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zstd_v01.c
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zstd_v01.c
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#ifndef USE_EXTERNAL_ZSTD
/*
* Copyright (c) Yann Collet, Meta Platforms, Inc. and affiliates.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
/******************************************
* Includes
******************************************/
#include <stddef.h> /* size_t, ptrdiff_t */
#include "zstd_v01.h"
#include "compiler.h"
#include "error_private.h"
/******************************************
* Static allocation
******************************************/
/* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
#define FSE_DTABLE_SIZE_U32(maxTableLog) (1 + (1<<maxTableLog))
/* You can statically allocate Huff0 DTable as a table of unsigned short using below macro */
#define HUF_DTABLE_SIZE_U16(maxTableLog) (1 + (1<<maxTableLog))
#define HUF_CREATE_STATIC_DTABLE(DTable, maxTableLog) \
unsigned short DTable[HUF_DTABLE_SIZE_U16(maxTableLog)] = { maxTableLog }
/******************************************
* Error Management
******************************************/
#define FSE_LIST_ERRORS(ITEM) \
ITEM(FSE_OK_NoError) ITEM(FSE_ERROR_GENERIC) \
ITEM(FSE_ERROR_tableLog_tooLarge) ITEM(FSE_ERROR_maxSymbolValue_tooLarge) ITEM(FSE_ERROR_maxSymbolValue_tooSmall) \
ITEM(FSE_ERROR_dstSize_tooSmall) ITEM(FSE_ERROR_srcSize_wrong)\
ITEM(FSE_ERROR_corruptionDetected) \
ITEM(FSE_ERROR_maxCode)
#define FSE_GENERATE_ENUM(ENUM) ENUM,
typedef enum { FSE_LIST_ERRORS(FSE_GENERATE_ENUM) } FSE_errorCodes; /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
/******************************************
* FSE symbol compression API
******************************************/
/*
This API consists of small unitary functions, which highly benefit from being inlined.
You will want to enable link-time-optimization to ensure these functions are properly inlined in your binary.
Visual seems to do it automatically.
For gcc or clang, you'll need to add -flto flag at compilation and linking stages.
If none of these solutions is applicable, include "fse.c" directly.
*/
typedef unsigned FSE_CTable; /* don't allocate that. It's just a way to be more restrictive than void* */
typedef unsigned FSE_DTable; /* don't allocate that. It's just a way to be more restrictive than void* */
typedef struct
{
size_t bitContainer;
int bitPos;
char* startPtr;
char* ptr;
char* endPtr;
} FSE_CStream_t;
typedef struct
{
ptrdiff_t value;
const void* stateTable;
const void* symbolTT;
unsigned stateLog;
} FSE_CState_t;
typedef struct
{
size_t bitContainer;
unsigned bitsConsumed;
const char* ptr;
const char* start;
} FSE_DStream_t;
typedef struct
{
size_t state;
const void* table; /* precise table may vary, depending on U16 */
} FSE_DState_t;
typedef enum { FSE_DStream_unfinished = 0,
FSE_DStream_endOfBuffer = 1,
FSE_DStream_completed = 2,
FSE_DStream_tooFar = 3 } FSE_DStream_status; /* result of FSE_reloadDStream() */
/* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... ?! */
/****************************************************************
* Tuning parameters
****************************************************************/
/* 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
* Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
#define FSE_MAX_MEMORY_USAGE 14
#define FSE_DEFAULT_MEMORY_USAGE 13
/* FSE_MAX_SYMBOL_VALUE :
* Maximum symbol value authorized.
* Required for proper stack allocation */
#define FSE_MAX_SYMBOL_VALUE 255
/****************************************************************
* template functions type & suffix
****************************************************************/
#define FSE_FUNCTION_TYPE BYTE
#define FSE_FUNCTION_EXTENSION
/****************************************************************
* Byte symbol type
****************************************************************/
typedef struct
{
unsigned short newState;
unsigned char symbol;
unsigned char nbBits;
} FSE_decode_t; /* size == U32 */
/****************************************************************
* Compiler specifics
****************************************************************/
#ifdef _MSC_VER /* Visual Studio */
# define FORCE_INLINE static __forceinline
# include <intrin.h> /* For Visual 2005 */
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
# pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */
#else
# define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# ifdef __GNUC__
# define FORCE_INLINE static inline __attribute__((always_inline))
# else
# define FORCE_INLINE static inline
# endif
# else
# define FORCE_INLINE static
# endif /* __STDC_VERSION__ */
#endif
/****************************************************************
* Includes
****************************************************************/
#include <stdlib.h> /* malloc, free, qsort */
#include <string.h> /* memcpy, memset */
#include <stdio.h> /* printf (debug) */
#ifndef MEM_ACCESS_MODULE
#define MEM_ACCESS_MODULE
/****************************************************************
* Basic Types
*****************************************************************/
#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# include <stdint.h>
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef int16_t S16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
typedef int64_t S64;
#else
typedef unsigned char BYTE;
typedef unsigned short U16;
typedef signed short S16;
typedef unsigned int U32;
typedef signed int S32;
typedef unsigned long long U64;
typedef signed long long S64;
#endif
#endif /* MEM_ACCESS_MODULE */
/****************************************************************
* Memory I/O
*****************************************************************/
static unsigned FSE_32bits(void)
{
return sizeof(void*)==4;
