#include "lz4.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>

Include dependency graph for lz4.c:

Macros
#define	LZ4_HEAPMODE 0
#define	LZ4_ACCELERATION_DEFAULT 1
#define	LZ4_ACCELERATION_MAX 65537
#define	LZ4_SRC_INCLUDED 1
#define	LZ4_DISABLE_DEPRECATE_WARNINGS
#define	LZ4_STATIC_LINKING_ONLY
#define	LZ4_FORCE_INLINE static
#define	LZ4_FORCE_O2
#define	expect(expr, value)
#define	likely(expr)
#define	unlikely(expr)
#define	LZ4_ALIGN_TEST 1
#define	ALLOC(s)
#define	ALLOC_AND_ZERO(s)
#define	FREEMEM(p)
#define	LZ4_memset(p, v, s)
#define	MEM_INIT(p, v, s)
#define	MINMATCH 4
#define	WILDCOPYLENGTH 8
#define	LASTLITERALS 5
#define	MFLIMIT 12
#define	MATCH_SAFEGUARD_DISTANCE
#define	FASTLOOP_SAFE_DISTANCE 64
#define	KB *(1 << 10)
#define	MB *(1 << 20)
#define	GB *(1U << 30)
#define	LZ4_DISTANCE_ABSOLUTE_MAX 65535
#define	ML_BITS 4
#define	ML_MASK ((1U << ML_BITS) - 1)
#define	RUN_BITS (8 - ML_BITS)
#define	RUN_MASK ((1U << RUN_BITS) - 1)
#define	assert(condition)
#define	LZ4_STATIC_ASSERT(c)
#define	DEBUGLOG(l, ...)
#define	LZ4_memcpy(dst, src, size)
#define	LZ4_memmove memmove
#define	LZ4_FAST_DEC_LOOP 0
#define	STEPSIZE sizeof(reg_t)
#define	HASH_UNIT sizeof(reg_t)
#define	MIN(a, b)

Typedefs
typedef unsigned char	BYTE
typedef unsigned short	U16
typedef unsigned int	U32
typedef signed int	S32
typedef unsigned long long	U64
typedef size_t	uptrval
typedef size_t	reg_t
typedef size_t	Rvl_t

Enumerations
enum	limitedOutput_directive { notLimited = 0 , limitedOutput = 1 , fillOutput = 2 }
enum	tableType_t { clearedTable = 0 , byPtr , byU32 , byU16 }
enum	dict_directive { noDict = 0 , withPrefix64k , usingExtDict , usingDictCtx }
enum	dictIssue_directive { noDictIssue = 0 , dictSmall }
enum	LoadDict_mode_e { _ld_fast , _ld_slow }
enum	earlyEnd_directive { decode_full_block = 0 , partial_decode = 1 }

Functions
int	LZ4_versionNumber (void)
const char *	LZ4_versionString (void)
int	LZ4_compressBound (int isize)
int	LZ4_sizeofState (void)
int	LZ4_compress_forceExtDict (LZ4_stream_t LZ4_dict, const char source, char *dest, int srcSize)
int	LZ4_decompress_safe_forceExtDict (const char source, char dest, int compressedSize, int maxOutputSize, const void *dictStart, size_t dictSize)
int	LZ4_decompress_safe_partial_forceExtDict (const char source, char dest, int compressedSize, int targetOutputSize, int dstCapacity, const void *dictStart, size_t dictSize)
int	LZ4_compress_fast_extState (void state, const char source, char *dest, int inputSize, int maxOutputSize, int acceleration)
int	LZ4_compress_fast_extState_fastReset (void state, const char src, char *dst, int srcSize, int dstCapacity, int acceleration)
int	LZ4_compress_fast (const char src, char dest, int srcSize, int dstCapacity, int acceleration)
int	LZ4_compress_default (const char src, char dst, int srcSize, int dstCapacity)
int	LZ4_compress_destSize_extState (void state, const char src, char dst, int srcSizePtr, int targetDstSize, int acceleration)
int	LZ4_compress_destSize (const char src, char dst, int *srcSizePtr, int targetDstSize)
LZ4_stream_t *	LZ4_createStream (void)
LZ4_stream_t *	LZ4_initStream (void *buffer, size_t size)
void	LZ4_resetStream (LZ4_stream_t *LZ4_stream)
void	LZ4_resetStream_fast (LZ4_stream_t *ctx)
int	LZ4_freeStream (LZ4_stream_t *LZ4_stream)
int	LZ4_loadDict_internal (LZ4_stream_t LZ4_dict, const char dictionary, int dictSize, LoadDict_mode_e _ld)
int	LZ4_loadDict (LZ4_stream_t LZ4_dict, const char dictionary, int dictSize)
int	LZ4_loadDictSlow (LZ4_stream_t LZ4_dict, const char dictionary, int dictSize)
void	LZ4_attach_dictionary (LZ4_stream_t workingStream, const LZ4_stream_t dictionaryStream)
int	LZ4_compress_fast_continue (LZ4_stream_t LZ4_stream, const char source, char *dest, int inputSize, int maxOutputSize, int acceleration)
int	LZ4_saveDict (LZ4_stream_t LZ4_dict, char safeBuffer, int dictSize)
int	LZ4_decompress_safe (const char source, char dest, int compressedSize, int maxDecompressedSize)
int	LZ4_decompress_safe_partial (const char src, char dst, int compressedSize, int targetOutputSize, int dstCapacity)
int	LZ4_decompress_fast (const char source, char dest, int originalSize)
int	LZ4_decompress_safe_withPrefix64k (const char source, char dest, int compressedSize, int maxOutputSize)
int	LZ4_decompress_fast_withPrefix64k (const char source, char dest, int originalSize)
LZ4_streamDecode_t *	LZ4_createStreamDecode (void)
int	LZ4_freeStreamDecode (LZ4_streamDecode_t *LZ4_stream)
int	LZ4_setStreamDecode (LZ4_streamDecode_t LZ4_streamDecode, const char dictionary, int dictSize)
int	LZ4_decoderRingBufferSize (int maxBlockSize)
int	LZ4_decompress_safe_continue (LZ4_streamDecode_t LZ4_streamDecode, const char source, char *dest, int compressedSize, int maxOutputSize)
int	LZ4_decompress_fast_continue (LZ4_streamDecode_t LZ4_streamDecode, const char source, char *dest, int originalSize)
int	LZ4_decompress_safe_usingDict (const char source, char dest, int compressedSize, int maxOutputSize, const char *dictStart, int dictSize)
int	LZ4_decompress_safe_partial_usingDict (const char source, char dest, int compressedSize, int targetOutputSize, int dstCapacity, const char *dictStart, int dictSize)
int	LZ4_decompress_fast_usingDict (const char source, char dest, int originalSize, const char *dictStart, int dictSize)
int	LZ4_compress_limitedOutput (const char source, char dest, int inputSize, int maxOutputSize)
int	LZ4_compress (const char src, char dest, int srcSize)
int	LZ4_compress_limitedOutput_withState (void state, const char src, char *dst, int srcSize, int dstSize)
int	LZ4_compress_withState (void state, const char src, char *dst, int srcSize)
int	LZ4_compress_limitedOutput_continue (LZ4_stream_t LZ4_stream, const char src, char *dst, int srcSize, int dstCapacity)
int	LZ4_compress_continue (LZ4_stream_t LZ4_stream, const char source, char *dest, int inputSize)
int	LZ4_uncompress (const char source, char dest, int outputSize)
int	LZ4_uncompress_unknownOutputSize (const char source, char dest, int isize, int maxOutputSize)
int	LZ4_sizeofStreamState (void)
int	LZ4_resetStreamState (void state, char inputBuffer)
void *	LZ4_create (char *inputBuffer)
char *	LZ4_slideInputBuffer (void *state)

Macro Definition Documentation

◆ ALLOC

#define ALLOC ( s )

Value:

malloc(s)

LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION : Disable relatively high-level LZ4/HC functions that use dynamic memory allocation functions (malloc(), calloc(), free()).

