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Diffstat (limited to 'lib/compress/zstd_double_fast.c')
| -rw-r--r-- | lib/compress/zstd_double_fast.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/lib/compress/zstd_double_fast.c b/lib/compress/zstd_double_fast.c new file mode 100644 index 000000000000..876a36042ce8 --- /dev/null +++ b/lib/compress/zstd_double_fast.c @@ -0,0 +1,308 @@ +/* + * 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_double_fast.h" + + +void ZSTD_fillDoubleHashTable(ZSTD_CCtx* cctx, const void* end, const U32 mls) +{ + U32* const hashLarge = cctx->hashTable; + U32 const hBitsL = cctx->appliedParams.cParams.hashLog; + U32* const hashSmall = cctx->chainTable; + U32 const hBitsS = cctx->appliedParams.cParams.chainLog; + const BYTE* const base = cctx->base; + const BYTE* ip = base + cctx->nextToUpdate; + const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; + const size_t fastHashFillStep = 3; + + while(ip <= iend) { + hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip - base); + hashLarge[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip - base); + ip += fastHashFillStep; + } +} + + +FORCE_INLINE_TEMPLATE +size_t ZSTD_compressBlock_doubleFast_generic(ZSTD_CCtx* cctx, + const void* src, size_t srcSize, + const U32 mls) +{ + U32* const hashLong = cctx->hashTable; + const U32 hBitsL = cctx->appliedParams.cParams.hashLog; + U32* const hashSmall = cctx->chainTable; + const U32 hBitsS = cctx->appliedParams.cParams.chainLog; + seqStore_t* seqStorePtr = &(cctx->seqStore); + const BYTE* const base = cctx->base; + const BYTE* const istart = (const BYTE*)src; + const BYTE* ip = istart; + const BYTE* anchor = istart; + const U32 lowestIndex = cctx->dictLimit; + const BYTE* const lowest = base + lowestIndex; + const BYTE* const iend = istart + srcSize; + const BYTE* const ilimit = iend - HASH_READ_SIZE; + U32 offset_1=seqStorePtr->rep[0], offset_2=seqStorePtr->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(seqStorePtr, 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) >> g_searchStrength) + 1; + continue; + } + + offset_2 = offset_1; + offset_1 = offset; + + ZSTD_storeSeq(seqStorePtr, 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(seqStorePtr, 0, anchor, 0, rLength-MINMATCH); + ip += rLength; + anchor = ip; + continue; /* faster when present ... (?) */ + } } } + + /* save reps for next block */ + seqStorePtr->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved; + seqStorePtr->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved; + + /* Return the last literals size */ + return iend - anchor; +} + + +size_t ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize) +{ + const U32 mls = ctx->appliedParams.cParams.searchLength; + switch(mls) + { + default: /* includes case 3 */ + case 4 : + return ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 4); + case 5 : + return ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 5); + case 6 : + return ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 6); + case 7 : + return ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 7); + } +} + + +static size_t ZSTD_compressBlock_doubleFast_extDict_generic(ZSTD_CCtx* ctx, + const void* src, size_t srcSize, + const U32 mls) +{ + U32* const hashLong = ctx->hashTable; + U32 const hBitsL = ctx->appliedParams.cParams.hashLog; + U32* const hashSmall = ctx->chainTable; + U32 const hBitsS = ctx->appliedParams.cParams.chainLog; + seqStore_t* seqStorePtr = &(ctx->seqStore); + const BYTE* const base = ctx->base; + const BYTE* const dictBase = ctx->dictBase; + const BYTE* const istart = (const BYTE*)src; + const BYTE* ip = istart; + const BYTE* anchor = istart; + const U32 lowestIndex = ctx->lowLimit; + const BYTE* const dictStart = dictBase + lowestIndex; + const U32 dictLimit = ctx->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=seqStorePtr->rep[0], offset_2=seqStorePtr->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(seqStorePtr, 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(seqStorePtr, 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(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH); + + } else { + ip += ((ip-anchor) >> g_searchStrength) + 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(seqStorePtr, 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 */ + seqStorePtr->repToConfirm[0] = offset_1; seqStorePtr->repToConfirm[1] = offset_2; + + /* Return the last literals size */ + return iend - anchor; +} + + +size_t ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx, + const void* src, size_t srcSize) +{ + U32 const mls = ctx->appliedParams.cParams.searchLength; + switch(mls) + { + default: /* includes case 3 */ + case 4 : + return ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 4); + case 5 : + return ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 5); + case 6 : + return ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 6); + case 7 : + return ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 7); + } +} |