| /* |
| 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. |
| */ |
| |
| |
| /************************************** |
| 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); |
| |
| |
| /* |
| The following functions are provided should you prefer to allocate table memory using your own allocation methods. |
| int LZ4_sizeofState(); |
| provides the size to allocate for compression tables. |
| |
| Tables must be aligned on 4-bytes boundaries, otherwise compression will fail (return code 0). |
| |
| The allocated memory can be provided to the compressions functions using 'void* state' parameter. |
| LZ4_compress_withState() and LZ4_compress_limitedOutput_withState() are equivalent to previously described functions. |
| They just use the externally allocated memory area instead of allocating their own one (on stack, or on heap). |
| */ |
| 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); |
| |
| |
| /************************************** |
| Experimental Streaming Functions |
| **************************************/ |
| |
| #define LZ4_DICTSIZE_U32 ((1 << (LZ4_MEMORY_USAGE-2)) + 8) |
| #define LZ4_DICTSIZE (LZ4_DICTSIZE_U32 * sizeof(unsigned int)) |
| /* |
| * LZ4_dict_t |
| * information structure to track an LZ4 stream. |
| * set it to zero, or use LZ4_loadDict() to init it before first use. |
| */ |
| typedef struct { unsigned int table[LZ4_DICTSIZE_U32]; } LZ4_dict_t; |
| |
| |
| /* |
| * LZ4_createStream |
| * provides a pointer (void*) towards an initialized LZ4_dict_t structure |
| */ |
| void* LZ4_createStream(); |
| int LZ4_free (void* LZ4_stream); |
| |
| /* |
| * LZ4_loadDict |
| * Use this function to load a static dictionary into LZ4_dict. |
| * You can load a size of 0 to init an LZ4_dict_t structure |
| * Return : 1 if OK, 0 if error |
| */ |
| int LZ4_loadDict (void* LZ4_stream, const char* dictionary, int dictSize); |
| |
| /* |
| * LZ4_compress_usingDict |
| * Compress data block 'source', using blocks compressed before to improve compression ratio |
| * Previous data blocks are assumed to still be present at their previous location. |
| */ |
| int LZ4_compress_usingDict (void* LZ4_stream, const char* source, char* dest, int inputSize); |
| |
| /* |
| * LZ4_compress_limitedOutput_usingDict |
| * Same as before, but also specify a maximum target compressed size (maxOutputSize) |
| * If it cannot be met, compression exits, and return a zero. |
| */ |
| int LZ4_compress_limitedOutput_usingDict (void* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize); |
| |
| /* |
| * LZ4_moveDict |
| * If previously compressed data block is not guaranteed to remain at its previous memory location |
| * save it into a safe place (char* safeBuffer) |
| * before calling again LZ4_compress_usingDict() |
| * Return : 1 if OK, 0 if error |
| * Note : any dictSize > 64 KB will be interpreted as 64KB. |
| */ |
| int LZ4_moveDict (void* LZ4_stream, char* safeBuffer, int dictSize); |
| |
| |
| /* |
| *_usingDict() : |
| These decoding functions work the same as their "normal" versions, |
| but can also use up to 64KB of dictionary data (dictStart, dictSize) |
| to decode chained blocks. |
| */ |
| 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); |
| |
| /* |
| *_withPrefix64k() : |
| These decoding functions work the same as their "normal" versions, |
| but can also use up to 64KB of data in front of 'char* dest' |
| to decode chained blocks. |
| The last 64KB of previous block must be present there. |
| */ |
| 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); |
| |
| |
| /************************************** |
| Obsolete 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 totally equivalent to LZ4_decompress_fast |
| - LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe |
| */ |
| 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 */ |
| void* LZ4_create (const char* inputBuffer); |
| int LZ4_sizeofStreamState(void); |
| int LZ4_resetStreamState(void* state, 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); |
| |
| |
| #if defined (__cplusplus) |
| } |
| #endif |