GRASS GIS 8 Programmer's Manual  8.5.0dev(2024)-36359e2344
lz4.c File Reference
#include "lz4.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>
Include dependency graph for lz4.c:

Go to the source code of this file.

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)   (expr)
 
#define likely(expr)   expect((expr) != 0, 1)
 
#define unlikely(expr)   expect((expr) != 0, 0)
 
#define LZ4_ALIGN_TEST   1
 
#define ALLOC(s)   malloc(s)
 
#define ALLOC_AND_ZERO(s)   calloc(1, s)
 
#define FREEMEM(p)   free(p)
 
#define LZ4_memset(p, v, s)   memset((p), (v), (s))
 
#define MEM_INIT(p, v, s)   LZ4_memset((p), (v), (s))
 
#define MINMATCH   4
 
#define WILDCOPYLENGTH   8
 
#define LASTLITERALS
 
#define MFLIMIT   12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
 
#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)   ((void)0)
 
#define LZ4_STATIC_ASSERT(c)
 
#define DEBUGLOG(l, ...)
 
#define LZ4_memcpy(dst, src, size)   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)   ((a) < (b) ? (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

LZ4_FORCE_INLINE void LZ4_wildCopy8 (void *dstPtr, const void *srcPtr, void *dstEnd)
 
LZ4_FORCE_INLINE unsigned LZ4_count (const BYTE *pIn, const BYTE *pMatch, const BYTE *pInLimit)
 
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)
 
LZ4_FORCE_INLINE U32 LZ4_hash4 (U32 sequence, tableType_t const tableType)
 
LZ4_FORCE_INLINE U32 LZ4_hash5 (U64 sequence, tableType_t const tableType)
 
LZ4_FORCE_INLINE U32 LZ4_hashPosition (const void *const p, tableType_t const tableType)
 
LZ4_FORCE_INLINE void LZ4_clearHash (U32 h, void *tableBase, tableType_t const tableType)
 
LZ4_FORCE_INLINE void LZ4_putIndexOnHash (U32 idx, U32 h, void *tableBase, tableType_t const tableType)
 
LZ4_FORCE_INLINE void LZ4_putPositionOnHash (const BYTE *p, U32 h, void *tableBase, tableType_t const tableType)
 
LZ4_FORCE_INLINE void LZ4_putPosition (const BYTE *p, void *tableBase, tableType_t tableType)
 
LZ4_FORCE_INLINE U32 LZ4_getIndexOnHash (U32 h, const void *tableBase, tableType_t tableType)
 
LZ4_FORCE_INLINE const BYTELZ4_getPosition (const BYTE *p, const void *tableBase, tableType_t tableType)
 
LZ4_FORCE_INLINE void LZ4_prepareTable (LZ4_stream_t_internal *const cctx, const int inputSize, const tableType_t tableType)
 
LZ4_FORCE_INLINE int LZ4_compress_generic_validated (LZ4_stream_t_internal *const cctx, const char *const source, char *const dest, const int inputSize, int *inputConsumed, const int maxOutputSize, const limitedOutput_directive outputDirective, const tableType_t tableType, const dict_directive dictDirective, const dictIssue_directive dictIssue, const int acceleration)
 
LZ4_FORCE_INLINE int LZ4_compress_generic (LZ4_stream_t_internal *const cctx, const char *const src, char *const dst, const int srcSize, int *inputConsumed, const int dstCapacity, const limitedOutput_directive outputDirective, const tableType_t tableType, const dict_directive dictDirective, const dictIssue_directive dictIssue, const int acceleration)
 
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_tLZ4_createStream (void)
 
LZ4_stream_tLZ4_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)
 
LZ4_FORCE_INLINE int LZ4_decompress_unsafe_generic (const BYTE *const istart, BYTE *const ostart, int decompressedSize, size_t prefixSize, const BYTE *const dictStart, const size_t dictSize)
 
LZ4_FORCE_INLINE Rvl_t read_variable_length (const BYTE **ip, const BYTE *ilimit, int initial_check)
 
LZ4_FORCE_INLINE int LZ4_decompress_generic (const char *const src, char *const dst, int srcSize, int outputSize, earlyEnd_directive partialDecoding, dict_directive dict, const BYTE *const lowPrefix, const BYTE *const dictStart, const size_t dictSize)
 
