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faster hc mode with repetitive data (experimental)

dev
Yann Collet 2015-12-29 22:26:09 +01:00
parent d94efbf95c
commit ee3f4515c1
1 changed files with 27 additions and 35 deletions
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62
lib/zstd_compress.c
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@ -1013,7 +1013,7 @@ size_t ZSTD_compressBlock_fast_extDict(ZSTD_CCtx* ctx,
/* *************************************
* Binary Tree search
***************************************/
/** ZSTD_insertBt1 : add one or multiple positions to tree
/*! ZSTD_insertBt1 : add one or multiple positions to tree
* @ip : assumed <= iend-8
* @return : nb of positions added */
static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares)
@ -1034,14 +1034,7 @@ static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, co
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 dummy32; /* to be nullified at the end */
const U32 windowLow = zc->lowLimit;
if ( (current-matchIndex == 1) /* RLE */
&& (matchIndex > windowLow)
&& (MEM_read64(match) == MEM_read64(ip)) )
{
size_t rleLength = ZSTD_count(ip+8, match+8, iend) + 8;
return (U32)(rleLength - mls);
}
U32 matchEndIdx = current;
hashTable[h] = current; /* Update Hash Table */
@ -1054,8 +1047,11 @@ static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, co
if (match[matchLength] == ip[matchLength])
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + matchLength;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
break; /* drop , to guarantee consistency ; miss a bit of compression, but required to not corrupt the tree */
if (match[matchLength] < ip[matchLength])
{
@ -1078,7 +1074,7 @@ static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, co
}
*smallerPtr = *largerPtr = 0;
return 1;
return (matchEndIdx > current + zc->params.searchLength) ? matchEndIdx - current - zc->params.searchLength : 1;
}
@ -1104,6 +1100,7 @@ size_t ZSTD_insertBtAndFindBestMatch (
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
size_t bestLength = 0;
U32 matchEndIdx = current;
U32 dummy32; /* to be nullified at the end */
hashTable[h] = current; /* Update Hash Table */
@ -1119,6 +1116,8 @@ size_t ZSTD_insertBtAndFindBestMatch (
if (matchLength > bestLength)
{
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + matchLength;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit(current-matchIndex+1) - ZSTD_highbit((U32)offsetPtr[0]+1)) )
bestLength = matchLength, *offsetPtr = current - matchIndex;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
@ -1147,12 +1146,12 @@ size_t ZSTD_insertBtAndFindBestMatch (
*smallerPtr = *largerPtr = 0;
zc->nextToUpdate = current+1; /* current has been inserted */
zc->nextToUpdate = (matchEndIdx > current + zc->params.searchLength) ? matchEndIdx - zc->params.searchLength : current+1;
return bestLength;
}
static const BYTE* ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
static void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
@ -1160,9 +1159,6 @@ static const BYTE* ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BY
for( ; idx < target ; )
idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares);
zc->nextToUpdate = idx;
return base + idx;
}
@ -1174,9 +1170,8 @@ size_t ZSTD_BtFindBestMatch (
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
const BYTE* nextToUpdate = ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
if (nextToUpdate > ip) /* RLE data */
{ *offsetPtr = 1; return ZSTD_count(ip, ip-1, iLimit); }
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls);
}
@ -1222,13 +1217,7 @@ static U32 ZSTD_insertBt1_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const U32
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 dummy32; /* to be nullified at the end */
const U32 windowLow = zc->lowLimit;
if ( (current-matchIndex == 1) /* RLE */
&& (MEM_read64(match) == MEM_read64(ip)) )
{
size_t rleLength = ZSTD_count(ip+8, match+8, iend) + 8;
return (U32)(rleLength - mls);
}
U32 matchEndIdx = current;
hashTable[h] = current; /* Update Hash Table */
@ -1251,6 +1240,9 @@ static U32 ZSTD_insertBt1_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const U32
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + matchLength;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
@ -1275,11 +1267,11 @@ static U32 ZSTD_insertBt1_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const U32
}
*smallerPtr = *largerPtr = 0;
return 1;
return (matchEndIdx > current + zc->params.searchLength) ? matchEndIdx - current - zc->params.searchLength : 1;
}
static const BYTE* ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
static void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
@ -1287,9 +1279,6 @@ static const BYTE* ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip,
for( ; idx < target ; )
idx += ZSTD_insertBt1_extDict(zc, base+idx, mls, iend, nbCompares);
zc->nextToUpdate = idx;
return base + idx;
}
@ -1319,6 +1308,7 @@ size_t ZSTD_insertBtAndFindBestMatch_extDict (
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
size_t bestLength = 0;
U32 matchEndIdx = current;
U32 dummy32; /* to be nullified at the end */
hashTable[h] = current; /* Update Hash Table */
@ -1345,6 +1335,8 @@ size_t ZSTD_insertBtAndFindBestMatch_extDict (
if (matchLength > bestLength)
{
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + matchLength;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit(current-matchIndex+1) - ZSTD_highbit((U32)offsetPtr[0]+1)) )
bestLength = matchLength, *offsetPtr = current - matchIndex;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
@ -1373,7 +1365,7 @@ size_t ZSTD_insertBtAndFindBestMatch_extDict (
*smallerPtr = *largerPtr = 0;
zc->nextToUpdate = current+1; /* current has been inserted */
zc->nextToUpdate = (matchEndIdx > current + zc->params.searchLength) ? matchEndIdx - zc->params.searchLength : current+1;
return bestLength;
}
@ -1385,9 +1377,8 @@ size_t ZSTD_BtFindBestMatch_extDict (
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
const BYTE* nextToUpdate = ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
if (nextToUpdate > ip) /* RLE data */
{ *offsetPtr = 1; return ZSTD_count(ip, ip-1, iLimit); }
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls);
}
@ -2067,6 +2058,7 @@ size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* zc, const void* src, size_t src
case ZSTD_btlazy2:
ZSTD_updateTree(zc, iend-8, iend, 1 << zc->params.searchLog, zc->params.searchLength);
zc->nextToUpdate = iend - zc->base;
break;
default: