GRASS GIS 7 Programmer's Manual  7.9.dev(2021)-e5379bbd7
Data Structures | Macros | Typedefs | Functions | Variables
lz4.h File Reference
#include <stddef.h>
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Data Structures

struct  LZ4_stream_t_internal
 
struct  LZ4_streamDecode_t_internal
 
union  LZ4_stream_u
 
union  LZ4_streamDecode_u
 

Macros

#define LZ4_H_2983827168210
 
#define LZ4LIB_VISIBILITY
 
#define LZ4LIB_API   LZ4LIB_VISIBILITY
 
#define LZ4_VERSION_MAJOR   1 /* for breaking interface changes */
 
#define LZ4_VERSION_MINOR   8 /* for new (non-breaking) interface capabilities */
 
#define LZ4_VERSION_RELEASE   2 /* for tweaks, bug-fixes, or development */
 
#define LZ4_VERSION_NUMBER   (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
 
#define LZ4_LIB_VERSION   LZ4_VERSION_MAJOR.LZ4_VERSION_MINOR.LZ4_VERSION_RELEASE
 
#define LZ4_QUOTE(str)   #str
 
#define LZ4_EXPAND_AND_QUOTE(str)   LZ4_QUOTE(str)
 
#define LZ4_VERSION_STRING   LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
 
#define LZ4_MEMORY_USAGE   14
 
#define LZ4_MAX_INPUT_SIZE   0x7E000000 /* 2 113 929 216 bytes */
 
#define LZ4_COMPRESSBOUND(isize)   ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
 
#define LZ4_DECODER_RING_BUFFER_SIZE(mbs)   (65536 + 14 + (mbs)) /* for static allocation; mbs presumed valid */
 
#define LZ4_HASHLOG   (LZ4_MEMORY_USAGE-2)
 
#define LZ4_HASHTABLESIZE   (1 << LZ4_MEMORY_USAGE)
 
#define LZ4_HASH_SIZE_U32   (1 << LZ4_HASHLOG) /* required as macro for static allocation */
 
#define LZ4_STREAMSIZE_U64   ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
 
#define LZ4_STREAMSIZE   (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
 
#define LZ4_STREAMDECODESIZE_U64   4
 
#define LZ4_STREAMDECODESIZE   (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
 
#define LZ4_GCC_VERSION   (__GNUC__ * 100 + __GNUC_MINOR__)
 
#define LZ4_DEPRECATED(message)
 

Typedefs

typedef union LZ4_stream_u LZ4_stream_t
 
typedef union LZ4_streamDecode_u LZ4_streamDecode_t
 
typedef struct LZ4_stream_t_internal LZ4_stream_t_internal
 

Functions

LZ4LIB_API int LZ4_versionNumber (void)
 
LZ4LIB_API const char * LZ4_versionString (void)
 
LZ4LIB_API int LZ4_compress_default (const char *src, char *dst, int srcSize, int dstCapacity)
 
LZ4LIB_API int LZ4_decompress_safe (const char *src, char *dst, int compressedSize, int dstCapacity)
 
LZ4LIB_API int LZ4_compressBound (int inputSize)
 
LZ4LIB_API int LZ4_compress_fast (const char *src, char *dst, int srcSize, int dstCapacity, int acceleration)
 
LZ4LIB_API int LZ4_sizeofState (void)
 
LZ4LIB_API int LZ4_compress_fast_extState (void *state, const char *src, char *dst, int srcSize, int dstCapacity, int acceleration)
 
LZ4LIB_API int LZ4_compress_destSize (const char *src, char *dst, int *srcSizePtr, int targetDstSize)
 
LZ4LIB_API int LZ4_decompress_fast (const char *src, char *dst, int originalSize)
 
LZ4LIB_API int LZ4_decompress_safe_partial (const char *src, char *dst, int srcSize, int targetOutputSize, int dstCapacity)
 
LZ4LIB_API LZ4_stream_t * LZ4_createStream (void)
 
LZ4LIB_API int LZ4_freeStream (LZ4_stream_t *streamPtr)
 
LZ4LIB_API void LZ4_resetStream (LZ4_stream_t *streamPtr)
 
LZ4LIB_API int LZ4_loadDict (LZ4_stream_t *streamPtr, const char *dictionary, int dictSize)
 
LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t *streamPtr, const char *src, char *dst, int srcSize, int dstCapacity, int acceleration)
 
LZ4LIB_API int LZ4_saveDict (LZ4_stream_t *streamPtr, char *safeBuffer, int maxDictSize)
 
LZ4LIB_API LZ4_streamDecode_t * LZ4_createStreamDecode (void)
 
LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t *LZ4_stream)
 
LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t *LZ4_streamDecode, const char *dictionary, int dictSize)
 
LZ4LIB_API int LZ4_decoderRingBufferSize (int maxBlockSize)
 
LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t *LZ4_streamDecode, const char *src, char *dst, int srcSize, int dstCapacity)
 
LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t *LZ4_streamDecode, const char *src, char *dst, int originalSize)
 
LZ4LIB_API int LZ4_decompress_safe_usingDict (const char *src, char *dst, int srcSize, int dstCapcity, const char *dictStart, int dictSize)
 
LZ4LIB_API int LZ4_decompress_fast_usingDict (const char *src, char *dst, int originalSize, const char *dictStart, int dictSize)
 
 LZ4_DEPRECATED ("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress(const char *source
 
 LZ4_DEPRECATED ("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState(void *state
 
 LZ4_DEPRECATED ("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue(LZ4_stream_t *LZ4_streamPtr
 
 LZ4_DEPRECATED ("use LZ4_decompress_fast() instead") LZ4LIB_API int LZ4_uncompress(const char *source
 
 LZ4_DEPRECATED ("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompress_unknownOutputSize(const char *source
 
 LZ4_DEPRECATED ("Use LZ4_createStream() instead") LZ4LIB_API void *LZ4_create(char *inputBuffer)
 
 LZ4_DEPRECATED ("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void *state
 
 LZ4_DEPRECATED ("Use LZ4_saveDict() instead") LZ4LIB_API char *LZ4_slideInputBuffer(void *state)
 
 LZ4_DEPRECATED ("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k(const char *src
 
 LZ4_DEPRECATED ("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k(const char *src
 

Variables

char * dest
 
char int sourceSize
 
char int int maxOutputSize
 
const char * source
 
const char char int inputSize
 
char int outputSize
 
char int isize
 
char * inputBuffer
 
char * dst
 
char int compressedSize
 
char int int maxDstSize
 
char int originalSize
 

Macro Definition Documentation

◆ LZ4_COMPRESSBOUND

#define LZ4_COMPRESSBOUND (   isize)    ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)

Definition at line 156 of file lz4.h.

Referenced by LZ4_compressBound().

◆ LZ4_DECODER_RING_BUFFER_SIZE

#define LZ4_DECODER_RING_BUFFER_SIZE (   mbs)    (65536 + 14 + (mbs)) /* for static allocation; mbs presumed valid */

Definition at line 326 of file lz4.h.

Referenced by LZ4_decoderRingBufferSize().

◆ LZ4_DEPRECATED

#define LZ4_DEPRECATED (   message)

Definition at line 568 of file lz4.h.

◆ LZ4_EXPAND_AND_QUOTE

#define LZ4_EXPAND_AND_QUOTE (   str)    LZ4_QUOTE(str)

Definition at line 102 of file lz4.h.

◆ LZ4_GCC_VERSION

#define LZ4_GCC_VERSION   (__GNUC__ * 100 + __GNUC_MINOR__)

Deprecation warnings Should deprecation warnings be a problem, it is generally possible to disable them, typically with -Wno-deprecated-declarations for gcc or _CRT_SECURE_NO_WARNINGS in Visual. Otherwise, it's also possible to define LZ4_DISABLE_DEPRECATE_WARNINGS

Definition at line 557 of file lz4.h.

