diff options
Diffstat (limited to 'src/compat/compat-lz4.h')
| -rw-r--r-- | src/compat/compat-lz4.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/src/compat/compat-lz4.h b/src/compat/compat-lz4.h new file mode 100644 index 0000000..a289fcf --- /dev/null +++ b/src/compat/compat-lz4.h @@ -0,0 +1,205 @@ +/* + LZ4 - Fast LZ compression algorithm + Header File + Copyright (C) 2011-2013, 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://fastcompression.blogspot.com/p/lz4.html + - LZ4 source repository : http://code.google.com/p/lz4/ +*/ +#pragma once + +#if defined (__cplusplus) +extern "C" { +#endif + + +//************************************** +// Compiler Options +//************************************** +#if defined(_MSC_VER) && !defined(__cplusplus) // Visual Studio +# define inline __inline // Visual C is not C99, but supports some kind of inline +#endif + + +//**************************** +// Simple Functions +//**************************** + +int LZ4_compress (const char* source, char* dest, int inputSize); +int LZ4_decompress_safe (const char* source, char* dest, int inputSize, 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() : + 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 source stream is detected malformed, the function will stop decoding and return a negative result. + This function is protected against buffer overflow exploits (never writes outside of output buffer, and never reads outside of input buffer). Therefore, it is protected against malicious data packets +*/ + + +//**************************** +// 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) +static inline int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); } + +/* +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. + inline function is recommended for the general case, + 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_compress_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize); + +/* +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_decompress_fast (const char* source, char* dest, int outputSize); + +/* +LZ4_decompress_fast() : + outputSize : is the original (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. + note : This function is a bit faster than LZ4_decompress_safe() + This function never writes outside of output buffers, but may read beyond input buffer in case of malicious data packet. + Use this function preferably into a trusted environment (data to decode comes from a trusted source). + Destination buffer must be already allocated. Its size must be a minimum of 'outputSize' bytes. +*/ + +int LZ4_decompress_safe_partial (const char* source, char* dest, int inputSize, int targetOutputSize, int maxOutputSize); + +/* +LZ4_decompress_safe_partial() : + This function decompress a compressed block of size 'inputSize' 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 +*/ + + +//**************************** +// Stream Functions +//**************************** + +void* LZ4_create (const char* inputBuffer); +int LZ4_compress_continue (void* LZ4_Data, const char* source, char* dest, int inputSize); +int LZ4_compress_limitedOutput_continue (void* LZ4_Data, const char* source, char* dest, int inputSize, int maxOutputSize); +char* LZ4_slideInputBuffer (void* LZ4_Data); +int LZ4_free (void* LZ4_Data); + +/* +These functions allow the compression of dependent blocks, where each block benefits from prior 64 KB within preceding blocks. +In order to achieve this, it is necessary to start creating the LZ4 Data Structure, thanks to the function : + +void* LZ4_create (const char* inputBuffer); +The result of the function is the (void*) pointer on the LZ4 Data Structure. +This pointer will be needed in all other functions. +If the pointer returned is NULL, then the allocation has failed, and compression must be aborted. +The only parameter 'const char* inputBuffer' must, obviously, point at the beginning of input buffer. +The input buffer must be already allocated, and size at least 192KB. +'inputBuffer' will also be the 'const char* source' of the first block. + +All blocks are expected to lay next to each other within the input buffer, starting from 'inputBuffer'. +To compress each block, use either LZ4_compress_continue() or LZ4_compress_limitedOutput_continue(). +Their behavior are identical to LZ4_compress() or LZ4_compress_limitedOutput(), +but require the LZ4 Data Structure as their first argument, and check that each block starts right after the previous one. +If next block does not begin immediately after the previous one, the compression will fail (return 0). + +When it's no longer possible to lay the next block after the previous one (not enough space left into input buffer), a call to : +char* LZ4_slideInputBuffer(void* LZ4_Data); +must be performed. It will typically copy the latest 64KB of input at the beginning of input buffer. +Note that, for this function to work properly, minimum size of an input buffer must be 192KB. +==> The memory position where the next input data block must start is provided as the result of the function. + +Compression can then resume, using LZ4_compress_continue() or LZ4_compress_limitedOutput_continue(), as usual. + +When compression is completed, a call to LZ4_free() will release the memory used by the LZ4 Data Structure. +*/ + + +int LZ4_decompress_safe_withPrefix64k (const char* source, char* dest, int inputSize, int maxOutputSize); +int LZ4_decompress_fast_withPrefix64k (const char* source, char* dest, int outputSize); + +/* +*_withPrefix64k() : + These decoding functions work the same as their "normal name" versions, + but can use up to 64KB of data in front of 'char* dest'. + These functions are necessary to decode inter-dependant blocks. +*/ + + +//**************************** +// Obsolete Functions +//**************************** + +static inline int LZ4_uncompress (const char* source, char* dest, int outputSize) { return LZ4_decompress_fast(source, dest, outputSize); } +static inline int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) { return LZ4_decompress_safe(source, dest, isize, maxOutputSize); } + +/* +These functions are deprecated and should no longer be used. +They are provided here for compatibility with existing user programs. +*/ + + + +#if defined (__cplusplus) +} +#endif |