forked from luck/tmp_suning_uos_patched
97a0efea65
Fix a few spelling and grammar errors, and two places where fast/safe in the documentation did not match the function. Link: http://lkml.kernel.org/r/20190321014452.13297-1-tomlevy93@gmail.com Signed-off-by: Tom Levy <tomlevy93@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
649 lines
26 KiB
C
649 lines
26 KiB
C
/* LZ4 Kernel Interface
|
|
*
|
|
* Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
|
|
* Copyright (C) 2016, Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This file is based on the original header file
|
|
* for LZ4 - Fast LZ compression algorithm.
|
|
*
|
|
* LZ4 - Fast LZ compression algorithm
|
|
* Copyright (C) 2011-2016, Yann Collet.
|
|
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following disclaimer
|
|
* in the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
* You can contact the author at :
|
|
* - LZ4 homepage : http://www.lz4.org
|
|
* - LZ4 source repository : https://github.com/lz4/lz4
|
|
*/
|
|
|
|
#ifndef __LZ4_H__
|
|
#define __LZ4_H__
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/string.h> /* memset, memcpy */
|
|
|
|
/*-************************************************************************
|
|
* CONSTANTS
|
|
**************************************************************************/
|
|
/*
|
|
* 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 can improve speed, due to cache effect
|
|
* Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
|
|
*/
|
|
#define LZ4_MEMORY_USAGE 14
|
|
|
|
#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
|
|
#define LZ4_COMPRESSBOUND(isize) (\
|
|
(unsigned int)(isize) > (unsigned int)LZ4_MAX_INPUT_SIZE \
|
|
? 0 \
|
|
: (isize) + ((isize)/255) + 16)
|
|
|
|
#define LZ4_ACCELERATION_DEFAULT 1
|
|
#define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
|
|
#define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
|
|
#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG)
|
|
|
|
#define LZ4HC_MIN_CLEVEL 3
|
|
#define LZ4HC_DEFAULT_CLEVEL 9
|
|
#define LZ4HC_MAX_CLEVEL 16
|
|
|
|
#define LZ4HC_DICTIONARY_LOGSIZE 16
|
|
#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
|
|
#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
|
|
#define LZ4HC_HASH_LOG (LZ4HC_DICTIONARY_LOGSIZE - 1)
|
|
#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG)
|
|
#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1)
|
|
|
|
/*-************************************************************************
|
|
* STREAMING CONSTANTS AND STRUCTURES
|
|
**************************************************************************/
|
|
#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE - 3)) + 4)
|
|
#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
|
|
|
|
#define LZ4_STREAMHCSIZE 262192
|
|
#define LZ4_STREAMHCSIZE_SIZET (262192 / sizeof(size_t))
|
|
|
|
#define LZ4_STREAMDECODESIZE_U64 4
|
|
#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * \
|
|
sizeof(unsigned long long))
|
|
|
|
/*
|
|
* LZ4_stream_t - information structure to track an LZ4 stream.
|
|
*/
|
|
typedef struct {
|
|
uint32_t hashTable[LZ4_HASH_SIZE_U32];
|
|
uint32_t currentOffset;
|
|
uint32_t initCheck;
|
|
const uint8_t *dictionary;
|
|
uint8_t *bufferStart;
|
|
uint32_t dictSize;
|
|
} LZ4_stream_t_internal;
|
|
typedef union {
|
|
unsigned long long table[LZ4_STREAMSIZE_U64];
|
|
LZ4_stream_t_internal internal_donotuse;
|
|
} LZ4_stream_t;
|
|
|
|
/*
|
|
* LZ4_streamHC_t - information structure to track an LZ4HC stream.