◆ LZ4_H_2983827168210

#define LZ4_H_2983827168210

Definition at line 40 of file lz4.h.

◆ LZ4_HASH_SIZE_U32

#define LZ4_HASH_SIZE_U32   (1 << LZ4_HASHLOG) /* required as macro for static allocation */

Definition at line 467 of file lz4.h.

◆ LZ4_HASHLOG

#define LZ4_HASHLOG   (LZ4_MEMORY_USAGE-2)

Definition at line 465 of file lz4.h.

◆ LZ4_HASHTABLESIZE

#define LZ4_HASHTABLESIZE   (1 << LZ4_MEMORY_USAGE)

Definition at line 466 of file lz4.h.

Referenced by LZ4_prepareTable().

◆ LZ4_LIB_VERSION

#define LZ4_LIB_VERSION   LZ4_VERSION_MAJOR.LZ4_VERSION_MINOR.LZ4_VERSION_RELEASE

Definition at line 100 of file lz4.h.

◆ LZ4_MAX_INPUT_SIZE

#define LZ4_MAX_INPUT_SIZE   0x7E000000 /* 2 113 929 216 bytes */

Definition at line 155 of file lz4.h.

Referenced by LZ4_compress_generic(), and LZ4_decoderRingBufferSize().

◆ LZ4_MEMORY_USAGE

#define LZ4_MEMORY_USAGE   14

LZ4_MEMORY_USAGE : Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) Increasing memory usage improves compression ratio Reduced memory usage may improve speed, thanks to cache effect Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache

Definition at line 120 of file lz4.h.

◆ LZ4_QUOTE

#define LZ4_QUOTE (   str)    #str

Definition at line 101 of file lz4.h.

◆ LZ4_STREAMDECODESIZE

#define LZ4_STREAMDECODESIZE   (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))

Definition at line 537 of file lz4.h.

◆ LZ4_STREAMDECODESIZE_U64

#define LZ4_STREAMDECODESIZE_U64   4

LZ4_streamDecode_t : information structure to track an LZ4 stream during decompression. init this structure using LZ4_setStreamDecode (or memset()) before first use note : only use in association with static linking ! this definition is not API/ABI safe, and may change in a future version !

Definition at line 536 of file lz4.h.

◆ LZ4_STREAMSIZE

#define LZ4_STREAMSIZE   (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))

Definition at line 521 of file lz4.h.

Referenced by LZ4_createStream(), LZ4_sizeofState(), and LZ4_sizeofStreamState().

◆ LZ4_STREAMSIZE_U64

#define LZ4_STREAMSIZE_U64   ((1 << (LZ4_MEMORY_USAGE-3)) + 4)

LZ4_stream_t : information structure to track an LZ4 stream. init this structure before first use. note : only use in association with static linking ! this definition is not API/ABI safe, it may change in a future version !

Definition at line 520 of file lz4.h.

◆ LZ4_VERSION_MAJOR

#define LZ4_VERSION_MAJOR   1 /* for breaking interface changes */

Definition at line 94 of file lz4.h.

◆ LZ4_VERSION_MINOR

#define LZ4_VERSION_MINOR   8 /* for new (non-breaking) interface capabilities */

Definition at line 95 of file lz4.h.

◆ LZ4_VERSION_NUMBER

#define LZ4_VERSION_NUMBER   (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)

Definition at line 98 of file lz4.h.

Referenced by LZ4_versionNumber().

◆ LZ4_VERSION_RELEASE

#define LZ4_VERSION_RELEASE   2 /* for tweaks, bug-fixes, or development */

Definition at line 96 of file lz4.h.

◆ LZ4_VERSION_STRING

#define LZ4_VERSION_STRING   LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)

Definition at line 103 of file lz4.h.

Referenced by LZ4_versionString().

