Mercurial > hg
view contrib/python-zstandard/zstd/dictBuilder/zdict.c @ 42937:69de49c4e39c
zstandard: vendor python-zstandard 0.12
The upstream source distribution from PyPI was extracted. Unwanted
files were removed.
The clang-format ignore list was updated to reflect the new source
of files.
test-repo-compengines.t was updated to reflect a change in behavior
of the zstd library.
The project contains a vendored copy of zstandard 1.4.3. The old
version was 1.3.8. This should result in some minor performance wins.
# no-check-commit because 3rd party code has different style guidelines
Differential Revision: https://phab.mercurial-scm.org/D6858
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 15 Sep 2019 20:04:00 -0700 |
parents | 675775c33ab6 |
children | de7838053207 |
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. */ /*-************************************** * Tuning parameters ****************************************/ #define MINRATIO 4 /* minimum nb of apparition to be selected in dictionary */ #define ZDICT_MAX_SAMPLES_SIZE (2000U << 20) #define ZDICT_MIN_SAMPLES_SIZE (ZDICT_CONTENTSIZE_MIN * MINRATIO) /*-************************************** * Compiler Options ****************************************/ /* Unix Large Files support (>4GB) */ #define _FILE_OFFSET_BITS 64 #if (defined(__sun__) && (!defined(__LP64__))) /* Sun Solaris 32-bits requires specific definitions */ # define _LARGEFILE_SOURCE #elif ! defined(__LP64__) /* No point defining Large file for 64 bit */ # define _LARGEFILE64_SOURCE #endif /*-************************************* * Dependencies ***************************************/ #include <stdlib.h> /* malloc, free */ #include <string.h> /* memset */ #include <stdio.h> /* fprintf, fopen, ftello64 */ #include <time.h> /* clock */ #include "mem.h" /* read */ #include "fse.h" /* FSE_normalizeCount, FSE_writeNCount */ #define HUF_STATIC_LINKING_ONLY #include "huf.h" /* HUF_buildCTable, HUF_writeCTable */ #include "zstd_internal.h" /* includes zstd.h */ #include "xxhash.h" /* XXH64 */ #include "divsufsort.h" #ifndef ZDICT_STATIC_LINKING_ONLY # define ZDICT_STATIC_LINKING_ONLY #endif #include "zdict.h" /*-************************************* * Constants ***************************************/ #define KB *(1 <<10) #define MB *(1 <<20) #define GB *(1U<<30) #define DICTLISTSIZE_DEFAULT 10000 #define NOISELENGTH 32 static const int g_compressionLevel_default = 3; static const U32 g_selectivity_default = 9; /*-************************************* * Console display ***************************************/ #define DISPLAY(...) { fprintf(stderr, __VA_ARGS__); fflush( stderr ); } #define DISPLAYLEVEL(l, ...) if (notificationLevel>=l) { DISPLAY(__VA_ARGS__); } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */ static clock_t ZDICT_clockSpan(clock_t nPrevious) { return clock() - nPrevious; } static void ZDICT_printHex(const void* ptr, size_t length) { const BYTE* const b = (const BYTE*)ptr; size_t u; for (u=0; u<length; u++) { BYTE c = b[u]; if (c<32 || c>126) c = '.'; /* non-printable char */ DISPLAY("%c", c); } } /*-******************************************************** * Helper functions **********************************************************/ unsigned ZDICT_isError(size_t errorCode) { return ERR_isError(errorCode); } const char* ZDICT_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); } unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize) { if (dictSize < 8) return 0; if (MEM_readLE32(dictBuffer) != ZSTD_MAGIC_DICTIONARY) return 0; return MEM_readLE32((const char*)dictBuffer + 4); } /*-******************************************************** * Dictionary training functions **********************************************************/ static unsigned ZDICT_NbCommonBytes (size_t val) { if (MEM_isLittleEndian()) { if (MEM_64bits()) { # if defined(_MSC_VER) && defined(_WIN64) unsigned long r = 0; _BitScanForward64( &r, (U64)val ); return (unsigned)(r>>3); # elif defined(__GNUC__) && (__GNUC__ >= 3) return (__builtin_ctzll((U64)val) >> 3); # else static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 }; return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58]; # endif } else { /* 32 bits */ # if defined(_MSC_VER) unsigned long r=0; _BitScanForward( &r, (U32)val ); return (unsigned)(r>>3); # elif defined(__GNUC__) && (__GNUC__ >= 3) return (__builtin_ctz((U32)val) >> 3); # else