LZ4_FORCE_O2 int LZ4_decompress_safe (const char *source, char *dest, int compressedSize, int maxDecompressedSize)
 
LZ4_FORCE_O2 int LZ4_decompress_safe_partial (const char *src, char *dst, int compressedSize, int targetOutputSize, int dstCapacity)
 
LZ4_FORCE_O2 int LZ4_decompress_fast (const char *source, char *dest, int originalSize)
 
LZ4_FORCE_O2 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_FORCE_INLINE int LZ4_decompress_safe_doubleDict (const char *source, char *dest, int compressedSize, int maxOutputSize, size_t prefixSize, const void *dictStart, size_t dictSize)
 
LZ4_streamDecode_tLZ4_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)
 
LZ4_FORCE_O2 int LZ4_decompress_safe_continue (LZ4_streamDecode_t *LZ4_streamDecode, const char *source, char *dest, int compressedSize, int maxOutputSize)
 
LZ4_FORCE_O2 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)    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 241 of file lz4.c.

◆ ALLOC_AND_ZERO

#define ALLOC_AND_ZERO (   s)    calloc(1, s)

Definition at line 242 of file lz4.c.

◆ assert

#define assert (   condition)    ((void)0)

Definition at line 291 of file lz4.c.

◆ DEBUGLOG

#define DEBUGLOG (   l,
  ... 
)
Value:
{ \
} /* disabled */

Definition at line 312 of file lz4.c.

◆ expect

#define expect (   expr,
  value 
)    (expr)

Definition at line 189 of file lz4.c.

◆ FASTLOOP_SAFE_DISTANCE

#define FASTLOOP_SAFE_DISTANCE   64

Definition at line 266 of file lz4.c.

◆ FREEMEM

#define FREEMEM (   p)    free(p)

Definition at line 243 of file lz4.c.

◆ GB

#define GB   *(1U << 30)

Definition at line 271 of file lz4.c.

◆ HASH_UNIT

#define HASH_UNIT   sizeof(reg_t)

Definition at line 1957 of file lz4.c.

◆ KB

#define KB   *(1 << 10)

Definition at line 269 of file lz4.c.

◆ LASTLITERALS

#define LASTLITERALS
Value:
5 /* see ../doc/lz4_Block_format.md#parsing-restrictions \
*/

Definition at line 260 of file lz4.c.

◆ likely

#define likely (   expr)    expect((expr) != 0, 1)

Definition at line 193 of file lz4.c.

◆ LZ4_ACCELERATION_DEFAULT

#define LZ4_ACCELERATION_DEFAULT   1

Definition at line 53 of file lz4.c.

◆ LZ4_ACCELERATION_MAX

#define LZ4_ACCELERATION_MAX   65537

Definition at line 59 of file lz4.c.

◆ LZ4_ALIGN_TEST

#define LZ4_ALIGN_TEST   1

Definition at line 202 of file lz4.c.

◆ LZ4_DISABLE_DEPRECATE_WARNINGS

#define LZ4_DISABLE_DEPRECATE_WARNINGS
Value:
/* due to \
LZ4_decompress_safe_withPrefix64k */

Definition at line 115 of file lz4.c.

◆ LZ4_DISTANCE_ABSOLUTE_MAX

#define LZ4_DISTANCE_ABSOLUTE_MAX   65535

Definition at line 273 of file lz4.c.

◆ LZ4_FAST_DEC_LOOP

#define LZ4_FAST_DEC_LOOP   0

Definition at line 561 of file lz4.c.

◆ LZ4_FORCE_INLINE

#define LZ4_FORCE_INLINE   static

Definition at line 155 of file lz4.c.

◆ LZ4_FORCE_O2

#define LZ4_FORCE_O2

Definition at line 181 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 
)    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 376 of file lz4.c.

◆ LZ4_memmove

#define LZ4_memmove   memmove

Definition at line 384 of file lz4.c.

◆ LZ4_memset

#define LZ4_memset (   p,
  v,
 
)    memset((p), (v), (s))

Definition at line 250 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)) }; \
} /* use after variable declarations */

Definition at line 295 of file lz4.c.

◆ LZ4_STATIC_LINKING_ONLY

#define LZ4_STATIC_LINKING_ONLY

Definition at line 119 of file lz4.c.

