zstd_compress_internal.h File Reference

#include "../common/zstd_internal.h"
#include "zstd_cwksp.h"

Go to the source code of this file.

Data Structures
struct	ZSTD_prefixDict_s
struct	ZSTD_localDict
struct	ZSTD_hufCTables_t
struct	ZSTD_fseCTables_t
struct	ZSTD_entropyCTables_t
struct	ZSTD_hufCTablesMetadata_t
struct	ZSTD_fseCTablesMetadata_t
struct	ZSTD_entropyCTablesMetadata_t
struct	ZSTD_match_t
struct	rawSeq
struct	rawSeqStore_t
struct	ZSTD_optimal_t
struct	optState_t
struct	ZSTD_compressedBlockState_t
struct	ZSTD_window_t
struct	ZSTD_matchState_t
struct	ZSTD_blockState_t
struct	ldmEntry_t
struct	ldmMatchCandidate_t
struct	ldmState_t
struct	ldmParams_t
struct	SeqCollector
struct	ZSTD_CCtx_params_s
struct	ZSTD_blockSplitCtx
struct	ZSTD_CCtx_s
struct	repcodes_s

Macros
#define	kSearchStrength   8
#define	HASH_READ_SIZE   8
#define	ZSTD_DUBT_UNSORTED_MARK
#define	ZSTD_WINDOW_START_INDEX   2
#define	ZSTD_ROW_HASH_CACHE_SIZE   8 /* Size of prefetching hash cache for row-based matchfinder */
#define	LDM_BATCH_SIZE   64
#define	COMPRESS_SEQUENCES_WORKSPACE_SIZE   (sizeof(unsigned) * (MaxSeq + 2))
#define	ENTROPY_WORKSPACE_SIZE   (HUF_WORKSPACE_SIZE + COMPRESS_SEQUENCES_WORKSPACE_SIZE)
#define	ZSTD_MAX_NB_BLOCK_SPLITS   196
#define	ZSTD_REP_MOVE   (ZSTD_REP_NUM-1)
#define	STORE_REPCODE_1   STORE_REPCODE(1)
#define	STORE_REPCODE_2   STORE_REPCODE(2)
#define	STORE_REPCODE_3   STORE_REPCODE(3)
#define	STORE_REPCODE(r)
#define	STORE_OFFSET(o)
#define	STORED_IS_OFFSET(o)
#define	STORED_IS_REPCODE(o)
#define	STORED_OFFSET(o)
#define	STORED_REPCODE(o)
#define	STORED_TO_OFFBASE(o)
#define	OFFBASE_TO_STORED(o)
#define	ZSTD_ROLL_HASH_CHAR_OFFSET   10
#define	ZSTD_CURRENT_MAX   ((3U << 29) + (1U << ZSTD_WINDOWLOG_MAX))
#define	ZSTD_CHUNKSIZE_MAX
#define	ZSTD_WINDOW_OVERFLOW_CORRECT_FREQUENTLY   0

Typedefs
typedef struct ZSTD_prefixDict_s	ZSTD_prefixDict
typedef struct ZSTD_matchState_t	ZSTD_matchState_t
typedef size_t(*	ZSTD_blockCompressor) (ZSTD_matchState_t *bs, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
typedef struct repcodes_s	repcodes_t

Enumerations
enum	ZSTD_compressionStage_e { ZSTDcs_created =0 , ZSTDcs_init , ZSTDcs_ongoing , ZSTDcs_ending }
enum	ZSTD_cStreamStage { zcss_init =0 , zcss_load , zcss_flush }
enum	ZSTD_OptPrice_e { zop_dynamic =0 , zop_predef }
enum	ZSTD_buffered_policy_e { ZSTDb_not_buffered , ZSTDb_buffered }
enum	ZSTD_dictTableLoadMethod_e { ZSTD_dtlm_fast , ZSTD_dtlm_full }
enum	ZSTD_dictMode_e { ZSTD_noDict = 0 , ZSTD_extDict = 1 , ZSTD_dictMatchState = 2 , ZSTD_dedicatedDictSearch = 3 }
enum	ZSTD_cParamMode_e { ZSTD_cpm_noAttachDict = 0 , ZSTD_cpm_attachDict = 1 , ZSTD_cpm_createCDict = 2 , ZSTD_cpm_unknown = 3 }