static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 }; return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27]; # endif } } else { /* Big Endian CPU */ if (MEM_64bits()) { # if defined(_MSC_VER) && defined(_WIN64) unsigned long r = 0; _BitScanReverse64( &r, val ); return (unsigned)(r>>3); # elif defined(__GNUC__) && (__GNUC__ >= 3) return (__builtin_clzll(val) >> 3); # else unsigned r; const unsigned n32 = sizeof(size_t)*4; /* calculate this way due to compiler complaining in 32-bits mode */ if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; } if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } r += (!val); return r; # endif } else { /* 32 bits */ # if defined(_MSC_VER) unsigned long r = 0; _BitScanReverse( &r, (unsigned long)val ); return (unsigned)(r>>3); # elif defined(__GNUC__) && (__GNUC__ >= 3) return (__builtin_clz((U32)val) >> 3); # else unsigned r; if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; } r += (!val); return r; # endif } } } /*! ZDICT_count() : Count the nb of common bytes between 2 pointers. Note : this function presumes end of buffer followed by noisy guard band. */ static size_t ZDICT_count(const void* pIn, const void* pMatch) { const char* const pStart = (const char*)pIn; for (;;) { size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn); if (!diff) { pIn = (const char*)pIn+sizeof(size_t); pMatch = (const char*)pMatch+sizeof(size_t); continue; } pIn = (const char*)pIn+ZDICT_NbCommonBytes(diff); return (size_t)((const char*)pIn - pStart); } } typedef struct { U32 pos; U32 length; U32 savings; } dictItem; static void ZDICT_initDictItem(dictItem* d) { d->pos = 1; d->length = 0; d->savings = (U32)(-1); } #define LLIMIT 64 /* heuristic determined experimentally */ #define MINMATCHLENGTH 7 /* heuristic determined experimentally */ static dictItem ZDICT_analyzePos( BYTE* doneMarks, const int* suffix, U32 start, const void* buffer, U32 minRatio, U32 notificationLevel) { U32 lengthList[LLIMIT] = {0}; U32 cumulLength[LLIMIT] = {0}; U32 savings[LLIMIT] = {0}; const BYTE* b = (const BYTE*)buffer; size_t maxLength = LLIMIT; size_t pos = suffix[start]; U32 end = start; dictItem solution; /* init */ memset(&solution, 0, sizeof(solution)); doneMarks[pos] = 1; /* trivial repetition cases */ if ( (MEM_read16(b+pos+0) == MEM_read16(b+pos+2)) ||(MEM_read16(b+pos+1) == MEM_read16(b+pos+3)) ||(MEM_read16(b+pos+2) == MEM_read16(b+pos+4)) ) { /* skip and mark segment */ U16 const pattern16 = MEM_read16(b+pos+4); U32 u, patternEnd = 6; while (MEM_read16(b+pos+patternEnd) == pattern16) patternEnd+=2 ; if (b[pos+patternEnd] == b[pos+patternEnd-1]) patternEnd++; for (u=1; u<patternEnd; u++) doneMarks[pos+u] = 1; return solution; } /* look forward */ { size_t length; do { end++; length = ZDICT_count(b + pos, b + suffix[end]); } while (length >= MINMATCHLENGTH); } /* look backward */ { size_t length; do { length = ZDICT_count(b + pos, b + *(suffix+start-1)); if (length >=MINMATCHLENGTH) start--; } while(length >= MINMATCHLENGTH); } /* exit if not found a minimum nb of repetitions */ if (end-start < minRatio) { U32 idx; for(idx=start; idx<end; idx++) doneMarks[suffix[idx]] = 1; return solution; } { int i; U32 mml; U32 refinedStart = start; U32 refinedEnd = end; DISPLAYLEVEL(4, "\n"); DISPLAYLEVEL(4, "found %3u matches of length >= %i at pos %7u ", (unsigned)(end-start), MINMATCHLENGTH, (unsigned)pos); DISPLAYLEVEL(4, "\n"); for (mml = MINMATCHLENGTH ; ; mml++) { BYTE currentChar = 0; U32 currentCount = 0; U32 currentID = refinedStart; U32 id; U32 selectedCount = 0; U32 selectedID = currentID; for (id =refinedStart; id < refinedEnd; id++) { if (b[suffix[id] + mml] != currentChar) { if (currentCount > selectedCount) { selectedCount = currentCount; selectedID = currentID; } currentID = id; currentChar = b[ suffix[id] + mml]; currentCount = 0; } currentCount ++; } if (currentCount > selectedCount) { /* for last */ selectedCount = currentCount; selectedID = currentID; } if (selectedCount < minRatio) break; refinedStart = selectedID; refinedEnd = refinedStart + selectedCount; } /* evaluate gain based on new dict */ start = refinedStart; pos = suffix[refinedStart]; end = start; memset(lengthList, 0, sizeof(lengthList)); /* look forward */ { size_t length; do { end++; length = ZDICT_count(b + pos, b + suffix[end]); if (length >= LLIMIT) length = LLIMIT-1; lengthList[length]++; } while (length >=MINMATCHLENGTH); } /* look backward */ { size_t length = MINMATCHLENGTH; while ((length >= MINMATCHLENGTH) & (start > 0)) { length = ZDICT_count(b + pos, b + suffix[start - 1]); if (length >= LLIMIT) length = LLIMIT - 1; lengthList[length]++; if (length >= MINMATCHLENGTH) start--; } } /* largest useful length */ memset(cumulLength, 0, sizeof(cumulLength)); cumulLength[maxLength-1] = lengthList[maxLength-1]; for (i=(int)(maxLength-2); i>=0; i--) cumulLength[i] = cumulLength[i+1] + lengthList[i]; for (i=LLIMIT-1; i>=MINMATCHLENGTH; i--) if (cumulLength[i]>=minRatio) break; maxLength = i; /* reduce maxLength in case of final into repetitive data */ { U32 l = (U32)maxLength; BYTE const c = b[pos + maxLength-1]; while (b[pos+l-2]==c) l--; maxLength = l; } if (maxLength < MINMATCHLENGTH) return solution; /* skip : no long-enough solution */ /* calculate savings */ savings[5] = 0; for (i=MINMATCHLENGTH; i<=(int)maxLength; i++) savings[i] = savings[i-1] + (lengthList[i] * (i-3)); DISPLAYLEVEL(4, "Selected dict at position %u, of length %u : saves %u (ratio: %.2f) \n", (unsigned)pos, (unsigned)maxLength, (unsigned)savings[maxLength], (double)savings[maxLength] / maxLength); solution.pos = (U32)pos; solution.length = (U32)maxLength; solution.savings = savings[maxLength]; /* mark positions done */ { U32 id; for (id=start; id<end; id++) { U32 p, pEnd, length; U32 const testedPos = suffix[id]; if (testedPos == pos) length = solution.length; else { length = (U32)ZDICT_count(b+pos, b+testedPos); if (length > solution.length) length = solution.length; } pEnd = (U32)(testedPos + length); for (p=testedPos; p<pEnd; p++) doneMarks[p] = 1; } } } return solution; } static int isIncluded(const void* in, const void* container, size_t length) { const char* const ip = (const char*) in; const char* const into = (const char*) container; size_t u; for (u=0; u<length; u++) { /* works because end of buffer is a noisy guard band */ if (ip[u] != into[u]) break; } return u==length; } /*! ZDICT_tryMerge() : check if dictItem can be merged, do it if possible @return : id of destination elt, 0 if not merged */ static U32 ZDICT_tryMerge(dictItem* table, dictItem elt, U32 eltNbToSkip, const void* buffer) { const U32 tableSize = table->pos; const U32 eltEnd = elt.pos + elt.length; const char* const buf = (const char*) buffer; /* tail overlap */ U32 u; for (u=1; u<tableSize; u++) { if (u==eltNbToSkip) continue; if ((table[u].pos > elt.pos) && (table[u].pos <= eltEnd)) { /* overlap, existing > new */ /* append */ U32 const addedLength = table[u].pos - elt.pos; table[u].length += addedLength; table[u].pos = elt.pos; table[u].savings += elt.savings * addedLength / elt.length; /* rough approx */ table[u].savings += elt.length / 8; /* rough approx bonus */ elt = table[u]; /* sort : improve rank */ while ((u>1) && (table[u-1].savings < elt.savings)) table[u] = table[u-1], u--; table[u] = elt; return u; } } /* front overlap */ for (u=1; u<tableSize; u++) { if (u==eltNbToSkip) continue; if ((table[u].pos + table[u].length >= elt.pos) && (table[u].pos < elt.pos)) { /* overlap, existing < new */ /* append */ int const addedLength = (int)eltEnd - (table[u].pos + table[u].length); table[u].savings += elt.length / 8; /* rough approx bonus */ if (addedLength > 0) { /* otherwise, elt fully included into existing */ table[u].length += addedLength; table[u].savings += elt.savings * addedLength / elt.length; /* rough approx */ } /* sort : improve rank */ elt = table[u]; while ((u>1) && (table[u-1].savings < elt.savings)) table[u] = table[u-1], u--; table[u] = elt; return u; } if (MEM_read64(buf + table[u].pos) == MEM_read64(buf + elt.pos + 1)) { if (isIncluded(buf + table[u].pos, buf + elt.pos + 1, table[u].length)) { size_t const addedLength = MAX( (int)elt.length - (int)table[u].length , 1 ); table[u].pos = elt.pos; table[u].savings += (U32)(elt.savings * addedLength / elt.length); table[u].length = MIN(elt.length, table[u].length + 1); return u; } } } return 0; } static void ZDICT_removeDictItem(dictItem* table, U32 id) { /* convention : table[0].pos stores nb of elts */ U32 const max = table[0].pos; U32 u; if (!id) return; /* protection, should never happen */ for (u=id; u<max-1; u++) table[u] = table[u+1]; table->pos--; } static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt, const void* buffer) { /* merge if possible */ U32 mergeId = ZDICT_tryMerge(table, elt, 0, buffer); if (mergeId) { U32 newMerge = 1; while (newMerge) { newMerge = ZDICT_tryMerge(table, table[mergeId], mergeId, buffer); if (newMerge) ZDICT_removeDictItem(table, mergeId); mergeId = newMerge; } return; } /* insert */ { U32 current; U32 nextElt = table->pos; if (nextElt >= maxSize) nextElt = maxSize-1; current = nextElt-1; while (table[current].savings < elt.savings) { table[current+1] = table[current]; current--; } table[current+1] = elt; table->pos = nextElt+1; } } static U32 ZDICT_dictSize(const dictItem* dictList) { U32 u, dictSize = 0; for (u=1; u<dictList[0].pos; u++) dictSize += dictList[u].length; return dictSize; } static size_t ZDICT_trainBuffer_legacy(dictItem* dictList, U32 dictListSize, const void* const buffer, size_t bufferSize, /* buffer must end with noisy guard band */ const size_t* fileSizes, unsigned nbFiles, unsigned minRatio, U32 notificationLevel) { int* const suffix0 = (int*)malloc((bufferSize+2)*sizeof(*suffix0)); int* const suffix = suffix0+1; U32* reverseSuffix = (U32*)malloc((bufferSize)*sizeof(*reverseSuffix)); BYTE* doneMarks = (BYTE*)malloc((bufferSize+16)*sizeof(*doneMarks)); /* +16 for overflow security */ U32* filePos = (U32*)malloc(nbFiles * sizeof(*filePos)); size_t result = 0; clock_t displayClock = 0; clock_t const refreshRate = CLOCKS_PER_SEC * 3 / 10; # define DISPLAYUPDATE(l, ...) if (notificationLevel>=l) { \ if (ZDICT_clockSpan(displayClock) > refreshRate) \ { displayClock = clock(); DISPLAY(__VA_ARGS__); \ if (notificationLevel>=4) fflush(stderr); } } /* init */ DISPLAYLEVEL(2, "\r%70s\r", ""); /* clean display line */ if (!suffix0 || !reverseSuffix || !doneMarks || !filePos) { result = ERROR(memory_allocation); goto _cleanup; } if (minRatio < MINRATIO) minRatio = MINRATIO; memset(doneMarks, 0, bufferSize+16); /* limit sample set size (divsufsort limitation)*/ if (bufferSize > ZDICT_MAX_SAMPLES_SIZE) DISPLAYLEVEL(3, "sample set too large : reduced to %u MB ...\n", (unsigned)(ZDICT_MAX_SAMPLES_SIZE>>20)); while (bufferSize > ZDICT_MAX_SAMPLES_SIZE) bufferSize -= fileSizes[--nbFiles]; /* sort */ DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (unsigned)(bufferSize>>20)); { int const divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0); if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; } } suffix[bufferSize] = (int)bufferSize; /* leads into noise */ suffix0[0] = (int)bufferSize; /* leads into noise */ /* build reverse suffix sort */ { size_t pos; for (pos=0; pos < bufferSize; pos++) reverseSuffix[suffix[pos]] = (U32)pos; /* note filePos tracks borders between samples. It's not used at this stage, but planned to become useful in a later update */ filePos[0] = 0; for (pos=1; pos<nbFiles; pos++) filePos[pos] = (U32)(filePos[pos-1] + fileSizes[pos-1]); } DISPLAYLEVEL(2, "finding patterns ... \n"); DISPLAYLEVEL(3, "minimum ratio : %u \n", minRatio); { U32 cursor; for (cursor=0; cursor < bufferSize; ) { dictItem solution; if (doneMarks[cursor]) { cursor++; continue; } solution = ZDICT_analyzePos(doneMarks, suffix, reverseSuffix[cursor], buffer, minRatio, notificationLevel); if (solution.length==0) { cursor++; continue; } ZDICT_insertDictItem(dictList, dictListSize, solution, buffer); cursor += solution.length; DISPLAYUPDATE(2, "\r%4.2f %% \r", (double)cursor / bufferSize * 100); } } _cleanup: free(suffix0); free(reverseSuffix); free(doneMarks); free(filePos); return result; } static void ZDICT_fillNoise(void* buffer, size_t length) { unsigned const prime1 = 2654435761U; unsigned const prime2 = 2246822519U; unsigned acc = prime1; size_t p=0;; for (p=0; p<length; p++) { acc *= prime2; ((unsigned char*)buffer)[p] = (unsigned char)(acc >> 21); } } typedef struct { ZSTD_CDict* dict; /* dictionary */ ZSTD_CCtx* zc; /* working context */ void* workPlace; /* must be ZSTD_BLOCKSIZE_MAX allocated */ } EStats_ress_t; #define MAXREPOFFSET 1024 static void ZDICT_countEStats(EStats_ress_t esr, ZSTD_parameters params, unsigned* countLit, unsigned* offsetcodeCount, unsigned* matchlengthCount, unsigned* litlengthCount, U32* repOffsets, const void* src, size_t srcSize, U32 notificationLevel) { size_t const blockSizeMax = MIN (ZSTD_BLOCKSIZE_MAX, 1 << params.cParams.windowLog); size_t cSize; if (srcSize > blockSizeMax) srcSize = blockSizeMax; /* protection vs large samples */ { size_t const errorCode = ZSTD_compressBegin_usingCDict(esr.zc, esr.dict); if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_compressBegin_usingCDict failed \n"); return; } } cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_MAX, src, srcSize); if (ZSTD_isError(cSize)) { DISPLAYLEVEL(3, "warning : could not compress sample size %u \n", (unsigned)srcSize); return; } if (cSize) { /* if == 0; block is not compressible */ const seqStore_t* const seqStorePtr = ZSTD_getSeqStore(esr.zc); /* literals stats */ { const BYTE* bytePtr; for(bytePtr = seqStorePtr->litStart; bytePtr < seqStorePtr->lit; bytePtr++) countLit[*bytePtr]++; } /* seqStats */ { U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); ZSTD_seqToCodes(seqStorePtr); { const BYTE* codePtr = seqStorePtr->ofCode; U32 u; for (u=0; u<nbSeq; u++) offsetcodeCount[codePtr[u]]++; } { const BYTE* codePtr = seqStorePtr->mlCode; U32 u; for (u=0; u<nbSeq; u++) matchlengthCount[codePtr[u]]++; } { const BYTE* codePtr = seqStorePtr->llCode; U32 u; for (u=0; u<nbSeq; u++) litlengthCount[codePtr[u]]++; } if (nbSeq >= 2) { /* rep offsets */ const seqDef* const seq = seqStorePtr->sequencesStart; U32 offset1 = seq[0].offset - 3; U32 offset2 = seq[1].offset - 3; if (offset1 >= MAXREPOFFSET) offset1 = 0; if (offset2 >= MAXREPOFFSET) offset2 = 0; repOffsets[offset1] += 3; repOffsets[offset2] += 1; } } } } static size_t ZDICT_totalSampleSize(const size_t* fileSizes, unsigned nbFiles) { size_t total=0; unsigned u; for (u=0; u<nbFiles; u++) total += fileSizes[u]; return total; } typedef struct { U32 offset; U32 count; } offsetCount_t; static void ZDICT_insertSortCount(offsetCount_t table[ZSTD_REP_NUM+1], U32 val, U32 count) { U32 u; table[ZSTD_REP_NUM].offset = val; table[ZSTD_REP_NUM].count = count; for (u=ZSTD_REP_NUM; u>0; u--) { offsetCount_t tmp; if (table[u-1].count >= table[u].count) break; tmp = table[u-1]; table[u-1] = table[u]; table[u] = tmp; } } /* ZDICT_flatLit() : * rewrite `countLit` to contain a mostly flat but still compressible distribution of literals. * necessary to avoid generating a non-compressible distribution that HUF_writeCTable() cannot encode. */ static void ZDICT_flatLit(unsigned* countLit) { int u; for (u=1; u<256; u++) countLit[u] = 2; countLit[0] = 4; countLit[253] = 1; countLit[254] = 1; } #define OFFCODE_MAX 30 /* only applicable to first block */ static size_t ZDICT_analyzeEntropy(void* dstBuffer, size_t maxDstSize, unsigned compressionLevel, const void* srcBuffer, const size_t* fileSizes, unsigned nbFiles, const void* dictBuffer, size_t dictBufferSize, unsigned notificationLevel) { unsigned countLit[256]; HUF_CREATE_STATIC_CTABLE(hufTable, 255); unsigned offcodeCount[OFFCODE_MAX+1]; short offcodeNCount[OFFCODE_MAX+1]; U32 offcodeMax = ZSTD_highbit32((U32)(dictBufferSize + 128 KB)); unsigned matchLengthCount[MaxML+1]; short matchLengthNCount[MaxML+1]; unsigned litLengthCount[MaxLL+1]; short litLengthNCount[MaxLL+1]; U32 repOffset[MAXREPOFFSET]; offsetCount_t bestRepOffset[ZSTD_REP_NUM+1]; EStats_ress_t esr = { NULL, NULL, NULL }; ZSTD_parameters params; U32 u, huffLog = 11, Offlog = OffFSELog, mlLog = MLFSELog, llLog = LLFSELog, total; size_t pos = 0, errorCode; size_t eSize = 0; size_t const totalSrcSize = ZDICT_totalSampleSize(fileSizes, nbFiles); size_t const averageSampleSize = totalSrcSize / (nbFiles + !nbFiles); BYTE* dstPtr = (BYTE*)dstBuffer; /* init */ DEBUGLOG(4, "ZDICT_analyzeEntropy"); if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionaryCreation_failed); goto _cleanup; } /* too large dictionary */ for (u=0; u<256; u++) countLit[u] = 1; /* any character must be described */ for (u=0; u<=offcodeMax; u++) offcodeCount[u] = 1; for (u=0; u<=MaxML; u++) matchLengthCount[u] = 1; for (u=0; u<=MaxLL; u++) litLengthCount[u] = 1; memset(repOffset, 0, sizeof(repOffset)); repOffset[1] = repOffset[4] = repOffset[8] = 1; memset(bestRepOffset, 0, sizeof(bestRepOffset)); if (compressionLevel==0) compressionLevel = g_compressionLevel_default; params = ZSTD_getParams(compressionLevel, averageSampleSize, dictBufferSize); esr.dict = ZSTD_createCDict_advanced(dictBuffer, dictBufferSize, ZSTD_dlm_byRef, ZSTD_dct_rawContent, params.cParams, ZSTD_defaultCMem); esr.zc = ZSTD_createCCtx(); esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX); if (!esr.dict || !esr.zc || !esr.workPlace) { eSize = ERROR(memory_allocation); DISPLAYLEVEL(1, "Not enough memory \n"); goto _cleanup; } /* collect stats on all samples */ for (u=0; u<nbFiles; u++) { ZDICT_countEStats(esr, params, countLit, offcodeCount, matchLengthCount, litLengthCount, repOffset, (const char*)srcBuffer + pos, fileSizes[u], notificationLevel); pos += fileSizes[u]; } /* analyze, build stats, starting with literals */ { size_t maxNbBits = HUF_buildCTable (hufTable, countLit, 255, huffLog); if (HUF_isError(maxNbBits)) { eSize = maxNbBits; DISPLAYLEVEL(1, " HUF_buildCTable error \n"); goto _cleanup; } if (maxNbBits==8) { /* not compressible : will fail on HUF_writeCTable() */ DISPLAYLEVEL(2, "warning : pathological dataset : literals are not compressible : samples are noisy or too regular \n"); ZDICT_flatLit(countLit); /* replace distribution by a fake "mostly flat but still compressible" distribution, that HUF_writeCTable() can encode */ maxNbBits = HUF_buildCTable (hufTable, countLit, 255, huffLog); assert(maxNbBits==9); } huffLog = (U32)maxNbBits; } /* looking for most common first offsets */ { U32 offset; for (offset=1; offset<MAXREPOFFSET; offset++) ZDICT_insertSortCount(bestRepOffset, offset, repOffset[offset]); } /* note : the result of this phase should be used to better appreciate the impact on statistics */ total=0; for (u=0; u<=offcodeMax; u++) total+=offcodeCount[u]; errorCode = FSE_normalizeCount(offcodeNCount, Offlog, offcodeCount, total, offcodeMax); if (FSE_isError(errorCode)) { eSize = errorCode; DISPLAYLEVEL(1, "FSE_normalizeCount error with offcodeCount \n"); goto _cleanup; } Offlog = (U32)errorCode; total=0; for (u=0; u<=MaxML; u++) total+=matchLengthCount[u]; errorCode = FSE_normalizeCount(matchLengthNCount, mlLog, matchLengthCount, total, MaxML); if (FSE_isError(errorCode)) { eSize = errorCode; DISPLAYLEVEL(1, "FSE_normalizeCount error with matchLengthCount \n"); goto _cleanup; } mlLog = (U32)errorCode; total=0; for (u=0; u<=MaxLL; u++) total+=litLengthCount[u]; errorCode = FSE_normalizeCount(litLengthNCount, llLog, litLengthCount, total, MaxLL); if (FSE_isError(errorCode)) { eSize = errorCode; DISPLAYLEVEL(1, "FSE_normalizeCount error with litLengthCount \n"); goto _cleanup; } llLog = (U32)errorCode; /* write result to buffer */ { size_t const hhSize = HUF_writeCTable(dstPtr, maxDstSize, hufTable, 255, huffLog); if (HUF_isError(hhSize)) { eSize = hhSize; DISPLAYLEVEL(1, "HUF_writeCTable error \n"); goto _cleanup; } dstPtr += hhSize; maxDstSize -= hhSize; eSize += hhSize; } { size_t const ohSize = FSE_writeNCount(dstPtr, maxDstSize, offcodeNCount, OFFCODE_MAX, Offlog); if (FSE_isError(ohSize)) { eSize = ohSize; DISPLAYLEVEL(1, "FSE_writeNCount error with offcodeNCount \n"); goto _cleanup; } dstPtr += ohSize; maxDstSize -= ohSize; eSize += ohSize; } { size_t const mhSize = FSE_writeNCount(dstPtr, maxDstSize, matchLengthNCount, MaxML, mlLog); if (FSE_isError(mhSize)) { eSize = mhSize; DISPLAYLEVEL(1, "FSE_writeNCount error with matchLengthNCount \n"); goto _cleanup; } dstPtr += mhSize; maxDstSize -= mhSize; eSize += mhSize; } { size_t const lhSize = FSE_writeNCount(dstPtr, maxDstSize, litLengthNCount, MaxLL, llLog); if (FSE_isError(lhSize)) { eSize = lhSize; DISPLAYLEVEL(1, "FSE_writeNCount error with litlengthNCount \n"); goto _cleanup; } dstPtr += lhSize; maxDstSize -= lhSize; eSize += lhSize; } if (maxDstSize<12) { eSize = ERROR(dstSize_tooSmall); DISPLAYLEVEL(1, "not enough space to write RepOffsets \n"); goto _cleanup; } # if 0 MEM_writeLE32(dstPtr+0, bestRepOffset[0].offset); MEM_writeLE32(dstPtr+4, bestRepOffset[1].offset); MEM_writeLE32(dstPtr+8, bestRepOffset[2].offset); #else /* at this stage, we don't use the result of "most common first offset", as the impact of statistics is not properly evaluated */ MEM_writeLE32(dstPtr+0, repStartValue[0]); MEM_writeLE32(dstPtr+4, repStartValue[1]); MEM_writeLE32(dstPtr+8, repStartValue[2]); #endif eSize += 12; _cleanup: ZSTD_freeCDict(esr.dict); ZSTD_freeCCtx(esr.zc); free(esr.workPlace); return eSize; } size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity, const void* customDictContent, size_t dictContentSize, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples, ZDICT_params_t params) { size_t hSize; #define HBUFFSIZE 256 /* should prove large enough for all entropy headers */ BYTE header[HBUFFSIZE]; int const compressionLevel = (params.compressionLevel == 0) ? g_compressionLevel_default : params.compressionLevel; U32 const notificationLevel = params.notificationLevel; /* check conditions */ DEBUGLOG(4, "ZDICT_finalizeDictionary"); if (dictBufferCapacity < dictContentSize) return ERROR(dstSize_tooSmall); if (dictContentSize < ZDICT_CONTENTSIZE_MIN) return