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Use existing repcode update function to implement updates

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This commit is contained in:
senhuang42 2020-11-12 16:38:23 -05:00
parent 674c9b9235
commit be4ac6c5bc
1 changed files with 13 additions and 40 deletions
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53
lib/compress/zstd_compress.c
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@ -2497,19 +2497,17 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex]; ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex];
size_t i; size_t i;
repcodes_t updatedRepcodes;
U32* rep = zc->blockState.prevCBlock->rep; U32* rep = zc->blockState.prevCBlock->rep;
U32 shouldUpdateRep;
assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences); assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences);
/* Ensure we have enough space for last literals "sequence" */ /* Ensure we have enough space for last literals "sequence" */
assert(zc->seqCollector.maxSequences >= seqStoreSeqSize + 1); assert(zc->seqCollector.maxSequences >= seqStoreSeqSize + 1);
for (i = 0; i < seqStoreSeqSize; ++i) { for (i = 0; i < seqStoreSeqSize; ++i) {
U32 rawOffset = seqStoreSeqs[i].offset - ZSTD_REP_NUM; U32 rawOffset = seqStoreSeqs[i].offset - ZSTD_REP_NUM;
outSeqs[i].litLength = seqStoreSeqs[i].litLength; outSeqs[i].litLength = seqStoreSeqs[i].litLength;
outSeqs[i].matchLength = seqStoreSeqs[i].matchLength + MINMATCH; outSeqs[i].matchLength = seqStoreSeqs[i].matchLength + MINMATCH;
outSeqs[i].rep = 0; outSeqs[i].rep = 0;
shouldUpdateRep = 1;
if (i == seqStore->longLengthPos) { if (i == seqStore->longLengthPos) {
if (seqStore->longLengthID == 1) { if (seqStore->longLengthID == 1) {
@ -2519,50 +2517,26 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
} }
} }
/* Derive the correct offset from the repcode in seqStore_t */
if (seqStoreSeqs[i].offset <= ZSTD_REP_NUM) { if (seqStoreSeqs[i].offset <= ZSTD_REP_NUM) {
/* Derive the correct offset corresponding to a repcode */
outSeqs[i].rep = seqStoreSeqs[i].offset; outSeqs[i].rep = seqStoreSeqs[i].offset;
if (seqStoreSeqs[i].litLength != 0) { if (outSeqs[i].litLength != 0) {
if (seqStoreSeqs[i].offset == 1) { rawOffset = rep[outSeqs[i].rep - 1];
shouldUpdateRep = 0;
rawOffset = rep[0];
} else if (seqStoreSeqs[i].offset == 2) {
U32 tmp;
rawOffset = rep[1];
/* Swap ranks of rep[0] and rep[1] */
tmp = rep[0];
rep[0] = rep[1];
rep[1] = tmp;
shouldUpdateRep = 0;
} else if (seqStoreSeqs[i].offset == 3) {
rawOffset = rep[2];
}
} else { } else {
/* Litlength == 0 is a special case for repcode handling */ if (outSeqs[i].rep == 3) {
if (seqStoreSeqs[i].offset == 1) {
U32 tmp;
rawOffset = rep[1];
/* Swap ranks of rep[0] and rep[1] */
tmp = rep[0];
rep[0] = rep[1];
rep[1] = tmp;
shouldUpdateRep = 0;
} else if (seqStoreSeqs[i].offset == 2) {
rawOffset = rep[2];
} else if (seqStoreSeqs[i].offset == 3) {
rawOffset = rep[0] - 1; rawOffset = rep[0] - 1;
} else {
rawOffset = rep[outSeqs[i].rep];
} }
} }
} }
outSeqs[i].offset = rawOffset; outSeqs[i].offset = rawOffset;
if (shouldUpdateRep) { updatedRepcodes = ZSTD_updateRep(rep, seqStoreSeqs[i].offset - 1, seqStoreSeqs[i].litLength == 0);
/* Purge the last repcode, move in new offset */ ZSTD_memcpy(rep, updatedRepcodes.rep, sizeof(repcodes_t));
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = outSeqs[i].offset;
}
literalsRead += outSeqs[i].litLength; literalsRead += outSeqs[i].litLength;
} }
/* Insert last literals (if any exist) in the block as a sequence with ml == off == 0. /* Insert last literals (if any exist) in the block as a sequence with ml == off == 0.
* If there are no last literals, then we'll emit (of: 0, ml: 0, ll: 0), which is a marker * If there are no last literals, then we'll emit (of: 0, ml: 0, ll: 0), which is a marker
* for the block boundary, according to the API. * for the block boundary, according to the API.
@ -2573,9 +2547,8 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
outSeqs[i].matchLength = outSeqs[i].offset = outSeqs[i].rep = 0; outSeqs[i].matchLength = outSeqs[i].offset = outSeqs[i].rep = 0;
seqStoreSeqSize++; seqStoreSeqSize++;
zc->blockState.nextCBlock->rep[0] = zc->blockState.prevCBlock->rep[0]; ZSTD_memcpy(zc->blockState.nextCBlock->rep, zc->blockState.prevCBlock->rep,
zc->blockState.nextCBlock->rep[1] = zc->blockState.prevCBlock->rep[1]; sizeof(zc->blockState.nextCBlock->rep));
zc->blockState.nextCBlock->rep[2] = zc->blockState.prevCBlock->rep[2];
zc->seqCollector.seqIndex += seqStoreSeqSize; zc->seqCollector.seqIndex += seqStoreSeqSize;
} }