Mercurial > hg
view contrib/python-zstandard/zstd/compress/zstd_fast.c @ 43994:de7838053207
zstandard: vendor python-zstandard 0.13.0
Version 0.13.0 of the package was just released. It contains
an upgraded zstd C library which can result in some performance
wins, official support for Python 3.8, and a blackened code base.
There were no meaningful code or functionality changes in this
release of python-zstandard: just reformatting and an upgraded
zstd library version. So the diff seems much larger than what it
is.
Files were added without modifications.
The clang-format-ignorelist file was updated to reflect a new
header file in the zstd distribution.
# no-check-commit because 3rd party code has different style guidelines
Differential Revision: https://phab.mercurial-scm.org/D7770
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 28 Dec 2019 09:55:45 -0800 |
parents | 69de49c4e39c |
children |
line wrap: on
line source
/* * 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" /* ZSTD_hashPtr, ZSTD_count, ZSTD_storeSeq */ #include "zstd_fast.h" void ZSTD_fillHashTable(ZSTD_matchState_t* ms, const 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) { const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashTable = ms->hashTable; U32 const hlog = cParams->hashLog; /* support stepSize of 0 */ size_t const stepSize = cParams->targetLength + !(cParams->targetLength) + 1; const BYTE* const base = ms->window.base; const BYTE* const istart = (const BYTE*)src; /* We check ip0 (ip + 0) and ip1 (ip + 1) each loop */ const BYTE* ip0 = istart; const BYTE* ip1; const BYTE* anchor = istart; const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); const U32 maxDistance = 1U << cParams->windowLog; const U32 validStartIndex = ms->window.dictLimit; const U32 prefixStartIndex = (endIndex - validStartIndex > maxDistance) ? endIndex - maxDistance : validStartIndex; 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; /* init */ DEBUGLOG(5, "ZSTD_compressBlock_fast_generic"); ip0 += (ip0 == prefixStart); ip1 = ip0 + 1; { U32 const maxRep = (U32)(ip0 - prefixStart); if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0; if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0; } /* Main Search Loop */ while (ip1 < ilimit) { /* < instead of <=, because check at ip0+2 */ size_t mLength; BYTE const* ip2 = ip0 + 2; size_t const h0 = ZSTD_hashPtr(ip0, hlog, mls); U32 const val0 = MEM_read32(ip0); size_t const h1 = ZSTD_hashPtr(ip1, hlog, mls); U32 const val1 = MEM_read32(ip1); U32 const current0 = (U32)(ip0-base); U32 const current1 = (U32)(ip1-base); U32 const matchIndex0 = hashTable[h0]; U32 const matchIndex1 = hashTable[h1]; BYTE const* repMatch = ip2-offset_1; const BYTE* match0 = base + matchIndex0; const BYTE* match1 = base + matchIndex1; U32 offcode; hashTable[h0] = current0; /* update hash table */ hashTable[h1] = current1; /* update hash table */ assert(ip0 + 1 == ip1); if ((offset_1 > 0) & (MEM_read32(repMatch) == MEM_read32(ip2))) { mLength = ip2[-1] == repMatch[-1] ? 1 : 0; ip0 = ip2 - mLength; match0 = repMatch - mLength; offcode = 0; goto _match; } if ((matchIndex0 > prefixStartIndex) && MEM_read32(match0) == val0) { /* found a regular match */ goto _offset; } if ((matchIndex1 > prefixStartIndex) && MEM_read32(match1) == val1) { /* found a regular match after one literal */ ip0 = ip1; match0 = match1; goto _offset; } { size_t const step = ((size_t)(ip0-anchor) >> (kSearchStrength - 1)) + stepSize; assert(step >= 2); ip0 += step; ip1 += step; continue; } _offset: /* Requires: ip0, match0 */ /* Compute the offset code */ offset_2 = offset_1; offset_1 = (U32)(ip0-match0); offcode = offset_1 + ZSTD_REP_MOVE; mLength = 0; /* Count the backwards match length */ while (((ip0>anchor) & (match0>prefixStart)) && (ip0[-1] == match0[-1])) { ip0--; match0--; mLength++; } /* catch up */ _match: /* Requires: ip0, match0, offcode */ /* Count the forward length */ mLength += ZSTD_count(ip0+mLength+4, match0+mLength+4, iend) + 4; ZSTD_storeSeq(seqStore, (size_t)(ip0-anchor), anchor, iend, offcode, mLength-MINMATCH); /* match found */ ip0 += mLength; anchor = ip0; ip1 = ip0 + 1; if (ip0 <= ilimit) { /* Fill Table */ assert(base+current0+2 > istart); /* check base overflow */ hashTable[ZSTD_hashPtr(base+current0+2, hlog, mls)] = current0+2; /* here because current+2 could be > iend-8 */ hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base); while ( ((ip0 <= ilimit) & (offset_2>0)) /* offset_2==0 means offset_2 is invalidated */ && (MEM_read32(ip0) == MEM_read32(ip0 - offset_2)) ) { /* store sequence */ size_t const rLength = ZSTD_count(ip0+4, ip0+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(ip0, hlog, mls)] = (U32)(ip0-base); ip0 += rLength; ip1 = ip0 + 1; ZSTD_storeSeq(seqStore, 0 /*litLen*/, anchor, iend, 0 /*offCode*/, rLength-MINMATCH); anchor = ip0; continue; /* faster when present (confirmed on gcc-8) ... (?) */ } } } /* 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 (size_t)(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) { U32 