diff options
Diffstat (limited to 'vendor/github.com/DataDog/zstd/zdict.c')
| -rw-r--r-- | vendor/github.com/DataDog/zstd/zdict.c | 1111 |
1 files changed, 1111 insertions, 0 deletions
diff --git a/vendor/github.com/DataDog/zstd/zdict.c b/vendor/github.com/DataDog/zstd/zdict.c new file mode 100644 index 000000000..c753da0db --- /dev/null +++ b/vendor/github.com/DataDog/zstd/zdict.c @@ -0,0 +1,1111 @@ +/* + * 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + 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 = ERROR(GENERIC); + DISPLAYLEVEL(1, "FSE_writeNCount error with litlengthNCount \n"); + goto _cleanup; + } + dstPtr += lhSize; + maxDstSize -= lhSize; + eSize += lhSize; + } + + if (maxDstSize<12) { + eSize = ERROR(GENERIC); + 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); +} |