| /* |
| * Copyright (c) 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 : curr >= btlow == (curr - btmask) |
| * doesn't fail */ |
| static void |
| ZSTD_insertDUBT1(ZSTD_matchState_t* ms, |
| U32 curr, 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 = (curr>=dictLimit) ? base + curr : dictBase + curr; |
| const BYTE* const iend = (curr>=dictLimit) ? inputEnd : dictBase + dictLimit; |
| const BYTE* const dictEnd = dictBase + dictLimit; |
| const BYTE* const prefixStart = base + dictLimit; |
| const BYTE* match; |
| U32* smallerPtr = bt + 2*(curr&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 windowValid = ms->window.lowLimit; |
| U32 const maxDistance = 1U << cParams->windowLog; |
| U32 const windowLow = (curr - windowValid > maxDistance) ? curr - maxDistance : windowValid; |
| |
| |
| DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)", |
| curr, dictLimit, windowLow); |
| assert(curr >= btLow); |
| assert(ip < iend); /* condition for ZSTD_count */ |
| |
| for (; nbCompares && (matchIndex > windowLow); --nbCompares) { |
| U32* const nextPtr = bt + 2*(matchIndex & btMask); |
| size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */ |
| assert(matchIndex < curr); |
| /* 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*/ |
| || (curr < 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 */ |
| || (curr < 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 ", |
| curr, 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 curr = (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); |
| |
| for (; nbCompares && (dictMatchIndex > dictLowLimit); --nbCompares) { |
| 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(curr-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)", |
| curr, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + curr - matchIndex, dictMatchIndex, matchIndex); |
| bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + curr - 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 = curr - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex; |
| DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)", |
| curr, (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 curr = (U32)(ip-base); |
| U32 const windowLow = ZSTD_getLowestMatchIndex(ms, curr, cParams->windowLog); |
| |
| U32* const bt = ms->chainTable; |
| U32 const btLog = cParams->chainLog - 1; |
| U32 const btMask = (1 << btLog) - 1; |
| U32 const btLow = (btMask >= curr) ? 0 : curr - 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) ", curr); |
| assert(ip <= iend-8); /* required for h calculation */ |
| assert(dictMode != ZSTD_dedicatedDictSearch); |
| |
| /* 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*(curr&btMask); |
| U32* largerPtr = bt + 2*(curr&btMask) + 1; |
| U32 matchEndIdx = curr + 8 + 1; |
| U32 dummy32; /* to be nullified at the end */ |
| size_t bestLength = 0; |
| |
| matchIndex = hashTable[h]; |
| hashTable[h] = curr; /* Update Hash Table */ |
| |
| for (; nbCompares && (matchIndex > windowLow); --nbCompares) { |
| 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(curr-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) |
| bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + curr - 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; |
| |
| assert(nbCompares <= (1U << ZSTD_SEARCHLOG_MAX)); /* Check we haven't underflowed. */ |
| if (dictMode == ZSTD_dictMatchState && nbCompares) { |
| bestLength = ZSTD_DUBT_findBetterDictMatch( |
| ms, ip, iend, |
| offsetPtr, bestLength, nbCompares, |
| mls, dictMode); |
| } |
| |
| assert(matchEndIdx > curr+8); /* ensure nextToUpdate is increased */ |
| ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */ |
| if (bestLength >= MINMATCH) { |
| U32 const mIndex = curr - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex; |
| DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)", |
| curr, (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) */ |
| FORCE_INLINE_TEMPLATE 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); |
| } |
| |
| void ZSTD_dedicatedDictSearch_lazy_loadDictionary(ZSTD_matchState_t* ms, const BYTE* const ip) |
| { |
| const BYTE* const base = ms->window.base; |
| U32 const target = (U32)(ip - base); |