Note that this is a compile-time switch. And since it disables public/stable LZ4 v1 API functions, we don't recommend using this symbol to generate a library for distribution.

The following public functions are removed when this symbol is defined.

lz4 : LZ4_createStream, LZ4_freeStream, LZ4_createStreamDecode, LZ4_freeStreamDecode, LZ4_create (deprecated)
lz4hc : LZ4_createStreamHC, LZ4_freeStreamHC, LZ4_createHC (deprecated), LZ4_freeHC (deprecated)
lz4frame, lz4file : All LZ4F_* functions

Definition at line 242 of file lz4.c.

Referenced by LZ4_compress_destSize(), LZ4_compress_fast(), and LZ4_createStream().

◆ ALLOC_AND_ZERO

#define ALLOC_AND_ZERO ( s )

Value:

calloc(1, s)

Definition at line 243 of file lz4.c.

Referenced by LZ4_createStreamDecode().

◆ assert

#define assert ( condition )

◆ DEBUGLOG

#define DEBUGLOG	(		l,
			... )

Value:

{ \

}

Definition at line 315 of file lz4.c.

Referenced by LZ4_attach_dictionary(), LZ4_compress_fast_continue(), LZ4_createStream(), LZ4_decompress_fast(), LZ4_decompress_fast_continue(), LZ4_decompress_safe_forceExtDict(), LZ4_freeStream(), LZ4_initStream(), LZ4_loadDict_internal(), LZ4_resetStream(), and LZ4_saveDict().

◆ expect

#define expect	(		expr,
			value )

Value:

(expr)

Definition at line 190 of file lz4.c.

◆ FASTLOOP_SAFE_DISTANCE

#define FASTLOOP_SAFE_DISTANCE 64

Definition at line 269 of file lz4.c.

◆ FREEMEM

#define FREEMEM ( p )

Value:

free(p)

Definition at line 244 of file lz4.c.

Referenced by LZ4_compress_destSize(), LZ4_compress_fast(), LZ4_freeStream(), and LZ4_freeStreamDecode().

◆ GB

#define GB *(1U << 30)

Definition at line 274 of file lz4.c.

◆ HASH_UNIT

#define HASH_UNIT sizeof(reg_t)

Definition at line 1960 of file lz4.c.

Referenced by LZ4_loadDict_internal().

◆ KB

#define KB *(1 << 10)

Definition at line 272 of file lz4.c.

Referenced by LZ4_attach_dictionary(), LZ4_compress_fast_continue(), LZ4_compress_forceExtDict(), LZ4_decompress_fast_withPrefix64k(), LZ4_decompress_safe_continue(), LZ4_decompress_safe_partial_usingDict(), LZ4_decompress_safe_usingDict(), LZ4_decompress_safe_withPrefix64k(), LZ4_loadDict_internal(), and LZ4_saveDict().

◆ LASTLITERALS

#define LASTLITERALS 5

Definition at line 261 of file lz4.c.

◆ likely

#define likely ( expr )

Value:

expect((expr) != 0, 1)

expect

#define expect(expr, value)

Definition lz4.c:190

Definition at line 194 of file lz4.c.

◆ LZ4_ACCELERATION_DEFAULT

#define LZ4_ACCELERATION_DEFAULT 1

Definition at line 53 of file lz4.c.

Referenced by LZ4_compress_fast_continue(), LZ4_compress_fast_extState(), and LZ4_compress_fast_extState_fastReset().

◆ LZ4_ACCELERATION_MAX

#define LZ4_ACCELERATION_MAX 65537

Definition at line 59 of file lz4.c.

Referenced by LZ4_compress_fast_continue(), LZ4_compress_fast_extState(), and LZ4_compress_fast_extState_fastReset().

◆ LZ4_ALIGN_TEST

#define LZ4_ALIGN_TEST 1

Definition at line 203 of file lz4.c.

◆ LZ4_DISABLE_DEPRECATE_WARNINGS

#define LZ4_DISABLE_DEPRECATE_WARNINGS

Definition at line 115 of file lz4.c.

◆ LZ4_DISTANCE_ABSOLUTE_MAX

#define LZ4_DISTANCE_ABSOLUTE_MAX 65535

Definition at line 276 of file lz4.c.

◆ LZ4_FAST_DEC_LOOP

#define LZ4_FAST_DEC_LOOP 0

Definition at line 564 of file lz4.c.

◆ LZ4_FORCE_INLINE

#define LZ4_FORCE_INLINE static

Definition at line 156 of file lz4.c.

◆ LZ4_FORCE_O2

#define LZ4_FORCE_O2

Definition at line 182 of file lz4.c.

◆ LZ4_HEAPMODE

#define LZ4_HEAPMODE 0

Definition at line 46 of file lz4.c.

◆ LZ4_memcpy

#define LZ4_memcpy	(	dst,
		src,
		size )

Value:

memcpy(dst, src, size)

LZ4 relies on memcpy with a constant size being inlined. In freestanding environments, the compiler can't assume the implementation of memcpy() is standard compliant, so it can't apply its specialized memcpy() inlining logic. When possible, use __builtin_memcpy() to tell the compiler to analyze memcpy() as if it were standard compliant, so it can inline it in freestanding environments. This is needed when decompressing the Linux Kernel, for example.

Definition at line 379 of file lz4.c.

Referenced by LZ4_compress_fast_continue().

◆ LZ4_memmove

#define LZ4_memmove memmove

Definition at line 387 of file lz4.c.

Referenced by LZ4_saveDict().

◆ LZ4_memset

#define LZ4_memset	(	p,
		v,
		s )

Value:

memset((p), (v), (s))

Definition at line 251 of file lz4.c.

◆ LZ4_SRC_INCLUDED

#define LZ4_SRC_INCLUDED 1

Definition at line 111 of file lz4.c.

◆ LZ4_STATIC_ASSERT

#define LZ4_STATIC_ASSERT ( c )

Value:

{                                                  \
    enum { LZ4_static_assert = 1 / (int)(!!(c)) }; \
}

Definition at line 298 of file lz4.c.

Referenced by LZ4_createStream(), and LZ4_createStreamDecode().

◆ LZ4_STATIC_LINKING_ONLY

#define LZ4_STATIC_LINKING_ONLY

Definition at line 120 of file lz4.c.

◆ MATCH_SAFEGUARD_DISTANCE

#define MATCH_SAFEGUARD_DISTANCE

Value:

((2 * WILDCOPYLENGTH) - \

MINMATCH)

MINMATCH

#define MINMATCH

Definition lz4.c:258

WILDCOPYLENGTH

#define WILDCOPYLENGTH

Definition lz4.c:260

Definition at line 265 of file lz4.c.

