| /* |
| * 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_double_fast.h" |
| |
| |
| void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms, |
| ZSTD_compressionParameters const* cParams, |
| void const* end) |
| { |
| U32* const hashLarge = ms->hashTable; |
| U32 const hBitsL = cParams->hashLog; |
| U32 const mls = cParams->searchLength; |
| U32* const hashSmall = ms->chainTable; |
| U32 const hBitsS = cParams->chainLog; |
| 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 tables. |
| * Insert the other positions into the large hash table if their entry |
| * is empty. |
| */ |
| for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) { |
| U32 const current = (U32)(ip - base); |
| U32 i; |
| for (i = 0; i < fastHashFillStep; ++i) { |
| size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls); |
| size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8); |
| if (i == 0) |
| hashSmall[smHash] = current + i; |
| if (i == 0 || hashLarge[lgHash] == 0) |
| hashLarge[lgHash] = current + i; |
| } |
| } |
| } |
| |
| |
| FORCE_INLINE_TEMPLATE |
| size_t ZSTD_compressBlock_doubleFast_generic( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize, |
| U32 const mls /* template */) |
| { |
| U32* const hashLong = ms->hashTable; |
| const U32 hBitsL = cParams->hashLog; |
| U32* const hashSmall = ms->chainTable; |
| const U32 hBitsS = cParams->chainLog; |
| const BYTE* const base = ms->window.base; |
| const BYTE* const istart = (const BYTE*)src; |
| const BYTE* ip = istart; |
| const BYTE* anchor = istart; |
| const U32 lowestIndex = ms->window.dictLimit; |
| const BYTE* const lowest = base + lowestIndex; |
| 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; |
| |
| /* init */ |
| ip += (ip==lowest); |
| { U32 const maxRep = (U32)(ip-lowest); |
| if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0; |
| if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0; |
| } |
| |
| /* Main Search Loop */ |
| while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */ |
| size_t mLength; |
| size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8); |
| size_t const h = ZSTD_hashPtr(ip, hBitsS, mls); |
| U32 const current = (U32)(ip-base); |
| U32 const matchIndexL = hashLong[h2]; |
| U32 const matchIndexS = hashSmall[h]; |
| const BYTE* matchLong = base + matchIndexL; |
| const BYTE* match = base + matchIndexS; |
| hashLong[h2] = hashSmall[h] = current; /* update hash tables */ |
| |
| assert(offset_1 <= current); /* supposed guaranteed by construction */ |
| if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) { |
| /* favor repcode */ |
| mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4; |
| ip++; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH); |
| } else { |
| U32 offset; |
| if ( (matchIndexL > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip)) ) { |
| mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8; |
| offset = (U32)(ip-matchLong); |
| while (((ip>anchor) & (matchLong>lowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */ |
| } else if ( (matchIndexS > lowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) { |
| size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8); |
| U32 const matchIndexL3 = hashLong[hl3]; |
| const BYTE* matchL3 = base + matchIndexL3; |
| hashLong[hl3] = current + 1; |
| if ( (matchIndexL3 > lowestIndex) && (MEM_read64(matchL3) == MEM_read64(ip+1)) ) { |
| mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8; |
| ip++; |
| offset = (U32)(ip-matchL3); |
| while (((ip>anchor) & (matchL3>lowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */ |
| } else { |
| mLength = ZSTD_count(ip+4, match+4, iend) + 4; |
| offset = (U32)(ip-match); |
| while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ |
| } |
| } else { |
| ip += ((ip-anchor) >> kSearchStrength) + 1; |
| continue; |
| } |
| |
| 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 */ |
| hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = |
| hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2; /* here because current+2 could be > iend-8 */ |
| hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = |
| hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base); |
| |
| /* check immediate repcode */ |
| 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 */ |
| hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base); |
| hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (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_doubleFast( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| { |
| const U32 mls = cParams->searchLength; |
| switch(mls) |
| { |
| default: /* includes case 3 */ |
| case 4 : |
| return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 4); |
| case 5 : |
| return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 5); |
| case 6 : |
| return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 6); |
| case 7 : |
| return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 7); |
| } |
| } |
| |
| |
| static size_t ZSTD_compressBlock_doubleFast_extDict_generic( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize, |
