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Merge pull request #1169 from felixhandte/zstd-lazy-in-place-dict

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ZSTD_lazy: Support Searching the Dictionary Context In-Place
This commit is contained in:
Yann Collet
2018-06-13 16:05:41 -04:00
committed by GitHub
parent c986dbf241 d53200a846
commit 854825caac
3 changed files with 294 additions and 83 deletions
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lib/compress/zstd_compress.c
+28 -14
View File
@@ -1233,18 +1233,18 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
8 KB, /* unused */
8 KB, /* ZSTD_fast */
16 KB, /* ZSTD_dfast */
16 KB, /* ZSTD_greedy */
16 KB, /* ZSTD_lazy */
16 KB, /* ZSTD_lazy2 */
16 KB, /* ZSTD_btlazy2 */
16 KB, /* ZSTD_btopt */
16 KB /* ZSTD_btultra */
32 KB, /* ZSTD_greedy */
32 KB, /* ZSTD_lazy */
32 KB, /* ZSTD_lazy2 */
256 KB, /* ZSTD_btlazy2 */
256 KB, /* ZSTD_btopt */
256 KB /* ZSTD_btultra */
};
const int attachDict = ( pledgedSrcSize <= attachDictSizeCutoffs[cdict->cParams.strategy]
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN )
&& !params.forceWindow /* dictMatchState isn't correctly
* handled in _enforceMaxDist */
&& cdict->cParams.strategy <= ZSTD_dfast
&& cdict->cParams.strategy <= ZSTD_lazy2
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
cdict->cParams);
@@ -2230,17 +2230,31 @@ ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMo
{
static const ZSTD_blockCompressor blockCompressor[3][(unsigned)ZSTD_btultra+1] = {
{ ZSTD_compressBlock_fast /* default for 0 */,
ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy,
ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2,
ZSTD_compressBlock_btopt, ZSTD_compressBlock_btultra },
ZSTD_compressBlock_fast,
ZSTD_compressBlock_doubleFast,
ZSTD_compressBlock_greedy,
ZSTD_compressBlock_lazy,
ZSTD_compressBlock_lazy2,
ZSTD_compressBlock_btlazy2,
ZSTD_compressBlock_btopt,
ZSTD_compressBlock_btultra },
{ ZSTD_compressBlock_fast_extDict /* default for 0 */,
ZSTD_compressBlock_fast_extDict, ZSTD_compressBlock_doubleFast_extDict, ZSTD_compressBlock_greedy_extDict,
ZSTD_compressBlock_lazy_extDict,ZSTD_compressBlock_lazy2_extDict, ZSTD_compressBlock_btlazy2_extDict,
ZSTD_compressBlock_btopt_extDict, ZSTD_compressBlock_btultra_extDict },
ZSTD_compressBlock_fast_extDict,
ZSTD_compressBlock_doubleFast_extDict,
ZSTD_compressBlock_greedy_extDict,
ZSTD_compressBlock_lazy_extDict,
ZSTD_compressBlock_lazy2_extDict,
ZSTD_compressBlock_btlazy2_extDict,
ZSTD_compressBlock_btopt_extDict,
ZSTD_compressBlock_btultra_extDict },
{ ZSTD_compressBlock_fast_dictMatchState /* default for 0 */,
ZSTD_compressBlock_fast_dictMatchState,
ZSTD_compressBlock_doubleFast_dictMatchState,
NULL, NULL, NULL, NULL, NULL, NULL /* unimplemented as of yet */ }
ZSTD_compressBlock_greedy_dictMatchState,
ZSTD_compressBlock_lazy_dictMatchState,
ZSTD_compressBlock_lazy2_dictMatchState,
ZSTD_compressBlock_btlazy2_dictMatchState,
NULL, NULL /* unimplemented as of yet */ }
};
ZSTD_blockCompressor selectedCompressor;
ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
lib/compress/zstd_lazy.c
+253 -69
View File
@@ -62,7 +62,7 @@ void ZSTD_updateDUBT(
static void ZSTD_insertDUBT1(
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
U32 current, const BYTE* inputEnd,
U32 nbCompares, U32 btLow, int extDict)
U32 nbCompares, U32 btLow, const ZSTD_dictMode_e dictMode)
{
U32* const bt = ms->chainTable;
U32 const btLog = cParams->chainLog - 1;
@@ -92,10 +92,12 @@ static void ZSTD_insertDUBT1(
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
assert(matchIndex < current);
if ( (!extDict)
if ( (dictMode != ZSTD_extDict)
|| (matchIndex+matchLength >= dictLimit) /* both in current segment*/
|| (current < dictLimit) /* both in extDict */) {
const BYTE* const mBase = !extDict || ((matchIndex+matchLength) >= dictLimit) ? base : dictBase;
const BYTE* const mBase = ( (dictMode != ZSTD_extDict)
|| (matchIndex+matchLength >= dictLimit)) ?
