AuroraMiddleware/zstd
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minor compression speed optimization

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This commit is contained in:
Yann Collet 2016-04-07 17:19:00 +02:00
parent 485371600a
commit 5d39357bc4
2 changed files with 19 additions and 13 deletions
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29
lib/zstd_compress.c
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@ -80,6 +80,7 @@ static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
ssPtr->lit = ssPtr->litStart;
ssPtr->litLength = ssPtr->litLengthStart;
ssPtr->matchLength = ssPtr->matchLengthStart;
ssPtr->longLengthID = 0;
}
@ -620,14 +621,16 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr, size_t const nbSeq)
24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24 };
const BYTE LL_deltaCode = 19;
U16* const llTable = seqStorePtr->litLengthStart;
const U16* const llTable = seqStorePtr->litLengthStart;
BYTE* const llCodeTable = seqStorePtr->llCodeStart;
size_t u;
for (u=0; u<nbSeq; u++) {
U32 ll = llTable[u];
if (llTable[u] == 65535) { ll = seqStorePtr->longLength; llTable[u] = (U16)ll; }
U32 const ll = llTable[u];
llCodeTable[u] = (ll>63) ? (BYTE)ZSTD_highbit(ll) + LL_deltaCode : LL_Code[ll];
} }
}
if (seqStorePtr->longLengthID==1)
llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
}
/* Offset codes */
{ const U32* const offsetTable = seqStorePtr->offsetStart;
@ -646,14 +649,16 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr, size_t const nbSeq)
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
const BYTE ML_deltaCode = 36;
U16* const mlTable = seqStorePtr->matchLengthStart;
const U16* const mlTable = seqStorePtr->matchLengthStart;
BYTE* const mlCodeTable = seqStorePtr->mlCodeStart;
size_t u;
for (u=0; u<nbSeq; u++) {
U32 ml = mlTable[u];
if (mlTable[u] == 65535) { ml = seqStorePtr->longLength; mlTable[u] = (U16)ml; }
U32 const ml = mlTable[u];
mlCodeTable[u] = (ml>127) ? (BYTE)ZSTD_highbit(ml) + ML_deltaCode : ML_Code[ml];
} }
}
if (seqStorePtr->longLengthID==2)
mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
}
}
@ -864,15 +869,15 @@ MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const B
seqStorePtr->lit += litLength;
/* literal Length */
if (litLength>=65535) { *(seqStorePtr->litLength++) = 65535; seqStorePtr->longLength = (U32)litLength; }
else *seqStorePtr->litLength++ = (U16)litLength;
if (litLength>0xFFFF) { seqStorePtr->longLengthID = 1; seqStorePtr->longLengthPos = (U32)(seqStorePtr->litLength - seqStorePtr->litLengthStart); }
*seqStorePtr->litLength++ = (U16)litLength;
/* match offset */
*(seqStorePtr->offset++) = (U32)offsetCode + 1;
/* match Length */
if (matchCode>=65535) { *(seqStorePtr->matchLength++) = 65535; seqStorePtr->longLength = (U32)matchCode; }
else *seqStorePtr->matchLength++ = (U16)matchCode;
if (matchCode>0xFFFF) { seqStorePtr->longLengthID = 2; seqStorePtr->longLengthPos = (U32)(seqStorePtr->matchLength - seqStorePtr->matchLengthStart); }
*seqStorePtr->matchLength++ = (U16)matchCode;
}

3
lib/zstd_internal.h
View File

@ -222,7 +222,8 @@ typedef struct {
U16* matchLengthStart;
U16* matchLength;
BYTE* mlCodeStart;
U32 longLength;
U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
U32 longLengthPos;
/* opt */
ZSTD_optimal_t* priceTable;
ZSTD_match_t* matchTable;