◆ MB

#define MB *(1 << 20)

Definition at line 273 of file lz4.c.

◆ MEM_INIT

#define MEM_INIT	(	p,
		v,
		s )

Value:

LZ4_memset((p), (v), (s))

LZ4_memset

#define LZ4_memset(p, v, s)

Definition lz4.c:251

Definition at line 253 of file lz4.c.

Referenced by LZ4_initStream(), and LZ4_resetStream().

◆ MFLIMIT

#define MFLIMIT 12

Definition at line 264 of file lz4.c.

◆ MIN

#define MIN	(		a,
			b )

Value:

((a) < (b) ? (a) : (b))

Definition at line 2276 of file lz4.c.

◆ MINMATCH

#define MINMATCH 4

Definition at line 258 of file lz4.c.

◆ ML_BITS

#define ML_BITS 4

Definition at line 282 of file lz4.c.

◆ ML_MASK

#define ML_MASK ((1U << ML_BITS) - 1)

Definition at line 283 of file lz4.c.

◆ RUN_BITS

#define RUN_BITS (8 - ML_BITS)

Definition at line 284 of file lz4.c.

◆ RUN_MASK

#define RUN_MASK ((1U << RUN_BITS) - 1)

Definition at line 285 of file lz4.c.

◆ STEPSIZE

#define STEPSIZE sizeof(reg_t)

Definition at line 785 of file lz4.c.

◆ unlikely

#define unlikely ( expr )

Value:

expect((expr) != 0, 0)

Definition at line 197 of file lz4.c.

◆ WILDCOPYLENGTH

#define WILDCOPYLENGTH 8

Definition at line 260 of file lz4.c.

Typedef Documentation

◆ BYTE

typedef unsigned char BYTE

Definition at line 342 of file lz4.c.

◆ reg_t

typedef size_t reg_t

Definition at line 353 of file lz4.c.

◆ Rvl_t

typedef size_t Rvl_t

Definition at line 2429 of file lz4.c.

◆ S32

typedef signed int S32

Definition at line 345 of file lz4.c.

◆ U16

typedef unsigned short U16

Definition at line 343 of file lz4.c.

◆ U32

typedef unsigned int U32

Definition at line 344 of file lz4.c.

◆ U64

typedef unsigned long long U64

Definition at line 346 of file lz4.c.

◆ uptrval

typedef size_t uptrval

Definition at line 347 of file lz4.c.

Enumeration Type Documentation

◆ dict_directive

enum dict_directive

This enum distinguishes several different modes of accessing previous content in the stream.

noDict : There is no preceding content.
withPrefix64k : Table entries up to ctx->dictSize before the current blob blob being compressed are valid and refer to the preceding content (of length ctx->dictSize), which is available contiguously preceding in memory the content currently being compressed.
usingExtDict : Like withPrefix64k, but the preceding content is somewhere else in memory, starting at ctx->dictionary with length ctx->dictSize.
usingDictCtx : Everything concerning the preceding content is in a separate context, pointed to by ctx->dictCtx. ctx->dictionary, ctx->dictSize, and table entries in the current context that refer to positions preceding the beginning of the current compression are ignored. Instead, ctx->dictCtx->dictionary and ctx->dictCtx ->dictSize describe the location and size of the preceding content, and matches are found by looking in the ctx ->dictCtx->hashTable.

Enumerator
noDict
withPrefix64k
usingExtDict
usingDictCtx

Definition at line 863 of file lz4.c.

◆ dictIssue_directive

enum dictIssue_directive

Enumerator
noDictIssue
dictSmall

Definition at line 869 of file lz4.c.

◆ earlyEnd_directive

enum earlyEnd_directive

Enumerator
decode_full_block
partial_decode

Definition at line 2273 of file lz4.c.

◆ limitedOutput_directive

enum limitedOutput_directive

Enumerator
notLimited
limitedOutput
fillOutput

Definition at line 356 of file lz4.c.

◆ LoadDict_mode_e

enum LoadDict_mode_e

Enumerator
_ld_fast
_ld_slow

Definition at line 1959 of file lz4.c.

◆ tableType_t

enum tableType_t

Enumerator
clearedTable
byPtr
byU32
byU16

Definition at line 838 of file lz4.c.

Function Documentation

◆ LZ4_attach_dictionary()

void LZ4_attach_dictionary	(	LZ4_stream_t *	workingStream,
		const LZ4_stream_t *	dictionaryStream )

LZ4_attach_dictionary() : stable since v1.10.0

This allows efficient re-use of a static dictionary multiple times.

Rather than re-loading the dictionary buffer into a working context before each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a working LZ4_stream_t, this function introduces a no-copy setup mechanism, in which the working stream references dictionaryStream in-place.

Several assumptions are made about the state of dictionaryStream. Currently, only states which have been prepared by LZ4_loadDict() or LZ4_loadDictSlow() should be expected to work.

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

If a dictionary is provided, it replaces any pre-existing stream history. The dictionary contents are the only history that can be referenced and logically immediately precede the data compressed in the first subsequent compression call.

The dictionary will only remain attached to the working stream through the first compression call, at the end of which it is cleared. dictionaryStream stream (and source buffer) must remain in-place / accessible / unchanged through the completion of the compression session.

Note: there is no equivalent LZ4_attach_*() method on the decompression side because there is no initialization cost, hence no need to share the cost across multiple sessions. To decompress LZ4 blocks using dictionary, attached or not, just employ the regular LZ4_setStreamDecode() for streaming, or the stateless LZ4_decompress_safe_usingDict() for one-shot decompression.

Definition at line 2038 of file lz4.c.

References LZ4_stream_t_internal::currentOffset, DEBUGLOG, LZ4_stream_t_internal::dictCtx, LZ4_stream_t_internal::dictSize, LZ4_stream_u::internal_donotuse, KB, LZ4_attach_dictionary(), and NULL.

Referenced by LZ4_attach_dictionary().

◆ LZ4_compress()

int LZ4_compress	(	const char *	src,
		char *	dest,
		int	srcSize )

Obsolete compression functions (since v1.7.3)

Definition at line 3386 of file lz4.c.

References LZ4_compress(), LZ4_compress_default(), and LZ4_compressBound().

Referenced by LZ4_compress().

◆ LZ4_compress_continue()

int LZ4_compress_continue	(	LZ4_stream_t *	LZ4_stream,
		const char *	source,
		char *	dest,
		int	inputSize )

Definition at line 3407 of file lz4.c.

References LZ4_compress_continue(), LZ4_compress_fast_continue(), and LZ4_compressBound().

Referenced by LZ4_compress_continue().

◆ LZ4_compress_default()

int LZ4_compress_default	(	const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity )

LZ4_compress_default() : Compresses 'srcSize' bytes from buffer 'src' into already allocated 'dst' buffer of size 'dstCapacity'. Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize). It also runs faster, so it's a recommended setting. If the function cannot compress 'src' into a more limited 'dst' budget, compression stops immediately, and the function result is zero. In which case, 'dst' content is undefined (invalid).

Parameters

srcSize	max supported value is LZ4_MAX_INPUT_SIZE.
dstCapacity	size of buffer 'dst' (which must be already allocated)

Returns: the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) or 0 if compression fails Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer).