◆ LZ4LIB_API

#define LZ4LIB_API   LZ4LIB_VISIBILITY

Definition at line 90 of file lz4.h.

◆ LZ4LIB_VISIBILITY

#define LZ4LIB_VISIBILITY

Introduction

LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core, scalable with multi-cores CPU. It features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

The LZ4 compression library provides in-memory compression and decompression functions. Compression can be done in:

  • a single step (described as Simple Functions)
  • a single step, reusing a context (described in Advanced Functions)
  • unbounded multiple steps (described as Streaming compression)

lz4.h provides block compression functions. It gives full buffer control to user. Decompressing an lz4-compressed block also requires metadata (such as compressed size). Each application is free to encode such metadata in whichever way it wants.

An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md), take care of encoding standard metadata alongside LZ4-compressed blocks. If your application requires interoperability, it's recommended to use it. A library is provided to take care of it, see lz4frame.h.

Definition at line 82 of file lz4.h.

Typedef Documentation

◆ LZ4_stream_t

typedef union LZ4_stream_u LZ4_stream_t

Definition at line 241 of file lz4.h.

◆ LZ4_stream_t_internal

typedef struct LZ4_stream_t_internal LZ4_stream_t_internal

Definition at line 492 of file lz4.h.

◆ LZ4_streamDecode_t

typedef union LZ4_streamDecode_u LZ4_streamDecode_t

Definition at line 296 of file lz4.h.

Function Documentation

◆ LZ4_compress_default()

LZ4LIB_API 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. Note : as a consequence, 'dst' content is not valid. Note 2 : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). srcSize : max supported value is LZ4_MAX_INPUT_SIZE. dstCapacity : size of buffer 'dst' (which must be already allocated) return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) or 0 if compression fails

Definition at line 1084 of file lz4.c.

References LZ4_compress_fast().

Referenced by LZ4_compress(), and LZ4_compress_limitedOutput().

◆ LZ4_compress_destSize()

LZ4LIB_API 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 'targetDestSize'. 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'. srcSizePtr : will be modified to indicate how many bytes where read from 'src' to fill 'dst'. New value is necessarily <= old value. return : Nb bytes written into 'dst' (necessarily <= targetDestSize) or 0 if compression fails

Definition at line 1123 of file lz4.c.

◆ LZ4_compress_fast()

LZ4LIB_API 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 ACCELERATION_DEFAULT (currently == 1, see lz4.c).

Definition at line 1065 of file lz4.c.

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

Referenced by LZ4_compress_default().

◆ LZ4_compress_fast_continue()

LZ4LIB_API 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.

Important : The previous 64KB of compressed data is assumed to remain present and unmodified in memory!

Special 1 : When input is a double-buffer, they can have any size, including < 64 KB. Make sure that buffers are separated by at least one byte. This way, each block only depends on previous block. Special 2 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.

Returns
: size of compressed block or 0 if there is an error (typically, cannot fit into 'dst'). After an error, the stream status is invalid, it can only be reset or freed.

Definition at line 1255 of file lz4.c.

References byU32, DEBUGLOG, LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, LZ4_stream_t_internal::initCheck, and LZ4_stream_u::internal_donotuse.

Referenced by LZ4_compress_continue().

◆ LZ4_compress_fast_extState()

LZ4LIB_API int LZ4_compress_fast_extState ( void *  state,
const char *  src,
char *  dst,
int  srcSize,
int  dstCapacity,
int  acceleration 
)

Definition at line 997 of file lz4.c.

References ACCELERATION_DEFAULT, LZ4_compressBound(), and LZ4_resetStream().

Referenced by LZ4_compress_fast().

◆ LZ4_compressBound()

LZ4LIB_API 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 495 of file lz4.c.

References LZ4_COMPRESSBOUND.

Referenced by G_lz4_compress_bound(), LZ4_compress(), LZ4_compress_continue(), and LZ4_compress_fast_extState().