const mls = ms->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); case 5 : return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5); case 6 : return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6); case 7 : return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7); } } FORCE_INLINE_TEMPLATE size_t ZSTD_compressBlock_fast_dictMatchState_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 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 = &dms->cParams ; const U32* const dictHashTable = dms->hashTable; const U32 dictStartIndex = dms->window.dictLimit; const BYTE* const dictBase = dms->window.base; const BYTE* const dictStart = dictBase + dictStartIndex; const BYTE* const dictEnd = dms->window.nextSrc; const U32 dictIndexDelta = prefixStartIndex - (U32)(dictEnd - dictBase); const U32 dictAndPrefixLength = (U32)(ip - prefixStart + dictEnd - dictStart); const U32 dictHLog = dictCParams->hashLog; /* if a dictionary is still attached, it necessarily means that * it is within window size. So we just check it. */ const U32 maxDistance = 1U << cParams->windowLog; const U32 endIndex = (U32)((size_t)(ip - base) + srcSize); assert(endIndex - prefixStartIndex <= maxDistance); (void)maxDistance; (void)endIndex; /* these variables are not used when assert() is disabled */ /* ensure there will be no no underflow * when translating a dict index into a local index */ assert(prefixStartIndex >= (U32)(dictEnd - dictBase)); /* init */ DEBUGLOG(5, "ZSTD_compressBlock_fast_dictMatchState_generic"); ip += (dictAndPrefixLength == 0); /* 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 = (repIndex < prefixStartIndex) ? dictBase + (repIndex - dictIndexDelta) : base + repIndex; hashTable[h] = current; /* update hash table */ if ( ((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, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH); } else if ( (matchIndex <= prefixStartIndex) ) { 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, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH); } } 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, (size_t)(ip-anchor), anchor, iend, 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 */ 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, iend, 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 ? offset_1 : offsetSaved; rep[1] = offset_2 ? offset_2 : offsetSaved; /* Return the last literals size */ return (size_t)(iend - anchor); } size_t ZSTD_compressBlock_fast_dictMatchState( ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], void const* src, size_t srcSize) { U32 const mls = ms->cParams.minMatch; assert(ms->dictMatchState != NULL); switch(mls) { default: /* includes case 3 */ case 4 : return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 4); case 5 : return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 5); case 6 : return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 6); case 7 : return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 7); } } 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 endIndex = (U32)((size_t)(istart - base) + srcSize); const U32 lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog); const U32 dictStartIndex = lowLimit; const BYTE* const dictStart = dictBase + dictStartIndex; const U32 dictLimit = ms->window.dictLimit; const U32 prefixStartIndex = dictLimit < lowLimit ? lowLimit : 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]; DEBUGLOG(5, "ZSTD_compressBlock_fast_extDict_generic"); /* switch to "regular" variant if extDict is invalidated due to maxDistance */ if (prefixStartIndex == dictStartIndex) return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, mls); /* 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; 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* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend; size_t const rLength = ZSTD_count_2segments(ip+1 +4, repMatch +4, iend, repMatchEnd, prefixStart) + 4; ip++; ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, rLength-MINMATCH); ip += rLength; anchor = ip; } else { if ( (matchIndex < dictStartIndex) || (MEM_read32(match) != MEM_read32(ip)) ) { assert(stepSize >= 1); ip += ((ip-anchor) >> kSearchStrength) + stepSize; continue; } { const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend; const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart; U32 const offset = current - matchIndex; size_t 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_2 = offset_1; offset_1 = offset; /* update offset history */ ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH); 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* const 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 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; } /* swap offset_2 <=> offset_1 */ ZSTD_storeSeq(seqStore, 0 /*litlen*/, anchor, iend, 0 /*offcode*/, 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 (size_t)(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) { U32 const mls = ms->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); } }