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- /*
- 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
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