Definition at line 1811 of file lz4.c.

References LZ4_compress_default(), and LZ4_compress_fast().

Referenced by G_lz4_compress(), LZ4_compress(), LZ4_compress_default(), and LZ4_compress_limitedOutput().

◆ LZ4_compress_destSize()

int LZ4_compress_destSize	(	const char *	src,
		char *	dst,
		int *	srcSizePtr,
		int	targetDstSize )

LZ4_compress_destSize() : Reverse the logic : compresses as much data as possible from 'src' buffer into already allocated buffer 'dst', of size >= 'dstCapacity'. This function either compresses the entire 'src' content into 'dst' if it's large enough, or fill 'dst' buffer completely with as much data as possible from 'src'. note: acceleration parameter is fixed to "default".

Parameters

[in,out] srcSizePtr Initially contains size of input. Will be modified to indicate how many bytes where read from 'src' to fill 'dst'. New value is necessarily <= input value.

Returns: Nb bytes written into 'dst' (necessarily <= dstCapacity) or 0 if compression fails.

Note : from v1.8.2 to v1.9.1, this function had a bug (fixed in v1.9.2+): the produced compressed content could, in specific circumstances, require to be decompressed into a destination buffer larger by at least 1 byte than the content to decompress. If an application uses LZ4_compress_destSize(), it's highly recommended to update liblz4 to v1.9.2 or better. If this can't be done or ensured, the receiving decompression function should provide a dstCapacity which is > decompressedSize, by at least 1 byte. See https://github.com/lz4/lz4/issues/859 for details

Definition at line 1868 of file lz4.c.

References ALLOC, FREEMEM, LZ4_compress_destSize(), and NULL.

Referenced by LZ4_compress_destSize().

◆ LZ4_compress_destSize_extState()

int LZ4_compress_destSize_extState	(	void *	state,
		const char *	src,
		char *	dst,
		int *	srcSizePtr,
		int	targetDstSize,
		int	acceleration )

Definition at line 1856 of file lz4.c.

References LZ4_compress_destSize_extState(), and LZ4_initStream().

Referenced by LZ4_compress_destSize_extState().

◆ LZ4_compress_fast()

int LZ4_compress_fast	(	const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity,
		int	acceleration )

LZ4_compress_fast() : Same as LZ4_compress_default(), but allows selection of "acceleration" factor. The larger the acceleration value, the faster the algorithm, but also the lesser the compression. It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. An acceleration value of "1" is the same as regular LZ4_compress_default() Values <= 0 will be replaced by LZ4_ACCELERATION_DEFAULT (currently == 1, see lz4.c). Values > LZ4_ACCELERATION_MAX will be replaced by LZ4_ACCELERATION_MAX (currently == 65537, see lz4.c).

Definition at line 1789 of file lz4.c.

References ALLOC, FREEMEM, LZ4_compress_fast(), LZ4_compress_fast_extState(), and NULL.

Referenced by LZ4_compress_default(), and LZ4_compress_fast().

◆ LZ4_compress_fast_continue()

int LZ4_compress_fast_continue	(	LZ4_stream_t *	streamPtr,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity,
		int	acceleration )

LZ4_compress_fast_continue() : Compress 'src' content using data from previously compressed blocks, for better compression ratio. 'dst' buffer must be already allocated. If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.

Returns: size of compressed block or 0 if there is an error (typically, cannot fit into 'dst').

Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block. Each block has precise boundaries. Each block must be decompressed separately, calling LZ4_decompress_*() with relevant metadata. It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together.

Note 2 : The previous 64KB of source data is assumed to remain present, unmodified, at same address in memory !

Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB. Make sure that buffers are separated, by at least one byte. This construction ensures that each block only depends on previous block.

Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.

Note 5 : After an error, the stream status is undefined (invalid), it can only be reset or freed.

Definition at line 2090 of file lz4.c.

References byU32, LZ4_stream_t_internal::currentOffset, DEBUGLOG, LZ4_stream_t_internal::dictCtx, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, dictSmall, LZ4_stream_u::internal_donotuse, KB, limitedOutput, LZ4_ACCELERATION_DEFAULT, LZ4_ACCELERATION_MAX, LZ4_compress_fast_continue(), LZ4_memcpy, noDictIssue, NULL, usingDictCtx, usingExtDict, and withPrefix64k.

Referenced by LZ4_compress_continue(), LZ4_compress_fast_continue(), and LZ4_compress_limitedOutput_continue().

◆ LZ4_compress_fast_extState()

int LZ4_compress_fast_extState	(	void *	state,
		const char *	source,
		char *	dest,
		int	inputSize,
		int	maxOutputSize,
		int	acceleration )

Definition at line 1669 of file lz4.c.

References assert, byPtr, byU16, byU32, LZ4_stream_u::internal_donotuse, limitedOutput, LZ4_ACCELERATION_DEFAULT, LZ4_ACCELERATION_MAX, LZ4_compress_fast_extState(), LZ4_compressBound(), LZ4_initStream(), noDict, noDictIssue, notLimited, and NULL.

Referenced by LZ4_compress_fast(), LZ4_compress_fast_extState(), LZ4_compress_limitedOutput_withState(), and LZ4_compress_withState().

◆ LZ4_compress_fast_extState_fastReset()

int LZ4_compress_fast_extState_fastReset	(	void *	state,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity,
		int	acceleration )

LZ4_compress_fast_extState_fastReset() : A variant of LZ4_compress_fast_extState().

Using this variant avoids an expensive initialization step. It is only safe to call if the state buffer is known to be correctly initialized already (see comment in lz4.h on LZ4_resetStream_fast() for a definition of "correctly initialized").

Definition at line 1723 of file lz4.c.

References assert, byPtr, byU16, byU32, LZ4_stream_t_internal::currentOffset, dictSmall, limitedOutput, LZ4_ACCELERATION_DEFAULT, LZ4_ACCELERATION_MAX, LZ4_compress_fast_extState_fastReset(), LZ4_compressBound(), noDict, noDictIssue, notLimited, and NULL.

Referenced by LZ4_compress_fast_extState_fastReset().

◆ LZ4_compress_forceExtDict()

int LZ4_compress_forceExtDict	(	LZ4_stream_t *	LZ4_dict,
		const char *	source,
		char *	dest,
		int	srcSize )

Definition at line 2207 of file lz4.c.

References byU32, LZ4_stream_t_internal::currentOffset, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, dictSmall, LZ4_stream_u::internal_donotuse, KB, LZ4_compress_forceExtDict(), noDictIssue, notLimited, NULL, and usingExtDict.

Referenced by LZ4_compress_forceExtDict().

◆ LZ4_compress_limitedOutput()

int LZ4_compress_limitedOutput	(	const char *	source,
		char *	dest,
		int	inputSize,
		int	maxOutputSize )

Definition at line 3381 of file lz4.c.

References LZ4_compress_default(), and LZ4_compress_limitedOutput().

Referenced by LZ4_compress_limitedOutput().

◆ LZ4_compress_limitedOutput_continue()

int LZ4_compress_limitedOutput_continue	(	LZ4_stream_t *	LZ4_stream,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity )

Definition at line 3400 of file lz4.c.

References LZ4_compress_fast_continue(), and LZ4_compress_limitedOutput_continue().

