lib/zstd/decompress/zstd_decompress_internal.h - linux - Git at Google

 /*
  * Copyright (c) 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 "../common/mem.h"             /* BYTE, U16, U32 */
 #include "../common/zstd_internal.h"   /* ZSTD_seqSymbol */


 /*-*******************************************************
  *  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 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 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))

 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];
     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;

 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;
     struct xxh64_state 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;
     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) */
     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) */

     /* 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;
     ZSTD_bufferMode_e outBufferMode;
     ZSTD_outBuffer expectedOutBuffer;

     /* workspace */
     BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
     BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];

     size_t oversizedDuration;

 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     void const* dictContentBeginForFuzzing;
     void const* dictContentEndForFuzzing;
 #endif

     /* Tracing */
 };  /* 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 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 */
	/*
	* Copyright (c) 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 "../common/mem.h" /* BYTE, U16, U32 */
	#include "../common/zstd_internal.h" /* ZSTD_seqSymbol */



	/-******************************************************
	* 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 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 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))

	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];
	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;

	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;
	struct xxh64_state 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;
	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) */
	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) */

	/* 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;
	ZSTD_bufferMode_e outBufferMode;
	ZSTD_outBuffer expectedOutBuffer;

	/* workspace */
	BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
	BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];

	size_t oversizedDuration;

	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	void const* dictContentBeginForFuzzing;
	void const* dictContentEndForFuzzing;
	#endif

	/* Tracing */
	}; /* 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 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 */