lz4hc.h File Reference

#include "lz4.h"

Go to the source code of this file.

Data Structures
struct	LZ4HC_CCtx_internal
union	LZ4_streamHC_u

Macros
#define	LZ4HC_CLEVEL_MIN   2
#define	LZ4HC_CLEVEL_DEFAULT   9
#define	LZ4HC_CLEVEL_OPT_MIN   10
#define	LZ4HC_CLEVEL_MAX   12
#define	LZ4HC_DICTIONARY_LOGSIZE   16
#define	LZ4HC_MAXD   (1<<LZ4HC_DICTIONARY_LOGSIZE)
#define	LZ4HC_MAXD_MASK   (LZ4HC_MAXD - 1)
#define	LZ4HC_HASH_LOG   15
#define	LZ4HC_HASHTABLESIZE   (1 << LZ4HC_HASH_LOG)
#define	LZ4HC_HASH_MASK   (LZ4HC_HASHTABLESIZE - 1)
#define	LZ4_STREAMHC_MINSIZE   262200 /* static size, for inter-version compatibility */

Functions
LZ4LIB_API int	LZ4_compress_HC (const char *src, char *dst, int srcSize, int dstCapacity, int compressionLevel)
LZ4LIB_API int	LZ4_sizeofStateHC (void)
LZ4LIB_API int	LZ4_compress_HC_extStateHC (void *stateHC, const char *src, char *dst, int srcSize, int maxDstSize, int compressionLevel)
LZ4LIB_API int	LZ4_compress_HC_destSize (void *stateHC, const char *src, char *dst, int *srcSizePtr, int targetDstSize, int compressionLevel)
LZ4LIB_API LZ4_streamHC_t *	LZ4_createStreamHC (void)
LZ4LIB_API int	LZ4_freeStreamHC (LZ4_streamHC_t *streamHCPtr)
LZ4LIB_API void	LZ4_resetStreamHC_fast (LZ4_streamHC_t *streamHCPtr, int compressionLevel)
LZ4LIB_API int	LZ4_loadDictHC (LZ4_streamHC_t *streamHCPtr, const char *dictionary, int dictSize)
LZ4LIB_API int	LZ4_compress_HC_continue (LZ4_streamHC_t *streamHCPtr, const char *src, char *dst, int srcSize, int maxDstSize)
LZ4LIB_API int	LZ4_compress_HC_continue_destSize (LZ4_streamHC_t *LZ4_streamHCPtr, const char *src, char *dst, int *srcSizePtr, int targetDstSize)
LZ4LIB_API int	LZ4_saveDictHC (LZ4_streamHC_t *streamHCPtr, char *safeBuffer, int maxDictSize)
LZ4LIB_API void	LZ4_attach_HC_dictionary (LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream)
LZ4LIB_API LZ4_streamHC_t *	LZ4_initStreamHC (void *buffer, size_t size)
	LZ4_DEPRECATED ("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC(const char *source
	LZ4_DEPRECATED ("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC(void *state
	LZ4_DEPRECATED ("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_continue(LZ4_streamHC_t *LZ4_streamHCPtr
	LZ4_DEPRECATED ("use LZ4_createStreamHC() instead") LZ4LIB_API void *LZ4_createHC(const char *inputBuffer)
	LZ4_DEPRECATED ("use LZ4_freeStreamHC() instead") LZ4LIB_API int LZ4_freeHC(void *LZ4HC_Data)
	LZ4_DEPRECATED ("use LZ4_saveDictHC() instead") LZ4LIB_API char *LZ4_slideInputBufferHC(void *LZ4HC_Data)
	LZ4_DEPRECATED ("use LZ4_initStreamHC() instead") LZ4LIB_API int LZ4_resetStreamStateHC(void *state
LZ4LIB_API void	LZ4_resetStreamHC (LZ4_streamHC_t *streamHCPtr, int compressionLevel)

Variables
char *	dest
char int	inputSize
char int int	maxOutputSize
char int int	compressionLevel
const char *	source
char *	inputBuffer