◆ LZ4_createStream()

LZ4LIB_API LZ4_stream_t* LZ4_createStream ( void  )

LZ4_createStream() and LZ4_freeStream() : LZ4_createStream() will allocate and initialize an LZ4_stream_t structure. LZ4_freeStream() releases its memory.

Definition at line 1147 of file lz4.c.

References ALLOC, DEBUGLOG, LZ4_resetStream(), LZ4_STATIC_ASSERT, LZ4_STREAMSIZE, and NULL.

Referenced by LZ4_create().

◆ LZ4_createStreamDecode()

LZ4LIB_API 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 1691 of file lz4.c.

References ALLOC_AND_ZERO.

◆ LZ4_decoderRingBufferSize()

LZ4LIB_API int LZ4_decoderRingBufferSize ( int  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).

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 1731 of file lz4.c.

References LZ4_DECODER_RING_BUFFER_SIZE, LZ4_FORCE_O2_GCC_PPC64LE, and LZ4_MAX_INPUT_SIZE.

◆ LZ4_decompress_fast()

LZ4LIB_API int LZ4_decompress_fast ( const char *  src,
char *  dst,
int  originalSize 
)

LZ4_decompress_fast() : unsafe! This function is a bit faster than LZ4_decompress_safe(), but it may misbehave on malformed input because it doesn't perform full validation of compressed data. originalSize : is the uncompressed size to regenerate Destination buffer must be already allocated, and its size must be >= 'originalSize' bytes. return : number of bytes read from source buffer (== compressed size). If the source stream is detected malformed, the function stops decoding and return a negative result. note : This function is only usable if the originalSize of uncompressed data is known in advance. The caller should also check that all the compressed input has been consumed properly, i.e. that the return value matches the size of the buffer with compressed input. The function never writes past the output buffer. However, since it doesn't know its 'src' size, it may read past the intended input. Also, because match offsets are not validated during decoding, reads from 'src' may underflow. Use this function in trusted environment only.

Definition at line 1614 of file lz4.c.

References endOnOutputSize, full, KB, LZ4_decompress_generic(), LZ4_FORCE_O2_GCC_PPC64LE, NULL, and withPrefix64k.

Referenced by LZ4_decompress_fast_continue(), LZ4_decompress_fast_usingDict(), LZ4_decompress_fast_withPrefix64k(), and LZ4_uncompress().

◆ LZ4_decompress_fast_continue()

LZ4LIB_API int LZ4_decompress_fast_continue ( LZ4_streamDecode_t *  LZ4_streamDecode,
const char *  src,
char *  dst,
int  originalSize 
)

Definition at line 1787 of file lz4.c.

References assert, dest, LZ4_streamDecode_t_internal::extDictSize, LZ4_streamDecode_t_internal::externalDict, LZ4_streamDecode_u::internal_donotuse, KB, LZ4_decompress_fast(), LZ4_decompress_fast_doubleDict(), originalSize, LZ4_streamDecode_t_internal::prefixEnd, and LZ4_streamDecode_t_internal::prefixSize.

◆ LZ4_decompress_fast_usingDict()

LZ4LIB_API int LZ4_decompress_fast_usingDict ( const char *  src,
char *  dst,
int  originalSize,
const char *  dictStart,
int  dictSize 
)

Definition at line 1840 of file lz4.c.

References LZ4_decompress_fast().

◆ LZ4_decompress_safe()

LZ4LIB_API 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. return : 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. This function is protected against malicious data packets.

Definition at line 1598 of file lz4.c.

References endOnInputSize, full, LZ4_decompress_generic(), LZ4_FORCE_O2_GCC_PPC64LE, noDict, and NULL.