|
|
*/
|
|
typedef struct {
|
|
unsigned int hashTable[LZ4HC_HASHTABLESIZE];
|
|
unsigned short chainTable[LZ4HC_MAXD];
|
|
/* next block to continue on current prefix */
|
|
const unsigned char *end;
|
|
/* All index relative to this position */
|
|
const unsigned char *base;
|
|
/* alternate base for extDict */
|
|
const unsigned char *dictBase;
|
|
/* below that point, need extDict */
|
|
unsigned int dictLimit;
|
|
/* below that point, no more dict */
|
|
unsigned int lowLimit;
|
|
/* index from which to continue dict update */
|
|
unsigned int nextToUpdate;
|
|
unsigned int compressionLevel;
|
|
} LZ4HC_CCtx_internal;
|
|
typedef union {
|
|
size_t table[LZ4_STREAMHCSIZE_SIZET];
|
|
LZ4HC_CCtx_internal internal_donotuse;
|
|
} LZ4_streamHC_t;
|
|
|
|
/*
|
|
* LZ4_streamDecode_t - information structure to track an
|
|
* LZ4 stream during decompression.
|
|
*
|
|
* init this structure using LZ4_setStreamDecode (or memset()) before first use
|
|
*/
|
|
typedef struct {
|
|
const uint8_t *externalDict;
|
|
size_t extDictSize;
|
|
const uint8_t *prefixEnd;
|
|
size_t prefixSize;
|
|
} LZ4_streamDecode_t_internal;
|
|
typedef union {
|
|
unsigned long long table[LZ4_STREAMDECODESIZE_U64];
|
|
LZ4_streamDecode_t_internal internal_donotuse;
|
|
} LZ4_streamDecode_t;
|
|
|
|
/*-************************************************************************
|
|
* SIZE OF STATE
|
|
**************************************************************************/
|
|
#define LZ4_MEM_COMPRESS LZ4_STREAMSIZE
|
|
#define LZ4HC_MEM_COMPRESS LZ4_STREAMHCSIZE
|
|
|
|
/*-************************************************************************
|
|
* Compression Functions
|
|
**************************************************************************/
|
|
|
|
/**
|
|
* LZ4_compressBound() - Max. output size in worst case szenarios
|
|
* @isize: Size of the input data
|
|
*
|
|
* Return: Max. size LZ4 may output in a "worst case" szenario
|
|
* (data not compressible)
|
|
*/
|
|
static inline int LZ4_compressBound(size_t isize)
|
|
{
|
|
return LZ4_COMPRESSBOUND(isize);
|
|
}
|
|
|
|
/**
|
|
* LZ4_compress_default() - Compress data from source to dest
|
|
* @source: source address of the original data
|
|
* @dest: output buffer address of the compressed data
|
|
* @inputSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
* @maxOutputSize: full or partial size of buffer 'dest'
|
|
* which must be already allocated
|
|
* @wrkmem: address of the working memory.
|
|
* This requires 'workmem' of LZ4_MEM_COMPRESS.
|
|
*
|
|
* Compresses 'sourceSize' bytes from buffer 'source'
|
|
* into already allocated 'dest' buffer of size 'maxOutputSize'.
|
|
* Compression is guaranteed to succeed if
|
|
* 'maxOutputSize' >= LZ4_compressBound(inputSize).
|
|
* It also runs faster, so it's a recommended setting.
|
|
* If the function cannot compress 'source' into a more limited 'dest' budget,
|
|
* compression stops *immediately*, and the function result is zero.
|
|
* As a consequence, 'dest' content is not valid.
|
|
*
|
|
* Return: Number of bytes written into buffer 'dest'
|
|
* (necessarily <= maxOutputSize) or 0 if compression fails
|
|
*/
|
|
int LZ4_compress_default(const char *source, char *dest, int inputSize,
|
|
int maxOutputSize, void *wrkmem);
|
|
|
|
/**
|
|
* LZ4_compress_fast() - As LZ4_compress_default providing an acceleration param
|
|
* @source: source address of the original data
|
|
* @dest: output buffer address of the compressed data
|
|
* @inputSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
* @maxOutputSize: full or partial size of buffer 'dest'
|
|
* which must be already allocated
|
|
* @acceleration: acceleration factor
|
|
* @wrkmem: address of the working memory.
