Files
easy7zip/C/lizard/liz_entropy_common.c
Tino Reichardt 5ff0657d9f Major changes, including Brotli and Lizard
- update of zstd-mt library
- add brotli v0.6.0
- add lizard v2.0
- xxhash is from zstd for lz4, lz5 and lizard now
- update also the documentation, where needed
2017-05-25 18:40:15 +02:00

223 lines
8.6 KiB
C

/*
Common functions of New Generation Entropy library
Copyright (C) 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 :
- FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
- Public forum : https://groups.google.com/forum/#!forum/lz4c
*************************************************************************** */
/* *************************************
* Dependencies
***************************************/
#include "mem.h"
#include "error_private.h" /* ERR_*, ERROR */
#define LIZFSE_STATIC_LINKING_ONLY /* LIZFSE_MIN_TABLELOG */
#include "fse.h"
#define LIZHUF_STATIC_LINKING_ONLY /* LIZHUF_TABLELOG_ABSOLUTEMAX */
#include "huf.h"
/*-****************************************
* FSE Error Management
******************************************/
unsigned LIZFSE_isError(size_t code) { return ERR_isError(code); }
const char* LIZFSE_getErrorName(size_t code) { return ERR_getErrorName(code); }
/* **************************************************************
* HUF Error Management
****************************************************************/
unsigned LIZHUF_isError(size_t code) { return ERR_isError(code); }
const char* LIZHUF_getErrorName(size_t code) { return ERR_getErrorName(code); }
/*-**************************************************************
* FSE NCount encoding-decoding
****************************************************************/
static short LIZFSE_abs(short a) { return (short)(a<0 ? -a : a); }
size_t LIZFSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
const void* headerBuffer, size_t hbSize)
{
const BYTE* const istart = (const BYTE*) headerBuffer;
const BYTE* const iend = istart + hbSize;
const BYTE* ip = istart;
int nbBits;
int remaining;
int threshold;
U32 bitStream;
int bitCount;
unsigned charnum = 0;
int previous0 = 0;
if (hbSize < 4) return ERROR(srcSize_wrong);
bitStream = MEM_readLE32(ip);
nbBits = (bitStream & 0xF) + LIZFSE_MIN_TABLELOG; /* extract tableLog */
if (nbBits > LIZFSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
bitStream >>= 4;
bitCount = 4;
*tableLogPtr = nbBits;
remaining = (1<<nbBits)+1;
threshold = 1<<nbBits;
nbBits++;
while ((remaining>1) & (charnum<=*maxSVPtr)) {
if (previous0) {
unsigned n0 = charnum;
while ((bitStream & 0xFFFF) == 0xFFFF) {
n0 += 24;
if (ip < iend-5) {
ip += 2;
bitStream = MEM_readLE32(ip) >> bitCount;
} else {
bitStream >>= 16;
bitCount += 16;
} }
while ((bitStream & 3) == 3) {
n0 += 3;
bitStream >>= 2;
bitCount += 2;
}
n0 += bitStream & 3;
bitCount += 2;
if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
while (charnum < n0) normalizedCounter[charnum++] = 0;
if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
ip += bitCount>>3;
bitCount &= 7;
bitStream = MEM_readLE32(ip) >> bitCount;
} else {
bitStream >>= 2;
} }
{ short const max = (short)((2*threshold-1)-remaining);
short count;
if ((bitStream & (threshold-1)) < (U32)max) {
count = (short)(bitStream & (threshold-1));
bitCount += nbBits-1;
} else {
count = (short)(bitStream & (2*threshold-1));
if (count >= threshold) count -= max;
bitCount += nbBits;
}
count--; /* extra accuracy */
remaining -= LIZFSE_abs(count);
normalizedCounter[charnum++] = count;
previous0 = !count;
while (remaining < threshold) {
nbBits--;
threshold >>= 1;
}
if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
ip += bitCount>>3;
bitCount &= 7;
} else {
bitCount -= (int)(8 * (iend - 4 - ip));
ip = iend - 4;
}
bitStream = MEM_readLE32(ip) >> (bitCount & 31);
} } /* while ((remaining>1) & (charnum<=*maxSVPtr)) */
if (remaining != 1) return ERROR(corruption_detected);
if (bitCount > 32) return ERROR(corruption_detected);
*maxSVPtr = charnum-1;
ip += (bitCount+7)>>3;
return ip-istart;
}
/*! LIZHUF_readStats() :
Read compact Huffman tree, saved by LIZHUF_writeCTable().
`huffWeight` is destination buffer.
@return : size read from `src` , or an error Code .
Note : Needed by LIZHUF_readCTable() and LIZHUF_readDTableX?() .
*/
size_t LIZHUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
U32* nbSymbolsPtr, U32* tableLogPtr,
const void* src, size_t srcSize)
{
U32 weightTotal;
const BYTE* ip = (const BYTE*) src;
size_t iSize = ip[0];
size_t oSize;
/* memset(huffWeight, 0, hwSize); *//* is not necessary, even though some analyzer complain ... */
if (iSize >= 128) { /* special header */
oSize = iSize - 127;
iSize = ((oSize+1)/2);
if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
if (oSize >= hwSize) return ERROR(corruption_detected);
ip += 1;
{ U32 n;
for (n=0; n<oSize; n+=2) {
huffWeight[n] = ip[n/2] >> 4;
huffWeight[n+1] = ip[n/2] & 15;
} } }
else { /* header compressed with FSE (normal case) */
if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
oSize = LIZFSE_decompress(huffWeight, hwSize-1, ip+1, iSize); /* max (hwSize-1) values decoded, as last one is implied */
if (LIZFSE_isError(oSize)) return oSize;
}
/* collect weight stats */
memset(rankStats, 0, (LIZHUF_TABLELOG_ABSOLUTEMAX + 1) * sizeof(U32));
weightTotal = 0;
{ U32 n; for (n=0; n<oSize; n++) {
if (huffWeight[n] >= LIZHUF_TABLELOG_ABSOLUTEMAX) return ERROR(corruption_detected);
rankStats[huffWeight[n]]++;
weightTotal += (1 << huffWeight[n]) >> 1;
} }
/* get last non-null symbol weight (implied, total must be 2^n) */
{ U32 const tableLog = BIT_highbit32(weightTotal) + 1;
if (tableLog > LIZHUF_TABLELOG_ABSOLUTEMAX) return ERROR(corruption_detected);
*tableLogPtr = tableLog;
/* determine last weight */
{ U32 const total = 1 << tableLog;
U32 const rest = total - weightTotal;
U32 const verif = 1 << BIT_highbit32(rest);
U32 const lastWeight = BIT_highbit32(rest) + 1;
if (verif != rest) return ERROR(corruption_detected); /* last value must be a clean power of 2 */
huffWeight[oSize] = (BYTE)lastWeight;
rankStats[lastWeight]++;
} }
/* check tree construction validity */
if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected); /* by construction : at least 2 elts of rank 1, must be even */
/* results */
*nbSymbolsPtr = (U32)(oSize+1);
return iSize+1;
}