zstd_decompress_internal.h
168 lines
| 6.5 KiB
| text/x-c
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CLexer
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r42237 | /* | ||
* 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. | ||||
*/ | ||||
/* 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" /* ZSTD_seqSymbol */ | ||||
/*-******************************************************* | ||||
* Constants | ||||
*********************************************************/ | ||||
static 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 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 const U32 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 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))) | ||||
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(HufLog)]; /* can accommodate HUF_decompress4X */ | ||||
U32 rep[ZSTD_REP_NUM]; | ||||
} 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; | ||||
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 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; | ||||
const BYTE* litPtr; | ||||
ZSTD_customMem customMem; | ||||
size_t litSize; | ||||
size_t rleSize; | ||||
size_t staticSize; | ||||
int bmi2; /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */ | ||||
/* 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) */ | ||||
/* 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; | ||||
void* legacyContext; | ||||
U32 previousLegacyVersion; | ||||
U32 legacyVersion; | ||||
U32 hostageByte; | ||||
int noForwardProgress; | ||||
/* workspace */ | ||||
BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH]; | ||||
BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; | ||||
}; /* typedef'd to ZSTD_DCtx within "zstd.h" */ | ||||
/*-******************************************************* | ||||
* Shared internal functions | ||||
*********************************************************/ | ||||
/*! ZSTD_loadDEntropy() : | ||||
* dict : must point at beginning of a valid zstd dictionary. | ||||
* @return : size of entropy tables read */ | ||||
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); | ||||
#endif /* ZSTD_DECOMPRESS_INTERNAL_H */ | ||||