diff options
Diffstat (limited to 'vendor/github.com/DataDog/zstd/zstd_lazy.c')
| -rw-r--r-- | vendor/github.com/DataDog/zstd/zstd_lazy.c | 1106 |
1 files changed, 0 insertions, 1106 deletions
diff --git a/vendor/github.com/DataDog/zstd/zstd_lazy.c b/vendor/github.com/DataDog/zstd/zstd_lazy.c deleted file mode 100644 index 53f998a43..000000000 --- a/vendor/github.com/DataDog/zstd/zstd_lazy.c +++ /dev/null @@ -1,1106 +0,0 @@ -/* - * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under both the BSD-style license (found in the - * LICENSE file in the root directory of this source tree) and the GPLv2 (found - * in the COPYING file in the root directory of this source tree). - * You may select, at your option, one of the above-listed licenses. - */ - -#include "zstd_compress_internal.h" -#include "zstd_lazy.h" - - -/*-************************************* -* Binary Tree search -***************************************/ - -static void -ZSTD_updateDUBT(ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* iend, - U32 mls) -{ - const ZSTD_compressionParameters* const cParams = &ms->cParams; - U32* const hashTable = ms->hashTable; - U32 const hashLog = cParams->hashLog; - - U32* const bt = ms->chainTable; - U32 const btLog = cParams->chainLog - 1; - U32 const btMask = (1 << btLog) - 1; - - const BYTE* const base = ms->window.base; - U32 const target = (U32)(ip - base); - U32 idx = ms->nextToUpdate; - - if (idx != target) - DEBUGLOG(7, "ZSTD_updateDUBT, from %u to %u (dictLimit:%u)", - idx, target, ms->window.dictLimit); - assert(ip + 8 <= iend); /* condition for ZSTD_hashPtr */ - (void)iend; - - assert(idx >= ms->window.dictLimit); /* condition for valid base+idx */ - for ( ; idx < target ; idx++) { - size_t const h = ZSTD_hashPtr(base + idx, hashLog, mls); /* assumption : ip + 8 <= iend */ - U32 const matchIndex = hashTable[h]; - - U32* const nextCandidatePtr = bt + 2*(idx&btMask); - U32* const sortMarkPtr = nextCandidatePtr + 1; - - DEBUGLOG(8, "ZSTD_updateDUBT: insert %u", idx); - hashTable[h] = idx; /* Update Hash Table */ - *nextCandidatePtr = matchIndex; /* update BT like a chain */ - *sortMarkPtr = ZSTD_DUBT_UNSORTED_MARK; - } - ms->nextToUpdate = target; -} - - -/** ZSTD_insertDUBT1() : - * sort one already inserted but unsorted position - * assumption : current >= btlow == (current - btmask) - * doesn't fail */ -static void -ZSTD_insertDUBT1(ZSTD_matchState_t* ms, - U32 current, const BYTE* inputEnd, - U32 nbCompares, U32 btLow, - const ZSTD_dictMode_e dictMode) -{ - const ZSTD_compressionParameters* const cParams = &ms->cParams; - U32* const bt = ms->chainTable; - U32 const btLog = cParams->chainLog - 1; - U32 const btMask = (1 << btLog) - 1; - size_t commonLengthSmaller=0, commonLengthLarger=0; - const BYTE* const base = ms->window.base; - const BYTE* const dictBase = ms->window.dictBase; - const U32 dictLimit = ms->window.dictLimit; - const BYTE* const ip = (current>=dictLimit) ? base + current : dictBase + current; - const BYTE* const iend = (current>=dictLimit) ? inputEnd : dictBase + dictLimit; - const BYTE* const dictEnd = dictBase + dictLimit; - const BYTE* const prefixStart = base + dictLimit; - const BYTE* match; - U32* smallerPtr = bt + 2*(current&btMask); - U32* largerPtr = smallerPtr + 1; - U32 matchIndex = *smallerPtr; /* this candidate is unsorted : next sorted candidate is reached through *smallerPtr, while *largerPtr contains previous unsorted candidate (which is already saved and can be overwritten) */ - U32 dummy32; /* to be nullified at the end */ - U32 const windowLow = ms->window.lowLimit; - - DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)", - current, dictLimit, windowLow); - assert(current >= btLow); - assert(ip < iend); /* condition for ZSTD_count */ - - while (nbCompares-- && (matchIndex > windowLow)) { - U32* const nextPtr = bt + 2*(matchIndex & btMask); - size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ - assert(matchIndex < current); - /* note : all candidates are now supposed sorted, - * but it's still possible to have nextPtr[1] == ZSTD_DUBT_UNSORTED_MARK - * when a real index has the same value as ZSTD_DUBT_UNSORTED_MARK */ - - if ( (dictMode != ZSTD_extDict) - || (matchIndex+matchLength >= dictLimit) /* both in current segment*/ - || (current < dictLimit) /* both in extDict */) { - 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; - matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend); - } else { - match = dictBase + matchIndex; - matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart); - if (matchIndex+matchLength >= dictLimit) - match = base + matchIndex; /* preparation for next read of match[matchLength] */ - } - - DEBUGLOG(8, "ZSTD_insertDUBT1: comparing %u with %u : found %u common bytes ", - current, matchIndex, (U32)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 tree */ - } - - if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */ - /* match is smaller than current */ - *smallerPtr = matchIndex; /* update smaller idx */ - commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ - if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop searching */ - DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is smaller : next => %u", - matchIndex, btLow, nextPtr[1]); - smallerPtr = nextPtr+1; /* new "candidate" => larger than match, which was smaller than target */ - matchIndex = nextPtr[1]; /* new matchIndex, larger than previous and closer to current */ - } else { - /* match is larger than current */ - *largerPtr = matchIndex; - commonLengthLarger = matchLength; - if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */ - DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is larger => %u", - matchIndex, btLow, nextPtr[0]); - largerPtr = nextPtr; - matchIndex = nextPtr[0]; - } } - - *smallerPtr = *largerPtr = 0; -} - - -static size_t -ZSTD_DUBT_findBetterDictMatch ( - ZSTD_matchState_t* ms, - const BYTE* const ip, const BYTE* const iend, - size_t* offsetPtr, - size_t bestLength, - U32 nbCompares, - U32 const mls, - const ZSTD_dictMode_e dictMode) -{ - const ZSTD_matchState_t * const dms = ms->dictMatchState; - const ZSTD_compressionParameters* const dmsCParams = &dms->cParams; - const U32 * const dictHashTable = dms->hashTable; - U32 const hashLog = dmsCParams->hashLog; - size_t const h = ZSTD_hashPtr(ip, hashLog, mls); - U32 dictMatchIndex = dictHashTable[h]; - - const BYTE* const base = ms->window.base; - const BYTE* const prefixStart = base + ms->window.dictLimit; - U32 const current = (U32)(ip-base); - const BYTE* const dictBase = dms->window.base; - const BYTE* const dictEnd = dms->window.nextSrc; - U32 const dictHighLimit = (U32)(dms->window.nextSrc - dms->window.base); - U32 const dictLowLimit = dms->window.lowLimit; - U32 const dictIndexDelta = ms->window.lowLimit - dictHighLimit; - - U32* const dictBt = dms->chainTable; - U32 const btLog = dmsCParams->chainLog - 1; - U32 const btMask = (1 << btLog) - 1; - U32 const btLow = (btMask >= dictHighLimit - dictLowLimit) ? dictLowLimit : dictHighLimit - btMask; - - size_t commonLengthSmaller=0, commonLengthLarger=0; - - (void)dictMode; - assert(dictMode == ZSTD_dictMatchState); - - while (nbCompares-- && (dictMatchIndex > dictLowLimit)) { - U32* const nextPtr = dictBt + 2*(dictMatchIndex & btMask); - size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ - const BYTE* match = dictBase + dictMatchIndex; - matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart); - if (dictMatchIndex+matchLength >= dictHighLimit) - match = base + dictMatchIndex + dictIndexDelta; /* to prepare for next usage of match[matchLength] */ - - if (matchLength > bestLength) { - U32 matchIndex = dictMatchIndex + dictIndexDelta; - if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) { - DEBUGLOG(9, "ZSTD_DUBT_findBetterDictMatch(%u) : found better match length %u -> %u and offsetCode %u -> %u (dictMatchIndex %u, matchIndex %u)", - current, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + current - matchIndex, dictMatchIndex, matchIndex); - bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex; - } - if (ip+matchLength == iend) { /* reached end of input : ip[matchLength] is not valid, no way to know if it's larger or smaller than match */ - break; /* drop, to guarantee consistency (miss a little bit of compression) */ - } - } - - if (match[matchLength] < ip[matchLength]) { - if (dictMatchIndex <= btLow) { break; } /* beyond tree size, stop the search */ - commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ - dictMatchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ - } else { - /* match is larger than current */ - if (dictMatchIndex <= btLow) { break; } /* beyond tree size, stop the search */ - commonLengthLarger = matchLength; - dictMatchIndex = nextPtr[0]; - } - } - - if (bestLength >= MINMATCH) { - U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex; - DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)", - current, (U32)bestLength, (U32)*offsetPtr, mIndex); - } - return bestLength; - -} - - -static size_t -ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms, - const BYTE* const ip, const BYTE* const iend, - size_t* offsetPtr, - U32 const mls, - const ZSTD_dictMode_e dictMode) -{ - const ZSTD_compressionParameters* const cParams = &ms->cParams; - U32* const hashTable = ms->hashTable; - U32 const hashLog = cParams->hashLog; - size_t const h = ZSTD_hashPtr(ip, hashLog, mls); - U32 matchIndex = hashTable[h]; - - const BYTE* const base = ms->window.base; - U32 const current = (U32)(ip-base); - U32 const windowLow = ms->window.lowLimit; - - U32* const bt = ms->chainTable; - U32 const btLog = cParams->chainLog - 1; - U32 const btMask = (1 << btLog) - 1; - U32 const btLow = (btMask >= current) ? 0 : current - btMask; - U32 const unsortLimit = MAX(btLow, windowLow); - - U32* nextCandidate = bt + 2*(matchIndex&btMask); - U32* unsortedMark = bt + 2*(matchIndex&btMask) + 1; - U32 nbCompares = 1U << cParams->searchLog; - U32 nbCandidates = nbCompares; - U32 previousCandidate = 0; - - DEBUGLOG(7, "ZSTD_DUBT_findBestMatch (%u) ", current); - assert(ip <= iend-8); /* required for h calculation */ - - /* reach end of unsorted candidates list */ - while ( (matchIndex > unsortLimit) - && (*unsortedMark == ZSTD_DUBT_UNSORTED_MARK) - && (nbCandidates > 1) ) { - DEBUGLOG(8, "ZSTD_DUBT_findBestMatch: candidate %u is unsorted", - matchIndex); - *unsortedMark = previousCandidate; /* the unsortedMark becomes a reversed chain, to move up back to original position */ - previousCandidate = matchIndex; - matchIndex = *nextCandidate; - nextCandidate = bt + 2*(matchIndex&btMask); - unsortedMark = bt + 2*(matchIndex&btMask) + 1; - nbCandidates --; - } - - /* nullify last candidate if it's still unsorted - * simplification, detrimental to compression ratio, beneficial for speed */ - if ( (matchIndex > unsortLimit) - && (*unsortedMark==ZSTD_DUBT_UNSORTED_MARK) ) { - DEBUGLOG(7, "ZSTD_DUBT_findBestMatch: nullify last unsorted candidate %u", - matchIndex); - *nextCandidate = *unsortedMark = 0; - } - - /* batch sort stacked candidates */ - matchIndex = previousCandidate; - while (matchIndex) { /* will end on matchIndex == 0 */ - U32* const nextCandidateIdxPtr = bt + 2*(matchIndex&btMask) + 1; - U32 const nextCandidateIdx = *nextCandidateIdxPtr; - ZSTD_insertDUBT1(ms, matchIndex, iend, - nbCandidates, unsortLimit, dictMode); - matchIndex = nextCandidateIdx; - nbCandidates++; - } - - /* find longest match */ - { size_t commonLengthSmaller = 0, commonLengthLarger = 0; - const BYTE* const dictBase = ms->window.dictBase; - const U32 dictLimit = ms->window.dictLimit; - const BYTE* const dictEnd = dictBase + dictLimit; - const BYTE* const prefixStart = base + dictLimit; - U32* smallerPtr = bt + 2*(current&btMask); - U32* largerPtr = bt + 2*(current&btMask) + 1; - U32 matchEndIdx = current + 8 + 1; - U32 dummy32; /* to be nullified at the end */ - size_t bestLength = 0; - - matchIndex = hashTable[h]; - hashTable[h] = current; /* Update Hash Table */ - - while (nbCompares-- && (matchIndex > windowLow)) { - U32* const nextPtr = bt + 2*(matchIndex & btMask); - size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ - const BYTE* match; - - if ((dictMode != ZSTD_extDict) || (matchIndex+matchLength >= dictLimit)) { - match = base + matchIndex; - matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend); - } else { - match = dictBase + matchIndex; - matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart); - if (matchIndex+matchLength >= dictLimit) - match = base + matchIndex; /* to prepare for next usage of match[matchLength] */ - } - - if (matchLength > bestLength) { - if (matchLength > matchEndIdx - matchIndex) - matchEndIdx = matchIndex + (U32)matchLength; - if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) - bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex; - if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */ - if (dictMode == ZSTD_dictMatchState) { - nbCompares = 0; /* in addition to avoiding checking any - * further in this loop, make sure we - * skip checking in the dictionary. */ - } - break; /* drop, to guarantee consistency (miss a little bit of compression) */ - } - } - - if (match[matchLength] < ip[matchLength]) { - /* match is smaller than current */ - *smallerPtr = matchIndex; /* update smaller idx */ - commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ - if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */ - smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ - matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ - } else { - /* match is larger than current */ - *largerPtr = matchIndex; - commonLengthLarger = matchLength; - if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ - largerPtr = nextPtr; - matchIndex = nextPtr[0]; - } } - - *smallerPtr = *largerPtr = 0; - - if (dictMode == ZSTD_dictMatchState && nbCompares) { - bestLength = ZSTD_DUBT_findBetterDictMatch( - ms, ip, iend, - offsetPtr, bestLength, nbCompares, - mls, dictMode); - } - - assert(matchEndIdx > current+8); /* ensure nextToUpdate is increased */ - ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */ - if (bestLength >= MINMATCH) { - U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex; - DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)", - current, (U32)bestLength, (U32)*offsetPtr, mIndex); - } - return bestLength; - } -} - - -/** ZSTD_BtFindBestMatch() : Tree updater, providing best match */ -FORCE_INLINE_TEMPLATE size_t -ZSTD_BtFindBestMatch( ZSTD_matchState_t* ms, - const BYTE* const ip, const BYTE* const iLimit, - size_t* offsetPtr, - 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, ip, iLimit, mls); - return ZSTD_DUBT_findBestMatch(ms, ip, iLimit, offsetPtr, mls, dictMode); -} - - -static size_t -ZSTD_BtFindBestMatch_selectMLS ( ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict); - case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict); - case 7 : - case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict); - } -} - - -static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS ( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState); - case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState); - case 7 : - case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState); - } -} - - -static size_t ZSTD_BtFindBestMatch_extDict_selectMLS ( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict); - case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict); - case 7 : - case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict); - } -} - - - -/* ********************************* -* Hash Chain -***********************************/ -#define NEXT_IN_CHAIN(d, mask) chainTable[(d) & (mask)] - -/* Update chains up to ip (excluded) - Assumption : always within prefix (i.e. not within extDict) */ -static U32 ZSTD_insertAndFindFirstIndex_internal( - ZSTD_matchState_t* ms, - const ZSTD_compressionParameters* const cParams, - const BYTE* ip, U32 const mls) -{ - U32* const hashTable = ms->hashTable; - const U32 hashLog = cParams->hashLog; - U32* const chainTable = ms->chainTable; - const U32 chainMask = (1 << cParams->chainLog) - 1; - const BYTE* const base = ms->window.base; - const U32 target = (U32)(ip - base); - U32 idx = ms->nextToUpdate; - - while(idx < target) { /* catch up */ - size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls); - NEXT_IN_CHAIN(idx, chainMask) = hashTable[h]; - hashTable[h] = idx; - idx++; - } - - ms->nextToUpdate = target; - return hashTable[ZSTD_hashPtr(ip, hashLog, mls)]; -} - -U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t* ms, const BYTE* ip) { - const ZSTD_compressionParameters* const cParams = &ms->cParams; - return ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, ms->cParams.minMatch); -} - - -/* inlining is important to hardwire a hot branch (template emulation) */ -FORCE_INLINE_TEMPLATE -size_t ZSTD_HcFindBestMatch_generic ( - ZSTD_matchState_t* ms, - const BYTE* const ip, const BYTE* const iLimit, - size_t* offsetPtr, - const U32 mls, const ZSTD_dictMode_e dictMode) -{ - const ZSTD_compressionParameters* const cParams = &ms->cParams; - U32* const chainTable = ms->chainTable; - const U32 chainSize = (1 << cParams->chainLog); - const U32 chainMask = chainSize-1; - const BYTE* const base = ms->window.base; - const BYTE* const dictBase = ms->window.dictBase; - const U32 dictLimit = ms->window.dictLimit; - const BYTE* const prefixStart = base + dictLimit; - const BYTE* const dictEnd = dictBase + dictLimit; - const U32 lowLimit = ms->window.lowLimit; - const U32 current = (U32)(ip-base); - const U32 minChain = current > chainSize ? current - chainSize : 0; - U32 nbAttempts = 1U << cParams->searchLog; - size_t ml=4-1; - - /* HC4 match finder */ - U32 matchIndex = ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, mls); - - for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) { - size_t currentMl=0; - if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) { - const BYTE* const match = base + matchIndex; - assert(matchIndex >= dictLimit); /* ensures this is true if dictMode != ZSTD_extDict */ - if (match[ml] == ip[ml]) /* potentially better */ - currentMl = ZSTD_count(ip, match, iLimit); - } else { - const BYTE* const match = dictBase + matchIndex; - assert(match+4 <= dictEnd); - if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */ - currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dictEnd, prefixStart) + 4; - } - - /* save best solution */ - if (currentMl > ml) { - ml = currentMl; - *offsetPtr = current - matchIndex + ZSTD_REP_MOVE; - if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */ - } - - if (matchIndex <= minChain) break; - 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 dmsChainSize = (1 << dms->cParams.chainLog); - const U32 dmsChainMask = dmsChainSize - 1; - 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 > dmsChainSize ? dmsSize - dmsChainSize : 0; - - matchIndex = dms->hashTable[ZSTD_hashPtr(ip, dms->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 & dmsChainMask]; - } - } - - return ml; -} - - -FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS ( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict); - case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict); - case 7 : - case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict); - } -} - - -static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS ( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState); - case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState); - case 7 : - case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState); - } -} - - -FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS ( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* const iLimit, - size_t* offsetPtr) -{ - switch(ms->cParams.minMatch) - { - default : /* includes case 3 */ - case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict); - case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict); - case 7 : - case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict); - } -} - - -/* ******************************* -* Common parser - lazy strategy -*********************************/ -FORCE_INLINE_TEMPLATE -size_t ZSTD_compressBlock_lazy_generic( - ZSTD_matchState_t* ms, seqStore_t* seqStore, - U32 rep[ZSTD_REP_NUM], - const void* src, size_t srcSize, - 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; - const U32 prefixLowestIndex = ms->window.dictLimit; - const BYTE* const prefixLowest = base + prefixLowestIndex; - - typedef size_t (*searchMax_f)( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr); - 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); - - /* init */ - ip += (dictAndPrefixLength == 0); - ms->nextToUpdate3 = ms->nextToUpdate; - 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) { - size_t matchLength=0; - size_t offset=0; - const BYTE* start=ip+1; - - /* check repCode */ - 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; - } - - /* first search (depth 0) */ - { size_t offsetFound = 999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offsetFound); - if (ml2 > matchLength) - matchLength = ml2, start = ip, offset=offsetFound; - } - - if (matchLength < 4) { - ip += ((ip-anchor) >> kSearchStrength) + 1; /* jump faster over incompressible sections */ - continue; - } - - /* let's try to find a better solution */ - if (depth>=1) - while (ip<ilimit) { - ip ++; - 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=999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offset2); - int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */ - int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4); - if ((ml2 >= 4) && (gain2 > gain1)) { - matchLength = ml2, offset = offset2, start = ip; - continue; /* search a better one */ - } } - - /* let's find an even better one */ - if ((depth==2) && (ip<ilimit)) { - ip ++; - 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 ((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=999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offset2); - int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */ - int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7); - if ((ml2 >= 4) && (gain2 > gain1)) { - matchLength = ml2, offset = offset2, start = ip; - continue; - } } } - break; /* nothing found : store previous solution */ - } - - /* NOTE: - * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior. - * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which - * overflows the pointer, which is undefined behavior. - */ - /* catch up */ - if (offset) { - 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 */ -_storeSequence: - { size_t const litLength = start - anchor; - ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH); - anchor = ip = start + matchLength; - } - - /* check immediate repcode */ - 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; - rep[1] = offset_2 ? offset_2 : savedOffset; - - /* Return the last literals size */ - return iend - anchor; -} - - -size_t ZSTD_compressBlock_btlazy2( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_noDict); -} - -size_t ZSTD_compressBlock_lazy2( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_noDict); -} - -size_t ZSTD_compressBlock_lazy( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_noDict); -} - -size_t ZSTD_compressBlock_greedy( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_noDict); -} - -size_t ZSTD_compressBlock_btlazy2_dictMatchState( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_dictMatchState); -} - -size_t ZSTD_compressBlock_lazy2_dictMatchState( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_dictMatchState); -} - -size_t ZSTD_compressBlock_lazy_dictMatchState( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_dictMatchState); -} - -size_t ZSTD_compressBlock_greedy_dictMatchState( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_dictMatchState); -} - - -FORCE_INLINE_TEMPLATE -size_t ZSTD_compressBlock_lazy_extDict_generic( - ZSTD_matchState_t* ms, seqStore_t* seqStore, - U32 rep[ZSTD_REP_NUM], - const void* src, size_t srcSize, - const U32 searchMethod, const U32 depth) -{ - 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; - const U32 dictLimit = ms->window.dictLimit; - const U32 lowestIndex = ms->window.lowLimit; - const BYTE* const prefixStart = base + dictLimit; - const BYTE* const dictBase = ms->window.dictBase; - const BYTE* const dictEnd = dictBase + dictLimit; - const BYTE* const dictStart = dictBase + lowestIndex; - - typedef size_t (*searchMax_f)( - ZSTD_matchState_t* ms, - const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr); - searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS; - - U32 offset_1 = rep[0], offset_2 = rep[1]; - - /* init */ - ms->nextToUpdate3 = ms->nextToUpdate; - ip += (ip == prefixStart); - - /* Match Loop */ - while (ip < ilimit) { - size_t matchLength=0; - size_t offset=0; - const BYTE* start=ip+1; - U32 current = (U32)(ip-base); - - /* check repCode */ - { const U32 repIndex = (U32)(current+1 - offset_1); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ - if (MEM_read32(ip+1) == MEM_read32(repMatch)) { - /* repcode detected we should take it */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repEnd, prefixStart) + 4; - if (depth==0) goto _storeSequence; - } } - - /* first search (depth 0) */ - { size_t offsetFound = 