| U32* const hashTable = ms->hashTable; |
| U32* const chainTable = ms->chainTable; |
| U32 const chainSize = 1 << ms->cParams.chainLog; |
| U32 idx = ms->nextToUpdate; |
| U32 const minChain = chainSize < target ? target - chainSize : idx; |
| U32 const bucketSize = 1 << ZSTD_LAZY_DDSS_BUCKET_LOG; |
| U32 const cacheSize = bucketSize - 1; |
| U32 const chainAttempts = (1 << ms->cParams.searchLog) - cacheSize; |
| U32 const chainLimit = chainAttempts > 255 ? 255 : chainAttempts; |
| |
| /* We know the hashtable is oversized by a factor of `bucketSize`. |
| * We are going to temporarily pretend `bucketSize == 1`, keeping only a |
| * single entry. We will use the rest of the space to construct a temporary |
| * chaintable. |
| */ |
| U32 const hashLog = ms->cParams.hashLog - ZSTD_LAZY_DDSS_BUCKET_LOG; |
| U32* const tmpHashTable = hashTable; |
| U32* const tmpChainTable = hashTable + ((size_t)1 << hashLog); |
| U32 const tmpChainSize = ((1 << ZSTD_LAZY_DDSS_BUCKET_LOG) - 1) << hashLog; |
| U32 const tmpMinChain = tmpChainSize < target ? target - tmpChainSize : idx; |
| |
| U32 hashIdx; |
| |
| assert(ms->cParams.chainLog <= 24); |
| assert(ms->cParams.hashLog >= ms->cParams.chainLog); |
| assert(idx != 0); |
| assert(tmpMinChain <= minChain); |
| |
| /* fill conventional hash table and conventional chain table */ |
| for ( ; idx < target; idx++) { |
| U32 const h = (U32)ZSTD_hashPtr(base + idx, hashLog, ms->cParams.minMatch); |
| if (idx >= tmpMinChain) { |
| tmpChainTable[idx - tmpMinChain] = hashTable[h]; |
| } |
| tmpHashTable[h] = idx; |
| } |
| |
| /* sort chains into ddss chain table */ |
| { |
| U32 chainPos = 0; |
| for (hashIdx = 0; hashIdx < (1U << hashLog); hashIdx++) { |
| U32 count; |
| U32 countBeyondMinChain = 0; |
| U32 i = tmpHashTable[hashIdx]; |
| for (count = 0; i >= tmpMinChain && count < cacheSize; count++) { |
| /* skip through the chain to the first position that won't be |
| * in the hash cache bucket */ |
| if (i < minChain) { |
| countBeyondMinChain++; |
| } |
| i = tmpChainTable[i - tmpMinChain]; |
| } |
| if (count == cacheSize) { |
| for (count = 0; count < chainLimit;) { |
| if (i < minChain) { |
| if (!i || countBeyondMinChain++ > cacheSize) { |
| /* only allow pulling `cacheSize` number of entries |
| * into the cache or chainTable beyond `minChain`, |
| * to replace the entries pulled out of the |
| * chainTable into the cache. This lets us reach |
| * back further without increasing the total number |
| * of entries in the chainTable, guaranteeing the |
| * DDSS chain table will fit into the space |
| * allocated for the regular one. */ |
| break; |
| } |
| } |
| chainTable[chainPos++] = i; |
| count++; |
| if (i < tmpMinChain) { |
| break; |
| } |
| i = tmpChainTable[i - tmpMinChain]; |
| } |
| } else { |
| count = 0; |
| } |
| if (count) { |
| tmpHashTable[hashIdx] = ((chainPos - count) << 8) + count; |
| } else { |
| tmpHashTable[hashIdx] = 0; |
| } |
| } |
| assert(chainPos <= chainSize); /* I believe this is guaranteed... */ |
| } |
| |
| /* move chain pointers into the last entry of each hash bucket */ |
| for (hashIdx = (1 << hashLog); hashIdx; ) { |
| U32 const bucketIdx = --hashIdx << ZSTD_LAZY_DDSS_BUCKET_LOG; |
| U32 const chainPackedPointer = tmpHashTable[hashIdx]; |
| U32 i; |
| for (i = 0; i < cacheSize; i++) { |
| hashTable[bucketIdx + i] = 0; |
| } |
| hashTable[bucketIdx + bucketSize - 1] = chainPackedPointer; |
| } |
| |
| /* fill the buckets of the hash table */ |
| for (idx = ms->nextToUpdate; idx < target; idx++) { |
| U32 const h = (U32)ZSTD_hashPtr(base + idx, hashLog, ms->cParams.minMatch) |
| << ZSTD_LAZY_DDSS_BUCKET_LOG; |
| U32 i; |
| /* Shift hash cache down 1. */ |
| for (i = cacheSize - 1; i; i--) |
| hashTable[h + i] = hashTable[h + i - 1]; |
| hashTable[h] = idx; |
| } |
| |
| ms->nextToUpdate = target; |
| } |
| |
| |
| /* 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 curr = (U32)(ip-base); |
| const U32 maxDistance = 1U << cParams->windowLog; |
| const U32 lowestValid = ms->window.lowLimit; |
| const U32 withinMaxDistance = (curr - lowestValid > maxDistance) ? curr - maxDistance : lowestValid; |
| const U32 isDictionary = (ms->loadedDictEnd != 0); |
| const U32 lowLimit = isDictionary ? lowestValid : withinMaxDistance; |
| const U32 minChain = curr > chainSize ? curr - chainSize : 0; |
| U32 nbAttempts = 1U << cParams->searchLog; |
| size_t ml=4-1; |
| |
| const ZSTD_matchState_t* const dms = ms->dictMatchState; |
| const U32 ddsHashLog = dictMode == ZSTD_dedicatedDictSearch |
| ? dms->cParams.hashLog - ZSTD_LAZY_DDSS_BUCKET_LOG : 0; |
| const size_t ddsIdx = dictMode == ZSTD_dedicatedDictSearch |
| ? ZSTD_hashPtr(ip, ddsHashLog, mls) << ZSTD_LAZY_DDSS_BUCKET_LOG : 0; |
| |
| U32 matchIndex; |
| |
| if (dictMode == ZSTD_dedicatedDictSearch) { |
| const U32* entry = &dms->hashTable[ddsIdx]; |
| PREFETCH_L1(entry); |
| } |
| |
| /* HC4 match finder */ |
| 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 = curr - 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); |
| } |
| |
| assert(nbAttempts <= (1U << ZSTD_SEARCHLOG_MAX)); /* Check we haven't underflowed. */ |
| if (dictMode == ZSTD_dedicatedDictSearch) { |
| const U32 ddsLowestIndex = dms->window.dictLimit; |
| const BYTE* const ddsBase = dms->window.base; |
| const BYTE* const ddsEnd = dms->window.nextSrc; |
| const U32 ddsSize = (U32)(ddsEnd - ddsBase); |
| const U32 ddsIndexDelta = dictLimit - ddsSize; |
| const U32 bucketSize = (1 << ZSTD_LAZY_DDSS_BUCKET_LOG); |
| const U32 bucketLimit = nbAttempts < bucketSize - 1 ? nbAttempts : bucketSize - 1; |
| U32 ddsAttempt; |
| |
| for (ddsAttempt = 0; ddsAttempt < bucketSize - 1; ddsAttempt++) { |
| PREFETCH_L1(ddsBase + dms->hashTable[ddsIdx + ddsAttempt]); |
| } |
| |
| { |
| U32 const chainPackedPointer = dms->hashTable[ddsIdx + bucketSize - 1]; |
| U32 const chainIndex = chainPackedPointer >> 8; |
| |
| PREFETCH_L1(&dms->chainTable[chainIndex]); |
| } |
| |
| for (ddsAttempt = 0; ddsAttempt < bucketLimit; ddsAttempt++) { |
| size_t currentMl=0; |
| const BYTE* match; |
| matchIndex = dms->hashTable[ddsIdx + ddsAttempt]; |
| match = ddsBase + matchIndex; |
| |
| if (!matchIndex) { |
| return ml; |
| } |
| |
| /* guaranteed by table construction */ |
| (void)ddsLowestIndex; |
| assert(matchIndex >= ddsLowestIndex); |
| assert(match+4 <= ddsEnd); |
| if (MEM_read32(match) == MEM_read32(ip)) { |
| /* assumption : matchIndex <= dictLimit-4 (by table construction) */ |
| currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, ddsEnd, prefixStart) + 4; |
| } |
| |
| /* save best solution */ |
| if (currentMl > ml) { |
| ml = currentMl; |
| *offsetPtr = curr - (matchIndex + ddsIndexDelta) + ZSTD_REP_MOVE; |
| if (ip+currentMl == iLimit) { |
| /* best possible, avoids read overflow on next attempt */ |
| return ml; |
| } |
| } |
| } |
| |
| { |
| U32 const chainPackedPointer = dms->hashTable[ddsIdx + bucketSize - 1]; |
| U32 chainIndex = chainPackedPointer >> 8; |
| U32 const chainLength = chainPackedPointer & 0xFF; |
| U32 const chainAttempts = nbAttempts - ddsAttempt; |
| U32 const chainLimit = chainAttempts > chainLength ? chainLength : chainAttempts; |
| U32 chainAttempt; |
| |
| for (chainAttempt = 0 ; chainAttempt < chainLimit; chainAttempt++) { |
| PREFETCH_L1(ddsBase + dms->chainTable[chainIndex + chainAttempt]); |
| } |
| |
| for (chainAttempt = 0 ; chainAttempt < chainLimit; chainAttempt++, chainIndex++) { |
| size_t currentMl=0; |
| const BYTE* match; |
| matchIndex = dms->chainTable[chainIndex]; |
| match = ddsBase + matchIndex; |
| |
| /* guaranteed by table construction */ |
| assert(matchIndex >= ddsLowestIndex); |
| assert(match+4 <= ddsEnd); |
| if (MEM_read32(match) == MEM_read32(ip)) { |
| /* assumption : matchIndex <= dictLimit-4 (by table construction) */ |
| currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, ddsEnd, prefixStart) + 4; |
| } |
| |
| /* save best solution */ |
| if (currentMl > ml) { |
| ml = currentMl; |
| *offsetPtr = curr - (matchIndex + ddsIndexDelta) + ZSTD_REP_MOVE; |
| if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */ |
| } |
| } |
| } |
| } else if (dictMode == ZSTD_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 = curr - (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); |
| } |
| } |
| |
| |
| static size_t ZSTD_HcFindBestMatch_dedicatedDictSearch_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_dedicatedDictSearch); |
| case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dedicatedDictSearch); |
