mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-06 21:05:37 +00:00
277 lines
12 KiB
C
277 lines
12 KiB
C
/*
|
|
LZ4 - Fast LZ compression algorithm
|
|
Header File
|
|
Copyright (C) 2011-2014, 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 source repository : http://code.google.com/p/lz4/
|
|
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
|
|
*/
|
|
#pragma once
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
/**************************************
|
|
Version
|
|
**************************************/
|
|
#define LZ4_VERSION_MAJOR 1 /* for major interface/format changes */
|
|
#define LZ4_VERSION_MINOR 2 /* for minor interface/format changes */
|
|
#define LZ4_VERSION_RELEASE 0 /* for tweaks, bug-fixes, or development */
|
|
|
|
|
|
/**************************************
|
|
Tuning parameter
|
|
**************************************/
|
|
/*
|
|
* 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
|
|
|
|
|
|
/**************************************
|
|
Simple Functions
|
|
**************************************/
|
|
|
|
int LZ4_compress (const char* source, char* dest, int inputSize);
|
|
int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxOutputSize);
|
|
|
|
/*
|
|
LZ4_compress() :
|
|
Compresses 'inputSize' bytes from 'source' into 'dest'.
|
|
Destination buffer must be already allocated,
|
|
and must be sized to handle worst cases situations (input data not compressible)
|
|
Worst case size evaluation is provided by function LZ4_compressBound()
|
|
inputSize : Max supported value is LZ4_MAX_INPUT_VALUE
|
|
return : the number of bytes written in buffer dest
|
|
or 0 if the compression fails
|
|
|
|
LZ4_decompress_safe() :
|
|
compressedSize : is obviously the source size
|
|
maxOutputSize : is the size of the destination buffer, which must be already allocated.
|
|
return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
|
|
If the destination buffer is not large enough, decoding will stop and output an error code (<0).
|
|
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 :
|
|
it never writes outside of output buffer, and never reads outside of input buffer.
|
|
Therefore, it is protected against malicious data packets.
|
|
*/
|
|
|
|
|
|
/*
|
|
Note :
|
|
Should you prefer to explicitly allocate compression-table memory using your own allocation method,
|
|
use the streaming functions provided below, simply reset the memory area between each call to LZ4_compress_continue()
|
|
*/
|
|
|
|
|
|
/**************************************
|
|
Advanced Functions
|
|
**************************************/
|
|
#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)
|
|
|
|
/*
|
|
LZ4_compressBound() :
|
|
Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible)
|
|
primarily useful for memory allocation of output buffer.
|
|
macro is also provided when result needs to be evaluated at compilation (such as stack memory allocation).
|
|
|
|
isize : is the input size. Max supported value is LZ4_MAX_INPUT_SIZE
|
|
return : maximum output size in a "worst case" scenario
|
|
or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
|
|
*/
|
|
int LZ4_compressBound(int isize);
|
|
|
|
|
|
/*
|
|
LZ4_compress_limitedOutput() :
|
|
Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
|
|
If it cannot achieve it, compression will stop, and result of the function will be zero.
|
|
This function never writes outside of provided output buffer.
|
|
|
|
inputSize : Max supported value is LZ4_MAX_INPUT_VALUE
|
|
maxOutputSize : is the size of the destination buffer (which must be already allocated)
|
|
return : the number of bytes written in buffer 'dest'
|
|
or 0 if the compression fails
|
|
*/
|
|
int LZ4_compress_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
|
|
|
|
|
|
/*
|
|
LZ4_decompress_fast() :
|
|
originalSize : is the original and therefore uncompressed size
|
|
return : the number of bytes read from the source buffer (in other words, the compressed size)
|
|
If the source stream is malformed, the function will stop decoding and return a negative result.
|
|
Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
|
|
note : This function is a bit faster than LZ4_decompress_safe()
|
|
It provides fast decompression and fully respect memory boundaries for properly formed compressed data.
|
|
It does not provide full protection against intentionnally modified data stream.
|
|
Use this function in a trusted environment (data to decode comes from a trusted source).
|
|
*/
|
|
int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
|
|
|
|
|
|
/*
|
|
LZ4_decompress_safe_partial() :
|
|
This function decompress a compressed block of size 'compressedSize' at position 'source'
|
|
into output buffer 'dest' of size 'maxOutputSize'.
|
|
The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
|
|
reducing decompression time.
|
|
return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
|
|
Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
|
|
Always control how many bytes were decoded.
|
|
If the source stream is detected malformed, the function will stop decoding and return a negative result.
|
|
This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
|
|
*/
|
|
int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxOutputSize);
|
|
|
|
|
|
/***********************************************
|
|
Experimental Streaming Compression Functions
|
|
***********************************************/
|
|
|
|
#define LZ4_STREAMSIZE_U32 ((1 << (LZ4_MEMORY_USAGE-2)) + 8)
|
|
#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U32 * sizeof(unsigned int))
|
|
/*
|
|
* LZ4_stream_t
|
|
* information structure to track an LZ4 stream.