Referenced by LZ4_compress_limitedOutput_continue().

◆ LZ4_compress_limitedOutput_withState()

int LZ4_compress_limitedOutput_withState	(	void *	state,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	dstSize )

Definition at line 3390 of file lz4.c.

References LZ4_compress_fast_extState(), and LZ4_compress_limitedOutput_withState().

Referenced by LZ4_compress_limitedOutput_withState().

◆ LZ4_compress_withState()

int LZ4_compress_withState	(	void *	state,
		const char *	src,
		char *	dst,
		int	srcSize )

Definition at line 3395 of file lz4.c.

References LZ4_compress_fast_extState(), LZ4_compress_withState(), and LZ4_compressBound().

Referenced by LZ4_compress_withState().

◆ LZ4_compressBound()

int LZ4_compressBound ( int inputSize )

LZ4_compressBound() : Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) This function is primarily useful for memory allocation purposes (destination buffer size). Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize)

Parameters

inputSize max supported value is LZ4_MAX_INPUT_SIZE

Returns: maximum output size in a "worst case" scenario or 0, if input size is incorrect (too large or negative)

Definition at line 882 of file lz4.c.

References LZ4_COMPRESSBOUND, and LZ4_compressBound().

Referenced by G_lz4_compress_bound(), LZ4_compress(), LZ4_compress_continue(), LZ4_compress_fast_extState(), LZ4_compress_fast_extState_fastReset(), LZ4_compress_withState(), and LZ4_compressBound().

◆ LZ4_create()

void * LZ4_create ( char * inputBuffer )

Definition at line 3445 of file lz4.c.

References LZ4_create(), and LZ4_createStream().

Referenced by LZ4_create().

◆ LZ4_createStream()

LZ4_stream_t * LZ4_createStream ( void )

Note about RC_INVOKED

RC_INVOKED is predefined symbol of rc.exe (the resource compiler which is part of MSVC/Visual Studio). https://docs.microsoft.com/en-us/windows/win32/menurc/predefined-macros
Since rc.exe is a legacy compiler, it truncates long symbol (> 30 chars) and reports warning "RC4011: identifier truncated".
To eliminate the warning, we surround long preprocessor symbol with "#if !defined(RC_INVOKED) ... #endif" block that means "skip this block when rc.exe is trying to read it".

Definition at line 1895 of file lz4.c.

References ALLOC, DEBUGLOG, LZ4_createStream(), LZ4_initStream(), LZ4_STATIC_ASSERT, and NULL.

Referenced by LZ4_create(), and LZ4_createStream().

◆ LZ4_createStreamDecode()

LZ4_streamDecode_t * LZ4_createStreamDecode ( void )

LZ4_createStreamDecode() and LZ4_freeStreamDecode() : creation / destruction of streaming decompression tracking context. A tracking context can be re-used multiple times.

Definition at line 3144 of file lz4.c.

References ALLOC_AND_ZERO, LZ4_createStreamDecode(), and LZ4_STATIC_ASSERT.

Referenced by LZ4_createStreamDecode().

◆ LZ4_decoderRingBufferSize()

int LZ4_decoderRingBufferSize ( int maxBlockSize )

LZ4_decoderRingBufferSize() : when setting a ring buffer for streaming decompression (optional scenario), provides the minimum size of this ring buffer to be compatible with any source respecting maxBlockSize condition. Note : in a ring buffer scenario, blocks are presumed decompressed next to each other. When not enough space remains for next block (remainingSize < maxBlockSize), decoding resumes from beginning of ring buffer.

Returns: : minimum ring buffer size, or 0 if there is an error (invalid maxBlockSize).

LZ4_decoderRingBufferSize() : v1.8.2+ Note : in a ring buffer scenario (optional), blocks are presumed decompressed next to each other up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize), at which stage it resumes from beginning of ring buffer. When setting such a ring buffer for streaming decompression, provides the minimum size of this ring buffer to be compatible with any source respecting maxBlockSize condition.

Returns: : minimum ring buffer size, or 0 if there is an error (invalid maxBlockSize).

Definition at line 3195 of file lz4.c.

References LZ4_DECODER_RING_BUFFER_SIZE, LZ4_decoderRingBufferSize(), and LZ4_MAX_INPUT_SIZE.

Referenced by LZ4_decoderRingBufferSize().

◆ LZ4_decompress_fast()

int LZ4_decompress_fast	(	const char *	src,
		char *	dst,
		int	originalSize )

Obsolete LZ4_decompress_fast variants (since v1.9.0) : These functions used to be faster than LZ4_decompress_safe(), but this is no longer the case. They are now slower. This is because LZ4_decompress_fast() doesn't know the input size, and therefore must progress more cautiously into the input buffer to not read beyond the end of block. On top of that LZ4_decompress_fast() is not protected vs malformed or malicious inputs, making it a security liability. As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated.

The last remaining LZ4_decompress_fast() specificity is that it can decompress a block without knowing its compressed size. Such functionality can be achieved in a more secure manner by employing LZ4_decompress_safe_partial().

Parameters:

Parameters

originalSize is the uncompressed size to regenerate. dst must be already allocated, its size must be >= 'originalSize' bytes.

Returns: number of bytes read from source buffer (== compressed size). The function expects to finish at block's end exactly. If the source stream is detected malformed, the function stops decoding and returns a negative result.

note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer. However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds. Also, since match offsets are not validated, match reads from 'src' may underflow too. These issues never happen if input (compressed) data is correct. But they may happen if input data is invalid (error or intentional tampering). As a consequence, use these functions in trusted environments with trusted data only.

Definition at line 3031 of file lz4.c.

References DEBUGLOG, LZ4_decompress_fast(), and NULL.

Referenced by LZ4_decompress_fast(), LZ4_decompress_fast_continue(), and LZ4_uncompress().

◆ LZ4_decompress_fast_continue()

int LZ4_decompress_fast_continue	(	LZ4_streamDecode_t *	LZ4_streamDecode,
		const char *	source,
		char *	dest,
		int	originalSize )

Definition at line 3266 of file lz4.c.

References assert, DEBUGLOG, LZ4_streamDecode_t_internal::extDictSize, LZ4_streamDecode_t_internal::externalDict, LZ4_streamDecode_u::internal_donotuse, LZ4_decompress_fast(), LZ4_decompress_fast_continue(), NULL, LZ4_streamDecode_t_internal::prefixEnd, and LZ4_streamDecode_t_internal::prefixSize.

Referenced by LZ4_decompress_fast_continue().

◆ LZ4_decompress_fast_usingDict()

int LZ4_decompress_fast_usingDict	(	const char *	source,
		char *	dest,
		int	originalSize,
		const char *	dictStart,
		int	dictSize )

Definition at line 3364 of file lz4.c.

References assert, LZ4_decompress_fast_usingDict(), and NULL.

Referenced by LZ4_decompress_fast_usingDict().

◆ LZ4_decompress_fast_withPrefix64k()

int LZ4_decompress_fast_withPrefix64k	(	const char *	source,
		char *	dest,
		int	originalSize )

Definition at line 3064 of file lz4.c.

References KB, LZ4_decompress_fast_withPrefix64k(), and NULL.

Referenced by LZ4_decompress_fast_withPrefix64k().

