From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- lib/zstd/compress/fse_compress.c | 625 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 625 insertions(+) create mode 100644 lib/zstd/compress/fse_compress.c (limited to 'lib/zstd/compress/fse_compress.c') diff --git a/lib/zstd/compress/fse_compress.c b/lib/zstd/compress/fse_compress.c new file mode 100644 index 000000000..436985b62 --- /dev/null +++ b/lib/zstd/compress/fse_compress.c @@ -0,0 +1,625 @@ +/* ****************************************************************** + * FSE : Finite State Entropy encoder + * Copyright (c) Yann Collet, Facebook, Inc. + * + * You can contact the author at : + * - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy + * - Public forum : https://groups.google.com/forum/#!forum/lz4c + * + * 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. +****************************************************************** */ + +/* ************************************************************** +* Includes +****************************************************************/ +#include "../common/compiler.h" +#include "../common/mem.h" /* U32, U16, etc. */ +#include "../common/debug.h" /* assert, DEBUGLOG */ +#include "hist.h" /* HIST_count_wksp */ +#include "../common/bitstream.h" +#define FSE_STATIC_LINKING_ONLY +#include "../common/fse.h" +#include "../common/error_private.h" +#define ZSTD_DEPS_NEED_MALLOC +#define ZSTD_DEPS_NEED_MATH64 +#include "../common/zstd_deps.h" /* ZSTD_malloc, ZSTD_free, ZSTD_memcpy, ZSTD_memset */ + + +/* ************************************************************** +* Error Management +****************************************************************/ +#define FSE_isError ERR_isError + + +/* ************************************************************** +* Templates +****************************************************************/ +/* + designed to be included + for type-specific functions (template emulation in C) + Objective is to write these functions only once, for improved maintenance +*/ + +/* safety checks */ +#ifndef FSE_FUNCTION_EXTENSION +# error "FSE_FUNCTION_EXTENSION must be defined" +#endif +#ifndef FSE_FUNCTION_TYPE +# error "FSE_FUNCTION_TYPE must be defined" +#endif + +/* Function names */ +#define FSE_CAT(X,Y) X##Y +#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y) +#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y) + + +/* Function templates */ + +/* FSE_buildCTable_wksp() : + * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`). + * wkspSize should be sized to handle worst case situation, which is `1<>1 : 1) ; + FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT); + U32 const step = FSE_TABLESTEP(tableSize); + + U32* cumul = (U32*)workSpace; + FSE_FUNCTION_TYPE* tableSymbol = (FSE_FUNCTION_TYPE*)(cumul + (maxSymbolValue + 2)); + + U32 highThreshold = tableSize-1; + + if ((size_t)workSpace & 3) return ERROR(GENERIC); /* Must be 4 byte aligned */ + if (FSE_BUILD_CTABLE_WORKSPACE_SIZE(maxSymbolValue, tableLog) > wkspSize) return ERROR(tableLog_tooLarge); + /* CTable header */ + tableU16[-2] = (U16) tableLog; + tableU16[-1] = (U16) maxSymbolValue; + assert(tableLog < 16); /* required for threshold strategy to work */ + + /* For explanations on how to distribute symbol values over the table : + * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */ + + #ifdef __clang_analyzer__ + ZSTD_memset(tableSymbol, 0, sizeof(*tableSymbol) * tableSize); /* useless initialization, just to keep scan-build happy */ + #endif + + /* symbol start positions */ + { U32 u; + cumul[0] = 0; + for (u=1; u <= maxSymbolValue+1; u++) { + if (normalizedCounter[u-1]==-1) { /* Low proba symbol */ + cumul[u] = cumul[u-1] + 1; + tableSymbol[highThreshold--] = (FSE_FUNCTION_TYPE)(u-1); + } else { + cumul[u] = cumul[u-1] + normalizedCounter[u-1]; + } } + cumul[maxSymbolValue+1] = tableSize+1; + } + + /* Spread symbols */ + { U32 position = 0; + U32 symbol; + for (symbol=0; symbol<=maxSymbolValue; symbol++) { + int nbOccurrences; + int const freq = normalizedCounter[symbol]; + for (nbOccurrences=0; nbOccurrences highThreshold) + position = (position + step) & tableMask; /* Low proba area */ + } } + + assert(position==0); /* Must have initialized all positions */ + } + + /* Build table */ + { U32 u; for (u=0; u> 3) + 3; + return maxSymbolValue ? maxHeaderSize : FSE_NCOUNTBOUND; /* maxSymbolValue==0 ? use default */ +} + +static size_t +FSE_writeNCount_generic (void* header, size_t headerBufferSize, + const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, + unsigned writeIsSafe) +{ + BYTE* const ostart = (BYTE*) header; + BYTE* out = ostart; + BYTE* const oend = ostart + headerBufferSize; + int nbBits; + const int tableSize = 1 << tableLog; + int remaining; + int threshold; + U32 bitStream = 0; + int bitCount = 0; + unsigned symbol = 0; + unsigned const alphabetSize = maxSymbolValue + 1; + int previousIs0 = 0; + + /* Table Size */ + bitStream += (tableLog-FSE_MIN_TABLELOG) << bitCount; + bitCount += 4; + + /* Init */ + remaining = tableSize+1; /* +1 for extra accuracy */ + threshold = tableSize; + nbBits = tableLog+1; + + while ((symbol < alphabetSize) && (remaining>1)) { /* stops at 1 */ + if (previousIs0) { + unsigned start = symbol; + while ((symbol < alphabetSize) && !normalizedCounter[symbol]) symbol++; + if (symbol == alphabetSize) break; /* incorrect distribution */ + while (symbol >= start+24) { + start+=24; + bitStream += 0xFFFFU << bitCount; + if ((!writeIsSafe) && (out > oend-2)) + return ERROR(dstSize_tooSmall); /* Buffer overflow */ + out[0] = (BYTE) bitStream; + out[1] = (BYTE)(bitStream>>8); + out+=2; + bitStream>>=16; + } + while (symbol >= start+3) { + start+=3; + bitStream += 3 << bitCount; + bitCount += 2; + } + bitStream += (symbol-start) << bitCount; + bitCount += 2; + if (bitCount>16) { + if ((!writeIsSafe) && (out > oend - 2)) + return ERROR(dstSize_tooSmall); /* Buffer overflow */ + out[0] = (BYTE)bitStream; + out[1] = (BYTE)(bitStream>>8); + out += 2; + bitStream >>= 16; + bitCount -= 16; + } } + { int count = normalizedCounter[symbol++]; + int const max = (2*threshold-1) - remaining; + remaining -= count < 0 ? -count : count; + count++; /* +1 for extra accuracy */ + if (count>=threshold) + count += max; /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */ + bitStream += count << bitCount; + bitCount += nbBits; + bitCount -= (count>=1; } + } + if (bitCount>16) { + if ((!writeIsSafe) && (out > oend - 2)) + return ERROR(dstSize_tooSmall); /* Buffer overflow */ + out[0] = (BYTE)bitStream; + out[1] = (BYTE)(bitStream>>8); + out += 2; + bitStream >>= 16; + bitCount -= 16; + } } + + if (remaining != 1) + return ERROR(GENERIC); /* incorrect normalized distribution */ + assert(symbol <= alphabetSize); + + /* flush remaining bitStream */ + if ((!writeIsSafe) && (out > oend - 2)) + return ERROR(dstSize_tooSmall); /* Buffer overflow */ + out[0] = (BYTE)bitStream; + out[1] = (BYTE)(bitStream>>8); + out+= (bitCount+7) /8; + + return (out-ostart); +} + + +size_t FSE_writeNCount (void* buffer, size_t bufferSize, + const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog) +{ + if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge); /* Unsupported */ + if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC); /* Unsupported */ + + if (bufferSize < FSE_NCountWriteBound(maxSymbolValue, tableLog)) + return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 0); + + return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1 /* write in buffer is safe */); +} + + +/*-************************************************************** +* FSE Compression Code +****************************************************************/ + +FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog) +{ + size_t size; + if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX; + size = FSE_CTABLE_SIZE_U32 (tableLog, maxSymbolValue) * sizeof(U32); + return (FSE_CTable*)ZSTD_malloc(size); +} + +void FSE_freeCTable (FSE_CTable* ct) { ZSTD_free(ct); } + +/* provides the minimum logSize to safely represent a distribution */ +static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue) +{ + U32 minBitsSrc = BIT_highbit32((U32)(srcSize)) + 1; + U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2; + U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols; + assert(srcSize > 1); /* Not supported, RLE should be used instead */ + return minBits; +} + +unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus) +{ + U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus; + U32 tableLog = maxTableLog; + U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue); + assert(srcSize > 1); /* Not supported, RLE should be used instead */ + if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG; + if (maxBitsSrc < tableLog) tableLog = maxBitsSrc; /* Accuracy can be reduced */ + if (minBits > tableLog) tableLog = minBits; /* Need a minimum to safely represent all symbol values */ + if (tableLog < FSE_MIN_TABLELOG) tableLog = FSE_MIN_TABLELOG; + if (tableLog > FSE_MAX_TABLELOG) tableLog = FSE_MAX_TABLELOG; + return tableLog; +} + +unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue) +{ + return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 2); +} + +/* Secondary normalization method. + To be used when primary method fails. */ + +static size_t FSE_normalizeM2(short* norm, U32 tableLog, const unsigned* count, size_t total, U32 maxSymbolValue, short lowProbCount) +{ + short const NOT_YET_ASSIGNED = -2; + U32 s; + U32 distributed = 0; + U32 ToDistribute; + + /* Init */ + U32 const lowThreshold = (U32)(total >> tableLog); + U32 lowOne = (U32)((total * 3) >> (tableLog + 1)); + + for (s=0; s<=maxSymbolValue; s++) { + if (count[s] == 0) { + norm[s]=0; + continue; + } + if (count[s] <= lowThreshold) { + norm[s] = lowProbCount; + distributed++; + total -= count[s]; + continue; + } + if (count[s] <= lowOne) { + norm[s] = 1; + distributed++; + total -= count[s]; + continue; + } + + norm[s]=NOT_YET_ASSIGNED; + } + ToDistribute = (1 << tableLog) - distributed; + + if (ToDistribute == 0) + return 0; + + if ((total / ToDistribute) > lowOne) { + /* risk of rounding to zero */ + lowOne = (U32)((total * 3) / (ToDistribute * 2)); + for (s=0; s<=maxSymbolValue; s++) { + if ((norm[s] == NOT_YET_ASSIGNED) && (count[s] <= lowOne)) { + norm[s] = 1; + distributed++; + total -= count[s]; + continue; + } } + ToDistribute = (1 << tableLog) - distributed; + } + + if (distributed == maxSymbolValue+1) { + /* all values are pretty poor; + probably incompressible data (should have already been detected); + find max, then give all remaining points to max */ + U32 maxV = 0, maxC = 0; + for (s=0; s<=maxSymbolValue; s++) + if (count[s] > maxC) { maxV=s; maxC=count[s]; } + norm[maxV] += (short)ToDistribute; + return 0; + } + + if (total == 0) { + /* all of the symbols were low enough for the lowOne or lowThreshold */ + for (s=0; ToDistribute > 0; s = (s+1)%(maxSymbolValue+1)) + if (norm[s] > 0) { ToDistribute--; norm[s]++; } + return 0; + } + + { U64 const vStepLog = 62 - tableLog; + U64 const mid = (1ULL << (vStepLog-1)) - 1; + U64 const rStep = ZSTD_div64((((U64)1<> vStepLog); + U32 const sEnd = (U32)(end >> vStepLog); + U32 const weight = sEnd - sStart; + if (weight < 1) + return ERROR(GENERIC); + norm[s] = (short)weight; + tmpTotal = end; + } } } + + return 0; +} + +size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog, + const unsigned* count, size_t total, + unsigned maxSymbolValue, unsigned useLowProbCount) +{ + /* Sanity checks */ + if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG; + if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC); /* Unsupported size */ + if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge); /* Unsupported size */ + if (tableLog < FSE_minTableLog(total, maxSymbolValue)) return ERROR(GENERIC); /* Too small tableLog, compression potentially impossible */ + + { static U32 const rtbTable[] = { 0, 473195, 504333, 520860, 550000, 700000, 750000, 830000 }; + short const lowProbCount = useLowProbCount ? -1 : 1; + U64 const scale = 62 - tableLog; + U64 const step = ZSTD_div64((U64)1<<62, (U32)total); /* <== here, one division ! */ + U64 const vStep = 1ULL<<(scale-20); + int stillToDistribute = 1<> tableLog); + + for (s=0; s<=maxSymbolValue; s++) { + if (count[s] == total) return 0; /* rle special case */ + if (count[s] == 0) { normalizedCounter[s]=0; continue; } + if (count[s] <= lowThreshold) { + normalizedCounter[s] = lowProbCount; + stillToDistribute--; + } else { + short proba = (short)((count[s]*step) >> scale); + if (proba<8) { + U64 restToBeat = vStep * rtbTable[proba]; + proba += (count[s]*step) - ((U64)proba< restToBeat; + } + if (proba > largestP) { largestP=proba; largest=s; } + normalizedCounter[s] = proba; + stillToDistribute -= proba; + } } + if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) { + /* corner case, need another normalization method */ + size_t const errorCode = FSE_normalizeM2(normalizedCounter, tableLog, count, total, maxSymbolValue, lowProbCount); + if (FSE_isError(errorCode)) return errorCode; + } + else normalizedCounter[largest] += (short)stillToDistribute; + } + +#if 0 + { /* Print Table (debug) */ + U32 s; + U32 nTotal = 0; + for (s=0; s<=maxSymbolValue; s++) + RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]); + for (s=0; s<=maxSymbolValue; s++) + nTotal += abs(normalizedCounter[s]); + if (nTotal != (1U<>1); /* assumption : tableLog >= 1 */ + FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT); + unsigned s; + + /* Sanity checks */ + if (nbBits < 1) return ERROR(GENERIC); /* min size */ + + /* header */ + tableU16[-2] = (U16) nbBits; + tableU16[-1] = (U16) maxSymbolValue; + + /* Build table */ + for (s=0; s FSE_MAX_TABLELOG*4+7 ) && (srcSize & 2)) { /* test bit 2 */ + FSE_encodeSymbol(&bitC, &CState2, *--ip); + FSE_encodeSymbol(&bitC, &CState1, *--ip); + FSE_FLUSHBITS(&bitC); + } + + /* 2 or 4 encoding per loop */ + while ( ip>istart ) { + + FSE_encodeSymbol(&bitC, &CState2, *--ip); + + if (sizeof(bitC.bitContainer)*8 < FSE_MAX_TABLELOG*2+7 ) /* this test must be static */ + FSE_FLUSHBITS(&bitC); + + FSE_encodeSymbol(&bitC, &CState1, *--ip); + + if (sizeof(bitC.bitContainer)*8 > FSE_MAX_TABLELOG*4+7 ) { /* this test must be static */ + FSE_encodeSymbol(&bitC, &CState2, *--ip); + FSE_encodeSymbol(&bitC, &CState1, *--ip); + } + + FSE_FLUSHBITS(&bitC); + } + + FSE_flushCState(&bitC, &CState2); + FSE_flushCState(&bitC, &CState1); + return BIT_closeCStream(&bitC); +} + +size_t FSE_compress_usingCTable (void* dst, size_t dstSize, + const void* src, size_t srcSize, + const FSE_CTable* ct) +{ + unsigned const fast = (dstSize >= FSE_BLOCKBOUND(srcSize)); + + if (fast) + return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 1); + else + return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 0); +} + + +size_t FSE_compressBound(size_t size) { return FSE_COMPRESSBOUND(size); } + + +#endif /* FSE_COMMONDEFS_ONLY */ -- cgit v1.2.3