|
|
* This requires 'workmem' of LZ4_MEM_COMPRESS.
|
|
*
|
|
* Same as LZ4_compress_default(), but allows to select an "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, which is 1.
|
|
*
|
|
* Return: Number of bytes written into buffer 'dest'
|
|
* (necessarily <= maxOutputSize) or 0 if compression fails
|
|
*/
|
|
int LZ4_compress_fast(const char *source, char *dest, int inputSize,
|
|
int maxOutputSize, int acceleration, void *wrkmem);
|
|
|
|
/**
|
|
* LZ4_compress_destSize() - Compress as much data as possible
|
|
* from source to dest
|
|
* @source: source address of the original data
|
|
* @dest: output buffer address of the compressed data
|
|
* @sourceSizePtr: will be modified to indicate how many bytes where read
|
|
* from 'source' to fill 'dest'. New value is necessarily <= old value.
|
|
* @targetDestSize: Size of buffer 'dest' which must be already allocated
|
|
* @wrkmem: address of the working memory.
|
|
* This requires 'workmem' of LZ4_MEM_COMPRESS.
|
|
*
|
|
* Reverse the logic, by compressing as much data as possible
|
|
* from 'source' buffer into already allocated buffer 'dest'
|
|
* of size 'targetDestSize'.
|
|
* This function either compresses the entire 'source' content into 'dest'
|
|
* if it's large enough, or fill 'dest' buffer completely with as much data as
|
|
* possible from 'source'.
|
|
*
|
|
* Return: Number of bytes written into 'dest' (necessarily <= targetDestSize)
|
|
* or 0 if compression fails
|
|
*/
|
|
int LZ4_compress_destSize(const char *source, char *dest, int *sourceSizePtr,
|
|
int targetDestSize, void *wrkmem);
|
|
|
|
/*-************************************************************************
|
|
* Decompression Functions
|
|
**************************************************************************/
|
|
|
|
/**
|
|
* LZ4_decompress_fast() - Decompresses data from 'source' into 'dest'
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated with 'originalSize' bytes
|
|
* @originalSize: is the original and therefore uncompressed size
|
|
*
|
|
* Decompresses data from 'source' into 'dest'.
|
|
* This function fully respect memory boundaries for properly formed
|
|
* compressed data.
|
|
* It is a bit faster than LZ4_decompress_safe().
|
|
* However, it does not provide any protection against intentionally
|
|
* modified data stream (malicious input).
|
|
* Use this function in trusted environment only
|
|
* (data to decode comes from a trusted source).
|
|
*
|
|
* Return: number of bytes read from the source buffer
|
|
* or a negative result if decompression fails.
|
|
*/
|
|
int LZ4_decompress_fast(const char *source, char *dest, int originalSize);
|
|
|
|
/**
|
|
* LZ4_decompress_safe() - Decompression protected against buffer overflow
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated
|
|
* @compressedSize: is the precise full size of the compressed block
|
|
* @maxDecompressedSize: is the size of 'dest' buffer
|
|
*
|
|
* Decompresses data from 'source' into 'dest'.
|
|
* If the source stream is detected malformed, the function will
|
|
* stop decoding and return a negative result.
|
|
* This function is protected against buffer overflow exploits,
|
|
* including malicious data packets. It never writes outside output buffer,
|
|
* nor reads outside input buffer.
|
|
*
|
|
* Return: number of bytes decompressed into destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*/
|
|
int LZ4_decompress_safe(const char *source, char *dest, int compressedSize,
|
|
int maxDecompressedSize);
|
|
|
|
/**
|
|
* LZ4_decompress_safe_partial() - Decompress a block of size 'compressedSize'
|
|
* at position 'source' into buffer 'dest'
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the decompressed data which must be
|
|
* already allocated
|
|
* @compressedSize: is the precise full size of the compressed block.