Functions
size_t	ZSTD_buildBlockEntropyStats (seqStore_t *seqStorePtr, const ZSTD_entropyCTables_t *prevEntropy, ZSTD_entropyCTables_t *nextEntropy, const ZSTD_CCtx_params *cctxParams, ZSTD_entropyCTablesMetadata_t *entropyMetadata, void *workspace, size_t wkspSize)
ZSTD_blockCompressor	ZSTD_selectBlockCompressor (ZSTD_strategy strat, ZSTD_paramSwitch_e rowMatchfinderMode, ZSTD_dictMode_e dictMode)
MEM_STATIC U32	ZSTD_LLcode (U32 litLength)
MEM_STATIC U32	ZSTD_MLcode (U32 mlBase)
MEM_STATIC int	ZSTD_cParam_withinBounds (ZSTD_cParameter cParam, int value)
MEM_STATIC size_t	ZSTD_noCompressBlock (void *dst, size_t dstCapacity, const void *src, size_t srcSize, U32 lastBlock)
MEM_STATIC size_t	ZSTD_rleCompressBlock (void *dst, size_t dstCapacity, BYTE src, size_t srcSize, U32 lastBlock)
MEM_STATIC size_t	ZSTD_minGain (size_t srcSize, ZSTD_strategy strat)
MEM_STATIC int	ZSTD_literalsCompressionIsDisabled (const ZSTD_CCtx_params *cctxParams)
HINT_INLINE UNUSED_ATTR void	ZSTD_storeSeq (seqStore_t *seqStorePtr, size_t litLength, const BYTE *literals, const BYTE *litLimit, U32 offBase_minus1, size_t matchLength)
MEM_STATIC void	ZSTD_updateRep (U32 rep[ZSTD_REP_NUM], U32 const offBase_minus1, U32 const ll0)
MEM_STATIC repcodes_t	ZSTD_newRep (U32 const rep[ZSTD_REP_NUM], U32 const offBase_minus1, U32 const ll0)
MEM_STATIC size_t	ZSTD_count (const BYTE *pIn, const BYTE *pMatch, const BYTE *const pInLimit)
MEM_STATIC size_t	ZSTD_count_2segments (const BYTE *ip, const BYTE *match, const BYTE *iEnd, const BYTE *mEnd, const BYTE *iStart)
MEM_STATIC size_t	ZSTD_hash3Ptr (const void *ptr, U32 h)
MEM_STATIC FORCE_INLINE_ATTR size_t	ZSTD_hashPtr (const void *p, U32 hBits, U32 mls)
MEM_STATIC U64	ZSTD_rollingHash_compute (void const *buf, size_t size)
MEM_STATIC U64	ZSTD_rollingHash_primePower (U32 length)
MEM_STATIC U64	ZSTD_rollingHash_rotate (U64 hash, BYTE toRemove, BYTE toAdd, U64 primePower)
MEM_STATIC void	ZSTD_window_clear (ZSTD_window_t *window)
MEM_STATIC U32	ZSTD_window_isEmpty (ZSTD_window_t const window)
MEM_STATIC U32	ZSTD_window_hasExtDict (ZSTD_window_t const window)
MEM_STATIC ZSTD_dictMode_e	ZSTD_matchState_dictMode (const ZSTD_matchState_t *ms)
MEM_STATIC U32	ZSTD_window_canOverflowCorrect (ZSTD_window_t const window, U32 cycleLog, U32 maxDist, U32 loadedDictEnd, void const *src)
MEM_STATIC U32	ZSTD_window_needOverflowCorrection (ZSTD_window_t const window, U32 cycleLog, U32 maxDist, U32 loadedDictEnd, void const *src, void const *srcEnd)
MEM_STATIC U32	ZSTD_window_correctOverflow (ZSTD_window_t *window, U32 cycleLog, U32 maxDist, void const *src)
MEM_STATIC void	ZSTD_window_enforceMaxDist (ZSTD_window_t *window, const void *blockEnd, U32 maxDist, U32 *loadedDictEndPtr, const ZSTD_matchState_t **dictMatchStatePtr)
MEM_STATIC void	ZSTD_checkDictValidity (const ZSTD_window_t *window, const void *blockEnd, U32 maxDist, U32 *loadedDictEndPtr, const ZSTD_matchState_t **dictMatchStatePtr)
MEM_STATIC void	ZSTD_window_init (ZSTD_window_t *window)
MEM_STATIC U32	ZSTD_window_update (ZSTD_window_t *window, void const *src, size_t srcSize, int forceNonContiguous)
MEM_STATIC U32	ZSTD_getLowestMatchIndex (const ZSTD_matchState_t *ms, U32 curr, unsigned windowLog)
MEM_STATIC U32	ZSTD_getLowestPrefixIndex (const ZSTD_matchState_t *ms, U32 curr, unsigned windowLog)
size_t	ZSTD_loadCEntropy (ZSTD_compressedBlockState_t *bs, void *workspace, const void *const dict, size_t dictSize)
void	ZSTD_reset_compressedBlockState (ZSTD_compressedBlockState_t *bs)
ZSTD_compressionParameters	ZSTD_getCParamsFromCCtxParams (const ZSTD_CCtx_params *CCtxParams, U64 srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode)
size_t	ZSTD_initCStream_internal (ZSTD_CStream *zcs, const void *dict, size_t dictSize, const ZSTD_CDict *cdict, const ZSTD_CCtx_params *params, unsigned long long pledgedSrcSize)
void	ZSTD_resetSeqStore (seqStore_t *ssPtr)
ZSTD_compressionParameters	ZSTD_getCParamsFromCDict (const ZSTD_CDict *cdict)
size_t	ZSTD_compressBegin_advanced_internal (ZSTD_CCtx *cctx, const void *dict, size_t dictSize, ZSTD_dictContentType_e dictContentType, ZSTD_dictTableLoadMethod_e dtlm, const ZSTD_CDict *cdict, const ZSTD_CCtx_params *params, unsigned long long pledgedSrcSize)
size_t	ZSTD_compress_advanced_internal (ZSTD_CCtx *cctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const void *dict, size_t dictSize, const ZSTD_CCtx_params *params)
size_t	ZSTD_writeLastEmptyBlock (void *dst, size_t dstCapacity)
size_t	ZSTD_referenceExternalSequences (ZSTD_CCtx *cctx, rawSeq *seq, size_t nbSeq)
U32	ZSTD_cycleLog (U32 hashLog, ZSTD_strategy strat)
void	ZSTD_CCtx_trace (ZSTD_CCtx *cctx, size_t extraCSize)