| case 7 : |
| case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dedicatedDictSearch); |
| } |
| } |
| |
| |
| 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 |
| *********************************/ |
| typedef enum { search_hashChain, search_binaryTree } searchMethod_e; |
| |
| 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 searchMethod_e 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); |
| |
| /* |
| * This table is indexed first by the four ZSTD_dictMode_e values, and then |
| * by the two searchMethod_e values. NULLs are placed for configurations |
| * that should never occur (extDict modes go to the other implementation |
| * below and there is no DDSS for binary tree search yet). |
| */ |
| const searchMax_f searchFuncs[4][2] = { |
| { |
| ZSTD_HcFindBestMatch_selectMLS, |
| ZSTD_BtFindBestMatch_selectMLS |
| }, |
| { |
| NULL, |
| NULL |
| }, |
| { |
| ZSTD_HcFindBestMatch_dictMatchState_selectMLS, |
| ZSTD_BtFindBestMatch_dictMatchState_selectMLS |
| }, |
| { |
| ZSTD_HcFindBestMatch_dedicatedDictSearch_selectMLS, |
| NULL |
| } |
| }; |
| |
| searchMax_f const searchMax = searchFuncs[dictMode][searchMethod == search_binaryTree]; |
| U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0; |
| |
| const int isDMS = dictMode == ZSTD_dictMatchState; |
| const int isDDS = dictMode == ZSTD_dedicatedDictSearch; |
| const int isDxS = isDMS || isDDS; |
| const ZSTD_matchState_t* const dms = ms->dictMatchState; |
| const U32 dictLowestIndex = isDxS ? dms->window.dictLimit : 0; |
| const BYTE* const dictBase = isDxS ? dms->window.base : NULL; |
| const BYTE* const dictLowest = isDxS ? dictBase + dictLowestIndex : NULL; |
| const BYTE* const dictEnd = isDxS ? dms->window.nextSrc : NULL; |
| const U32 dictIndexDelta = isDxS ? |
| prefixLowestIndex - (U32)(dictEnd - dictBase) : |
| 0; |
| const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictLowest)); |
| |
| assert(searchMax != NULL); |
| |
| DEBUGLOG(5, "ZSTD_compressBlock_lazy_generic (dictMode=%u)", (U32)dictMode); |
| |
| /* init */ |
| ip += (dictAndPrefixLength == 0); |
| if (dictMode == ZSTD_noDict) { |
| U32 const curr = (U32)(ip - base); |
| U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, curr, ms->cParams.windowLog); |
| U32 const maxRep = curr - windowLow; |
| if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0; |
| if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0; |
| } |
| if (isDxS) { |
| /* dictMatchState repCode checks don't currently handle repCode == 0 |
| * disabling. */ |
| assert(offset_1 <= dictAndPrefixLength); |
| assert(offset_2 <= dictAndPrefixLength); |
| } |
| |
| /* Match Loop */ |
| #if defined(__x86_64__) |
| /* I've measured random a 5% speed loss on levels 5 & 6 (greedy) when the |
| * code alignment is perturbed. To fix the instability align the loop on 32-bytes. |
| */ |
| __asm__(".p2align 5"); |
| #endif |
| while (ip < ilimit) { |
| size_t matchLength=0; |
| size_t offset=0; |
| const BYTE* start=ip+1; |
| |
| /* check repCode */ |
| if (isDxS) { |
| const U32 repIndex = (U32)(ip - base) + 1 - offset_1; |
| const BYTE* repMatch = ((dictMode == ZSTD_dictMatchState || dictMode == ZSTD_dedicatedDictSearch) |
| && 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 (isDxS) { |
| 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 (isDxS) { |
| 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 (isDxS) { |
| 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, iend, (U32)offset, matchLength-MINMATCH); |
| anchor = ip = start + matchLength; |
| } |
| |
| /* check immediate repcode */ |
| if (isDxS) { |
| while (ip <= ilimit) { |
| U32 const current2 = (U32)(ip-base); |
| U32 const repIndex = current2 - offset_2; |
| const BYTE* repMatch = 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, iend, 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, iend, 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 (size_t)(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, search_binaryTree, 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, search_hashChain, 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, search_hashChain, 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, search_hashChain, 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, search_binaryTree, 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, search_hashChain, 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, search_hashChain, 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, search_hashChain, 0, ZSTD_dictMatchState); |
