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Diffstat (limited to 'contrib/zstd/zstd_decompress_internal.h')
| -rw-r--r-- | contrib/zstd/zstd_decompress_internal.h | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/contrib/zstd/zstd_decompress_internal.h b/contrib/zstd/zstd_decompress_internal.h new file mode 100644 index 0000000..a164de3 --- /dev/null +++ b/contrib/zstd/zstd_decompress_internal.h @@ -0,0 +1,238 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * 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. + */ + + +/* zstd_decompress_internal: + * objects and definitions shared within lib/decompress modules */ + + #ifndef ZSTD_DECOMPRESS_INTERNAL_H + #define ZSTD_DECOMPRESS_INTERNAL_H + + +/*-******************************************************* + * Dependencies + *********************************************************/ +#include "mem.h" /* BYTE, U16, U32 */ +#include "zstd_internal.h" /* constants : MaxLL, MaxML, MaxOff, LLFSELog, etc. */ + + + +/*-******************************************************* + * Constants + *********************************************************/ +static UNUSED_ATTR const U32 LL_base[MaxLL+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 18, 20, 22, 24, 28, 32, 40, + 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, + 0x2000, 0x4000, 0x8000, 0x10000 }; + +static UNUSED_ATTR const U32 OF_base[MaxOff+1] = { + 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D, + 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD, + 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, + 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD }; + +static UNUSED_ATTR const U8 OF_bits[MaxOff+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31 }; + +static UNUSED_ATTR const U32 ML_base[MaxML+1] = { + 3, 4, 5, 6, 7, 8, 9, 10, + 11, 12, 13, 14, 15, 16, 17, 18, + 19, 20, 21, 22, 23, 24, 25, 26, + 27, 28, 29, 30, 31, 32, 33, 34, + 35, 37, 39, 41, 43, 47, 51, 59, + 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, + 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 }; + + +/*-******************************************************* + * Decompression types + *********************************************************/ + typedef struct { + U32 fastMode; + U32 tableLog; + } ZSTD_seqSymbol_header; + + typedef struct { + U16 nextState; + BYTE nbAdditionalBits; + BYTE nbBits; + U32 baseValue; + } ZSTD_seqSymbol; + + #define SEQSYMBOL_TABLE_SIZE(log) (1 + (1 << (log))) + +#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE (sizeof(S16) * (MaxSeq + 1) + (1u << MaxFSELog) + sizeof(U64)) +#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32 ((ZSTD_BUILD_FSE_TABLE_WKSP_SIZE + sizeof(U32) - 1) / sizeof(U32)) +#define ZSTD_HUFFDTABLE_CAPACITY_LOG 12 + +typedef struct { + ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)]; /* Note : Space reserved for FSE Tables */ + ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)]; /* is also used as temporary workspace while building hufTable during DDict creation */ + ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)]; /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */ + HUF_DTable hufTable[HUF_DTABLE_SIZE(ZSTD_HUFFDTABLE_CAPACITY_LOG)]; /* can accommodate HUF_decompress4X */ + U32 rep[ZSTD_REP_NUM]; + U32 workspace[ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32]; +} ZSTD_entropyDTables_t; + +typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader, + ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock, + ZSTDds_decompressLastBlock, ZSTDds_checkChecksum, + ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage; + +typedef enum { zdss_init=0, zdss_loadHeader, + zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage; + +typedef enum { + ZSTD_use_indefinitely = -1, /* Use the dictionary indefinitely */ + ZSTD_dont_use = 0, /* Do not use the dictionary (if one exists free it) */ + ZSTD_use_once = 1 /* Use the dictionary once and set to ZSTD_dont_use */ +} ZSTD_dictUses_e; + +/* Hashset for storing references to multiple ZSTD_DDict within ZSTD_DCtx */ +typedef struct { + const ZSTD_DDict** ddictPtrTable; + size_t ddictPtrTableSize; + size_t ddictPtrCount; +} ZSTD_DDictHashSet; + +#ifndef ZSTD_DECODER_INTERNAL_BUFFER +# define ZSTD_DECODER_INTERNAL_BUFFER (1 << 16) +#endif + +#define ZSTD_LBMIN 64 +#define ZSTD_LBMAX (128 << 