Macro Definition Documentation

COMPRESS_SEQUENCES_WORKSPACE_SIZE

#define COMPRESS_SEQUENCES_WORKSPACE_SIZE   (sizeof(unsigned) * (MaxSeq + 2))

ENTROPY_WORKSPACE_SIZE

#define ENTROPY_WORKSPACE_SIZE   (HUF_WORKSPACE_SIZE + COMPRESS_SEQUENCES_WORKSPACE_SIZE)

HASH_READ_SIZE

#define HASH_READ_SIZE   8

kSearchStrength

#define kSearchStrength   8

LDM_BATCH_SIZE

#define LDM_BATCH_SIZE   64

OFFBASE_TO_STORED

#define OFFBASE_TO_STORED

(

o

)

Value:

((o)-1)

STORE_OFFSET

#define STORE_OFFSET

(

o

)

Value:

(assert((o)>0), o + ZSTD_REP_MOVE)

STORE_REPCODE

#define STORE_REPCODE

(

r

)

Value:

(assert((r)>=1), assert((r)<=3), (r)-1)

STORE_REPCODE_1

#define STORE_REPCODE_1   STORE_REPCODE(1)

STORE_REPCODE_2

#define STORE_REPCODE_2   STORE_REPCODE(2)

STORE_REPCODE_3

#define STORE_REPCODE_3   STORE_REPCODE(3)

STORED_IS_OFFSET

#define STORED_IS_OFFSET

(

o

)

Value:

((o) > ZSTD_REP_MOVE)

STORED_IS_REPCODE

#define STORED_IS_REPCODE

(

o

)

Value:

((o) <= ZSTD_REP_MOVE)

STORED_OFFSET

#define STORED_OFFSET

(

o

)

Value:

(assert(STORED_IS_OFFSET(o)), (o)-ZSTD_REP_MOVE)

STORED_REPCODE

#define STORED_REPCODE

(

o

)

Value:

(assert(STORED_IS_REPCODE(o)), (o)+1)  /* returns ID 1,2,3 */

STORED_TO_OFFBASE

#define STORED_TO_OFFBASE

(

o

)

