/* ****************************************************************** * huff0 huffman codec, * part of Finite State Entropy library * Copyright (c) Meta Platforms, Inc. and affiliates. * * You can contact the author at : * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy * * 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. ****************************************************************** */ #if defined (__cplusplus) extern "C" { #endif #ifndef HUF_H_298734234 #define HUF_H_298734234 /* *** Dependencies *** */ #include "zstd_deps.h" /* size_t */ #include "mem.h" /* U32 */ #define FSE_STATIC_LINKING_ONLY #include "fse.h" /* *** Tool functions *** */ #define HUF_BLOCKSIZE_MAX … size_t HUF_compressBound(size_t size); /**< maximum compressed size (worst case) */ /* Error Management */ unsigned HUF_isError(size_t code); /**< tells if a return value is an error code */ const char* HUF_getErrorName(size_t code); /**< provides error code string (useful for debugging) */ #define HUF_WORKSPACE_SIZE … #define HUF_WORKSPACE_SIZE_U64 … /* *** Constants *** */ #define HUF_TABLELOG_MAX … #define HUF_TABLELOG_DEFAULT … #define HUF_SYMBOLVALUE_MAX … #define HUF_TABLELOG_ABSOLUTEMAX … #if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX) # error "HUF_TABLELOG_MAX is too large !" #endif /* **************************************** * Static allocation ******************************************/ /* HUF buffer bounds */ #define HUF_CTABLEBOUND … #define HUF_BLOCKBOUND(size) … #define HUF_COMPRESSBOUND(size) … /* static allocation of HUF's Compression Table */ /* this is a private definition, just exposed for allocation and strict aliasing purpose. never EVER access its members directly */ HUF_CElt; /* consider it an incomplete type */ #define HUF_CTABLE_SIZE_ST(maxSymbolValue) … #define HUF_CTABLE_SIZE(maxSymbolValue) … #define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) … /* static allocation of HUF's DTable */ HUF_DTable; #define HUF_DTABLE_SIZE(maxTableLog) … #define HUF_CREATE_STATIC_DTABLEX1(DTable, maxTableLog) … #define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) … /* **************************************** * Advanced decompression functions ******************************************/ /** * Huffman flags bitset. * For all flags, 0 is the default value. */ HUF_flags_e; /* **************************************** * HUF detailed API * ****************************************/ #define HUF_OPTIMAL_DEPTH_THRESHOLD … /*! HUF_compress() does the following: * 1. count symbol occurrence from source[] into table count[] using FSE_count() (exposed within "fse.h") * 2. (optional) refine tableLog using HUF_optimalTableLog() * 3. build Huffman table from count using HUF_buildCTable() * 4. save Huffman table to memory buffer using HUF_writeCTable() * 5. encode the data stream using HUF_compress4X_usingCTable() * * The following API allows targeting specific sub-functions for advanced tasks. * For example, it's possible to compress several blocks using the same 'CTable', * or to save and regenerate 'CTable' using external methods. */ unsigned HUF_minTableLog(unsigned symbolCardinality); unsigned HUF_cardinality(const unsigned* count, unsigned maxSymbolValue); unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, void* workSpace, size_t wkspSize, HUF_CElt* table, const unsigned* count, int flags); /* table is used as scratch space for building and testing tables, not a return value */ size_t HUF_writeCTable_wksp(void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog, void* workspace, size_t workspaceSize); size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int flags); size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue); int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue); HUF_repeat; /** HUF_compress4X_repeat() : * Same as HUF_compress4X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none. * If it uses hufTable it does not modify hufTable or repeat. * If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used. * If preferRepeat then the old table will always be used if valid. * If suspectUncompressible then some sampling checks will be run to potentially skip huffman coding */ size_t HUF_compress4X_repeat(void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize, /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */ HUF_CElt* hufTable, HUF_repeat* repeat, int flags); /** HUF_buildCTable_wksp() : * Same as