| /* |
| * 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_fast.h" |
| |
| |
| void ZSTD_fillHashTable(ZSTD_matchState_t* ms, |
| void const* end, ZSTD_dictTableLoadMethod_e dtlm) |
| { |
| const ZSTD_compressionParameters* const cParams = &ms->cParams; |
| U32* const hashTable = ms->hashTable; |
| U32 const hBits = cParams->hashLog; |
| U32 const mls = cParams->minMatch; |
| const BYTE* const base = ms->window.base; |
| const BYTE* ip = base + ms->nextToUpdate; |
| const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; |
| const U32 fastHashFillStep = 3; |
| |
| /* Always insert every fastHashFillStep position into the hash table. |
| * Insert the other positions if their hash entry is empty. |
| */ |
| for ( ; ip + fastHashFillStep < iend + 2; ip += fastHashFillStep) { |
| U32 const current = (U32)(ip - base); |
| size_t const hash0 = ZSTD_hashPtr(ip, hBits, mls); |
| hashTable[hash0] = current; |
| if (dtlm == ZSTD_dtlm_fast) continue; |
| /* Only load extra positions for ZSTD_dtlm_full */ |
| { U32 p; |
| for (p = 1; p < fastHashFillStep; ++p) { |
| size_t const hash = ZSTD_hashPtr(ip + p, hBits, mls); |
| if (hashTable[hash] == 0) { /* not yet filled */ |
| hashTable[hash] = current + p; |
| } } } } |
| } |
| |
| FORCE_INLINE_TEMPLATE |
| size_t ZSTD_compressBlock_fast_generic( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| void const* src, size_t srcSize, |
| U32 const mls, ZSTD_dictMode_e const dictMode) |
| { |
| const ZSTD_compressionParameters* const cParams = &ms->cParams; |
| U32* const hashTable = ms->hashTable; |
| U32 const hlog = cParams->hashLog; |
| /* support stepSize of 0 */ |
| U32 const stepSize = cParams->targetLength + !(cParams->targetLength); |
| const BYTE* const base = ms->window.base; |
| const BYTE* const istart = (const BYTE*)src; |
| const BYTE* ip = istart; |
| const BYTE* anchor = istart; |
| const U32 prefixStartIndex = ms->window.dictLimit; |
| const BYTE* const prefixStart = base + prefixStartIndex; |
| const BYTE* const iend = istart + srcSize; |
| const BYTE* const ilimit = iend - HASH_READ_SIZE; |
| U32 offset_1=rep[0], offset_2=rep[1]; |
| U32 offsetSaved = 0; |
| |
| const ZSTD_matchState_t* const dms = ms->dictMatchState; |
| const ZSTD_compressionParameters* const dictCParams = |
| dictMode == ZSTD_dictMatchState ? |
| &dms->cParams : NULL; |
| const U32* const dictHashTable = dictMode == ZSTD_dictMatchState ? |
| dms->hashTable : NULL; |
| const U32 dictStartIndex = dictMode == ZSTD_dictMatchState ? |
| dms->window.dictLimit : 0; |
| const BYTE* const dictBase = dictMode == ZSTD_dictMatchState ? |
| dms->window.base : NULL; |
| const BYTE* const dictStart = dictMode == ZSTD_dictMatchState ? |
| dictBase + dictStartIndex : NULL; |
| const BYTE* const dictEnd = dictMode == ZSTD_dictMatchState ? |
| dms->window.nextSrc : NULL; |
| const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ? |
| prefixStartIndex - (U32)(dictEnd - dictBase) : |
| 0; |
| const U32 dictAndPrefixLength = (U32)(ip - prefixStart + dictEnd - dictStart); |
| const U32 dictHLog = dictMode == ZSTD_dictMatchState ? |
| dictCParams->hashLog : hlog; |
| |
| assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState); |
| |
| /* otherwise, we would get index underflow when translating a dict index |
| * into a local index */ |
| assert(dictMode != ZSTD_dictMatchState |
| || prefixStartIndex >= (U32)(dictEnd - dictBase)); |
| |
| /* init */ |
| ip += (dictAndPrefixLength == 0); |
| if (dictMode == ZSTD_noDict) { |
| U32 const maxRep = (U32)(ip - prefixStart); |
| if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0; |
| if (offset_1 > maxRep) offsetSaved = 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); |
| } |
| |
| /* Main Search Loop */ |
| while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */ |
| size_t mLength; |
| size_t const h = ZSTD_hashPtr(ip, hlog, mls); |
| U32 const current = (U32)(ip-base); |
| U32 const matchIndex = hashTable[h]; |
| const BYTE* match = base + matchIndex; |
| const U32 repIndex = current + 1 - offset_1; |
| const BYTE* repMatch = (dictMode == ZSTD_dictMatchState |
| && repIndex < prefixStartIndex) ? |
| dictBase + (repIndex - dictIndexDelta) : |
| base + repIndex; |
| hashTable[h] = current; /* update hash table */ |
| |
| if ( (dictMode == ZSTD_dictMatchState) |
| && ((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex isn't overlapping dict + prefix */ |
| && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { |
| const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend; |
| mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4; |
| ip++; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH); |
