--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/python-zstandard/zstd/common/huf.h Thu Nov 10 21:45:29 2016 -0800
@@ -0,0 +1,228 @@
+/* ******************************************************************
+ Huffman coder, part of New Generation Entropy library
+ header file
+ 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 HUF_H_298734234
+#define HUF_H_298734234
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+/* *** Dependencies *** */
+#include <stddef.h> /* size_t */
+
+
+/* *** simple functions *** */
+/**
+HUF_compress() :
+ Compress content from buffer 'src', of size 'srcSize', into buffer 'dst'.
+ 'dst' buffer must be already allocated.
+ Compression runs faster if `dstCapacity` >= HUF_compressBound(srcSize).
+ `srcSize` must be <= `HUF_BLOCKSIZE_MAX` == 128 KB.
+ @return : size of compressed data (<= `dstCapacity`).
+ Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
+ if return == 1, srcData is a single repeated byte symbol (RLE compression).
+ if HUF_isError(return), compression failed (more details using HUF_getErrorName())
+*/
+size_t HUF_compress(void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize);
+
+/**
+HUF_decompress() :
+ Decompress HUF data from buffer 'cSrc', of size 'cSrcSize',
+ into already allocated buffer 'dst', of minimum size 'dstSize'.
+ `dstSize` : **must** be the ***exact*** size of original (uncompressed) data.
+ Note : in contrast with FSE, HUF_decompress can regenerate
+ RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data,
+ because it knows size to regenerate.
+ @return : size of regenerated data (== dstSize),
+ or an error code, which can be tested using HUF_isError()
+*/
+size_t HUF_decompress(void* dst, size_t dstSize,
+ const void* cSrc, size_t cSrcSize);
+
+
+/* ****************************************
+* Tool functions
+******************************************/
+#define HUF_BLOCKSIZE_MAX (128 * 1024)
+size_t HUF_compressBound(size_t size); /**< maximum compressed size (worst case) */
+
+/* Error Management */
+unsigned HUF_isError(size_t code); /**< tells if a return value is an error code */
+const char* HUF_getErrorName(size_t code); /**< provides error code string (useful for debugging) */
+
+
+/* *** Advanced function *** */
+
+/** HUF_compress2() :
+* Same as HUF_compress(), but offers direct control over `maxSymbolValue` and `tableLog` */
+size_t HUF_compress2 (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
+
+
+#ifdef HUF_STATIC_LINKING_ONLY
+
+/* *** Dependencies *** */
+#include "mem.h" /* U32 */
+
+
+/* *** Constants *** */
+#define HUF_TABLELOG_ABSOLUTEMAX 16 /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
+#define HUF_TABLELOG_MAX 12 /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
+#define HUF_TABLELOG_DEFAULT 11 /* tableLog by default, when not specified */
+#define HUF_SYMBOLVALUE_MAX 255
+#if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX)
+# error "HUF_TABLELOG_MAX is too large !"
+#endif
+
+
+/* ****************************************
+* Static allocation
+******************************************/
+/* HUF 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 HUF'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 HUF's DTable */
+typedef U32 HUF_DTable;
+#define HUF_DTABLE_SIZE(maxTableLog) (1 + (1<<(maxTableLog)))
+#define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
+ HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1)*0x1000001) }
+#define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
+ HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog)*0x1000001) }
+
+
+/* ****************************************
+* 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_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< decodes RLE and uncompressed */
+size_t HUF_decompress4X_hufOnly(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< considers RLE and uncompressed as errors */
+size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< single-symbol decoder */
+size_t HUF_decompress4X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< double-symbols decoder */
+
+size_t HUF_decompress1X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
+size_t HUF_decompress1X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< single-symbol decoder */
+size_t HUF_decompress1X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< double-symbols decoder */
+
+
+/* ****************************************
+* HUF detailed API
+******************************************/
+/*!
+HUF_compress() does the following:
+1. count symbol occurrence from source[] into table count[] using FSE_count()
+2. (optional) refine tableLog using HUF_optimalTableLog()
+3. build Huffman table from count using HUF_buildCTable()
+4. save Huffman table to memory buffer using HUF_writeCTable()
+5. encode the data stream using HUF_compress4X_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" */
+unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
+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_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
+
+
+/*! HUF_readStats() :
+ Read compact Huffman tree, saved by HUF_writeCTable().
+ `huffWeight` is destination buffer.
+ @return : size read from `src` , or an error Code .
+ Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */
+size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+ U32* nbSymbolsPtr, U32* tableLogPtr,
+ const void* src, size_t srcSize);
+
+/** HUF_readCTable() :
+* Loading a CTable saved with HUF_writeCTable() */
+size_t HUF_readCTable (HUF_CElt* CTable, unsigned maxSymbolValue, const void* src, size_t srcSize);
+
+
+/*
+HUF_decompress() does the following:
+1. select the decompression algorithm (X2, X4) 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
+*/
+
+/** HUF_selectDecoder() :
+* Tells which decoder is likely to decode faster,
+* based on a set of pre-determined metrics.
+* @return : 0==HUF_decompress4X2, 1==HUF_decompress4X4 .
+* Assumption : 0 < cSrcSize < dstSize <= 128 KB */
+U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);
+
+size_t HUF_readDTableX2 (HUF_DTable* DTable, const void* src, size_t srcSize);
+size_t HUF_readDTableX4 (HUF_DTable* DTable, const void* src, size_t srcSize);
+
+size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+size_t HUF_decompress4X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* 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_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+size_t HUF_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+size_t HUF_decompress1X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+
+
+#endif /* HUF_STATIC_LINKING_ONLY */
+
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* HUF_H_298734234 */