|
|
* important : set this structure content to zero before first use !
|
|
*/
|
|
typedef struct { unsigned int table[LZ4_STREAMSIZE_U32]; } LZ4_stream_t;
|
|
|
|
/*
|
|
* If you prefer dynamic allocation methods,
|
|
* LZ4_createStream
|
|
* provides a pointer (void*) towards an initialized LZ4_stream_t structure.
|
|
* LZ4_free just frees it.
|
|
*/
|
|
void* LZ4_createStream();
|
|
int LZ4_free (void* LZ4_stream);
|
|
|
|
|
|
/*
|
|
* LZ4_loadDict
|
|
* 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 (same effect as init).
|
|
* Return : 1 if OK, 0 if error
|
|
*/
|
|
int LZ4_loadDict (void* LZ4_stream, const char* dictionary, int dictSize);
|
|
|
|
/*
|
|
* LZ4_compress_continue
|
|
* Compress data block 'source', using blocks compressed before as dictionary to improve compression ratio
|
|
* Previous data blocks are assumed to still be present at their previous location.
|
|
*/
|
|
int LZ4_compress_continue (void* LZ4_stream, const char* source, char* dest, int inputSize);
|
|
|
|
/*
|
|
* LZ4_compress_limitedOutput_continue
|
|
* Same as before, but also specify a maximum target compressed size (maxOutputSize)
|
|
* If objective cannot be met, compression exits, and returns a zero.
|
|
*/
|
|
int LZ4_compress_limitedOutput_continue (void* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize);
|
|
|
|
/*
|
|
* LZ4_saveDict
|
|
* If previously compressed data block is not guaranteed to remain at its previous memory location
|
|
* save it into a safe place (char* safeBuffer)
|
|
* Note : you don't need to call LZ4_loadDict() afterwards,
|
|
* dictionary is immediately usable, you can therefore call again LZ4_compress_continue()
|
|
* Return : 1 if OK, 0 if error
|
|
* Note : any dictSize > 64 KB will be interpreted as 64KB.
|
|
*/
|
|
int LZ4_saveDict (void* LZ4_stream, char* safeBuffer, int dictSize);
|
|
|
|
|
|
/************************************************
|
|
Experimental Streaming Decompression Functions
|
|
************************************************/
|
|
|
|
#define LZ4_STREAMDECODESIZE_U32 4
|
|
#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U32 * sizeof(unsigned int))
|
|
/*
|
|
* LZ4_streamDecode_t
|
|
* information structure to track an LZ4 stream.
|
|
* important : set this structure content to zero before first use !
|
|
*/
|
|
typedef struct { unsigned int table[LZ4_STREAMDECODESIZE_U32]; } LZ4_streamDecode_t;
|
|
|
|
/*
|
|
* If you prefer dynamic allocation methods,
|
|
* LZ4_createStreamDecode()
|
|
* provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
|
|
* LZ4_free just frees it.
|
|
*/
|
|
void* LZ4_createStreamDecode();
|
|
int LZ4_free (void* LZ4_stream); /* yes, it's the same one as for compression */
|
|
|
|
/*
|
|
*_continue() :
|
|
These decoding functions allow decompression of multiple blocks in "streaming" mode.
|
|
Previously decoded blocks must still be available at the memory position where they were decoded.
|
|
If it's not possible, save the relevant part of decoded data into a safe buffer,
|
|
and indicate where it stands using LZ4_setDictDecode()
|
|
*/
|
|
int LZ4_decompress_safe_continue (void* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize);
|
|
int LZ4_decompress_fast_continue (void* LZ4_streamDecode, const char* source, char* dest, int originalSize);
|
|
|
|
/*
|
|
* LZ4_setDictDecode
|
|
* Use this function to instruct where to find the dictionary.
|
|
* This function can be used to specify a static dictionary,
|
|
* or to instruct where to find some previously decoded data saved into a different memory space.
|
|
* Setting a size of 0 is allowed (same effect as no dictionary).
|
|
* Return : 1 if OK, 0 if error
|
|
*/
|
|
int LZ4_setDictDecode (void* LZ4_streamDecode, const char* dictionary, int dictSize);
|
|
|
|
|
|
/*
|
|
Advanced decoding functions :
|
|
*_usingDict() :
|
|
These decoding functions work the same as
|
|
a combination of LZ4_setDictDecode() followed by LZ4_decompress_x_continue()
|
|
all together into a single function call.
|
|
It doesn't use nor update an LZ4_streamDecode_t structure.
|
|
*/
|
|
int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize);
|
|
int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
|
|
|
|
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|