Value:

((o)+1)

ZSTD_CHUNKSIZE_MAX

#define ZSTD_CHUNKSIZE_MAX

Value:

    ( ((U32)-1)                  /* Maximum ending current index */            \
    - ZSTD_CURRENT_MAX)          /* Maximum beginning lowLimit */

ZSTD_CURRENT_MAX

#define ZSTD_CURRENT_MAX   ((3U << 29) + (1U << ZSTD_WINDOWLOG_MAX))

ZSTD_DUBT_UNSORTED_MARK

#define ZSTD_DUBT_UNSORTED_MARK

Value:

                                       1   /* For btlazy2 strategy, index ZSTD_DUBT_UNSORTED_MARK==1 means "unsorted".
                                       It could be confused for a real successor at index "1", if sorted as larger than its predecessor.
                                       It's not a big deal though : candidate will just be sorted again.
                                       Additionally, candidate position 1 will be lost.
                                       But candidate 1 cannot hide a large tree of candidates, so it's a minimal loss.
                                       The benefit is that ZSTD_DUBT_UNSORTED_MARK cannot be mishandled after table re-use with a different strategy.
                                       This constant is required by ZSTD_compressBlock_btlazy2() and ZSTD_reduceTable_internal() */

ZSTD_MAX_NB_BLOCK_SPLITS

#define ZSTD_MAX_NB_BLOCK_SPLITS   196

Struct that contains all elements of block splitter that should be allocated in a wksp.

ZSTD_REP_MOVE

#define ZSTD_REP_MOVE   (ZSTD_REP_NUM-1)

ZSTD_ROLL_HASH_CHAR_OFFSET

#define ZSTD_ROLL_HASH_CHAR_OFFSET   10

ZSTD_ROW_HASH_CACHE_SIZE

#define ZSTD_ROW_HASH_CACHE_SIZE   8 /* Size of prefetching hash cache for row-based matchfinder */

ZSTD_WINDOW_OVERFLOW_CORRECT_FREQUENTLY

#define ZSTD_WINDOW_OVERFLOW_CORRECT_FREQUENTLY   0

ZSTD_WINDOW_START_INDEX

#define ZSTD_WINDOW_START_INDEX   2

Typedef Documentation

repcodes_t

typedef struct repcodes_s repcodes_t

ZSTD_blockCompressor

typedef size_t(* ZSTD_blockCompressor) (ZSTD_matchState_t *bs, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)

ZSTD_matchState_t

typedef struct ZSTD_matchState_t ZSTD_matchState_t

ZSTD_prefixDict

typedef struct ZSTD_prefixDict_s ZSTD_prefixDict

Enumeration Type Documentation

ZSTD_buffered_policy_e

enum ZSTD_buffered_policy_e

Indicates whether this compression proceeds directly from user-provided source buffer to user-provided destination buffer (ZSTDb_not_buffered), or whether the context needs to buffer the input/output (ZSTDb_buffered).

Enumerator
ZSTDb_not_buffered
ZSTDb_buffered

ZSTD_compressionStage_e

enum ZSTD_compressionStage_e

Enumerator
ZSTDcs_created
ZSTDcs_init
ZSTDcs_ongoing
ZSTDcs_ending

ZSTD_cParamMode_e

enum ZSTD_cParamMode_e

Enumerator
ZSTD_cpm_noAttachDict
ZSTD_cpm_attachDict
ZSTD_cpm_createCDict
ZSTD_cpm_unknown

ZSTD_cStreamStage

enum ZSTD_cStreamStage

Enumerator
zcss_init
zcss_load
zcss_flush

ZSTD_dictMode_e

enum ZSTD_dictMode_e

Enumerator
ZSTD_noDict
ZSTD_extDict
ZSTD_dictMatchState
ZSTD_dedicatedDictSearch

ZSTD_dictTableLoadMethod_e

enum ZSTD_dictTableLoadMethod_e

Enumerator
ZSTD_dtlm_fast
ZSTD_dtlm_full

ZSTD_OptPrice_e

enum ZSTD_OptPrice_e

Enumerator
zop_dynamic
zop_predef

Function Documentation

ZSTD_buildBlockEntropyStats()

size_t ZSTD_buildBlockEntropyStats	(	seqStore_t *	seqStorePtr,
		const ZSTD_entropyCTables_t *	prevEntropy,
		ZSTD_entropyCTables_t *	nextEntropy,
		const ZSTD_CCtx_params *	cctxParams,
		ZSTD_entropyCTablesMetadata_t *	entropyMetadata,
		void *	workspace,
		size_t	wkspSize )

ZSTD_buildBlockEntropyStats() : Builds entropy for the block.