999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offsetFound); - if (ml2 > matchLength) - matchLength = ml2, start = ip, offset=offsetFound; - } - - if (matchLength < 4) { - ip += ((ip-anchor) >> kSearchStrength) + 1; /* jump faster over incompressible sections */ - continue; - } - - /* let's try to find a better solution */ - if (depth>=1) - while (ip<ilimit) { - ip ++; - current++; - /* check repCode */ - if (offset) { - const U32 repIndex = (U32)(current - offset_1); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ - if (MEM_read32(ip) == MEM_read32(repMatch)) { - /* repcode detected */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4; - int const gain2 = (int)(repLength * 3); - int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1); - if ((repLength >= 4) && (gain2 > gain1)) - matchLength = repLength, offset = 0, start = ip; - } } - - /* search match, depth 1 */ - { size_t offset2=999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offset2); - int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */ - int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4); - if ((ml2 >= 4) && (gain2 > gain1)) { - matchLength = ml2, offset = offset2, start = ip; - continue; /* search a better one */ - } } - - /* let's find an even better one */ - if ((depth==2) && (ip<ilimit)) { - ip ++; - current++; - /* check repCode */ - if (offset) { - const U32 repIndex = (U32)(current - offset_1); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ - if (MEM_read32(ip) == MEM_read32(repMatch)) { - /* repcode detected */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4; - int const gain2 = (int)(repLength * 4); - int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1); - if ((repLength >= 4) && (gain2 > gain1)) - matchLength = repLength, offset = 0, start = ip; - } } - - /* search match, depth 2 */ - { size_t offset2=999999999; - size_t const ml2 = searchMax(ms, ip, iend, &offset2); - int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */ - int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7); - if ((ml2 >= 4) && (gain2 > gain1)) { - matchLength = ml2, offset = offset2, start = ip; - continue; - } } } - break; /* nothing found : store previous solution */ - } - - /* catch up */ - if (offset) { - U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE)); - const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex; - const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart; - 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 */ -_storeSequence: - { size_t const litLength = start - anchor; - ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH); - anchor = ip = start + matchLength; - } - - /* check immediate repcode */ - while (ip <= ilimit) { - const U32 repIndex = (U32)((ip-base) - offset_2); - const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; - const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */ - if (MEM_read32(ip) == MEM_read32(repMatch)) { - /* repcode detected we should take it */ - const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; - matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4; - offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset history */ - ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH); - ip += matchLength; - anchor = ip; - continue; /* faster when present ... (?) */ - } - break; - } } - - /* Save reps for next block */ - rep[0] = offset_1; - rep[1] = offset_2; - - /* Return the last literals size */ - return iend - anchor; -} - - -size_t ZSTD_compressBlock_greedy_extDict( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) -{ - return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 0); -} - -size_t ZSTD_compressBlock_lazy_extDict( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) - -{ - return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 1); -} - -size_t ZSTD_compressBlock_lazy2_extDict( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) - -{ - return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 2); -} - -size_t ZSTD_compressBlock_btlazy2_extDict( - ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], - void const* src, size_t srcSize) - -{ - return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 1, 2); -} |