Classes
struct	LZ4F_frameInfo_t
struct	LZ4F_preferences_t
struct	LZ4F_compressOptions_t
struct	LZ4F_decompressOptions_t

Macros
#define	LZ4FLIB_API
	Introduction.
#define	LZ4F_DEPRECATE(x) x /* no deprecation warning for this compiler */
#define	LZ4F_OBSOLETE_ENUM(x) , LZ4F_DEPRECATE(x) = LZ4F_##x
#define	LZ4F_VERSION 100
#define	LZ4F_HEADER_SIZE_MAX 15

Typedefs
typedef size_t	LZ4F_errorCode_t
typedef LZ4F_blockSizeID_t	blockSizeID_t
typedef LZ4F_blockMode_t	blockMode_t
typedef LZ4F_frameType_t	frameType_t
typedef LZ4F_contentChecksum_t	contentChecksum_t
typedef struct LZ4F_cctx_s	LZ4F_cctx
typedef LZ4F_cctx *	LZ4F_compressionContext_t
typedef struct LZ4F_dctx_s	LZ4F_dctx
typedef LZ4F_dctx *	LZ4F_decompressionContext_t

Enumerations
enum	LZ4F_blockSizeID_t { LZ4F_default = 0, LZ4F_max64KB = 4, LZ4F_max256KB = 5, LZ4F_max1MB = 6, LZ4F_max4MB = 7 }
enum	LZ4F_blockMode_t { LZ4F_blockLinked = 0, LZ4F_blockIndependent }
enum	LZ4F_contentChecksum_t { LZ4F_noContentChecksum = 0, LZ4F_contentChecksumEnabled }
enum	LZ4F_frameType_t { LZ4F_frame = 0, LZ4F_skippableFrame }

Functions
LZ4FLIB_API unsigned	LZ4F_isError (LZ4F_errorCode_t code)
	tells if a `LZ4F_errorCode_t` function result is an error code
LZ4FLIB_API const char *	LZ4F_getErrorName (LZ4F_errorCode_t code)
	return error code string; useful for debugging
LZ4FLIB_API size_t	LZ4F_compressFrameBound (size_t srcSize, const LZ4F_preferences_t *preferencesPtr)
LZ4FLIB_API size_t	LZ4F_compressFrame (void dstBuffer, size_t dstCapacity, const void srcBuffer, size_t srcSize, const LZ4F_preferences_t *preferencesPtr)
LZ4FLIB_API unsigned	LZ4F_getVersion (void)
LZ4FLIB_API LZ4F_errorCode_t	LZ4F_createCompressionContext (LZ4F_cctx **cctxPtr, unsigned version)
LZ4FLIB_API LZ4F_errorCode_t	LZ4F_freeCompressionContext (LZ4F_cctx *cctx)
LZ4FLIB_API size_t	LZ4F_compressBegin (LZ4F_cctx cctx, void dstBuffer, size_t dstCapacity, const LZ4F_preferences_t *prefsPtr)
LZ4FLIB_API size_t	LZ4F_compressBound (size_t srcSize, const LZ4F_preferences_t *prefsPtr)
LZ4FLIB_API size_t	LZ4F_compressUpdate (LZ4F_cctx cctx, void dstBuffer, size_t dstCapacity, const void srcBuffer, size_t srcSize, const LZ4F_compressOptions_t cOptPtr)
LZ4FLIB_API size_t	LZ4F_flush (LZ4F_cctx cctx, void dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t *cOptPtr)
LZ4FLIB_API size_t	LZ4F_compressEnd (LZ4F_cctx cctx, void dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t *cOptPtr)
LZ4FLIB_API LZ4F_errorCode_t	LZ4F_createDecompressionContext (LZ4F_dctx **dctxPtr, unsigned version)
LZ4FLIB_API LZ4F_errorCode_t	LZ4F_freeDecompressionContext (LZ4F_dctx *const dctx)
LZ4FLIB_API size_t	LZ4F_getFrameInfo (LZ4F_dctx dctx, LZ4F_frameInfo_t frameInfoPtr, const void srcBuffer, size_t srcSizePtr)
LZ4FLIB_API size_t	LZ4F_decompress (LZ4F_dctx dctx, void dstBuffer, size_t dstSizePtr, const void srcBuffer, size_t srcSizePtr, const LZ4F_decompressOptions_t dOptPtr)

Macro Definition Documentation

#define LZ4FLIB_API

Introduction.

lz4frame.h implements LZ4 frame specification (doc/lz4_Frame_format.md). lz4frame.h provides frame compression functions that take care of encoding standard metadata alongside LZ4-compressed blocks.

