| /* |
| LZ4 HC - High Compression Mode of LZ4 |
| 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 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 |
| |
| |
| int LZ4_compressHC (const char* source, char* dest, int inputSize); |
| /* |
| LZ4_compressHC : |
| return : the number of bytes in compressed buffer dest |
| or 0 if compression fails. |
| note : destination buffer must be already allocated. |
| To avoid any problem, size it to handle worst cases situations (input data not compressible) |
| Worst case size evaluation is provided by function LZ4_compressBound() (see "lz4.h") |
| */ |
| |
| int LZ4_compressHC_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 1 GB |
| maxOutputSize : is maximum allowed size into the destination buffer (which must be already allocated) |
| return : the number of output bytes written in buffer 'dest' |
| or 0 if compression fails. |
| */ |
| |
| |
| int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel); |
| int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); |
| /* |
| Same functions as above, but with programmable 'compressionLevel'. |
| Recommended values are between 4 and 9, although any value between 0 and 16 will work. |
| 'compressionLevel'==0 means use default 'compressionLevel' value. |
| Values above 16 behave the same as 16. |
| Equivalent variants exist for all other compression functions below. |
| */ |
| |
| /* Note : |
| Decompression functions are provided within LZ4 source code (see "lz4.h") (BSD license) |
| */ |
| |
| |
| /************************************** |
| Using an external allocation |
| **************************************/ |
| int LZ4_sizeofStateHC(void); |
| int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize); |
| int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); |
| |
| int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel); |
| int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); |
| |
| /* |
| These functions are provided should you prefer to allocate memory for compression tables with your own allocation methods. |
| To know how much memory must be allocated for the compression tables, use : |
| int LZ4_sizeofStateHC(); |
| |
| Note that tables must be aligned for pointer (32 or 64 bits), otherwise compression will fail (return code 0). |
| |
| The allocated memory can be provided to the compression functions using 'void* state' parameter. |
| LZ4_compress_withStateHC() and LZ4_compress_limitedOutput_withStateHC() are equivalent to previously described functions. |
| They just use the externally allocated memory for state instead of allocating their own (on stack, or on heap). |
| */ |
| |
| |
| |
| /************************************** |
| Experimental Streaming Functions |
| **************************************/ |
| #define LZ4_STREAMHCSIZE_U32 65548 |
| #define LZ4_STREAMHCSIZE (LZ4_STREAMHCSIZE_U32 * sizeof(unsigned int)) |
| typedef struct { unsigned int table[LZ4_STREAMHCSIZE_U32]; } LZ4_streamHC_t; |
| |
| /* |
| This structure allows static allocation of LZ4 HC streaming state. |
| State must then be initialized using LZ4_resetStreamHC() before first use. |
| |
| If you prefer dynamic allocation, please refer to functions below. |
| */ |
| |
| LZ4_streamHC_t* LZ4_createStreamHC(void); |
| int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr); |
| |
| /* |
| These functions create and release memory for LZ4 HC streaming state. |
| Newly created states are already initialized. |
| Existing state space can be re-used anytime using LZ4_resetStreamHC(). |
| */ |
| |
| void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); |
| int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize); |
| |
| int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize); |
| int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize); |
| |
| int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int maxDictSize); |
| |
| /* |
| These functions compress data in successive blocks of any size, using previous blocks as dictionary. |
| One key assumption is that each previous block will remain read-accessible while compressing next block. |
| |
| Before starting compression, state must be properly initialized, using LZ4_resetStreamHC(). |
| A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional). |
| |
| Then, use LZ4_compressHC_continue() or LZ4_compressHC_limitedOutput_continue() to compress each successive block. |
| They work like usual LZ4_compressHC() or LZ4_compressHC_limitedOutput(), but use previous memory blocks to improve compression. |
| Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression. |
| |
| If, for any reason, previous data block can't be preserved in memory during next compression block, |
| you must save it to a safer memory space, |
| using LZ4_saveDictHC(). |
| */ |
| |
| |
| |
| /************************************** |
| Deprecated Streaming Functions |
| **************************************/ |
| /* Note : these streaming functions still follows the older model */ |
| void* LZ4_createHC (const char* inputBuffer); |
| //int LZ4_compressHC_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize); |
| //int LZ4_compressHC_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize); |
| char* LZ4_slideInputBufferHC (void* LZ4HC_Data); |
| int LZ4_freeHC (void* LZ4HC_Data); |
| |
| int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel); |
| int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); |
| |
| /* |
| 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 LZ4HC Data Structure, thanks to the function : |
| |
| void* LZ4_createHC (const char* inputBuffer); |
| The result of the function is the (void*) pointer on the LZ4HC 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_compressHC_continue() or LZ4_compressHC_limitedOutput_continue(). |
| Their behavior are identical to LZ4_compressHC() or LZ4_compressHC_limitedOutput(), |
| but require the LZ4HC 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_slideInputBufferHC(void* LZ4HC_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_compressHC_continue() or LZ4_compressHC_limitedOutput_continue(), as usual. |
| |
| When compression is completed, a call to LZ4_freeHC() will release the memory used by the LZ4HC Data Structure. |
| */ |
| |
| int LZ4_sizeofStreamStateHC(void); |
| int LZ4_resetStreamStateHC(void* state, const char* inputBuffer); |
| |
| /* |
| These functions achieve the same result as : |
| void* LZ4_createHC (const char* inputBuffer); |
| |
| They are provided here to allow the user program to allocate memory using its own routines. |
| |
| To know how much space must be allocated, use LZ4_sizeofStreamStateHC(); |
| Note also that space must be aligned for pointers (32 or 64 bits). |
| |
| Once space is allocated, you must initialize it using : LZ4_resetStreamStateHC(void* state, const char* inputBuffer); |
| void* state is a pointer to the space allocated. |
| It must be aligned for pointers (32 or 64 bits), and be large enough. |
| The 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. |
| |
| The same space can be re-used multiple times, just by initializing it each time with LZ4_resetStreamState(). |
| return value of LZ4_resetStreamStateHC() must be 0 is OK. |
| Any other value means there was an error (typically, state is not aligned for pointers (32 or 64 bits)). |
| */ |
| |
| |
| #if defined (__cplusplus) |
| } |
| #endif |