|
|
* @targetOutputSize: the decompression operation will try
|
|
* to stop as soon as 'targetOutputSize' has been reached
|
|
* @maxDecompressedSize: is the size of destination buffer
|
|
*
|
|
* This function decompresses a compressed block of size 'compressedSize'
|
|
* at position 'source' into destination buffer 'dest'
|
|
* of size 'maxDecompressedSize'.
|
|
* The function tries to stop decompressing operation as soon as
|
|
* 'targetOutputSize' has been reached, reducing decompression time.
|
|
* This function never writes outside of output buffer,
|
|
* and never reads outside of input buffer.
|
|
* It is therefore protected against malicious data packets.
|
|
*
|
|
* Return: the number of bytes decoded in the destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*
|
|
*/
|
|
int LZ4_decompress_safe_partial(const char *source, char *dest,
|
|
int compressedSize, int targetOutputSize, int maxDecompressedSize);
|
|
|
|
/*-************************************************************************
|
|
* LZ4 HC Compression
|
|
**************************************************************************/
|
|
|
|
/**
|
|
* LZ4_compress_HC() - Compress data from `src` into `dst`, using HC algorithm
|
|
* @src: source address of the original data
|
|
* @dst: output buffer address of the compressed data
|
|
* @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
* @dstCapacity: full or partial size of buffer 'dst',
|
|
* which must be already allocated
|
|
* @compressionLevel: Recommended values are between 4 and 9, although any
|
|
* value between 1 and LZ4HC_MAX_CLEVEL will work.
|
|
* Values >LZ4HC_MAX_CLEVEL behave the same as 16.
|
|
* @wrkmem: address of the working memory.
|
|
* This requires 'wrkmem' of size LZ4HC_MEM_COMPRESS.
|
|
*
|
|
* Compress data from 'src' into 'dst', using the more powerful
|
|
* but slower "HC" algorithm. Compression is guaranteed to succeed if
|
|
* `dstCapacity >= LZ4_compressBound(srcSize)
|
|
*
|
|
* Return : the number of bytes written into 'dst' or 0 if compression fails.
|
|
*/
|
|
int LZ4_compress_HC(const char *src, char *dst, int srcSize, int dstCapacity,
|
|
int compressionLevel, void *wrkmem);
|
|
|
|
/**
|
|
* LZ4_resetStreamHC() - Init an allocated 'LZ4_streamHC_t' structure
|
|
* @streamHCPtr: pointer to the 'LZ4_streamHC_t' structure
|
|
* @compressionLevel: Recommended values are between 4 and 9, although any
|
|
* value between 1 and LZ4HC_MAX_CLEVEL will work.
|
|
* Values >LZ4HC_MAX_CLEVEL behave the same as 16.
|
|
*
|
|
* An LZ4_streamHC_t structure can be allocated once
|
|
* and re-used multiple times.
|
|
* Use this function to init an allocated `LZ4_streamHC_t` structure
|
|
* and start a new compression.
|
|
*/
|
|
void LZ4_resetStreamHC(LZ4_streamHC_t *streamHCPtr, int compressionLevel);
|
|
|
|
/**
|
|
* LZ4_loadDictHC() - Load a static dictionary into LZ4_streamHC
|
|
* @streamHCPtr: pointer to the LZ4HC_stream_t
|
|
* @dictionary: dictionary to load
|
|
* @dictSize: size of dictionary
|
|
*
|
|
* Use this function to load a static dictionary into LZ4HC_stream.
|
|
* Any previous data will be forgotten, only 'dictionary'
|
|
* will remain in memory.
|
|
* Loading a size of 0 is allowed.