#define LZ4F_DEPRECATE ( x ) x /* no deprecation warning for this compiler */

#define LZ4F_OBSOLETE_ENUM ( x ) , LZ4F_DEPRECATE(x) = LZ4F_##x

#define LZ4F_VERSION 100

#define LZ4F_HEADER_SIZE_MAX 15

Typedef Documentation

typedef size_t LZ4F_errorCode_t

typedef LZ4F_blockSizeID_t blockSizeID_t

typedef LZ4F_blockMode_t blockMode_t

typedef LZ4F_frameType_t frameType_t

typedef LZ4F_contentChecksum_t contentChecksum_t

typedef struct LZ4F_cctx_s LZ4F_cctx

typedef LZ4F_cctx* LZ4F_compressionContext_t

typedef struct LZ4F_dctx_s LZ4F_dctx

typedef LZ4F_dctx* LZ4F_decompressionContext_t

Enumeration Type Documentation

enum LZ4F_blockSizeID_t

Enumerator:

LZ4F_default
LZ4F_max64KB
LZ4F_max256KB
LZ4F_max1MB
LZ4F_max4MB

enum LZ4F_blockMode_t

Enumerator:

LZ4F_blockLinked
LZ4F_blockIndependent

enum LZ4F_contentChecksum_t

Enumerator:

LZ4F_noContentChecksum
LZ4F_contentChecksumEnabled

enum LZ4F_frameType_t

Enumerator:

LZ4F_frame
LZ4F_skippableFrame

Function Documentation

LZ4FLIB_API unsigned LZ4F_isError ( LZ4F_errorCode_t code )

tells if a LZ4F_errorCode_t function result is an error code

LZ4FLIB_API const char* LZ4F_getErrorName ( LZ4F_errorCode_t code )

return error code string; useful for debugging

LZ4FLIB_API size_t LZ4F_compressFrameBound	(	size_t	srcSize,
		const LZ4F_preferences_t *	preferencesPtr
	)

LZ4F_compressFrameBound() : Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences. Note : this result is only usable with LZ4F_compressFrame(), not with multi-segments compression.

LZ4FLIB_API size_t LZ4F_compressFrame	(	void *	dstBuffer,
		size_t	dstCapacity,
		const void *	srcBuffer,
		size_t	srcSize,
		const LZ4F_preferences_t *	preferencesPtr
	)

LZ4F_compressFrame() : Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.5.1 An important rule is that dstBuffer MUST be large enough (dstCapacity) to store the result in worst case situation. This value is supplied by LZ4F_compressFrameBound(). If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode). The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.

Returns: : number of bytes written into dstBuffer. or an error code if it fails (can be tested using LZ4F_isError())

LZ4FLIB_API unsigned LZ4F_getVersion ( void )

LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext	(	LZ4F_cctx **	cctxPtr,
		unsigned	version
	)

LZ4F_createCompressionContext() : The first thing to do is to create a compressionContext object, which will be used in all compression operations. This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure. The version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL. The function will provide a pointer to a fully allocated LZ4F_cctx object. If

Returns: != zero, there was an error during context creation. Object can release its memory using LZ4F_freeCompressionContext();

LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext ( LZ4F_cctx * cctx )

LZ4FLIB_API size_t LZ4F_compressBegin	(	LZ4F_cctx *	cctx,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_preferences_t *	prefsPtr
	)

LZ4F_compressBegin() : will write the frame header into dstBuffer. dstCapacity must be large enough to store the header. Maximum header size is LZ4F_HEADER_SIZE_MAX bytes. prefsPtr is optional : you can provide NULL as argument, all preferences will then be set to default.

Returns: : number of bytes written into dstBuffer for the header or an error code (which can be tested using LZ4F_isError())

LZ4FLIB_API size_t LZ4F_compressBound	(	size_t	srcSize,
		const LZ4F_preferences_t *	prefsPtr
	)

LZ4F_compressBound() : Provides dstCapacity given a srcSize to guarantee operation success in worst case situations. prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario. Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers. When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.

LZ4FLIB_API size_t LZ4F_compressUpdate	(	LZ4F_cctx *	cctx,
		void *	dstBuffer,
		size_t	dstCapacity,
		const void *	srcBuffer,
		size_t	srcSize,
		const LZ4F_compressOptions_t *	cOptPtr
	)

LZ4F_compressUpdate() : LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary. An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations. This value is provided by LZ4F_compressBound(). If this condition is not respected, LZ4F_compress() will fail (result is an errorCode). LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized. cOptPtr is optional : NULL can be provided, in which case all options are set to default.