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

◆ LZ4_decompress_safe_continue()

LZ4LIB_API int LZ4_decompress_safe_continue ( LZ4_streamDecode_t *  LZ4_streamDecode,
const char *  src,
char *  dst,
int  srcSize,
int  dstCapacity 
)

LZ4_decompress_*_continue() : These decoding functions allow decompression of consecutive blocks in "streaming" mode. A block is an unsplittable entity, it must be presented entirely to a decompression function. Decompression functions only accepts one block at a time. The last 64KB of previously decoded data must remain available and unmodified at the memory position where they were 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 1747 of file lz4.c.

References assert, dest, 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_partial()

LZ4LIB_API int LZ4_decompress_safe_partial ( const char *  src,
char *  dst,
int  srcSize,
int  targetOutputSize,
int  dstCapacity 
)

LZ4_decompress_safe_partial() : This function decompress a compressed block of size 'srcSize' at position 'src' into destination buffer 'dst' of size 'dstCapacity'. The function will decompress a minimum of 'targetOutputSize' bytes, and stop after that. However, it's not accurate, and may write more than 'targetOutputSize' (but always <= dstCapacity).

Returns
: the number of bytes decoded in the destination buffer (necessarily <= dstCapacity) Note : this number can also be < targetOutputSize, if compressed block contains less data. Therefore, always control how many bytes were decoded. If source stream is detected malformed, function returns a negative result. This function is protected against malicious data packets.

Definition at line 1606 of file lz4.c.

References endOnInputSize, LZ4_decompress_generic(), LZ4_FORCE_O2_GCC_PPC64LE, noDict, NULL, and partial.

◆ LZ4_decompress_safe_usingDict()

LZ4LIB_API int LZ4_decompress_safe_usingDict ( const char *  src,
char *  dst,
int  srcSize,
int  dstCapcity,
const char *  dictStart,
int  dictSize 
)

LZ4_decompress_*_usingDict() : These decoding functions work the same as a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue() They are stand-alone, and don't need an LZ4_streamDecode_t structure. Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.

Definition at line 1828 of file lz4.c.

References KB, LZ4_decompress_safe(), and LZ4_decompress_safe_withPrefix64k().

◆ LZ4_DEPRECATED() [1/10]

LZ4_DEPRECATED ( "use LZ4_compress_default() instead"  ) const

◆ LZ4_DEPRECATED() [2/10]

LZ4_DEPRECATED ( "use LZ4_compress_fast_extState() instead"  )

◆ LZ4_DEPRECATED() [3/10]

LZ4_DEPRECATED ( "use LZ4_compress_fast_continue() instead"  )

◆ LZ4_DEPRECATED() [4/10]

LZ4_DEPRECATED ( "use LZ4_decompress_fast() instead"  ) const

◆ LZ4_DEPRECATED() [5/10]

LZ4_DEPRECATED ( "use LZ4_decompress_safe() instead"  ) const

◆ LZ4_DEPRECATED() [6/10]

LZ4_DEPRECATED ( "Use LZ4_createStream() instead"  )

◆ LZ4_DEPRECATED() [7/10]

LZ4_DEPRECATED ( "Use LZ4_resetStream() instead"  )

◆ LZ4_DEPRECATED() [8/10]

LZ4_DEPRECATED ( "Use LZ4_saveDict() instead"  )

◆ LZ4_DEPRECATED() [9/10]

LZ4_DEPRECATED ( "use LZ4_decompress_safe_usingDict() instead"  ) const

◆ LZ4_DEPRECATED() [10/10]

LZ4_DEPRECATED ( "use LZ4_decompress_fast_usingDict() instead"  ) const

◆ LZ4_freeStream()

LZ4LIB_API int LZ4_freeStream ( LZ4_stream_t *  streamPtr)

Definition at line 1167 of file lz4.c.

References DEBUGLOG, and FREEMEM.

◆ LZ4_freeStreamDecode()

LZ4LIB_API int LZ4_freeStreamDecode ( LZ4_streamDecode_t *  LZ4_stream)

Definition at line 1697 of file lz4.c.

References FREEMEM.