◆ MATCH_SAFEGUARD_DISTANCE

#define MATCH_SAFEGUARD_DISTANCE
Value:
((2 * WILDCOPYLENGTH) - \
MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without \
overflowing output buffer */
#define MINMATCH
Definition: lz4.c:257
#define WILDCOPYLENGTH
Definition: lz4.c:259

Definition at line 263 of file lz4.c.

◆ MB

#define MB   *(1 << 20)

Definition at line 270 of file lz4.c.

◆ MEM_INIT

#define MEM_INIT (   p,
  v,
 
)    LZ4_memset((p), (v), (s))

Definition at line 252 of file lz4.c.

◆ MFLIMIT

#define MFLIMIT   12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */

Definition at line 262 of file lz4.c.

◆ MIN

#define MIN (   a,
  b 
)    ((a) < (b) ? (a) : (b))

Definition at line 2273 of file lz4.c.

◆ MINMATCH

#define MINMATCH   4

Definition at line 257 of file lz4.c.

◆ ML_BITS

#define ML_BITS   4

Definition at line 279 of file lz4.c.

◆ ML_MASK

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

Definition at line 280 of file lz4.c.

◆ RUN_BITS

#define RUN_BITS   (8 - ML_BITS)

Definition at line 281 of file lz4.c.

◆ RUN_MASK

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

Definition at line 282 of file lz4.c.

◆ STEPSIZE

#define STEPSIZE   sizeof(reg_t)

Definition at line 782 of file lz4.c.

◆ unlikely

#define unlikely (   expr)    expect((expr) != 0, 0)

Definition at line 196 of file lz4.c.

◆ WILDCOPYLENGTH

#define WILDCOPYLENGTH   8

Definition at line 259 of file lz4.c.

Typedef Documentation

◆ BYTE

typedef unsigned char BYTE

Definition at line 339 of file lz4.c.

◆ reg_t

typedef size_t reg_t

Definition at line 350 of file lz4.c.

◆ Rvl_t

typedef size_t Rvl_t

Definition at line 2426 of file lz4.c.

◆ S32

typedef signed int S32

Definition at line 342 of file lz4.c.

◆ U16

typedef unsigned short U16

Definition at line 340 of file lz4.c.

◆ U32

typedef unsigned int U32

Definition at line 341 of file lz4.c.

◆ U64

typedef unsigned long long U64

Definition at line 343 of file lz4.c.

◆ uptrval

typedef size_t uptrval

Definition at line 344 of file lz4.c.

Enumeration Type Documentation

◆ 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 860 of file lz4.c.

◆ dictIssue_directive

Enumerator
noDictIssue 
dictSmall 

Definition at line 866 of file lz4.c.

◆ earlyEnd_directive

Enumerator
decode_full_block 
partial_decode 

Definition at line 2270 of file lz4.c.

◆ limitedOutput_directive

Enumerator
notLimited 
limitedOutput 
fillOutput 

Definition at line 353 of file lz4.c.

◆ LoadDict_mode_e

Enumerator
_ld_fast 
_ld_slow 

Definition at line 1956 of file lz4.c.

◆ tableType_t

Enumerator
clearedTable 
byPtr 
byU32 
byU16 

Definition at line 835 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 2035 of file lz4.c.

◆ LZ4_clearHash()

LZ4_FORCE_INLINE void LZ4_clearHash ( U32  h,
void *  tableBase,
tableType_t const  tableType 
)

Definition at line 946 of file lz4.c.

◆ LZ4_compress()

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

Obsolete compression functions (since v1.7.3)

Definition at line 3383 of file lz4.c.

References LZ4_compress_default().

◆ LZ4_compress_continue()

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

Definition at line 3404 of file lz4.c.

◆ 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). 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 1808 of file lz4.c.

Referenced by G_lz4_compress(), LZ4_compress(), and LZ4_compress_limitedOutput_withState().

◆ 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".

*srcSizePtr : in+out parameter. 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 1865 of file lz4.c.

◆ 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 1853 of file lz4.c.

◆ 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 1786 of file lz4.c.

◆ 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 2087 of file lz4.c.

◆ 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 1666 of file lz4.c.

Referenced by 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 1720 of file lz4.c.

References assert, LZ4_ACCELERATION_DEFAULT, LZ4_ACCELERATION_MAX, LZ4_compressBound(), NULL, and state.