Returns: : number of bytes written into dstBuffer (it can be zero, meaning input data was just buffered). or an error code if it fails (which can be tested using LZ4F_isError())

LZ4FLIB_API size_t LZ4F_flush	(	LZ4F_cctx *	cctx,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_compressOptions_t *	cOptPtr
	)

LZ4F_flush() : When data must be generated and sent immediately, without waiting for a block to be completely filled, it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx. dstCapacity must be large enough to ensure the operation will be successful. cOptPtr is optional : it's possible to provide NULL, all options will be set to default.

Returns: : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx) or an error code if it fails (which can be tested using LZ4F_isError())

LZ4FLIB_API size_t LZ4F_compressEnd	(	LZ4F_cctx *	cctx,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_compressOptions_t *	cOptPtr
	)

LZ4F_compressEnd() : To properly finish an LZ4 frame, invoke LZ4F_compressEnd(). It will flush whatever data remained within cctx (like LZ4_flush()) and properly finalize the frame, with an endMark and a checksum. cOptPtr is optional : NULL can be provided, in which case all options will be set to default.

Returns: : number of bytes written into dstBuffer (necessarily >= 4 (endMark), or 8 if optional frame checksum is enabled) or an error code if it fails (which can be tested using LZ4F_isError()) A successful call to LZ4F_compressEnd() makes cctx available again for another compression task.

LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext	(	LZ4F_dctx **	dctxPtr,
		unsigned	version
	)

LZ4F_createDecompressionContext() : Create an LZ4F_decompressionContext_t object, which will be used to track all decompression operations. The version provided MUST be LZ4F_VERSION. It is intended to track potential breaking differences between different versions. The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext_t object. The result is an errorCode, which can be tested using LZ4F_isError(). dctx memory can be released using LZ4F_freeDecompressionContext(); The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released. That is, it should be == 0 if decompression has been completed fully and correctly.

LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext ( LZ4F_dctx *const dctx )

LZ4FLIB_API size_t LZ4F_getFrameInfo	(	LZ4F_dctx *	dctx,
		LZ4F_frameInfo_t *	frameInfoPtr,
		const void *	srcBuffer,
		size_t *	srcSizePtr
	)

LZ4F_getFrameInfo() : This function decodes frame header information (such as max blockSize, frame checksum, etc.). Its usage is optional. The objective is to extract frame header information, typically for allocation purposes. A header size is variable and can length from 7 to 15 bytes. It's possible to provide more input bytes than that. The number of bytes consumed from srcBuffer will be updated within srcSizePtr (necessarily <= original value). Decompression must resume from this point (srcBuffer + *srcSizePtr). Note that LZ4F_getFrameInfo() can also be used anytime *after decompression is started, in which case 0 input byte can be enough. Frame header info is copied into an already allocated LZ4F_frameInfo_t structure.

Returns: : an hint about how many srcSize bytes LZ4F_decompress() expects for next call, or an error code which can be tested using LZ4F_isError() (typically, when there is not enough src bytes to fully decode the frame header)

LZ4FLIB_API size_t LZ4F_decompress	(	LZ4F_dctx *	dctx,
		void *	dstBuffer,
		size_t *	dstSizePtr,
		const void *	srcBuffer,
		size_t *	srcSizePtr,
		const LZ4F_decompressOptions_t *	dOptPtr
	)

LZ4F_decompress() : Call this function repetitively to regenerate data compressed within srcBuffer. The function will attempt to decode up to *srcSizePtr bytes from srcBuffer, into dstBuffer of capacity *dstSizePtr.

The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value).

The number of bytes read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value). Number of bytes read can be < number of bytes provided, meaning there is some more data to decode. It typically happens when dstBuffer is not large enough to contain all decoded data. Remaining data will have to be presented again in a subsequent invocation.

dstBuffer content is expected to be flushed between each invocation, as its content will be overwritten. dstBuffer can be changed at will between each consecutive function invocation.

Returns: is an hint of how many srcSize bytes LZ4F_decompress() expects for next call. Schematically, it's the size of the current (or remaining) compressed block + header of next block. Respecting the hint provides some boost to performance, since it does skip intermediate buffers. This is just a hint though, it's always possible to provide any srcSize. When a frame is fully decoded,; will be 0 (no more data expected). If decompression failed,; is an error code, which can be tested using LZ4F_isError().

After a frame is fully decoded, dctx can be used again to decompress another frame.

Classes

Macros

Typedefs

Enumerations

Functions

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation