zstd/lib/huff0_static.h

/* ******************************************************************
   Huff0 : Huffman codec, part of New Generation Entropy library
   header file, for static linking only
   Copyright (C) 2013-2016, 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 :
   - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
****************************************************************** */
#ifndef HUFF0_STATIC_H
#define HUFF0_STATIC_H

#if defined (__cplusplus)
extern "C" {
#endif


/* ****************************************
*  Dependency
******************************************/
#include "huff0.h"


/* ****************************************
*  Static allocation
******************************************/
/* Huff0 buffer bounds */
#define HUF_CTABLEBOUND 129
#define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
#define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */

/* static allocation of Huff0's Compression Table */
#define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) \
    U32 name##hb[maxSymbolValue+1]; \
    void* name##hv = &(name##hb); \
    HUF_CElt* name = (HUF_CElt*)(name##hv)   /* no final ; */

/* static allocation of Huff0's DTable */
#define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<maxTableLog))
#define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
        unsigned short DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
#define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
        unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog)] = { maxTableLog }
#define HUF_CREATE_STATIC_DTABLEX6(DTable, maxTableLog) \
        unsigned int DTable[HUF_DTABLE_SIZE(maxTableLog) * 3 / 2] = { maxTableLog }


/* ****************************************
*  Advanced decompression functions
******************************************/
size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbols decoder */
size_t HUF_decompress4X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* quad-symbols decoder */


/* ****************************************
*  Huff0 detailed API
******************************************/
/*!
HUF_compress() does the following:
1. count symbol occurrence from source[] into table count[] using FSE_count()
2. build Huffman table from count using HUF_buildCTable()
3. save Huffman table to memory buffer using HUF_writeCTable()
4. encode the data stream using HUF_compress_usingCTable()

The following API allows targeting specific sub-functions for advanced tasks.
For example, it's possible to compress several blocks using the same 'CTable',
or to save and regenerate 'CTable' using external methods.
*/
/* FSE_count() : find it within "fse.h" */
typedef struct HUF_CElt_s HUF_CElt;   /* incomplete type */
size_t HUF_buildCTable (HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue, unsigned maxNbBits);
size_t HUF_writeCTable (void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog);
size_t HUF_compress4X_into4Segments(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);


/*!
HUF_decompress() does the following:
1. select the decompression algorithm (X2, X4, X6) based on pre-computed heuristics
2. build Huffman table from save, using HUF_readDTableXn()
3. decode 1 or 4 segments in parallel using HUF_decompressSXn_usingDTable
*/
size_t HUF_readDTableX2 (unsigned short* DTable, const void* src, size_t srcSize);
size_t HUF_readDTableX4 (unsigned* DTable, const void* src, size_t srcSize);
size_t HUF_readDTableX6 (unsigned* DTable, const void* src, size_t srcSize);

size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned short* DTable);
size_t HUF_decompress4X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned* DTable);
size_t HUF_decompress4X6_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned* DTable);


/* single stream variants */

size_t HUF_compress1X (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);

size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
size_t HUF_decompress1X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
size_t HUF_decompress1X6 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* quad-symbol decoder */

size_t HUF_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned short* DTable);
size_t HUF_decompress1X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned* DTable);
size_t HUF_decompress1X6_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const unsigned* DTable);


/* Loading a CTable saved with HUF_writeCTable() */

size_t HUF_readCTable (HUF_CElt* CTable, unsigned maxSymbolValue, const void* src, size_t srcSize);


#if defined (__cplusplus)
}
#endif

#endif /* HUFF0_STATIC_H */