Macro Definition Documentation

LZ4_STREAMHC_MINSIZE

#define LZ4_STREAMHC_MINSIZE   262200 /* static size, for inter-version compatibility */

LZ4HC_CLEVEL_DEFAULT

#define LZ4HC_CLEVEL_DEFAULT   9

LZ4HC_CLEVEL_MAX

#define LZ4HC_CLEVEL_MAX   12

LZ4HC_CLEVEL_MIN

#define LZ4HC_CLEVEL_MIN   2

LZ4HC_CLEVEL_OPT_MIN

#define LZ4HC_CLEVEL_OPT_MIN   10

LZ4HC_DICTIONARY_LOGSIZE

#define LZ4HC_DICTIONARY_LOGSIZE   16

LZ4HC_HASH_LOG

#define LZ4HC_HASH_LOG   15

LZ4HC_HASH_MASK

#define LZ4HC_HASH_MASK   (LZ4HC_HASHTABLESIZE - 1)

LZ4HC_HASHTABLESIZE

#define LZ4HC_HASHTABLESIZE   (1 << LZ4HC_HASH_LOG)

LZ4HC_MAXD

#define LZ4HC_MAXD   (1<<LZ4HC_DICTIONARY_LOGSIZE)

LZ4HC_MAXD_MASK

#define LZ4HC_MAXD_MASK   (LZ4HC_MAXD - 1)

Function Documentation

LZ4_attach_HC_dictionary()

LZ4LIB_API void LZ4_attach_HC_dictionary	(	LZ4_streamHC_t *	working_stream,
		const LZ4_streamHC_t *	dictionary_stream )

LZ4_attach_HC_dictionary() : stable since v1.10.0 This API allows for the efficient re-use of a static dictionary many times.

Rather than re-loading the dictionary buffer into a working context before each compression, or copying a pre-loaded dictionary's LZ4_streamHC_t into a working LZ4_streamHC_t, this function introduces a no-copy setup mechanism, in which the working stream references the dictionary stream in-place.

Several assumptions are made about the state of the dictionary stream. Currently, only streams which have been prepared by LZ4_loadDictHC() should be expected to work.

Alternatively, the provided dictionary stream pointer may be NULL, in which case any existing dictionary stream is unset.

A dictionary should only be attached to a stream without any history (i.e., a stream that has just been reset).

The dictionary will remain attached to the working stream only for the current stream session. Calls to LZ4_resetStreamHC(_fast) will remove the dictionary context association from the working stream. The dictionary stream (and source buffer) must remain in-place / accessible / unchanged through the lifetime of the stream session.

LZ4_compress_HC()

LZ4LIB_API int LZ4_compress_HC	(	const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity,
		int	compressionLevel )

LZ4_compress_HC() : Compress data from src into dst, using the powerful but slower "HC" algorithm. dst must be already allocated. Compression is guaranteed to succeed if dstCapacity >= LZ4_compressBound(srcSize) (see "lz4.h") Max supported srcSize value is LZ4_MAX_INPUT_SIZE (see "lz4.h") compressionLevel : any value between 1 and LZ4HC_CLEVEL_MAX will work. Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.

Returns

: the number of bytes written into 'dst' or 0 if compression fails.

LZ4_compress_HC_continue()

LZ4LIB_API int LZ4_compress_HC_continue	(	LZ4_streamHC_t *	streamHCPtr,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	maxDstSize )

LZ4_compress_HC_continue_destSize()

LZ4LIB_API int LZ4_compress_HC_continue_destSize	(	LZ4_streamHC_t *	LZ4_streamHCPtr,
		const char *	src,
		char *	dst,
		int *	srcSizePtr,
		int	targetDstSize )

LZ4_compress_HC_continue_destSize() : v1.9.0+ Similar to LZ4_compress_HC_continue(), but will read as much data as possible from src to fit into targetDstSize budget. Result is provided into 2 parts :

Returns

: the number of bytes written into 'dst' (necessarily <= targetDstSize) or 0 if compression fails. srcSizePtr : on success, *srcSizePtr will be updated to indicate how much bytes were read from src. Note that this function may not consume the entire input.