◆ LZ4_compress_forceExtDict()

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

Definition at line 2204 of file lz4.c.

◆ LZ4_compress_generic()

LZ4_FORCE_INLINE int LZ4_compress_generic ( LZ4_stream_t_internal *const  cctx,
const char *const  src,
char *const  dst,
const int  srcSize,
int *  inputConsumed,
const int  dstCapacity,
const limitedOutput_directive  outputDirective,
const tableType_t  tableType,
const dict_directive  dictDirective,
const dictIssue_directive  dictIssue,
const int  acceleration 
)

LZ4_compress_generic() : inlined, to ensure branches are decided at compilation time; takes care of src == (NULL, 0) and forward the rest to LZ4_compress_generic_validated

Definition at line 1630 of file lz4.c.

References assert, DEBUGLOG, dst, fillOutput, LZ4_compress_generic_validated(), LZ4_MAX_INPUT_SIZE, notLimited, NULL, and src.

◆ LZ4_compress_generic_validated()

LZ4_FORCE_INLINE int LZ4_compress_generic_validated ( LZ4_stream_t_internal *const  cctx,
const char *const  source,
char *const  dest,
const int  inputSize,
int *  inputConsumed,
const int  maxOutputSize,
const limitedOutput_directive  outputDirective,
const tableType_t  tableType,
const dict_directive  dictDirective,
const dictIssue_directive  dictIssue,
const int  acceleration 
)

LZ4_compress_generic_validated() : inlined, to ensure branches are decided at compilation time. The following conditions are presumed already validated:

  • source != NULL
  • inputSize > 0

Definition at line 1104 of file lz4.c.

References assert, byU16, LZ4_stream_t_internal::currentOffset, DEBUGLOG, LZ4_stream_t_internal::dictCtx, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, dictSize, LASTLITERALS, MFLIMIT, NULL, usingDictCtx, and usingExtDict.

Referenced by LZ4_compress_generic().

◆ LZ4_compress_limitedOutput()

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

Definition at line 3378 of file lz4.c.

◆ 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 3397 of file lz4.c.

◆ LZ4_compress_limitedOutput_withState()

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

Definition at line 3387 of file lz4.c.

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

◆ LZ4_compress_withState()

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

Definition at line 3392 of file lz4.c.

References dst, LZ4_compress_fast_extState(), src, and state.

◆ 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) inputSize : max supported value is LZ4_MAX_INPUT_SIZE return : maximum output size in a "worst case" scenario or 0, if input size is incorrect (too large or negative)

Definition at line 879 of file lz4.c.

References LZ4_VERSION_STRING.

Referenced by G_lz4_compress_bound(), LZ4_compress_fast_extState_fastReset(), and LZ4_compress_limitedOutput_withState().

◆ LZ4_count()

LZ4_FORCE_INLINE unsigned LZ4_count ( const BYTE pIn,
const BYTE pMatch,
const BYTE pInLimit 
)

Definition at line 784 of file lz4.c.

References likely, and STEPSIZE.

◆ LZ4_create()

void* LZ4_create ( char *  inputBuffer)

Definition at line 3442 of file lz4.c.

◆ 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 1892 of file lz4.c.

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

◆ 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 3141 of file lz4.c.

References LZ4_STATIC_ASSERT.

◆ 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).

Definition at line 3192 of file lz4.c.

References LZ4_DECODER_RING_BUFFER_SIZE, and LZ4_MAX_INPUT_SIZE.

◆ LZ4_decompress_fast()

LZ4_FORCE_O2 int LZ4_decompress_fast ( const char *  source,
char *  dest,
int  originalSize 
)

Definition at line 3028 of file lz4.c.

Referenced by LZ4_uncompress_unknownOutputSize().

◆ LZ4_decompress_fast_continue()

LZ4_FORCE_O2 int LZ4_decompress_fast_continue ( LZ4_streamDecode_t LZ4_streamDecode,
const char *  source,
char *  dest,
int  originalSize 
)

Definition at line 3263 of file lz4.c.

◆ LZ4_decompress_fast_usingDict()

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

Definition at line 3361 of file lz4.c.

◆ LZ4_decompress_fast_withPrefix64k()

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

Definition at line 3061 of file lz4.c.