Returns

: 0 on success or error code

ZSTD_buildBlockEntropyStats() : Builds entropy for the block. Requires workspace size ENTROPY_WORKSPACE_SIZE

Returns

: 0 on success or error code

ZSTD_CCtx_trace()

void ZSTD_CCtx_trace	(	ZSTD_CCtx *	cctx,
		size_t	extraCSize )

ZSTD_CCtx_trace() : Trace the end of a compression call.

ZSTD_checkDictValidity()

MEM_STATIC void ZSTD_checkDictValidity	(	const ZSTD_window_t *	window,
		const void *	blockEnd,
		U32	maxDist,
		U32 *	loadedDictEndPtr,
		const ZSTD_matchState_t **	dictMatchStatePtr )

ZSTD_compress_advanced_internal()

size_t ZSTD_compress_advanced_internal	(	ZSTD_CCtx *	cctx,
		void *	dst,
		size_t	dstCapacity,
		const void *	src,
		size_t	srcSize,
		const void *	dict,
		size_t	dictSize,
		const ZSTD_CCtx_params *	params )

ZSTD_compressBegin_advanced_internal()

size_t ZSTD_compressBegin_advanced_internal	(	ZSTD_CCtx *	cctx,
		const void *	dict,
		size_t	dictSize,
		ZSTD_dictContentType_e	dictContentType,
		ZSTD_dictTableLoadMethod_e	dtlm,
		const ZSTD_CDict *	cdict,
		const ZSTD_CCtx_params *	params,
		unsigned long long	pledgedSrcSize )

ZSTD_count()

MEM_STATIC size_t ZSTD_count	(	const BYTE *	pIn,
		const BYTE *	pMatch,
		const BYTE *const	pInLimit )

ZSTD_count_2segments()

MEM_STATIC size_t ZSTD_count_2segments	(	const BYTE *	ip,
		const BYTE *	match,
		const BYTE *	iEnd,
		const BYTE *	mEnd,
		const BYTE *	iStart )

ZSTD_count_2segments() : can count match length with ip & match in 2 different segments. convention : on reaching mEnd, match count continue starting from iStart

ZSTD_cParam_withinBounds()

MEM_STATIC int ZSTD_cParam_withinBounds	(	ZSTD_cParameter	cParam,
		int	value )

ZSTD_cycleLog()

U32 ZSTD_cycleLog	(	U32	hashLog,
		ZSTD_strategy	strat )

ZSTD_cycleLog() : condition for correct operation : hashLog > 1

ZSTD_getCParamsFromCCtxParams()

ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams	(	const ZSTD_CCtx_params *	CCtxParams,
		U64	srcSizeHint,
		size_t	dictSize,
		ZSTD_cParamMode_e	mode )

ZSTD_getCParamsFromCDict()

ZSTD_compressionParameters ZSTD_getCParamsFromCDict

(

const ZSTD_CDict *

cdict

)

ZSTD_getCParamsFromCDict() : as the name implies

ZSTD_getLowestMatchIndex()

MEM_STATIC U32 ZSTD_getLowestMatchIndex	(	const ZSTD_matchState_t *	ms,
		U32	curr,
		unsigned	windowLog )

Returns the lowest allowed match index. It may either be in the ext-dict or the prefix.

ZSTD_getLowestPrefixIndex()

MEM_STATIC U32 ZSTD_getLowestPrefixIndex	(	const ZSTD_matchState_t *	ms,
		U32	curr,
		unsigned	windowLog )

Returns the lowest allowed match index in the prefix.

ZSTD_hash3Ptr()

MEM_STATIC size_t ZSTD_hash3Ptr	(	const void *	ptr,
		U32	h )

ZSTD_hashPtr()

MEM_STATIC FORCE_INLINE_ATTR size_t ZSTD_hashPtr	(	const void *	p,
		U32	hBits,
		U32	mls )

ZSTD_initCStream_internal()

size_t ZSTD_initCStream_internal	(	ZSTD_CStream *	zcs,
		const void *	dict,
		size_t	dictSize,
		const ZSTD_CDict *	cdict,
		const ZSTD_CCtx_params *	params,
		unsigned long long	pledgedSrcSize )

ZSTD_initCStream_internal() : Private use only. Init streaming operation. expects params to be valid. must receive dict, or cdict, or none, but not both.