10) + +/* extra buffer, compensates when dst is not large enough to store litBuffer */ +#define ZSTD_LITBUFFEREXTRASIZE BOUNDED(ZSTD_LBMIN, ZSTD_DECODER_INTERNAL_BUFFER, ZSTD_LBMAX) + +typedef enum { + ZSTD_not_in_dst = 0, /* Stored entirely within litExtraBuffer */ + ZSTD_in_dst = 1, /* Stored entirely within dst (in memory after current output write) */ + ZSTD_split = 2 /* Split between litExtraBuffer and dst */ +} ZSTD_litLocation_e; + +struct ZSTD_DCtx_s +{ + const ZSTD_seqSymbol* LLTptr; + const ZSTD_seqSymbol* MLTptr; + const ZSTD_seqSymbol* OFTptr; + const HUF_DTable* HUFptr; + ZSTD_entropyDTables_t entropy; + U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32]; /* space needed when building huffman tables */ + const void* previousDstEnd; /* detect continuity */ + const void* prefixStart; /* start of current segment */ + const void* virtualStart; /* virtual start of previous segment if it was just before current one */ + const void* dictEnd; /* end of previous segment */ + size_t expected; + ZSTD_frameHeader fParams; + U64 processedCSize; + U64 decodedSize; + blockType_e bType; /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */ + ZSTD_dStage stage; + U32 litEntropy; + U32 fseEntropy; + XXH64_state_t xxhState; + size_t headerSize; + ZSTD_format_e format; + ZSTD_forceIgnoreChecksum_e forceIgnoreChecksum; /* User specified: if == 1, will ignore checksums in compressed frame. Default == 0 */ + U32 validateChecksum; /* if == 1, will validate checksum. Is == 1 if (fParams.checksumFlag == 1) and (forceIgnoreChecksum == 0). */ + const BYTE* litPtr; + ZSTD_customMem customMem; + size_t litSize; + size_t rleSize; + size_t staticSize; +#if DYNAMIC_BMI2 != 0 + int bmi2; /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */ +#endif + + /* dictionary */ + ZSTD_DDict* ddictLocal; + const ZSTD_DDict* ddict; /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */ + U32 dictID; + int ddictIsCold; /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */ + ZSTD_dictUses_e dictUses; + ZSTD_DDictHashSet* ddictSet; /* Hash set for multiple ddicts */ + ZSTD_refMultipleDDicts_e refMultipleDDicts; /* User specified: if == 1, will allow references to multiple DDicts. Default == 0 (disabled) */ + int disableHufAsm; + + /* streaming */ + ZSTD_dStreamStage streamStage; + char* inBuff; + size_t inBuffSize; + size_t inPos; + size_t maxWindowSize; + char* outBuff; + size_t outBuffSize; + size_t outStart; + size_t outEnd; + size_t lhSize; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + void* legacyContext; + U32 previousLegacyVersion; + U32 legacyVersion; +#endif + U32 hostageByte; + int noForwardProgress; + ZSTD_bufferMode_e outBufferMode; + ZSTD_outBuffer expectedOutBuffer; + + /* workspace */ + BYTE* litBuffer; + const BYTE* litBufferEnd; + ZSTD_litLocation_e litBufferLocation; + BYTE litExtraBuffer[ZSTD_LITBUFFEREXTRASIZE + WILDCOPY_OVERLENGTH]; /* literal buffer can be split between storage within dst and within this scratch buffer */ + BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; + + size_t oversizedDuration; + +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + void const* dictContentBeginForFuzzing; + void const* dictContentEndForFuzzing; +#endif + + /* Tracing */ +#if ZSTD_TRACE + ZSTD_TraceCtx traceCtx; +#endif +}; /* typedef'd to ZSTD_DCtx within "zstd.h" */ + +MEM_STATIC int ZSTD_DCtx_get_bmi2(const struct ZSTD_DCtx_s *dctx) { +#if DYNAMIC_BMI2 != 0 + return dctx->bmi2; +#else + (void)dctx; + return 0; +#endif +} + +/*-******************************************************* + * Shared internal functions + *********************************************************/ + +/*! ZSTD_loadDEntropy() : + * dict : must point at beginning of a valid zstd dictionary. + * @return : size of dictionary header (size of magic number + dict ID + entropy tables) */ +size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy, + const void* const dict, size_t const dictSize); + +/*! ZSTD_checkContinuity() : + * check if next `dst` follows previous position, where decompression ended. + * If yes, do nothing (continue on current segment). + * If not, classify previous segment as "external dictionary", and start a new segment. + * This function cannot fail. */ +void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize); + + +#endif /* ZSTD_DECOMPRESS_INTERNAL_H */ |