◆ LZ4_loadDict()

LZ4LIB_API int LZ4_loadDict ( LZ4_stream_t *  streamPtr,
const char *  dictionary,
int  dictSize 
)

LZ4_loadDict() : Use this function to load a static dictionary into LZ4_stream_t. Any previous data will be forgotten, only 'dictionary' will remain in memory. Loading a size of 0 is allowed, and is the same as reset.

Returns
: dictionary size, in bytes (necessarily <= 64 KB)

Definition at line 1177 of file lz4.c.

References 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_putPosition(), LZ4_resetStream(), and LZ4_stream_t_internal::tableType.

◆ LZ4_resetStream()

LZ4LIB_API void LZ4_resetStream ( LZ4_stream_t *  streamPtr)

LZ4_resetStream() : An LZ4_stream_t structure can be allocated once and re-used multiple times. Use this function to start compressing a new stream.

Definition at line 1157 of file lz4.c.

References DEBUGLOG, and MEM_INIT.

Referenced by LZ4_compress_fast_extState(), LZ4_compress_fast_force(), LZ4_createStream(), LZ4_loadDict(), and LZ4_resetStreamState().

◆ LZ4_saveDict()

LZ4LIB_API int LZ4_saveDict ( LZ4_stream_t *  LZ4_dict,
char *  safeBuffer,
int  dictSize 
)

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.

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 : you don't need to call LZ4_loadDict() afterwards, dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue(). Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.

Definition at line 1355 of file lz4.c.

References LZ4_stream_t_internal::dictionary, LZ4_stream_t_internal::dictSize, LZ4_stream_u::internal_donotuse, KB, and LZ4_FORCE_O2_GCC_PPC64LE.

◆ LZ4_setStreamDecode()

LZ4LIB_API int LZ4_setStreamDecode ( LZ4_streamDecode_t *  LZ4_streamDecode,
const char *  dictionary,
int  dictSize 
)

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 optionnally 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

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 1710 of file lz4.c.

References 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()

LZ4LIB_API int LZ4_sizeofState ( void  )

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

Definition at line 496 of file lz4.c.

References LZ4_STREAMSIZE.

◆ LZ4_versionNumber()

LZ4LIB_API int LZ4_versionNumber ( void  )

library version number; useful to check dll version

Definition at line 493 of file lz4.c.

References LZ4_VERSION_NUMBER.

◆ LZ4_versionString()

LZ4LIB_API const char* LZ4_versionString ( void  )

library version string; unseful to check dll version

Definition at line 494 of file lz4.c.

References LZ4_VERSION_STRING.

Variable Documentation

◆ compressedSize

char int compressedSize

Definition at line 599 of file lz4.h.

◆ dest

char * dest

Definition at line 573 of file lz4.h.

Referenced by LZ4_decompress_fast_continue(), LZ4_decompress_safe_continue(), and Rast3d_long_decode().

◆ dst

char * dst

Definition at line 599 of file lz4.h.

Referenced by NetA_betweenness_closeness(), and Rast_close_gdal_write_link().

◆ inputBuffer

char* inputBuffer

Definition at line 595 of file lz4.h.

◆ inputSize

const char char int inputSize

Definition at line 575 of file lz4.h.

Referenced by LZ4_compress_generic().

◆ isize

char int isize

Definition at line 582 of file lz4.h.

Referenced by dfread_header(), dfread_header_old(), and dfwrite_header().

◆ maxDstSize

char int int maxDstSize

Definition at line 599 of file lz4.h.

◆ maxOutputSize

char int int maxOutputSize

Definition at line 574 of file lz4.h.

Referenced by LZ4_compress_generic().

◆ originalSize

char int originalSize

Definition at line 600 of file lz4.h.

Referenced by LZ4_decompress_fast_continue().

◆ outputSize

char int outputSize

Definition at line 581 of file lz4.h.

◆ source

const char * source

Definition at line 575 of file lz4.h.

◆ sourceSize

char int sourceSize

Definition at line 573 of file lz4.h.