| } |
| |
| |
| size_t ZSTD_compressBlock_lazy2_dedicatedDictSearch( |
| 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, search_hashChain, 2, ZSTD_dedicatedDictSearch); |
| } |
| |
| size_t ZSTD_compressBlock_lazy_dedicatedDictSearch( |
| 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, search_hashChain, 1, ZSTD_dedicatedDictSearch); |
| } |
| |
| size_t ZSTD_compressBlock_greedy_dedicatedDictSearch( |
| 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, search_hashChain, 0, ZSTD_dedicatedDictSearch); |
| } |
| |
| |
| 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 searchMethod_e 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 BYTE* const prefixStart = base + dictLimit; |
| const BYTE* const dictBase = ms->window.dictBase; |
| const BYTE* const dictEnd = dictBase + dictLimit; |
| const BYTE* const dictStart = dictBase + ms->window.lowLimit; |
| const U32 windowLog = ms->cParams.windowLog; |
| |
| typedef size_t (*searchMax_f)( |
| ZSTD_matchState_t* ms, |
| const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr); |
| searchMax_f searchMax = searchMethod==search_binaryTree ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS; |
| |
| U32 offset_1 = rep[0], offset_2 = rep[1]; |
| |
| DEBUGLOG(5, "ZSTD_compressBlock_lazy_extDict_generic"); |
| |
| /* init */ |
| ip += (ip == prefixStart); |
| |
| /* Match Loop */ |
| #if defined(__x86_64__) |
| /* I've measured random a 5% speed loss on levels 5 & 6 (greedy) when the |
| * code alignment is perturbed. To fix the instability align the loop on 32-bytes. |
| */ |
| __asm__(".p2align 5"); |
| #endif |
| while (ip < ilimit) { |
| size_t matchLength=0; |
| size_t offset=0; |
| const BYTE* start=ip+1; |
| U32 curr = (U32)(ip-base); |
| |
| /* check repCode */ |
| { const U32 windowLow = ZSTD_getLowestMatchIndex(ms, curr+1, windowLog); |
| const U32 repIndex = (U32)(curr+1 - offset_1); |
| const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; |
| const BYTE* const repMatch = repBase + repIndex; |
| if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* 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 ++; |
| curr++; |
| /* check repCode */ |
| if (offset) { |
| const U32 windowLow = ZSTD_getLowestMatchIndex(ms, curr, windowLog); |
| const U32 repIndex = (U32)(curr - offset_1); |
| const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; |
| const BYTE* const repMatch = repBase + repIndex; |
| if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* 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 ++; |
| curr++; |
| /* check repCode */ |
| if (offset) { |
| const U32 windowLow = ZSTD_getLowestMatchIndex(ms, curr, windowLog); |
| const U32 repIndex = (U32)(curr - offset_1); |
| const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; |
| const BYTE* const repMatch = repBase + repIndex; |
| if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* 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, iend, (U32)offset, matchLength-MINMATCH); |
| anchor = ip = start + matchLength; |
| } |
| |
| /* check immediate repcode */ |
| while (ip <= ilimit) { |
| const U32 repCurrent = (U32)(ip-base); |
| const U32 windowLow = ZSTD_getLowestMatchIndex(ms, repCurrent, windowLog); |
| const U32 repIndex = repCurrent - offset_2; |
| const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; |
| const BYTE* const repMatch = repBase + repIndex; |
| if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* 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, iend, 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 (size_t)(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, search_hashChain, 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, search_hashChain, 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, search_hashChain, 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, search_binaryTree, 2); |
| } |