base : dictBase;
assert( (matchIndex+matchLength >= dictLimit) /* might be wrong if extDict is incorrectly set to 0 */
|| (current < dictLimit) );
match = mBase + matchIndex;
@@ -143,7 +145,7 @@ static size_t ZSTD_DUBT_findBestMatch (
const BYTE* const ip, const BYTE* const iend,
size_t* offsetPtr,
U32 const mls,
U32 const extDict)
const ZSTD_dictMode_e dictMode)
{
U32* const hashTable = ms->hashTable;
U32 const hashLog = cParams->hashLog;
@@ -196,7 +198,7 @@ static size_t ZSTD_DUBT_findBestMatch (
U32* const nextCandidateIdxPtr = bt + 2*(matchIndex&btMask) + 1;
U32 const nextCandidateIdx = *nextCandidateIdxPtr;
ZSTD_insertDUBT1(ms, cParams, matchIndex, iend,
nbCandidates, unsortLimit, extDict);
nbCandidates, unsortLimit, dictMode);
matchIndex = nextCandidateIdx;
nbCandidates++;
}
@@ -221,7 +223,7 @@ static size_t ZSTD_DUBT_findBestMatch (
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
if ((dictMode != ZSTD_extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
} else {
@@ -276,12 +278,13 @@ static size_t ZSTD_BtFindBestMatch (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 mls /* template */)
const U32 mls /* template */,
const ZSTD_dictMode_e dictMode)
{
DEBUGLOG(7, "ZSTD_BtFindBestMatch");
if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
ZSTD_updateDUBT(ms, cParams, ip, iLimit, mls);
return ZSTD_DUBT_findBestMatch(ms, cParams, ip, iLimit, offsetPtr, mls, 0);
return ZSTD_DUBT_findBestMatch(ms, cParams, ip, iLimit, offsetPtr, mls, dictMode);
}
@@ -293,29 +296,15 @@ static size_t ZSTD_BtFindBestMatch_selectMLS (
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 4);
case 5 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 5);
case 4 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
case 5 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
case 7 :
case 6 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 6);
case 6 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
}
}
/** Tree updater, providing best match */
static size_t ZSTD_BtFindBestMatch_extDict (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 mls)
{
DEBUGLOG(7, "ZSTD_BtFindBestMatch_extDict");
if (ip < ms->window.base + ms->nextToUpdate) return 0; /* skipped area */
ZSTD_updateDUBT(ms, cParams, ip, iLimit, mls);
return ZSTD_DUBT_findBestMatch(ms, cParams, ip, iLimit, offsetPtr, mls, 1);
}
static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr)
@@ -323,10 +312,26 @@ static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 4);
case 5 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 5);
case 4 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
case 5 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
case 7 :
case 6 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 6);
case 6 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
}
}
static size_t ZSTD_BtFindBestMatch_extDict_selectMLS (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr)
{
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
case 5 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
case 7 :
case 6 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
}
}
@@ -376,7 +381,7 @@ size_t ZSTD_HcFindBestMatch_generic (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 mls, const U32 extDict)
const U32 mls, const ZSTD_dictMode_e dictMode)
{
U32* const chainTable = ms->chainTable;
const U32 chainSize = (1 << cParams->chainLog);
@@ -397,7 +402,7 @@ size_t ZSTD_HcFindBestMatch_generic (
for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
size_t currentMl=0;
if ((!extDict) || matchIndex >= dictLimit) {
if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) {
const BYTE* const match = base + matchIndex;
if (match[ml] == ip[ml]) /* potentially better */
currentMl = ZSTD_count(ip, match, iLimit);
@@ -419,6 +424,37 @@ size_t ZSTD_HcFindBestMatch_generic (
matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
}
if (dictMode == ZSTD_dictMatchState) {
const ZSTD_matchState_t* const dms = ms->dictMatchState;
const U32* const dmsChainTable = dms->chainTable;
const U32 dmsLowestIndex = dms->window.dictLimit;
const BYTE* const dmsBase = dms->window.base;
const BYTE* const dmsEnd = dms->window.nextSrc;
const U32 dmsSize = (U32)(dmsEnd - dmsBase);
const U32 dmsIndexDelta = dictLimit - dmsSize;
const U32 dmsMinChain = dmsSize > chainSize ? dmsSize - chainSize : 0;
matchIndex = dms->hashTable[ZSTD_hashPtr(ip, cParams->hashLog, mls)];
for ( ; (matchIndex>dmsLowestIndex) & (nbAttempts>0) ; nbAttempts--) {
size_t currentMl=0;