| } else if ( dictMode == ZSTD_noDict |
| && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) { |
| mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4; |
| ip++; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH); |
| } else if ( (matchIndex <= prefixStartIndex) ) { |
| if (dictMode == ZSTD_dictMatchState) { |
| size_t const dictHash = ZSTD_hashPtr(ip, dictHLog, mls); |
| U32 const dictMatchIndex = dictHashTable[dictHash]; |
| const BYTE* dictMatch = dictBase + dictMatchIndex; |
| if (dictMatchIndex <= dictStartIndex || |
| MEM_read32(dictMatch) != MEM_read32(ip)) { |
| assert(stepSize >= 1); |
| ip += ((ip-anchor) >> kSearchStrength) + stepSize; |
| continue; |
| } else { |
| /* found a dict match */ |
| U32 const offset = (U32)(current-dictMatchIndex-dictIndexDelta); |
| mLength = ZSTD_count_2segments(ip+4, dictMatch+4, iend, dictEnd, prefixStart) + 4; |
| while (((ip>anchor) & (dictMatch>dictStart)) |
| && (ip[-1] == dictMatch[-1])) { |
| ip--; dictMatch--; mLength++; |
| } /* catch up */ |
| offset_2 = offset_1; |
| offset_1 = offset; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH); |
| } |
| } else { |
| assert(stepSize >= 1); |
| ip += ((ip-anchor) >> kSearchStrength) + stepSize; |
| continue; |
| } |
| } else if (MEM_read32(match) != MEM_read32(ip)) { |
| /* it's not a match, and we're not going to check the dictionary */ |
| assert(stepSize >= 1); |
| ip += ((ip-anchor) >> kSearchStrength) + stepSize; |
| continue; |
| } else { |
| /* found a regular match */ |
| U32 const offset = (U32)(ip-match); |
| mLength = ZSTD_count(ip+4, match+4, iend) + 4; |
| while (((ip>anchor) & (match>prefixStart)) |
| && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ |
| offset_2 = offset_1; |
| offset_1 = offset; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH); |
| } |
| |
| /* match found */ |
| ip += mLength; |
| anchor = ip; |
| |
| if (ip <= ilimit) { |
| /* Fill Table */ |
| assert(base+current+2 > istart); /* check base overflow */ |
| hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2; /* here because current+2 could be > iend-8 */ |
| hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base); |
| |
| /* check immediate repcode */ |
| if (dictMode == ZSTD_dictMatchState) { |
| while (ip <= ilimit) { |
| U32 const current2 = (U32)(ip-base); |
| U32 const repIndex2 = current2 - offset_2; |
| const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? |
| dictBase - dictIndexDelta + repIndex2 : |
| base + repIndex2; |
| if ( ((U32)((prefixStartIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */) |
| && (MEM_read32(repMatch2) == MEM_read32(ip)) ) { |
| const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend; |
| size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4; |
| U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */ |
| ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH); |
| hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2; |
| ip += repLength2; |
| anchor = ip; |
| continue; |
| } |
| break; |
| } |
| } |
| |
| if (dictMode == ZSTD_noDict) { |
| while ( (ip <= ilimit) |
| && ( (offset_2>0) |
| & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) { |
| /* store sequence */ |
| size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4; |
| U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */ |
| hashTable[ZSTD_hashPtr(ip, hlog, mls)] = (U32)(ip-base); |
| ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH); |
| ip += rLength; |
| anchor = ip; |
| continue; /* faster when present ... (?) */ |
| } } } } |
| |
| /* save reps for next block */ |
| rep[0] = offset_1 ? offset_1 : offsetSaved; |
| rep[1] = offset_2 ? offset_2 : offsetSaved; |
| |
| /* Return the last literals size */ |
| return iend - anchor; |
| } |
| |
| |
| size_t ZSTD_compressBlock_fast( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| void const* src, size_t srcSize) |
| { |
| ZSTD_compressionParameters const* cParams = &ms->cParams; |
| U32 const mls = cParams->minMatch; |
| assert(ms->dictMatchState == NULL); |
| switch(mls) |
| { |
| default: /* includes case 3 */ |
| case 4 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict); |
| case 5 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict); |
| case 6 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict); |
| case 7 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict); |
| } |
| } |
| |
| size_t ZSTD_compressBlock_fast_dictMatchState( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| void const* src, size_t srcSize) |
| { |
| ZSTD_compressionParameters const* cParams = &ms->cParams; |
| U32 const mls = cParams->minMatch; |
| assert(ms->dictMatchState != NULL); |
| switch(mls) |
| { |
| default: /* includes case 3 */ |
| case 4 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState); |
| case 5 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState); |
| case 6 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState); |
| case 7 : |
| return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState); |
| } |
| } |
| |
| |
| static size_t ZSTD_compressBlock_fast_extDict_generic( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| void const* src, size_t srcSize, U32 const mls) |
| { |
| const ZSTD_compressionParameters* const cParams = &ms->cParams; |
| U32* const hashTable = ms->hashTable; |
| U32 const hlog = cParams->hashLog; |
| /* support stepSize of 0 */ |
| U32 const stepSize = cParams->targetLength + !(cParams->targetLength); |
| const BYTE* const base = ms->window.base; |
| const BYTE* const dictBase = ms->window.dictBase; |
| const BYTE* const istart = (const BYTE*)src; |
| const BYTE* ip = istart; |
| const BYTE* anchor = istart; |
| const U32 dictStartIndex = ms->window.lowLimit; |
| const BYTE* const dictStart = dictBase + dictStartIndex; |
| const U32 prefixStartIndex = ms->window.dictLimit; |
| const BYTE* const prefixStart = base + prefixStartIndex; |
| const BYTE* const dictEnd = dictBase + prefixStartIndex; |
| const BYTE* const iend = istart + srcSize; |
| const BYTE* const ilimit = iend - 8; |
| U32 offset_1=rep[0], offset_2=rep[1]; |
| |
| /* Search Loop */ |
| while (ip < ilimit) { /* < instead of <=, because (ip+1) */ |
| const size_t h = ZSTD_hashPtr(ip, hlog, mls); |
| const U32 matchIndex = hashTable[h]; |
| const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base; |
| const BYTE* match = matchBase + matchIndex; |
| const U32 current = (U32)(ip-base); |
| const U32 repIndex = current + 1 - offset_1; |
| const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base; |
| const BYTE* const repMatch = repBase + repIndex; |
| size_t mLength; |
| hashTable[h] = current; /* update hash table */ |
| assert(offset_1 <= current +1); /* check repIndex */ |
| |
| if ( (((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > dictStartIndex)) |
| && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { |
| const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend; |
| mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4; |
| ip++; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH); |
| } else { |
| if ( (matchIndex < dictStartIndex) || |
| (MEM_read32(match) != MEM_read32(ip)) ) { |
| assert(stepSize >= 1); |
| ip += ((ip-anchor) >> kSearchStrength) + stepSize; |
| continue; |
| } |
| { const BYTE* matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend; |
| const BYTE* lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart; |
| U32 offset; |
| mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4; |
| while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ |
| offset = current - matchIndex; |
| offset_2 = offset_1; |
| offset_1 = offset; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH); |
| } } |
| |
| /* found a match : store it */ |
| ip += mLength; |
| anchor = ip; |
| |
| if (ip <= ilimit) { |
| /* Fill Table */ |
| hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2; |
| hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base); |
| /* check immediate repcode */ |
| while (ip <= ilimit) { |
| U32 const current2 = (U32)(ip-base); |
| U32 const repIndex2 = current2 - offset_2; |
| const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2; |
| if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (repIndex2 > dictStartIndex)) /* intentional overflow */ |
| && (MEM_read32(repMatch2) == MEM_read32(ip)) ) { |
| const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend; |
| size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4; |
| U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */ |
| ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH); |
| hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2; |
| ip += repLength2; |
| anchor = ip; |
| continue; |
| } |
| 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_fast_extDict( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| void const* src, size_t srcSize) |
| { |
| ZSTD_compressionParameters const* cParams = &ms->cParams; |
| U32 const mls = cParams->minMatch; |
| switch(mls) |
| { |
| default: /* includes case 3 */ |
| case 4 : |
| return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 4); |
| case 5 : |
| return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 5); |
| case 6 : |
| return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 6); |
| case 7 : |
| return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 7); |
| } |
| } |