| U32 const mls /* template */) |
| { |
| U32* const hashLong = ms->hashTable; |
| U32 const hBitsL = cParams->hashLog; |
| U32* const hashSmall = ms->chainTable; |
| U32 const hBitsS = cParams->chainLog; |
| 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 lowestIndex = ms->window.lowLimit; |
| const BYTE* const dictStart = dictBase + lowestIndex; |
| const U32 dictLimit = ms->window.dictLimit; |
| const BYTE* const lowPrefixPtr = base + dictLimit; |
| const BYTE* const dictEnd = dictBase + dictLimit; |
| 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 hSmall = ZSTD_hashPtr(ip, hBitsS, mls); |
| const U32 matchIndex = hashSmall[hSmall]; |
| const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base; |
| const BYTE* match = matchBase + matchIndex; |
| |
| const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8); |
| const U32 matchLongIndex = hashLong[hLong]; |
| const BYTE* matchLongBase = matchLongIndex < dictLimit ? dictBase : base; |
| const BYTE* matchLong = matchLongBase + matchLongIndex; |
| |
| const U32 current = (U32)(ip-base); |
| const U32 repIndex = current + 1 - offset_1; /* offset_1 expected <= current +1 */ |
| const BYTE* repBase = repIndex < dictLimit ? dictBase : base; |
| const BYTE* repMatch = repBase + repIndex; |
| size_t mLength; |
| hashSmall[hSmall] = hashLong[hLong] = current; /* update hash table */ |
| |
| if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex)) |
| && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { |
| const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend; |
| mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4; |
| ip++; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH); |
| } else { |
| if ((matchLongIndex > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) { |
| const BYTE* matchEnd = matchLongIndex < dictLimit ? dictEnd : iend; |
| const BYTE* lowMatchPtr = matchLongIndex < dictLimit ? dictStart : lowPrefixPtr; |
| U32 offset; |
| mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, lowPrefixPtr) + 8; |
| offset = current - matchLongIndex; |
| while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */ |
| offset_2 = offset_1; |
| offset_1 = offset; |
| ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH); |
| |
| } else if ((matchIndex > lowestIndex) && (MEM_read32(match) == MEM_read32(ip))) { |
| size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8); |
| U32 const matchIndex3 = hashLong[h3]; |
| const BYTE* const match3Base = matchIndex3 < dictLimit ? dictBase : base; |
| const BYTE* match3 = match3Base + matchIndex3; |
| U32 offset; |
| hashLong[h3] = current + 1; |
| if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) { |
| const BYTE* matchEnd = matchIndex3 < dictLimit ? dictEnd : iend; |
| const BYTE* lowMatchPtr = matchIndex3 < dictLimit ? dictStart : lowPrefixPtr; |
| mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, lowPrefixPtr) + 8; |
| ip++; |
| offset = current+1 - matchIndex3; |
| while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */ |
| } else { |
| const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend; |
| const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr; |
| mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4; |
| offset = current - matchIndex; |
| while (((ip>anchor) & (match>lowMatchPtr)) && (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); |
| |
| } else { |
| ip += ((ip-anchor) >> kSearchStrength) + 1; |
| continue; |
| } } |
| |
| /* found a match : store it */ |
| ip += mLength; |
| anchor = ip; |
| |
| if (ip <= ilimit) { |
| /* Fill Table */ |
| hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2; |
| hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = current+2; |
| hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base); |
| hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (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 < dictLimit ? dictBase + repIndex2 : base + repIndex2; |
| if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex)) /* intentional overflow */ |
| && (MEM_read32(repMatch2) == MEM_read32(ip)) ) { |
| const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend; |
| size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, lowPrefixPtr) + 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); |
| hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2; |
| hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = 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_doubleFast_extDict( |
| ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], |
| ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize) |
| { |
| U32 const mls = cParams->searchLength; |
| switch(mls) |
| { |
| default: /* includes case 3 */ |
| case 4 : |
| return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 4); |
| case 5 : |
| return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 5); |
| case 6 : |
| return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 6); |
| case 7 : |
| return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 7); |
| } |
| } |