const BYTE* const match = dmsBase + matchIndex;
assert(match+4 <= dmsEnd);
if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */
currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dmsEnd, prefixStart) + 4;
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
*offsetPtr = current - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
if (matchIndex <= dmsMinChain) break;
matchIndex = dmsChainTable[matchIndex & chainMask];
}
}
return ml;
}
@@ -431,10 +467,26 @@ FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, 0);
case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, 0);
case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, 0);
case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
}
}
static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr)
{
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
}
}
@@ -442,15 +494,15 @@ FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* const iLimit,
size_t* const offsetPtr)
size_t* offsetPtr)
{
switch(cParams->searchLength)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, 1);
case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, 1);
case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, 1);
case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
}
}
@@ -464,28 +516,56 @@ size_t ZSTD_compressBlock_lazy_generic(
U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams,
const void* src, size_t srcSize,
const U32 searchMethod, const U32 depth)
const U32 searchMethod, const U32 depth,
ZSTD_dictMode_e const dictMode)
{
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ms->window.base + ms->window.dictLimit;
const BYTE* const base = ms->window.base;
const U32 prefixLowestIndex = ms->window.dictLimit;
const BYTE* const prefixLowest = base + prefixLowestIndex;
typedef size_t (*searchMax_f)(
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
searchMax_f const searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
searchMax_f const searchMax = dictMode == ZSTD_dictMatchState ?
(searchMethod ? ZSTD_BtFindBestMatch_dictMatchState_selectMLS : ZSTD_HcFindBestMatch_dictMatchState_selectMLS) :
(searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS);
U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0;
const ZSTD_matchState_t* const dms = ms->dictMatchState;
const U32 dictLowestIndex = dictMode == ZSTD_dictMatchState ?
dms->window.dictLimit : 0;
const BYTE* const dictBase = dictMode == ZSTD_dictMatchState ?
dms->window.base : NULL;
const BYTE* const dictLowest = dictMode == ZSTD_dictMatchState ?
dictBase + dictLowestIndex : NULL;
const BYTE* const dictEnd = dictMode == ZSTD_dictMatchState ?
dms->window.nextSrc : NULL;
const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ?
prefixLowestIndex - (U32)(dictEnd - dictBase) :
0;
const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
(void)dictMode;
/* init */
ip += (ip==base);
ip += (dictAndPrefixLength == 0);
ms->nextToUpdate3 = ms->nextToUpdate;
{ U32 const maxRep = (U32)(ip-base);
if (dictMode == ZSTD_noDict) {
U32 const maxRep = (U32)(ip - prefixLowest);
if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
}
if (dictMode == ZSTD_dictMatchState) {
/* dictMatchState repCode checks don't currently handle repCode == 0
* disabling. */
assert(offset_1 <= dictAndPrefixLength);
assert(offset_2 <= dictAndPrefixLength);
}
/* Match Loop */
while (ip < ilimit) {
@@ -494,8 +574,21 @@ size_t ZSTD_compressBlock_lazy_generic(
const BYTE* start=ip+1;
/* check repCode */
if ((offset_1>0) & (MEM_read32(ip+1) == MEM_read32(ip+1 - offset_1))) {
/* repcode : we take it */
if (dictMode == ZSTD_dictMatchState) {
const U32 repIndex = (U32)(ip - base) + 1 - offset_1;
const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
&& repIndex < prefixLowestIndex) ?
dictBase + (repIndex - dictIndexDelta) :
base + repIndex;
if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
if (depth==0) goto _storeSequence;
}
}
if ( dictMode == ZSTD_noDict
&& ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
matchLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
if (depth==0) goto _storeSequence;
}
@@ -516,13 +609,29 @@ size_t ZSTD_compressBlock_lazy_generic(
if (depth>=1)
while (ip<ilimit) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
if ( (dictMode == ZSTD_noDict)
&& (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(mlRep * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
if (dictMode == ZSTD_dictMatchState) {
const U32 repIndex = (U32)(ip - base) - offset_1;
const BYTE* repMatch = repIndex < prefixLowestIndex ?