◆ LZ4_decompress_safe()

int LZ4_decompress_safe	(	const char *	src,
		char *	dst,
		int	compressedSize,
		int	dstCapacity )

LZ4_decompress_safe() :

Parameters

src
dst
compressedSize	is the exact complete size of the compressed block.
dstCapacity	is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size.

Returns: the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) If destination buffer is not large enough, decoding will stop and output an error code (negative value). If the source stream is detected malformed, the function will stop decoding and return a negative result.

Note 1 : This function is protected against malicious data packets : it will never write outside 'dst' buffer, nor read outside 'source' buffer, even if the compressed block is maliciously modified to order the decoder to do these actions. In such case, the decoder stops immediately, andconsiders the compressed block malformed.

Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them. The implementation is free to send / store / derive this information in whichever way is most beneficial. If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead.

Definition at line 3013 of file lz4.c.

References decode_full_block, LZ4_decompress_safe(), noDict, and NULL.

Referenced by G_lz4_expand(), LZ4_decompress_safe(), LZ4_decompress_safe_continue(), LZ4_decompress_safe_usingDict(), and LZ4_uncompress_unknownOutputSize().

◆ LZ4_decompress_safe_continue()

int LZ4_decompress_safe_continue	(	LZ4_streamDecode_t *	LZ4_streamDecode,
		const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity )

LZ4_decompress_safe_continue() : This decoding function allows decompression of consecutive blocks in "streaming" mode. The difference with the usual independent blocks is that new blocks are allowed to find references into former blocks. A block is an unsplittable entity, and must be presented entirely to the decompression function. LZ4_decompress_safe_continue() only accepts one block at a time. It's modeled after LZ4_decompress_safe() and behaves similarly.

Parameters

LZ4_streamDecode	decompression state, tracking the position in memory of past data
compressedSize	exact complete size of one compressed block.
dstCapacity	size of destination buffer (which must be already allocated), must be an upper bound of decompressed size.

Returns: number of bytes decompressed into destination buffer (necessarily <= dstCapacity) If destination buffer is not large enough, decoding will stop and output an error code (negative value). If the source stream is detected malformed, the function will stop decoding and return a negative result.

The last 64KB of previously decoded data must remain available and unmodified at the memory position where they were previously decoded. If less than 64KB of data has been decoded, all the data must be present.

Special : if decompression side sets a ring buffer, it must respect one of the following conditions :

Decompression buffer size is at least LZ4_decoderRingBufferSize(maxBlockSize). maxBlockSize is the maximum size of any single block. It can have any value > 16 bytes. In which case, encoding and decoding buffers do not need to be synchronized. Actually, data can be produced by any source compliant with LZ4 format specification, and respecting maxBlockSize.
Synchronized mode : Decompression buffer size is exactly the same as compression buffer size, and follows exactly same update rule (block boundaries at same positions), and decoding function is provided with exact decompressed size of each block (exception for last block of the stream), then decoding & encoding ring buffer can have any size, including small ones ( < 64 KB).
Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes. In which case, encoding and decoding buffers do not need to be synchronized, and encoding ring buffer can have any size, including small ones ( < 64 KB).

Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer where it can't be modified during decompression, then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block.

Definition at line 3215 of file lz4.c.

References assert, LZ4_streamDecode_t_internal::extDictSize, LZ4_streamDecode_t_internal::externalDict, LZ4_streamDecode_u::internal_donotuse, KB, LZ4_decompress_safe(), LZ4_decompress_safe_continue(), LZ4_decompress_safe_forceExtDict(), LZ4_decompress_safe_withPrefix64k(), LZ4_streamDecode_t_internal::prefixEnd, and LZ4_streamDecode_t_internal::prefixSize.

Referenced by LZ4_decompress_safe_continue().

◆ LZ4_decompress_safe_forceExtDict()

int LZ4_decompress_safe_forceExtDict	(	const char *	source,
		char *	dest,
		int	compressedSize,
		int	maxOutputSize,
		const void *	dictStart,
		size_t	dictSize )

Definition at line 3094 of file lz4.c.

References DEBUGLOG, decode_full_block, LZ4_decompress_safe_forceExtDict(), and usingExtDict.

Referenced by LZ4_decompress_safe_continue(), LZ4_decompress_safe_forceExtDict(), and LZ4_decompress_safe_usingDict().

◆ LZ4_decompress_safe_partial()

int LZ4_decompress_safe_partial	(	const char *	src,
		char *	dst,
		int	srcSize,
		int	targetOutputSize,
		int	dstCapacity )

LZ4_decompress_safe_partial() : Decompress an LZ4 compressed block, of size 'srcSize' at position 'src', into destination buffer 'dst' of size 'dstCapacity'. Up to 'targetOutputSize' bytes will be decoded. The function stops decoding on reaching this objective. This can be useful to boost performance whenever only the beginning of a block is required.

Returns: the number of bytes decoded in dst (necessarily <= targetOutputSize) If source stream is detected malformed, function returns a negative result.

Note 1 :

Returns: can be < targetOutputSize, if compressed block contains less data.

Note 2 : targetOutputSize must be <= dstCapacity

Note 3 : this function effectively stops decoding on reaching targetOutputSize, so dstCapacity is kind of redundant. This is because in older versions of this function, decoding operation would still write complete sequences. Therefore, there was no guarantee that it would stop writing at exactly targetOutputSize, it could write more bytes, though only up to dstCapacity. Some "margin" used to be required for this operation to work properly. Thankfully, this is no longer necessary. The function nonetheless keeps the same signature, in an effort to preserve API compatibility.

Note 4 : If srcSize is the exact size of the block, then targetOutputSize can be any value, including larger than the block's decompressed size. The function will, at most, generate block's decompressed size.

Note 5 : If srcSize is larger than block's compressed size, then targetOutputSize MUST be <= block's decompressed size. Otherwise, silent corruption will occur.

Definition at line 3022 of file lz4.c.

References LZ4_decompress_safe_partial(), MIN, noDict, NULL, and partial_decode.

Referenced by LZ4_decompress_safe_partial(), and LZ4_decompress_safe_partial_usingDict().

◆ LZ4_decompress_safe_partial_forceExtDict()

int LZ4_decompress_safe_partial_forceExtDict	(	const char *	source,
		char *	dest,
		int	compressedSize,
		int	targetOutputSize,
		int	dstCapacity,
		const void *	dictStart,
		size_t	dictSize )

Definition at line 3105 of file lz4.c.

References LZ4_decompress_safe_partial_forceExtDict(), MIN, partial_decode, and usingExtDict.

Referenced by LZ4_decompress_safe_partial_forceExtDict(), and LZ4_decompress_safe_partial_usingDict().

◆ LZ4_decompress_safe_partial_usingDict()

int LZ4_decompress_safe_partial_usingDict	(	const char *	src,
		char *	dst,
		int	compressedSize,
		int	targetOutputSize,
		int	maxOutputSize,
		const char *	dictStart,
		int	dictSize )

LZ4_decompress_safe_partial_usingDict() : Behaves the same as LZ4_decompress_safe_partial() with the added ability to specify a memory segment for past data. Performance tip : Decompression speed can be substantially increased when dst == dictStart + dictSize.

Definition at line 3340 of file lz4.c.

References assert, KB, LZ4_decompress_safe_partial(), LZ4_decompress_safe_partial_forceExtDict(), and LZ4_decompress_safe_partial_usingDict().

