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Diffstat (limited to 'lib/lz4.h')
| -rw-r--r-- | lib/lz4.h | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/lib/lz4.h b/lib/lz4.h new file mode 100644 index 0000000..22bbcb5 --- /dev/null +++ b/lib/lz4.h @@ -0,0 +1,310 @@ +/* + 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 + +/* + * lz4.h provides raw compression format functions, for optimal performance and integration into programs. + * If you need to generate data using an inter-operable format (respecting the framing specification), + * please use lz4frame.h instead. +*/ + +/************************************** + Version +**************************************/ +#define LZ4_VERSION_MAJOR 1 /* for major interface/format changes */ +#define LZ4_VERSION_MINOR 4 /* for minor interface/format changes */ +#define LZ4_VERSION_RELEASE 1 /* for tweaks, bug-fixes, or development */ +#define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE) +int LZ4_versionNumber (void); + +/************************************** + 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 sourceSize); +int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize); + +/* +LZ4_compress() : + Compresses 'sourceSize' 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_SIZE + return : the number of bytes written in buffer dest + or 0 if the compression fails + +LZ4_decompress_safe() : + compressedSize : is obviously the source size + maxDecompressedSize : is the size of the destination buffer, which must be already allocated. + return : the number of bytes decompressed into the destination buffer (necessarily <= maxDecompressedSize) + 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, + and never writes outside of output buffer, nor reads outside of input buffer. + It is also 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) + +/* +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 (output buffer size). + Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). + + 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 'sourceSize' 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 saves time and memory on detecting non-compressible (or barely compressible) data. + This function never writes outside of provided output buffer. + + sourceSize : 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 compression fails +*/ +int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize); + + +/* +LZ4_compress_withState() : + Same compression functions, but using an externally allocated memory space to store compression state. + Use LZ4_sizeofState() to know how much memory must be allocated, + and then, provide it as 'void* state' to compression functions. +*/ +int LZ4_sizeofState(void); +int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); +int LZ4_compress_limitedOutput_withState (void* state, 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 detected 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 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). +*/ +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 destination buffer 'dest' of size 'maxDecompressedSize'. + 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 <= maxDecompressedSize) + 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 maxDecompressedSize); + + +/*********************************************** + Streaming Compression Functions +***********************************************/ + +#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4) +#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(long long)) +/* + * LZ4_stream_t + * information structure to track an LZ4 stream. + * important : init this structure content before first use ! + */ +typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t; + +/* + * LZ4_resetStream + * Use this function to init an allocated LZ4_stream_t structure + */ +void LZ4_resetStream (LZ4_stream_t* LZ4_streamPtr); + +/* + * If you prefer dynamic allocation methods, + * LZ4_createStream will allocate and initialize an LZ4_stream_t structure + * LZ4_freeStream releases its memory. + */ +LZ4_stream_t* LZ4_createStream(void); +int LZ4_freeStream (LZ4_stream_t* LZ4_streamPtr); + +/* + * 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. + * Return : dictionary size, in bytes (necessarily <= 64 KB) + */ +int LZ4_loadDict (LZ4_stream_t* LZ4_streamPtr, 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 (LZ4_stream_t* LZ4_streamPtr, 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 (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize); + +/* + * 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 again LZ4_compress_continue() + * Return : dictionary size in bytes, or 0 if error + * Note : any dictSize > 64 KB will be interpreted as 64KB. + */ +int LZ4_saveDict (LZ4_stream_t* LZ4_streamPtr, char* safeBuffer, int dictSize); + + +/************************************************ + Streaming Decompression Functions +************************************************/ + +#define LZ4_STREAMDECODESIZE_U64 4 +#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long)) +typedef struct { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; } LZ4_streamDecode_t; +/* + * LZ4_streamDecode_t + * information structure to track an LZ4 stream. + * init this structure content using LZ4_setStreamDecode or memset() before first use ! + * If you prefer dynamic allocation methods : + * LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure + * LZ4_freeStreamDecode releases its memory. + */ +LZ4_streamDecode_t* LZ4_createStreamDecode(void); +int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream); + +/* + * LZ4_setStreamDecode + * 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); + +/* +*_continue() : + These decoding functions allow 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) + If this condition is not possible, save the relevant part of decoded data into a safe buffer, + and indicate where is its new address using LZ4_setStreamDecode() +*/ +int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize); +int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize); + + +/* +Advanced decoding functions : +*_usingDict() : + These decoding functions work the same as + a combination of LZ4_setDictDecode() followed by LZ4_decompress_x_continue() + They are stand-alone and don't use nor update an LZ4_streamDecode_t structure. +*/ +int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize); +int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize); + + + +/************************************** + Obsolete Functions +**************************************/ +/* +Obsolete decompression functions +These function names are deprecated and should no longer be used. +They are only provided here for compatibility with older user programs. +- LZ4_uncompress is the same as LZ4_decompress_fast +- LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe +These function prototypes are now disabled; uncomment them if you really need them. +It is highly recommended to stop using these functions and migrate to newer ones */ +/* int LZ4_uncompress (const char* source, char* dest, int outputSize); */ +/* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */ + + +/* Obsolete streaming functions; use new streaming interface whenever possible */ +void* LZ4_create (const char* inputBuffer); +int LZ4_sizeofStreamState(void); +int LZ4_resetStreamState(void* state, const char* inputBuffer); +char* LZ4_slideInputBuffer (void* state); + +/* Obsolete streaming decoding functions */ +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); + + +#if defined (__cplusplus) +} +#endif |