dictBase + (repIndex - dictIndexDelta) :
base + repIndex;
if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
&& (MEM_read32(repMatch) == MEM_read32(ip)) ) {
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
int const gain2 = (int)(mlRep * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
@@ -535,12 +644,28 @@ size_t ZSTD_compressBlock_lazy_generic(
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const ml2 = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(ml2 * 4);
if ( (dictMode == ZSTD_noDict)
&& (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(mlRep * 4);
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((ml2 >= 4) && (gain2 > gain1))
matchLength = ml2, offset = 0, start = ip;
if ((mlRep >= 4) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
if (dictMode == ZSTD_dictMatchState) {
const U32 repIndex = (U32)(ip - base) - offset_1;
const BYTE* repMatch = repIndex < prefixLowestIndex ?
dictBase + (repIndex - dictIndexDelta) :
base + repIndex;
if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
&& (MEM_read32(repMatch) == MEM_read32(ip)) ) {
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
int const gain2 = (int)(mlRep * 4);
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
@@ -560,9 +685,17 @@ size_t ZSTD_compressBlock_lazy_generic(
*/
/* catch up */
if (offset) {
while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > base))
&& (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) ) /* only search for offset within prefix */
{ start--; matchLength++; }
if (dictMode == ZSTD_noDict) {
while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > prefixLowest))
&& (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) ) /* only search for offset within prefix */
{ start--; matchLength++; }
}
if (dictMode == ZSTD_dictMatchState) {
U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
const BYTE* match = (matchIndex < prefixLowestIndex) ? dictBase + matchIndex - dictIndexDelta : base + matchIndex;
const BYTE* const mStart = (matchIndex < prefixLowestIndex) ? dictLowest : prefixLowest;
while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
}
offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
}
/* store sequence */
@@ -573,16 +706,39 @@ _storeSequence:
}
/* check immediate repcode */
while ( ((ip <= ilimit) & (offset_2>0))
&& (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
/* store sequence */
matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
} }
if (dictMode == ZSTD_dictMatchState) {
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex = current2 - offset_2;
const BYTE* repMatch = dictMode == ZSTD_dictMatchState
&& repIndex < prefixLowestIndex ?
dictBase - dictIndexDelta + repIndex :
base + repIndex;
if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex) >= 3 /* intentional overflow */)
&& (MEM_read32(repMatch) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex < prefixLowestIndex ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd2, prefixLowest) + 4;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue;
}
break;
}
}
if (dictMode == ZSTD_noDict) {
while ( ((ip <= ilimit) & (offset_2>0))
&& (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
/* store sequence */
matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
/* Save reps for next block */
rep[0] = offset_1 ? offset_1 : savedOffset;
@@ -597,28 +753,56 @@ size_t ZSTD_compressBlock_btlazy2(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 1, 2);
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 1, 2, ZSTD_noDict);
}
size_t ZSTD_compressBlock_lazy2(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 2);
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 2, ZSTD_noDict);
}
size_t ZSTD_compressBlock_lazy(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 1);
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 1, ZSTD_noDict);
}
size_t ZSTD_compressBlock_greedy(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 0);
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 0, ZSTD_noDict);
}
size_t ZSTD_compressBlock_btlazy2_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 1, 2, ZSTD_dictMatchState);
}
size_t ZSTD_compressBlock_lazy2_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 2, ZSTD_dictMatchState);
}
size_t ZSTD_compressBlock_lazy_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 1, ZSTD_dictMatchState);
}
size_t ZSTD_compressBlock_greedy_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
{
return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 0, ZSTD_dictMatchState);
}
@@ -646,7 +830,7 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
typedef size_t (*searchMax_f)(
ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS_extDict : ZSTD_HcFindBestMatch_extDict_selectMLS;
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS;
U32 offset_1 = rep[0], offset_2 = rep[1];
lib/compress/zstd_lazy.h
+13
View File
@@ -36,6 +36,19 @@ size_t ZSTD_compressBlock_greedy(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_btlazy2_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_lazy2_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_lazy_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_greedy_dictMatchState(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
size_t ZSTD_compressBlock_greedy_extDict(
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);