Returns

: 0, or an error code

ZSTD_initCStream_internal() : Note : for lib/compress only. Used by zstdmt_compress.c. Assumption 1 : params are valid Assumption 2 : either dict, or cdict, is defined, not both

ZSTD_literalsCompressionIsDisabled()

MEM_STATIC int ZSTD_literalsCompressionIsDisabled

(

const ZSTD_CCtx_params *

cctxParams

)

ZSTD_LLcode()

MEM_STATIC U32 ZSTD_LLcode

(

U32

litLength

)

ZSTD_loadCEntropy()

size_t ZSTD_loadCEntropy	(	ZSTD_compressedBlockState_t *	bs,
		void *	workspace,
		const void *const	dict,
		size_t	dictSize )

ZSTD_matchState_dictMode()

MEM_STATIC ZSTD_dictMode_e ZSTD_matchState_dictMode

(

const ZSTD_matchState_t *

ms

)

ZSTD_matchState_dictMode(): Inspects the provided matchState and figures out what dictMode should be passed to the compressor.

ZSTD_minGain()

MEM_STATIC size_t ZSTD_minGain	(	size_t	srcSize,
		ZSTD_strategy	strat )

ZSTD_MLcode()

MEM_STATIC U32 ZSTD_MLcode

(

U32

mlBase

)

ZSTD_newRep()

MEM_STATIC repcodes_t ZSTD_newRep	(	U32 const	rep[ZSTD_REP_NUM],
		U32 const	offBase_minus1,
		U32 const	ll0 )

ZSTD_noCompressBlock()

MEM_STATIC size_t ZSTD_noCompressBlock	(	void *	dst,
		size_t	dstCapacity,
		const void *	src,
		size_t	srcSize,
		U32	lastBlock )

ZSTD_referenceExternalSequences()

size_t ZSTD_referenceExternalSequences	(	ZSTD_CCtx *	cctx,
		rawSeq *	seq,
		size_t	nbSeq )

ZSTD_reset_compressedBlockState()

void ZSTD_reset_compressedBlockState

(

ZSTD_compressedBlockState_t *

bs

)

ZSTD_resetSeqStore()

void ZSTD_resetSeqStore

(

seqStore_t *

ssPtr

)

ZSTD_rleCompressBlock()

MEM_STATIC size_t ZSTD_rleCompressBlock	(	void *	dst,
		size_t	dstCapacity,
		BYTE	src,
		size_t	srcSize,
		U32	lastBlock )

ZSTD_rollingHash_compute()

MEM_STATIC U64 ZSTD_rollingHash_compute	(	void const *	buf,
		size_t	size )

ZSTD_rollingHash_compute() : Compute the rolling hash value of the buffer.

ZSTD_rollingHash_primePower()

MEM_STATIC U64 ZSTD_rollingHash_primePower

(

U32

length

)

ZSTD_rollingHash_primePower() : Compute the primePower to be passed to ZSTD_rollingHash_rotate() for a hash over a window of length bytes.

ZSTD_rollingHash_rotate()

MEM_STATIC U64 ZSTD_rollingHash_rotate	(	U64	hash,
		BYTE	toRemove,
		BYTE	toAdd,
		U64	primePower )

ZSTD_rollingHash_rotate() : Rotate the rolling hash by one byte.

ZSTD_selectBlockCompressor()

ZSTD_blockCompressor ZSTD_selectBlockCompressor	(	ZSTD_strategy	strat,
		ZSTD_paramSwitch_e	rowMatchfinderMode,
		ZSTD_dictMode_e	dictMode )

ZSTD_storeSeq()

HINT_INLINE UNUSED_ATTR void ZSTD_storeSeq	(	seqStore_t *	seqStorePtr,
		size_t	litLength,
		const BYTE *	literals,
		const BYTE *	litLimit,
		U32	offBase_minus1,
		size_t	matchLength )

ZSTD_storeSeq() : Store a sequence (litlen, litPtr, offCode and matchLength) into seqStore_t. @offBase_minus1 : Users should use employ macros STORE_REPCODE_X and STORE_OFFSET(). @matchLength : must be >= MINMATCH Allowed to overread literals up to litLimit.