◆ LZ4_decompress_generic()

LZ4_FORCE_INLINE int LZ4_decompress_generic ( const char *const  src,
char *const  dst,
int  srcSize,
int  outputSize,
earlyEnd_directive  partialDecoding,
dict_directive  dict,
const BYTE *const  lowPrefix,
const BYTE *const  dictStart,
const size_t  dictSize 
)

LZ4_decompress_generic() : This generic decompression function covers all use cases. It shall be instantiated several times, using different sets of directives. Note that it is important for performance that this function really get inlined, in order to remove useless branches during compilation optimization.

Definition at line 2472 of file lz4.c.

References assert, DEBUGLOG, dictSize, dictStart, dst, FASTLOOP_SAFE_DISTANCE, KB, ML_BITS, NULL, read_variable_length(), RUN_MASK, src, and unlikely.

Referenced by LZ4_decompress_safe(), LZ4_decompress_safe_doubleDict(), and LZ4_decompress_safe_withPrefix64k().

◆ LZ4_decompress_safe()

LZ4_FORCE_O2 int LZ4_decompress_safe ( const char *  src,
char *  dst,
int  compressedSize,
int  dstCapacity 
)

LZ4_decompress_safe() : @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 writes 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, and considers 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 3010 of file lz4.c.

References decode_full_block, LZ4_decompress_generic(), noDict, and NULL.

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

◆ LZ4_decompress_safe_continue()

LZ4_FORCE_O2 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.

@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 3212 of file lz4.c.

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

◆ LZ4_decompress_safe_doubleDict()

LZ4_FORCE_INLINE int LZ4_decompress_safe_doubleDict ( const char *  source,
char *  dest,
int  compressedSize,
int  maxOutputSize,
size_t  prefixSize,
const void *  dictStart,
size_t  dictSize 
)

Definition at line 3127 of file lz4.c.

References decode_full_block, dictSize, dictStart, LZ4_decompress_generic(), and usingExtDict.

◆ LZ4_decompress_safe_forceExtDict()

LZ4_FORCE_O2 int LZ4_decompress_safe_forceExtDict ( const char *  source,
char *  dest,
int  compressedSize,
int  maxOutputSize,
const void *  dictStart,
size_t  dictSize 
)

Definition at line 3091 of file lz4.c.

◆ LZ4_decompress_safe_partial()

LZ4_FORCE_O2 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 3019 of file lz4.c.

◆ LZ4_decompress_safe_partial_forceExtDict()

LZ4_FORCE_O2 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 3102 of file lz4.c.

◆ 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 3337 of file lz4.c.

◆ 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 3316 of file lz4.c.

References assert, dictSize, dictStart, KB, LZ4_decompress_safe(), and LZ4_decompress_safe_withPrefix64k().

◆ LZ4_decompress_safe_withPrefix64k()

LZ4_FORCE_O2 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 3039 of file lz4.c.

References decode_full_block, KB, LZ4_decompress_generic(), NULL, and withPrefix64k.

Referenced by LZ4_decompress_safe_continue(), and LZ4_decompress_safe_usingDict().

◆ LZ4_decompress_unsafe_generic()

LZ4_FORCE_INLINE int LZ4_decompress_unsafe_generic ( const BYTE *const  istart,
BYTE *const  ostart,
int  decompressedSize,
size_t  prefixSize,
const BYTE *const  dictStart,
const size_t  dictSize 
)

Definition at line 2301 of file lz4.c.

References assert, DEBUGLOG, dictSize, dictStart, ML_BITS, and NULL.

◆ LZ4_freeStream()

int LZ4_freeStream ( LZ4_stream_t LZ4_stream)

Definition at line 1946 of file lz4.c.

◆ LZ4_freeStreamDecode()

int LZ4_freeStreamDecode ( LZ4_streamDecode_t LZ4_stream)

Definition at line 3148 of file lz4.c.

◆ LZ4_getIndexOnHash()

LZ4_FORCE_INLINE U32 LZ4_getIndexOnHash ( U32  h,
const void *  tableBase,
tableType_t  tableType 
)

Definition at line 1021 of file lz4.c.

◆ LZ4_getPosition()

LZ4_FORCE_INLINE const BYTE* LZ4_getPosition ( const BYTE p,
const void *  tableBase,
tableType_t  tableType 
)

Definition at line 1051 of file lz4.c.