|
|
*
|
|
* Return : dictionary size, in bytes (necessarily <= 64 KB)
|
|
*/
|
|
int LZ4_loadDictHC(LZ4_streamHC_t *streamHCPtr, const char *dictionary,
|
|
int dictSize);
|
|
|
|
/**
|
|
* LZ4_compress_HC_continue() - Compress 'src' using data from previously
|
|
* compressed blocks as a dictionary using the HC algorithm
|
|
* @streamHCPtr: Pointer to the previous 'LZ4_streamHC_t' structure
|
|
* @src: source address of the original data
|
|
* @dst: output buffer address of the compressed data,
|
|
* which must be already allocated
|
|
* @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
* @maxDstSize: full or partial size of buffer 'dest'
|
|
* which must be already allocated
|
|
*
|
|
* These functions compress data in successive blocks of any size, using
|
|
* previous blocks as dictionary. One key assumption is that previous
|
|
* blocks (up to 64 KB) remain read-accessible while
|
|
* compressing next blocks. There is an exception for ring buffers,
|
|
* which can be smaller than 64 KB.
|
|
* Ring buffers scenario is automatically detected and handled by
|
|
* LZ4_compress_HC_continue().
|
|
* Before starting compression, state must be properly initialized,
|
|
* using LZ4_resetStreamHC().
|
|
* A first "fictional block" can then be designated as
|
|
* initial dictionary, using LZ4_loadDictHC() (Optional).
|
|
* Then, use LZ4_compress_HC_continue()
|
|
* to compress each successive block. Previous memory blocks
|
|
* (including initial dictionary when present) must remain accessible
|
|
* and unmodified during compression.
|
|
* 'dst' buffer should be sized to handle worst case scenarios, using
|
|
* LZ4_compressBound(), to ensure operation success.
|
|
* If, for any reason, previous data blocks can't be preserved unmodified
|
|
* in memory during next compression block,
|
|
* you must save it to a safer memory space, using LZ4_saveDictHC().
|
|
* Return value of LZ4_saveDictHC() is the size of dictionary
|
|
* effectively saved into 'safeBuffer'.
|
|
*
|
|
* Return: Number of bytes written into buffer 'dst' or 0 if compression fails
|
|
*/
|
|
int LZ4_compress_HC_continue(LZ4_streamHC_t *streamHCPtr, const char *src,
|
|
char *dst, int srcSize, int maxDstSize);
|
|
|
|
/**
|
|
* LZ4_saveDictHC() - Save static dictionary from LZ4HC_stream
|
|
* @streamHCPtr: pointer to the 'LZ4HC_stream_t' structure
|
|
* @safeBuffer: buffer to save dictionary to, must be already allocated
|
|
* @maxDictSize: size of 'safeBuffer'
|
|
*
|
|
* 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_loadDictHC() afterwards,
|
|
* dictionary is immediately usable, you can therefore call
|
|
* LZ4_compress_HC_continue().
|
|
*
|
|
* Return : saved dictionary size in bytes (necessarily <= maxDictSize),
|
|
* or 0 if error.
|
|
*/
|
|
int LZ4_saveDictHC(LZ4_streamHC_t *streamHCPtr, char *safeBuffer,
|
|
int maxDictSize);
|
|
|
|
/*-*********************************************
|
|
* Streaming Compression Functions
|
|
***********************************************/
|
|
|
|
/**
|
|
* LZ4_resetStream() - Init an allocated 'LZ4_stream_t' structure
|
|
* @LZ4_stream: pointer to the 'LZ4_stream_t' structure
|
|
*
|
|
* An LZ4_stream_t structure can be allocated once
|
|
* and re-used multiple times.
|
|
* Use this function to init an allocated `LZ4_stream_t` structure
|
|
* and start a new compression.
|
|
*/
|
|
void LZ4_resetStream(LZ4_stream_t *LZ4_stream);
|
|
|
|
/**
|
|
* LZ4_loadDict() - Load a static dictionary into LZ4_stream
|
|
* @streamPtr: pointer to the LZ4_stream_t
|
|
* @dictionary: dictionary to load
|
|
* @dictSize: size of dictionary
|
|
*
|
|
* Use this function to load a static dictionary into LZ4_stream.
