -569,37 +569,60 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
if (!exists) {
int nScore = cur_arrival[j].score + 2;
for (n = 0; n < nMatchesPerArrival; n++) {
lzsa_arrival* pDestArrival = &pDestSlots[n];
if (nRepCodingChoiceCost < pDestArrival->cost ||
(nRepCodingChoiceCost == pDestArrival->cost && nScore < (pDestArrival->score + nDisableScore))) {
if (pDestArrival->from_slot) {
int z;
for (z = n; z < nMatchesPerArrival - 1; z++) {
if (pDestSlots[z].rep_offset == nRepOffset)
break;
}
memmove(&pDestSlots[n + 1],
&pDestSlots[n],
sizeof(lzsa_arrival) * (z - n));
}
pDestArrival->cost = nRepCodingChoiceCost;
pDestArrival->from_pos = i;
pDestArrival->from_slot = j + 1;
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;
for (;
n < nMatchesPerArrival && pDestSlots[n].cost == nRepCodingChoiceCost && nScore >= (pDestSlots[n].score + nDisableScore);
n++) {
if (pDestSlots[n].rep_offset == nRepOffset) {
exists = 1;
break;
}
}
if (!exists) {
int nn;
for (nn = n;
nn < nMatchesPerArrival && pDestSlots[nn].cost == nRepCodingChoiceCost;
nn++) {
if (pDestSlots[nn].rep_offset == nRepOffset) {
exists = 1;
break;
}
}
if (!exists) {
for (; n < nMatchesPerArrival; n++) {
lzsa_arrival* pDestArrival = &pDestSlots[n];
if (nRepCodingChoiceCost < pDestArrival->cost || nScore < (pDestArrival->score + nDisableScore)) {
if (pDestArrival->from_slot) {
int z;
for (z = n; z < nMatchesPerArrival - 1; z++) {
if (pDestSlots[z].rep_offset == nRepOffset)
break;
}
memmove(&pDestSlots[n + 1],
&pDestSlots[n],
sizeof(lzsa_arrival) * (z - n));
}
pDestArrival->cost = nRepCodingChoiceCost;
pDestArrival->from_pos = i;
pDestArrival->from_slot = j + 1;
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;
}
}
}
}
}
}
else {