LZ4_compress_HC_destSize()

LZ4LIB_API int LZ4_compress_HC_destSize	(	void *	stateHC,
		const char *	src,
		char *	dst,
		int *	srcSizePtr,
		int	targetDstSize,
		int	compressionLevel )

LZ4_compress_HC_destSize() : v1.9.0+ Will compress as much data as possible from src to fit into targetDstSize budget. Result is provided in 2 parts :

Returns

: the number of bytes written into 'dst' (necessarily <= targetDstSize) or 0 if compression fails. srcSizePtr : on success, *srcSizePtr is updated to indicate how much bytes were read from src

LZ4_compress_HC_extStateHC()

LZ4LIB_API int LZ4_compress_HC_extStateHC	(	void *	stateHC,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	maxDstSize,
		int	compressionLevel )

LZ4_createStreamHC()

LZ4LIB_API LZ4_streamHC_t * LZ4_createStreamHC

(

void

)

LZ4_createStreamHC() and LZ4_freeStreamHC() : These functions create and release memory for LZ4 HC streaming state. Newly created states are automatically initialized. A same state can be used multiple times consecutively, starting with LZ4_resetStreamHC_fast() to start a new stream of blocks.

LZ4_DEPRECATED() [1/7]

LZ4_DEPRECATED

(

"use LZ4_compress_HC() instead"

)

const

LZ4_DEPRECATED() [2/7]

LZ4_DEPRECATED

(

"use LZ4_compress_HC_continue() instead"

)

LZ4_DEPRECATED() [3/7]

LZ4_DEPRECATED

(

"use LZ4_compress_HC_extStateHC() instead"

)

LZ4_DEPRECATED() [4/7]

LZ4_DEPRECATED

(

"use LZ4_createStreamHC() instead"

)

const

LZ4_DEPRECATED() [5/7]

LZ4_DEPRECATED

(

"use LZ4_freeStreamHC() instead"

)

LZ4_DEPRECATED() [6/7]

LZ4_DEPRECATED

(

"use LZ4_initStreamHC() instead"

)

LZ4_DEPRECATED() [7/7]

LZ4_DEPRECATED

(

"use LZ4_saveDictHC() instead"

)

LZ4_freeStreamHC()

LZ4LIB_API int LZ4_freeStreamHC

(

LZ4_streamHC_t *

streamHCPtr

)

LZ4_initStreamHC()

LZ4LIB_API LZ4_streamHC_t * LZ4_initStreamHC	(	void *	buffer,
		size_t	size )

LZ4_loadDictHC()

LZ4LIB_API int LZ4_loadDictHC	(	LZ4_streamHC_t *	streamHCPtr,
		const char *	dictionary,
		int	dictSize )

LZ4_resetStreamHC()

LZ4LIB_API void LZ4_resetStreamHC	(	LZ4_streamHC_t *	streamHCPtr,
		int	compressionLevel )

LZ4_resetStreamHC_fast()

LZ4LIB_API void LZ4_resetStreamHC_fast	(	LZ4_streamHC_t *	streamHCPtr,
		int	compressionLevel )

LZ4_saveDictHC()

LZ4LIB_API int LZ4_saveDictHC	(	LZ4_streamHC_t *	streamHCPtr,
		char *	safeBuffer,
		int	maxDictSize )

LZ4_sizeofStateHC()

LZ4LIB_API int LZ4_sizeofStateHC

(

void

)

LZ4_compress_HC_extStateHC() : Same as LZ4_compress_HC(), but using an externally allocated memory segment for state. state size is provided by LZ4_sizeofStateHC(). Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly).

Variable Documentation

compressionLevel

const char char int int int compressionLevel

dest

const char char* dest

inputBuffer

char* inputBuffer

inputSize

const char char int inputSize

maxOutputSize

const char char int int maxOutputSize

source

const char* source