|
|
* Any previous data will be forgotten, only 'dictionary'
|
|
* will remain in memory.
|
|
* Loading a size of 0 is allowed.
|
|
*
|
|
* Return : dictionary size, in bytes (necessarily <= 64 KB)
|
|
*/
|
|
int LZ4_loadDict(LZ4_stream_t *streamPtr, const char *dictionary,
|
|
int dictSize);
|
|
|
|
/**
|
|
* LZ4_saveDict() - Save static dictionary from LZ4_stream
|
|
* @streamPtr: pointer to the 'LZ4_stream_t' structure
|
|
* @safeBuffer: buffer to save dictionary to, must be already allocated
|
|
* @dictSize: size of 'safeBuffer'
|
|
*
|
|
* 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.
|
|
*/
|
|
int LZ4_saveDict(LZ4_stream_t *streamPtr, char *safeBuffer, int dictSize);
|
|
|
|
/**
|
|
* LZ4_compress_fast_continue() - Compress 'src' using data from previously
|
|
* compressed blocks as a dictionary
|
|
* @streamPtr: Pointer to the previous 'LZ4_stream_t' structure
|
|
* @src: source address of the original data
|
|
* @dst: output buffer address of the compressed data,
|
|
* which must be already allocated
|
|
* @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
* @maxDstSize: full or partial size of buffer 'dest'
|
|
* which must be already allocated
|
|
* @acceleration: acceleration factor
|
|
*
|
|
* Compress buffer content 'src', using data from previously compressed blocks
|
|
* as dictionary to improve compression ratio.
|
|
* Important : Previous data blocks are assumed to still
|
|
* be present and unmodified !
|
|
* If maxDstSize >= LZ4_compressBound(srcSize),
|
|
* compression is guaranteed to succeed, and runs faster.
|
|
*
|
|
* Return: Number of bytes written into buffer 'dst' or 0 if compression fails
|
|
*/
|
|
int LZ4_compress_fast_continue(LZ4_stream_t *streamPtr, const char *src,
|
|
char *dst, int srcSize, int maxDstSize, int acceleration);
|
|
|
|
/**
|
|
* LZ4_setStreamDecode() - Instruct where to find dictionary
|
|
* @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure
|
|
* @dictionary: dictionary to use
|
|
* @dictSize: size of dictionary
|
|
*
|
|
* Use this function to instruct where to find the dictionary.
|
|
* Setting a size of 0 is allowed (same effect as reset).
|
|
*
|
|
* Return: 1 if OK, 0 if error
|
|
*/
|
|
int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode,
|
|
const char *dictionary, int dictSize);
|
|
|
|
/**
|
|
* LZ4_decompress_safe_continue() - Decompress blocks in streaming mode
|
|
* @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated
|
|
* @compressedSize: is the precise full size of the compressed block
|
|
* @maxDecompressedSize: is the size of 'dest' buffer
|
|
*
|
|
* This decoding function allows decompression of multiple blocks
|
|
* in "streaming" mode.
|
|
* Previously decoded blocks *must* remain available at the memory position
|
|
* where they were decoded (up to 64 KB)
|
|
* In the case of a ring buffers, decoding buffer must be either :
|
|
* - Exactly same size as encoding buffer, with same update rule
|
|
* (block boundaries at same positions) In which case,
|
|
* the decoding & encoding ring buffer can have any size,
|
|
* including very small ones ( < 64 KB).
|
|
* - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
|
|
* maxBlockSize is implementation dependent.
|
|
* It's the maximum size you intend to compress into a single block.
|
|
* 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).
|
|
* - _At least_ 64 KB + 8 bytes + maxBlockSize.