ZSTD_updateRep()

MEM_STATIC void ZSTD_updateRep	(	U32	rep[ZSTD_REP_NUM],
		U32 const	offBase_minus1,
		U32 const	ll0 )

ZSTD_window_canOverflowCorrect()

MEM_STATIC U32 ZSTD_window_canOverflowCorrect	(	ZSTD_window_t const	window,
		U32	cycleLog,
		U32	maxDist,
		U32	loadedDictEnd,
		void const *	src )

ZSTD_window_canOverflowCorrect(): Returns non-zero if the indices are large enough for overflow correction to work correctly without impacting compression ratio.

ZSTD_window_clear()

MEM_STATIC void ZSTD_window_clear

(

ZSTD_window_t *

window

)

ZSTD_window_clear(): Clears the window containing the history by simply setting it to empty.

ZSTD_window_correctOverflow()

MEM_STATIC U32 ZSTD_window_correctOverflow	(	ZSTD_window_t *	window,
		U32	cycleLog,
		U32	maxDist,
		void const *	src )

ZSTD_window_correctOverflow(): Reduces the indices to protect from index overflow. Returns the correction made to the indices, which must be applied to every stored index.

The least significant cycleLog bits of the indices must remain the same, which may be 0. Every index up to maxDist in the past must be valid.

ZSTD_window_enforceMaxDist()

MEM_STATIC void ZSTD_window_enforceMaxDist	(	ZSTD_window_t *	window,
		const void *	blockEnd,
		U32	maxDist,
		U32 *	loadedDictEndPtr,
		const ZSTD_matchState_t **	dictMatchStatePtr )

ZSTD_window_enforceMaxDist(): Updates lowLimit so that: (srcEnd - base) - lowLimit == maxDist + loadedDictEnd

It ensures index is valid as long as index >= lowLimit. This must be called before a block compression call.

loadedDictEnd is only defined if a dictionary is in use for current compression. As the name implies, loadedDictEnd represents the index at end of dictionary. The value lies within context's referential, it can be directly compared to blockEndIdx.

If loadedDictEndPtr is NULL, no dictionary is in use, and we use loadedDictEnd == 0. If loadedDictEndPtr is not NULL, we set it to zero after updating lowLimit. This is because dictionaries are allowed to be referenced fully as long as the last byte of the dictionary is in the window. Once input has progressed beyond window size, dictionary cannot be referenced anymore.

In normal dict mode, the dictionary lies between lowLimit and dictLimit. In dictMatchState mode, lowLimit and dictLimit are the same, and the dictionary is below them. forceWindow and dictMatchState are therefore incompatible.

ZSTD_window_hasExtDict()

MEM_STATIC U32 ZSTD_window_hasExtDict

(

ZSTD_window_t const

window

)

ZSTD_window_hasExtDict(): Returns non-zero if the window has a non-empty extDict.

ZSTD_window_init()

MEM_STATIC void ZSTD_window_init

(

ZSTD_window_t *

window

)

ZSTD_window_isEmpty()

MEM_STATIC U32 ZSTD_window_isEmpty

(

ZSTD_window_t const

window

)

ZSTD_window_needOverflowCorrection()

MEM_STATIC U32 ZSTD_window_needOverflowCorrection	(	ZSTD_window_t const	window,
		U32	cycleLog,
		U32	maxDist,
		U32	loadedDictEnd,
		void const *	src,
		void const *	srcEnd )

ZSTD_window_needOverflowCorrection(): Returns non-zero if the indices are getting too large and need overflow protection.

ZSTD_window_update()

MEM_STATIC U32 ZSTD_window_update	(	ZSTD_window_t *	window,
		void const *	src,
		size_t	srcSize,
		int	forceNonContiguous )

ZSTD_window_update(): Updates the window by appending [src, src + srcSize) to the window. If it is not contiguous, the current prefix becomes the extDict, and we forget about the extDict. Handles overlap of the prefix and extDict. Returns non-zero if the segment is contiguous.

ZSTD_writeLastEmptyBlock()

size_t ZSTD_writeLastEmptyBlock	(	void *	dst,
		size_t	dstCapacity )