ddidderr/zstd-rs
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support for ZSTD_REP_NUM == 1 and ZSTD_REP_NUM == 4

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inikep
2016-03-17 11:21:00 +01:00
parent 5945308983
commit 7d1742825b
4 changed files with 30 additions and 11 deletions
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lib/zstd_compress.c
+11 -5
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@@ -1092,7 +1092,7 @@ static void ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
mlCode = ZSTD_count_2segments(ip+1+MINMATCH, repMatch+MINMATCH, iend, repMatchEnd, lowPrefixPtr);
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset, mlCode);
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mlCode);
} else {
if ( (matchIndex < lowLimit) ||
(MEM_read32(match) != MEM_read32(ip)) )
@@ -1563,8 +1563,8 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
/* init */
U32 rep[ZSTD_REP_NUM];
for (int i=0; i<ZSTD_REP_NUM; i++)
U32 rep[ZSTD_REP_NUM+1];
for (int i=0; i<ZSTD_REP_NUM+1; i++)
rep[i]=REPCODE_STARTVALUE;
ZSTD_resetSeqStore(seqStorePtr);
@@ -1586,8 +1586,8 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
if (depth==0) goto _storeSequence;
} else {
size_t mlRep = ZSTD_count(ip+1+MINMATCH, ip+1+MINMATCH-rep[i], iend) + MINMATCH;
int gain2 = (int)(mlRep * 3 - (i+1));
int gain1 = (int)(matchLength*3 - (offset+1) + 1);
int gain2 = (int)(mlRep * 3 /*- ZSTD_highbit((U32)i+1)*/);
int gain1 = (int)(matchLength*3 - /*ZSTD_highbit((U32)offset+1)*/ + 1);
if (gain2 > gain1)
matchLength = mlRep, offset = i;
}
@@ -1660,6 +1660,7 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
/* store sequence */
_storeSequence:
{
#if ZSTD_REP_NUM == 4
if (offset >= ZSTD_REP_NUM) {
rep[3] = rep[2];
rep[2] = rep[1];
@@ -1676,6 +1677,11 @@ _storeSequence:
rep[0] = temp;
}
}
#else
if (offset >= ZSTD_REP_NUM) {
rep[1] = rep[0]; rep[0] = offset - (ZSTD_REP_NUM - 1);
}
#endif
size_t litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;