|
|
* In which case, encoding and decoding buffers do not need to be
|
|
* synchronized, and encoding ring buffer can have any size,
|
|
* including larger than decoding buffer. W
|
|
* Whenever these conditions are not possible, save the last 64KB of decoded
|
|
* data into a safe buffer, and indicate where it is saved
|
|
* using LZ4_setStreamDecode()
|
|
*
|
|
* Return: number of bytes decompressed into destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*/
|
|
int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode,
|
|
const char *source, char *dest, int compressedSize,
|
|
int maxDecompressedSize);
|
|
|
|
/**
|
|
* LZ4_decompress_fast_continue() - Decompress blocks in streaming mode
|
|
* @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated with 'originalSize' bytes
|
|
* @originalSize: is the original and therefore uncompressed size
|
|
*
|
|
* This decoding function allows decompression of multiple blocks
|
|
* in "streaming" mode.
|
|
* Previously decoded blocks *must* remain available at the memory position
|
|
* where they were decoded (up to 64 KB)
|
|
* In the case of a ring buffers, decoding buffer must be either :
|
|
* - Exactly same size as encoding buffer, with same update rule
|
|
* (block boundaries at same positions) In which case,
|
|
* the decoding & encoding ring buffer can have any size,
|
|
* including very small ones ( < 64 KB).
|
|
* - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
|
|
* maxBlockSize is implementation dependent.
|
|
* It's the maximum size you intend to compress into a single block.
|
|
* 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).
|
|
* - _At least_ 64 KB + 8 bytes + maxBlockSize.
|
|
* In which case, encoding and decoding buffers do not need to be
|
|
* synchronized, and encoding ring buffer can have any size,
|
|
* including larger than decoding buffer. W
|
|
* Whenever these conditions are not possible, save the last 64KB of decoded
|
|
* data into a safe buffer, and indicate where it is saved
|
|
* using LZ4_setStreamDecode()
|
|
*
|
|
* Return: number of bytes decompressed into destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*/
|
|
int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode,
|
|
const char *source, char *dest, int originalSize);
|
|
|
|
/**
|
|
* LZ4_decompress_safe_usingDict() - Same as LZ4_setStreamDecode()
|
|
* followed by LZ4_decompress_safe_continue()
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated
|
|
* @compressedSize: is the precise full size of the compressed block
|
|
* @maxDecompressedSize: is the size of 'dest' buffer
|
|
* @dictStart: pointer to the start of the dictionary in memory
|
|
* @dictSize: size of dictionary
|
|
*
|
|
* This decoding function works the same as
|
|
* a combination of LZ4_setStreamDecode() followed by
|
|
* LZ4_decompress_safe_continue()
|
|
* It is stand-alone, and doesn't need an LZ4_streamDecode_t structure.
|
|
*
|
|
* Return: number of bytes decompressed into destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*/
|
|
int LZ4_decompress_safe_usingDict(const char *source, char *dest,
|
|
int compressedSize, int maxDecompressedSize, const char *dictStart,
|
|
int dictSize);
|
|
|
|
/**
|
|
* LZ4_decompress_fast_usingDict() - Same as LZ4_setStreamDecode()
|
|
* followed by LZ4_decompress_fast_continue()
|
|
* @source: source address of the compressed data
|
|
* @dest: output buffer address of the uncompressed data
|
|
* which must be already allocated with 'originalSize' bytes
|
|
* @originalSize: is the original and therefore uncompressed size
|
|
* @dictStart: pointer to the start of the dictionary in memory
|
|
* @dictSize: size of dictionary
|
|
*
|
|
* This decoding function works the same as
|
|
* a combination of LZ4_setStreamDecode() followed by
|
|
* LZ4_decompress_fast_continue()
|
|
* It is stand-alone, and doesn't need an LZ4_streamDecode_t structure.
|
|
*
|
|
* Return: number of bytes decompressed into destination buffer
|
|
* (necessarily <= maxDecompressedSize)
|
|
* or a negative result in case of error
|
|
*/
|
|
int LZ4_decompress_fast_usingDict(const char *source, char *dest,
|
|
int originalSize, const char *dictStart, int dictSize);
|
|
|
|
#endif
|