◆ LZ4_hash4()

LZ4_FORCE_INLINE U32 LZ4_hash4 ( U32  sequence,
tableType_t const  tableType 
)

Definition at line 911 of file lz4.c.

References byU16, LZ4_HASHLOG, and MINMATCH.

◆ LZ4_hash5()

LZ4_FORCE_INLINE U32 LZ4_hash5 ( U64  sequence,
tableType_t const  tableType 
)

Definition at line 920 of file lz4.c.

◆ LZ4_hashPosition()

LZ4_FORCE_INLINE U32 LZ4_hashPosition ( const void *const  p,
tableType_t const  tableType 
)

Definition at line 933 of file lz4.c.

◆ 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 1917 of file lz4.c.

Referenced by LZ4_createStream().

◆ 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 2024 of file lz4.c.

◆ LZ4_loadDict_internal()

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

Definition at line 1958 of file lz4.c.

References _ld_fast, and _ld_slow.

◆ 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 2029 of file lz4.c.

◆ LZ4_prepareTable()

LZ4_FORCE_INLINE void LZ4_prepareTable ( LZ4_stream_t_internal *const  cctx,
const int  inputSize,
const tableType_t  tableType 
)

Definition at line 1057 of file lz4.c.

◆ LZ4_putIndexOnHash()

LZ4_FORCE_INLINE void LZ4_putIndexOnHash ( U32  idx,
U32  h,
void *  tableBase,
tableType_t const  tableType 
)

Definition at line 973 of file lz4.c.

◆ LZ4_putPosition()

LZ4_FORCE_INLINE void LZ4_putPosition ( const BYTE p,
void *  tableBase,
tableType_t  tableType 
)

Definition at line 1008 of file lz4.c.

◆ LZ4_putPositionOnHash()

LZ4_FORCE_INLINE void LZ4_putPositionOnHash ( const BYTE p,
U32  h,
void *  tableBase,
tableType_t const  tableType 
)

Definition at line 998 of file lz4.c.

◆ 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 1934 of file lz4.c.

References DEBUGLOG.

◆ 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 1940 of file lz4.c.

◆ LZ4_resetStreamState()

int LZ4_resetStreamState ( void *  state,
char *  inputBuffer 
)

Definition at line 3434 of file lz4.c.

◆ LZ4_saveDict()

int LZ4_saveDict ( LZ4_stream_t LZ4_dict,
char *  safeBuffer,
int  dictSize 
)

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.

Definition at line 2238 of file lz4.c.

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

◆ 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

Definition at line 3164 of file lz4.c.

References assert, dictSize, LZ4_streamDecode_t_internal::extDictSize, LZ4_streamDecode_t_internal::externalDict, LZ4_streamDecode_u::internal_donotuse, NULL, LZ4_streamDecode_t_internal::prefixEnd, and LZ4_streamDecode_t_internal::prefixSize.

◆ 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 883 of file lz4.c.

References LZ4_COMPRESSBOUND.

◆ LZ4_sizeofStreamState()

int LZ4_sizeofStreamState ( void  )

Definition at line 3429 of file lz4.c.

◆ LZ4_slideInputBuffer()

char* LZ4_slideInputBuffer ( void *  state)

Definition at line 3449 of file lz4.c.

◆ LZ4_uncompress()

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

Obsolete decompression functions (since v1.8.0)

Definition at line 3417 of file lz4.c.

◆ LZ4_uncompress_unknownOutputSize()

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

Definition at line 3421 of file lz4.c.

References LZ4_decompress_fast().

◆ LZ4_versionNumber()

int LZ4_versionNumber ( void  )

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

Definition at line 871 of file lz4.c.

◆ LZ4_versionString()

const char* LZ4_versionString ( void  )

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

Definition at line 875 of file lz4.c.

References LZ4_VERSION_NUMBER.

◆ LZ4_wildCopy8()

LZ4_FORCE_INLINE void LZ4_wildCopy8 ( void *  dstPtr,
const void *  srcPtr,
void *  dstEnd 
)

Definition at line 534 of file lz4.c.

◆ read_variable_length()

LZ4_FORCE_INLINE Rvl_t read_variable_length ( const BYTE **  ip,
const BYTE ilimit,
int  initial_check 
)

Definition at line 2428 of file lz4.c.

Referenced by LZ4_decompress_generic().