ERROR(srcSize_wrong); if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) return ERROR(dstSize_tooSmall); /* dictionary header */ MEM_writeLE32(header, ZSTD_MAGIC_DICTIONARY); { U64 const randomID = XXH64(customDictContent, dictContentSize, 0); U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768; U32 const dictID = params.dictID ? params.dictID : compliantID; MEM_writeLE32(header+4, dictID); } hSize = 8; /* entropy tables */ DISPLAYLEVEL(2, "\r%70s\r", ""); /* clean display line */ DISPLAYLEVEL(2, "statistics ... \n"); { size_t const eSize = ZDICT_analyzeEntropy(header+hSize, HBUFFSIZE-hSize, compressionLevel, samplesBuffer, samplesSizes, nbSamples, customDictContent, dictContentSize, notificationLevel); if (ZDICT_isError(eSize)) return eSize; hSize += eSize; } /* copy elements in final buffer ; note : src and dst buffer can overlap */ if (hSize + dictContentSize > dictBufferCapacity) dictContentSize = dictBufferCapacity - hSize; { size_t const dictSize = hSize + dictContentSize; char* dictEnd = (char*)dictBuffer + dictSize; memmove(dictEnd - dictContentSize, customDictContent, dictContentSize); memcpy(dictBuffer, header, hSize); return dictSize; } } static size_t ZDICT_addEntropyTablesFromBuffer_advanced( void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples, ZDICT_params_t params) { int const compressionLevel = (params.compressionLevel == 0) ? g_compressionLevel_default : params.compressionLevel; U32 const notificationLevel = params.notificationLevel; size_t hSize = 8; /* calculate entropy tables */ DISPLAYLEVEL(2, "\r%70s\r", ""); /* clean display line */ DISPLAYLEVEL(2, "statistics ... \n"); { size_t const eSize = ZDICT_analyzeEntropy((char*)dictBuffer+hSize, dictBufferCapacity-hSize, compressionLevel, samplesBuffer, samplesSizes, nbSamples, (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize, notificationLevel); if (ZDICT_isError(eSize)) return eSize; hSize += eSize; } /* add dictionary header (after entropy tables) */ MEM_writeLE32(dictBuffer, ZSTD_MAGIC_DICTIONARY); { U64 const randomID = XXH64((char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize, 0); U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768; U32 const dictID = params.dictID ? params.dictID : compliantID; MEM_writeLE32((char*)dictBuffer+4, dictID); } if (hSize + dictContentSize < dictBufferCapacity) memmove((char*)dictBuffer + hSize, (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize); return MIN(dictBufferCapacity, hSize+dictContentSize); } /* Hidden declaration for dbio.c */ size_t ZDICT_trainFromBuffer_unsafe_legacy( void* dictBuffer, size_t maxDictSize, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples, ZDICT_legacy_params_t params); /*! ZDICT_trainFromBuffer_unsafe_legacy() : * Warning : `samplesBuffer` must be followed by noisy guard band. * @return : size of dictionary, or an error code which can be tested with ZDICT_isError() */ size_t ZDICT_trainFromBuffer_unsafe_legacy( void* dictBuffer, size_t maxDictSize, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples, ZDICT_legacy_params_t params) { U32 const dictListSize = MAX(MAX(DICTLISTSIZE_DEFAULT, nbSamples), (U32)(maxDictSize/16)); dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList)); unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel; unsigned const minRep = (selectivity > 30) ? MINRATIO : nbSamples >> selectivity; size_t const targetDictSize = maxDictSize; size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples); size_t dictSize = 0; U32 const notificationLevel = params.zParams.notificationLevel; /* checks */ if (!dictList) return ERROR(memory_allocation); if (maxDictSize < ZDICT_DICTSIZE_MIN) { free(dictList); return ERROR(dstSize_tooSmall); } /* requested dictionary size is too small */ if (samplesBuffSize < ZDICT_MIN_SAMPLES_SIZE) { free(dictList); return ERROR(dictionaryCreation_failed); } /* not enough source to create dictionary */ /* init */ ZDICT_initDictItem(dictList); /* build dictionary */ ZDICT_trainBuffer_legacy(dictList, dictListSize, samplesBuffer, samplesBuffSize, samplesSizes, nbSamples, minRep, notificationLevel); /* display best matches */ if (params.zParams.notificationLevel>= 3) { unsigned const nb = MIN(25, dictList[0].pos); unsigned const dictContentSize = ZDICT_dictSize(dictList); unsigned u; DISPLAYLEVEL(3, "\n %u segments found, of total size %u \n", (unsigned)dictList[0].pos-1, dictContentSize); DISPLAYLEVEL(3, "list %u best segments \n", nb-1); for (u=1; u<nb; u++) { unsigned const pos = dictList[u].pos; unsigned const length = dictList[u].length; U32 const printedLength = MIN(40, length); if ((pos > samplesBuffSize) || ((pos + length) > samplesBuffSize)) { free(dictList); return ERROR(GENERIC); /* should never happen */ } DISPLAYLEVEL(3, "%3u:%3u bytes at pos %8u, savings %7u bytes |", u, length, pos, (unsigned)dictList[u].savings); ZDICT_printHex((const char*)samplesBuffer+pos, printedLength); DISPLAYLEVEL(3, "| \n"); } } /* create dictionary */ { unsigned dictContentSize = ZDICT_dictSize(dictList); if (dictContentSize < ZDICT_CONTENTSIZE_MIN) { free(dictList); return ERROR(dictionaryCreation_failed); } /* dictionary content too small */ if (dictContentSize < targetDictSize/4) { DISPLAYLEVEL(2, "! warning : selected content significantly smaller than requested (%u < %u) \n", dictContentSize, (unsigned)maxDictSize); if (samplesBuffSize < 10 * targetDictSize) DISPLAYLEVEL(2, "! consider increasing the number of samples (total size : %u MB)\n", (unsigned)(samplesBuffSize>>20)); if (minRep > MINRATIO) { DISPLAYLEVEL(2, "! consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1); DISPLAYLEVEL(2, "! note : larger dictionaries are not necessarily better, test its efficiency on samples \n"); } } if ((dictContentSize > targetDictSize*3) && (nbSamples > 2*MINRATIO) && (selectivity>1)) { unsigned proposedSelectivity = selectivity-1; while ((nbSamples >> proposedSelectivity) <= MINRATIO) { proposedSelectivity--; } DISPLAYLEVEL(2, "! note : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (unsigned)maxDictSize); DISPLAYLEVEL(2, "! consider increasing dictionary size, or produce denser dictionary (-s%u) \n", proposedSelectivity); DISPLAYLEVEL(2, "! always test dictionary efficiency on real samples \n"); } /* limit dictionary size */ { U32 const max = dictList->pos; /* convention : nb of useful elts within dictList */ U32 currentSize = 0; U32 n; for (n=1; n<max; n++) { currentSize += dictList[n].length; if (currentSize > targetDictSize) { currentSize -= dictList[n].length; break; } } dictList->pos = n; dictContentSize = currentSize; } /* build dict content */ { U32 u; BYTE* ptr = (BYTE*)dictBuffer + maxDictSize; for (u=1; u<dictList->pos; u++) { U32 l = dictList[u].length; ptr -= l; if (ptr<(BYTE*)dictBuffer) { free(dictList); return ERROR(GENERIC); } /* should not happen */ memcpy(ptr, (const char*)samplesBuffer+dictList[u].pos, l); } } dictSize = ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, maxDictSize, samplesBuffer, samplesSizes, nbSamples, params.zParams); } /* clean up */ free(dictList); return dictSize; } /* ZDICT_trainFromBuffer_legacy() : * issue : samplesBuffer need to be followed by a noisy guard band. * work around : duplicate the buffer, and add the noise */ size_t ZDICT_trainFromBuffer_legacy(void* dictBuffer, size_t dictBufferCapacity, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples, ZDICT_legacy_params_t params) { size_t result; void* newBuff; size_t const sBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples); if (sBuffSize < ZDICT_MIN_SAMPLES_SIZE) return 0; /* not enough content => no dictionary */ newBuff = malloc(sBuffSize + NOISELENGTH); if (!newBuff) return ERROR(memory_allocation); memcpy(newBuff, samplesBuffer, sBuffSize); ZDICT_fillNoise((char*)newBuff + sBuffSize, NOISELENGTH); /* guard band, for end of buffer condition */ result = ZDICT_trainFromBuffer_unsafe_legacy(dictBuffer, dictBufferCapacity, newBuff, samplesSizes, nbSamples, params); free(newBuff); return result; } size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples) { ZDICT_fastCover_params_t params; DEBUGLOG(3, "ZDICT_trainFromBuffer"); memset(¶ms, 0, sizeof(params)); params.d = 8; params.steps = 4; /* Default to level 6 since no compression level information is available */ params.zParams.compressionLevel = 3; #if defined(DEBUGLEVEL) && (DEBUGLEVEL>=1) params.zParams.notificationLevel = DEBUGLEVEL; #endif return ZDICT_optimizeTrainFromBuffer_fastCover(dictBuffer, dictBufferCapacity, samplesBuffer, samplesSizes, nbSamples, ¶ms); } size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity, const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples) { ZDICT_params_t params; memset(¶ms, 0, sizeof(params)); return ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, dictBufferCapacity, samplesBuffer, samplesSizes, nbSamples, params); }