Referenced by LZ4_decompress_safe_partial_usingDict().

◆ LZ4_decompress_safe_usingDict()

int LZ4_decompress_safe_usingDict	(	const char *	src,
		char *	dst,
		int	srcSize,
		int	dstCapacity,
		const char *	dictStart,
		int	dictSize )

LZ4_decompress_safe_usingDict() : Works the same as a combination of LZ4_setStreamDecode() followed by LZ4_decompress_safe_continue() However, it's stateless: it doesn't need any LZ4_streamDecode_t state. Dictionary is presumed stable : it must remain accessible and unmodified during decompression. Performance tip : Decompression speed can be substantially increased when dst == dictStart + dictSize.

Definition at line 3319 of file lz4.c.

References assert, KB, LZ4_decompress_safe(), LZ4_decompress_safe_forceExtDict(), LZ4_decompress_safe_usingDict(), and LZ4_decompress_safe_withPrefix64k().

Referenced by LZ4_decompress_safe_usingDict().

◆ LZ4_decompress_safe_withPrefix64k()

int LZ4_decompress_safe_withPrefix64k	(	const char *	src,
		char *	dst,
		int	compressedSize,
		int	maxDstSize )

Obsolete streaming decoding functions (since v1.7.0)

Definition at line 3042 of file lz4.c.

References decode_full_block, KB, LZ4_decompress_safe_withPrefix64k(), NULL, and withPrefix64k.

Referenced by LZ4_decompress_safe_continue(), LZ4_decompress_safe_usingDict(), and LZ4_decompress_safe_withPrefix64k().

◆ LZ4_freeStream()

int LZ4_freeStream ( LZ4_stream_t * LZ4_stream )

Definition at line 1949 of file lz4.c.

References DEBUGLOG, FREEMEM, and LZ4_freeStream().

Referenced by LZ4_freeStream().

◆ LZ4_freeStreamDecode()

int LZ4_freeStreamDecode ( LZ4_streamDecode_t * LZ4_stream )

Definition at line 3151 of file lz4.c.

References FREEMEM, LZ4_freeStreamDecode(), and NULL.

Referenced by LZ4_freeStreamDecode().

◆ LZ4_initStream()

LZ4_stream_t * LZ4_initStream	(	void *	stateBuffer,
		size_t	size )

LZ4_initStream() : v1.9.0+ An LZ4_stream_t structure must be initialized at least once. This is automatically done when invoking LZ4_createStream(), but it's not when the structure is simply declared on stack (for example).

Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t. It can also initialize any arbitrary buffer of sufficient size, and will

Returns: a pointer of proper type upon initialization.

Note : initialization fails if size and alignment conditions are not respected. In which case, the function will

Returns: NULL. Note2: An LZ4_stream_t structure guarantees correct alignment and size. Note3: Before v1.9.0, use LZ4_resetStream() instead

Definition at line 1920 of file lz4.c.

References DEBUGLOG, LZ4_initStream(), MEM_INIT, and NULL.

Referenced by LZ4_compress_destSize_extState(), LZ4_compress_fast_extState(), LZ4_createStream(), and LZ4_initStream().

◆ LZ4_loadDict()

int LZ4_loadDict	(	LZ4_stream_t *	streamPtr,
		const char *	dictionary,
		int	dictSize )

LZ4_loadDict() : Use this function to reference a static dictionary into LZ4_stream_t. The dictionary must remain available during compression. LZ4_loadDict() triggers a reset, so any previous data will be forgotten. The same dictionary will have to be loaded on decompression side for successful decoding. Dictionary are useful for better compression of small data (KB range). While LZ4 itself accepts any input as dictionary, dictionary efficiency is also a topic. When in doubt, employ the Zstandard's Dictionary Builder. Loading a size of 0 is allowed, and is the same as reset.

Returns: loaded dictionary size, in bytes (note: only the last 64 KB are loaded)

Definition at line 2027 of file lz4.c.

References _ld_fast, LZ4_loadDict(), and LZ4_loadDict_internal().

Referenced by LZ4_loadDict().

◆ LZ4_loadDict_internal()

int LZ4_loadDict_internal	(	LZ4_stream_t *	LZ4_dict,
		const char *	dictionary,
		int	dictSize,
		LoadDict_mode_e	_ld )

Definition at line 1961 of file lz4.c.

References _ld_slow, byU32, LZ4_stream_t_internal::currentOffset, DEBUGLOG, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, HASH_UNIT, LZ4_stream_t_internal::hashTable, LZ4_stream_u::internal_donotuse, KB, LZ4_loadDict_internal(), LZ4_resetStream(), and LZ4_stream_t_internal::tableType.

Referenced by LZ4_loadDict(), LZ4_loadDict_internal(), and LZ4_loadDictSlow().

◆ LZ4_loadDictSlow()

int LZ4_loadDictSlow	(	LZ4_stream_t *	streamPtr,
		const char *	dictionary,
		int	dictSize )

LZ4_loadDictSlow() : v1.10.0+ Same as LZ4_loadDict(), but uses a bit more cpu to reference the dictionary content more thoroughly. This is expected to slightly improve compression ratio. The extra-cpu cost is likely worth it if the dictionary is re-used across multiple sessions.

Returns: loaded dictionary size, in bytes (note: only the last 64 KB are loaded)

Definition at line 2032 of file lz4.c.

References _ld_slow, LZ4_loadDict_internal(), and LZ4_loadDictSlow().

Referenced by LZ4_loadDictSlow().

◆ LZ4_resetStream()

void LZ4_resetStream ( LZ4_stream_t * streamPtr )

LZ4_resetStream() : An LZ4_stream_t structure must be initialized at least once. This is done with LZ4_initStream(), or LZ4_resetStream(). Consider switching to LZ4_initStream(), invoking LZ4_resetStream() will trigger deprecation warnings in the future.

Definition at line 1937 of file lz4.c.

References DEBUGLOG, LZ4_resetStream(), and MEM_INIT.

Referenced by LZ4_loadDict_internal(), LZ4_resetStream(), and LZ4_resetStreamState().

◆ LZ4_resetStream_fast()

void LZ4_resetStream_fast ( LZ4_stream_t * streamPtr )

LZ4_resetStream_fast() : v1.9.0+ Use this to prepare an LZ4_stream_t for a new chain of dependent blocks (e.g., LZ4_compress_fast_continue()).

An LZ4_stream_t must be initialized once before usage. This is automatically done when created by LZ4_createStream(). However, should the LZ4_stream_t be simply declared on stack (for example), it's necessary to initialize it first, using LZ4_initStream().

After init, start any new stream with LZ4_resetStream_fast(). A same LZ4_stream_t can be re-used multiple times consecutively and compress multiple streams, provided that it starts each new stream with LZ4_resetStream_fast().

LZ4_resetStream_fast() is much faster than LZ4_initStream(), but is not compatible with memory regions containing garbage data.

Note: it's only useful to call LZ4_resetStream_fast() in the context of streaming compression. The extState functions perform their own resets. Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive.

Definition at line 1943 of file lz4.c.

References byU32, LZ4_stream_u::internal_donotuse, and LZ4_resetStream_fast().

Referenced by LZ4_resetStream_fast().