HUF_buildCTable(), but using externally allocated scratch buffer. * `workSpace` must be aligned on 4-bytes boundaries, and its size must be >= HUF_CTABLE_WORKSPACE_SIZE. */ #define HUF_CTABLE_WORKSPACE_SIZE_U32 … #define HUF_CTABLE_WORKSPACE_SIZE … size_t HUF_buildCTable_wksp (HUF_CElt* tree, const unsigned* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize); /*! HUF_readStats() : * Read compact Huffman tree, saved by HUF_writeCTable(). * `huffWeight` is destination buffer. * @return : size read from `src` , or an error Code . * Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr, const void* src, size_t srcSize); /*! HUF_readStats_wksp() : * Same as HUF_readStats() but takes an external workspace which must be * 4-byte aligned and its size must be >= HUF_READ_STATS_WORKSPACE_SIZE. * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0. */ #define HUF_READ_STATS_WORKSPACE_SIZE_U32 … #define HUF_READ_STATS_WORKSPACE_SIZE … size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr, const void* src, size_t srcSize, void* workspace, size_t wkspSize, int flags); /** HUF_readCTable() : * Loading a CTable saved with HUF_writeCTable() */ size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned *hasZeroWeights); /** HUF_getNbBitsFromCTable() : * Read nbBits from CTable symbolTable, for symbol `symbolValue` presumed <= HUF_SYMBOLVALUE_MAX * Note 1 : If symbolValue > HUF_readCTableHeader(symbolTable).maxSymbolValue, returns 0 * Note 2 : is not inlined, as HUF_CElt definition is private */ U32 HUF_getNbBitsFromCTable(const HUF_CElt* symbolTable, U32 symbolValue); HUF_CTableHeader; /** HUF_readCTableHeader() : * @returns The header from the CTable specifying the tableLog and the maxSymbolValue. */ HUF_CTableHeader HUF_readCTableHeader(HUF_CElt const* ctable); /* * HUF_decompress() does the following: * 1. select the decompression algorithm (X1, X2) based on pre-computed heuristics * 2. build Huffman table from save, using HUF_readDTableX?() * 3. decode 1 or 4 segments in parallel using HUF_decompress?X?_usingDTable() */ /** HUF_selectDecoder() : * Tells which decoder is likely to decode faster, * based on a set of pre-computed metrics. * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 . * Assumption : 0 < dstSize <= 128 KB */ U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize); /** * The minimum workspace size for the `workSpace` used in * HUF_readDTableX1_wksp() and HUF_readDTableX2_wksp(). * * The space used depends on HUF_TABLELOG_MAX, ranging from ~1500 bytes when * HUF_TABLE_LOG_MAX=12 to ~1850 bytes when HUF_TABLE_LOG_MAX=15. * Buffer overflow errors may potentially occur if code modifications result in * a required workspace size greater than that specified in the following * macro. */ #define HUF_DECOMPRESS_WORKSPACE_SIZE … #define HUF_DECOMPRESS_WORKSPACE_SIZE_U32 … /* ====================== */ /* single stream variants */ /* ====================== */ size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int flags); /** HUF_compress1X_repeat() : * Same as HUF_compress1X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none. * If it uses hufTable it does not modify hufTable or repeat. * If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used. * If preferRepeat then the old table will always be used if valid. * If suspectUncompressible then some sampling checks will be run to potentially skip huffman coding */ size_t HUF_compress1X_repeat(void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize, /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */ HUF_CElt* hufTable, HUF_repeat* repeat, int flags); size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags); #ifndef HUF_FORCE_DECOMPRESS_X1 size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags); /**< double-symbols decoder */ #endif /* BMI2 variants. * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0. */ size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags); #ifndef HUF_FORCE_DECOMPRESS_X2 size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags); #endif size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags); size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags); #ifndef HUF_FORCE_DECOMPRESS_X2 size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags); #endif #ifndef HUF_FORCE_DECOMPRESS_X1 size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags); #endif #endif /* HUF_H_298734234 */ #if defined (__cplusplus) } #endif