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Diffstat (limited to 'lz4.h')
-rw-r--r-- | lz4.h | 310 |
1 files changed, 0 insertions, 310 deletions
@@ -1,310 +0,0 @@ -/* - 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 |