◆ LZ4_resetStreamState()

int LZ4_resetStreamState	(	void *	state,
		char *	inputBuffer )

Definition at line 3437 of file lz4.c.

References LZ4_resetStream(), and LZ4_resetStreamState().

Referenced by LZ4_resetStreamState().

◆ LZ4_saveDict()

int LZ4_saveDict	(	LZ4_stream_t *	streamPtr,
		char *	safeBuffer,
		int	maxDictSize )

LZ4_saveDict() : If previously compressed data block is not guaranteed to remain available at its memory location, save it into a safer place (char* safeBuffer). Note : no need to call LZ4_loadDict() afterwards, dictionary is immediately usable, one can therefore call LZ4_compress_fast_continue() right after.

Returns: : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.

LZ4_saveDict() : If last 64KB data cannot be guaranteed to remain available at its current memory location, save it into a safer place (char* safeBuffer). This is schematically equivalent to a memcpy() followed by LZ4_loadDict(), but is much faster, because LZ4_saveDict() doesn't need to rebuild tables.

Returns: saved dictionary size in bytes (necessarily <= maxDictSize), or 0 if error.

Definition at line 2241 of file lz4.c.

References assert, DEBUGLOG, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, LZ4_stream_u::internal_donotuse, KB, LZ4_memmove, LZ4_saveDict(), and NULL.

Referenced by LZ4_saveDict().

◆ LZ4_setStreamDecode()

int LZ4_setStreamDecode	(	LZ4_streamDecode_t *	LZ4_streamDecode,
		const char *	dictionary,
		int	dictSize )

LZ4_setStreamDecode() : Use this function to instruct where to find the dictionary. This function is not necessary if previous data is still available where it was decoded. Loading a size of 0 is allowed (same effect as no dictionary).

Returns: : 1 if OK, 0 if error

LZ4_setStreamDecode() : An LZ4_streamDecode_t context can be allocated once and re-used multiple times. Use this function to start decompression of a new stream of blocks. A dictionary can optionally be set. Use NULL or size 0 for a reset order. Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.

Returns: 1 if OK, 0 if error

Definition at line 3167 of file lz4.c.

References assert, LZ4_streamDecode_t_internal::extDictSize, LZ4_streamDecode_t_internal::externalDict, LZ4_streamDecode_u::internal_donotuse, LZ4_setStreamDecode(), NULL, LZ4_streamDecode_t_internal::prefixEnd, and LZ4_streamDecode_t_internal::prefixSize.

Referenced by LZ4_setStreamDecode().

◆ LZ4_sizeofState()

int LZ4_sizeofState ( void )

LZ4_compress_fast_extState() : Same as LZ4_compress_fast(), using an externally allocated memory space for its state. Use LZ4_sizeofState() to know how much memory must be allocated, and allocate it on 8-bytes boundaries (using malloc() typically). Then, provide this buffer as void* state to compression function.

Definition at line 886 of file lz4.c.

References LZ4_sizeofState().

Referenced by LZ4_sizeofState().

◆ LZ4_sizeofStreamState()

int LZ4_sizeofStreamState ( void )

Definition at line 3432 of file lz4.c.

References LZ4_sizeofStreamState().

Referenced by LZ4_sizeofStreamState().

◆ LZ4_slideInputBuffer()

char * LZ4_slideInputBuffer ( void * state )

Definition at line 3452 of file lz4.c.

References LZ4_slideInputBuffer().

Referenced by LZ4_slideInputBuffer().

◆ LZ4_uncompress()

int LZ4_uncompress	(	const char *	source,
		char *	dest,
		int	outputSize )

Obsolete decompression functions (since v1.8.0)

Definition at line 3420 of file lz4.c.

References LZ4_decompress_fast(), and LZ4_uncompress().

Referenced by LZ4_uncompress().

◆ LZ4_uncompress_unknownOutputSize()

int LZ4_uncompress_unknownOutputSize	(	const char *	source,
		char *	dest,
		int	isize,
		int	maxOutputSize )

Definition at line 3424 of file lz4.c.

References LZ4_decompress_safe(), and LZ4_uncompress_unknownOutputSize().

Referenced by LZ4_uncompress_unknownOutputSize().

◆ LZ4_versionNumber()

int LZ4_versionNumber ( void )

library version number; useful to check dll version; requires v1.3.0+

Definition at line 874 of file lz4.c.

References LZ4_VERSION_NUMBER, and LZ4_versionNumber().

Referenced by LZ4_versionNumber().

◆ LZ4_versionString()

const char * LZ4_versionString ( void )

library version string; useful to check dll version; requires v1.7.5+

Definition at line 878 of file lz4.c.

References LZ4_VERSION_STRING, and LZ4_versionString().

Referenced by LZ4_versionString().

Macros

Typedefs

Enumerations

Functions

Macro Definition Documentation

◆ ALLOC

◆ ALLOC_AND_ZERO

◆ assert

◆ DEBUGLOG

◆ expect

◆ FASTLOOP_SAFE_DISTANCE

◆ FREEMEM

◆ GB

◆ HASH_UNIT

◆ KB

◆ LASTLITERALS

◆ likely

◆ LZ4_ACCELERATION_DEFAULT

◆ LZ4_ACCELERATION_MAX

◆ LZ4_ALIGN_TEST

◆ LZ4_DISABLE_DEPRECATE_WARNINGS

◆ LZ4_DISTANCE_ABSOLUTE_MAX

◆ LZ4_FAST_DEC_LOOP

◆ LZ4_FORCE_INLINE

◆ LZ4_FORCE_O2

◆ LZ4_HEAPMODE

◆ LZ4_memcpy

◆ LZ4_memmove

◆ LZ4_memset

◆ LZ4_SRC_INCLUDED

◆ LZ4_STATIC_ASSERT

◆ LZ4_STATIC_LINKING_ONLY

◆ MATCH_SAFEGUARD_DISTANCE

◆ MB

◆ MEM_INIT

◆ MFLIMIT

◆ MIN

◆ MINMATCH

◆ ML_BITS

◆ ML_MASK

◆ RUN_BITS

◆ RUN_MASK

◆ STEPSIZE

◆ unlikely

◆ WILDCOPYLENGTH

Typedef Documentation

◆ BYTE

◆ reg_t

◆ Rvl_t

◆ S32

◆ U16

◆ U32

◆ U64

◆ uptrval

Enumeration Type Documentation

◆ dict_directive

◆ dictIssue_directive

◆ earlyEnd_directive

◆ limitedOutput_directive

◆ LoadDict_mode_e

◆ tableType_t

Function Documentation

◆ LZ4_attach_dictionary()

◆ LZ4_compress()

◆ LZ4_compress_continue()

◆ LZ4_compress_default()

◆ LZ4_compress_destSize()

◆ LZ4_compress_destSize_extState()

◆ LZ4_compress_fast()

◆ LZ4_compress_fast_continue()

◆ LZ4_compress_fast_extState()

◆ LZ4_compress_fast_extState_fastReset()

◆ LZ4_compress_forceExtDict()

◆ LZ4_compress_limitedOutput()

◆ LZ4_compress_limitedOutput_continue()

◆ LZ4_compress_limitedOutput_withState()

◆ LZ4_compress_withState()

◆ LZ4_compressBound()

◆ LZ4_create()

◆ LZ4_createStream()