}
static unsigned FSE_isLittleEndian(void)
{
const union { U32 i; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */
return one.c[0];
}
static U16 FSE_read16(const void* memPtr)
{
U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
}
static U32 FSE_read32(const void* memPtr)
{
U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
}
static U64 FSE_read64(const void* memPtr)
{
U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
}
static U16 FSE_readLE16(const void* memPtr)
{
if (FSE_isLittleEndian())
return FSE_read16(memPtr);
else
{
const BYTE* p = (const BYTE*)memPtr;
return (U16)(p[0] + (p[1]<<8));
}
}
static U32 FSE_readLE32(const void* memPtr)
{
if (FSE_isLittleEndian())
return FSE_read32(memPtr);
else
{
const BYTE* p = (const BYTE*)memPtr;
return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
}
}
static U64 FSE_readLE64(const void* memPtr)
{
if (FSE_isLittleEndian())
return FSE_read64(memPtr);
else
{
const BYTE* p = (const BYTE*)memPtr;
return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
+ ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
}
}
static size_t FSE_readLEST(const void* memPtr)
{
if (FSE_32bits())
return (size_t)FSE_readLE32(memPtr);
else
return (size_t)FSE_readLE64(memPtr);
}
/****************************************************************
* Constants
*****************************************************************/
#define FSE_MAX_TABLELOG (FSE_MAX_MEMORY_USAGE-2)
#define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
#define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
#define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
#define FSE_MIN_TABLELOG 5
#define FSE_TABLELOG_ABSOLUTE_MAX 15
#if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
#error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
#endif
/****************************************************************
* Error Management
****************************************************************/
#define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
/****************************************************************
* Complex types
****************************************************************/
typedef struct
{
int deltaFindState;
U32 deltaNbBits;
} FSE_symbolCompressionTransform; /* total 8 bytes */
typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
/****************************************************************
* Internal functions
****************************************************************/
FORCE_INLINE unsigned FSE_highbit32 (U32 val)
{
# if defined(_MSC_VER) /* Visual */
unsigned long r;
return _BitScanReverse(&r, val) ? (unsigned)r : 0;
# elif defined(__GNUC__) && (GCC_VERSION >= 304) /* GCC Intrinsic */
return __builtin_clz (val) ^ 31;
# else /* Software version */
static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
U32 v = val;
unsigned r;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
return r;
# endif
}
/****************************************************************
* Templates
****************************************************************/
/*
designed to be included
for type-specific functions (template emulation in C)
Objective is to write these functions only once, for improved maintenance
*/
/* safety checks */
#ifndef FSE_FUNCTION_EXTENSION
# error "FSE_FUNCTION_EXTENSION must be defined"
#endif
#ifndef FSE_FUNCTION_TYPE
# error "FSE_FUNCTION_TYPE must be defined"
#endif
/* Function names */
#define FSE_CAT(X,Y) X##Y
#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
#define FSE_DECODE_TYPE FSE_decode_t
typedef struct {
U16 tableLog;
U16 fastMode;
} FSE_DTableHeader; /* sizeof U32 */
static size_t FSE_buildDTable
(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
{
void* ptr = dt;
FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)(ptr) + 1; /* because dt is unsigned, 32-bits aligned on 32-bits */
const U32 tableSize = 1 << tableLog;
const U32 tableMask = tableSize-1;
const U32 step = FSE_tableStep(tableSize);
U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
U32 position = 0;
U32 highThreshold = tableSize-1;
const S16 largeLimit= (S16)(1 << (tableLog-1));
U32 noLarge = 1;
U32 s;
/* Sanity Checks */
if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return (size_t)-FSE_ERROR_maxSymbolValue_tooLarge;
if (tableLog > FSE_MAX_TABLELOG) return (size_t)-FSE_ERROR_tableLog_tooLarge;
/* Init, lay down lowprob symbols */
DTableH[0].tableLog = (U16)tableLog;
for (s=0; s<=maxSymbolValue; s++)
{
if (normalizedCounter[s]==-1)
{
tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
symbolNext[s] = 1;
}
else
{
if (normalizedCounter[s] >= largeLimit) noLarge=0;
symbolNext[s] = normalizedCounter[s];
}
}
/* Spread symbols */
for (s=0; s<=maxSymbolValue; s++)
{
int i;
for (i=0; i<normalizedCounter[s]; i++)
{
tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
position = (position + step) & tableMask;
while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */
}
}
if (position!=0) return (size_t)-FSE_ERROR_GENERIC; /* position must reach all cells once, otherwise normalizedCounter is incorrect */
/* Build Decoding table */
{
U32 i;
for (i=0; i<tableSize; i++)
{
FSE_FUNCTION_TYPE symbol = (FSE_FUNCTION_TYPE)(tableDecode[i].symbol);
U16 nextState = symbolNext[symbol]++;
tableDecode[i].nbBits = (BYTE) (tableLog - FSE_highbit32 ((U32)nextState) );
tableDecode[i].newState = (U16) ( (nextState << tableDecode[i].nbBits) - tableSize);
}
}
DTableH->fastMode = (U16)noLarge;
return 0;
}
/******************************************
* FSE byte symbol
******************************************/
#ifndef FSE_COMMONDEFS_ONLY
static unsigned FSE_isError(size_t code) { return (code > (size_t)(-FSE_ERROR_maxCode)); }
static short FSE_abs(short a)
{
return a<0? -a : a;
}
/****************************************************************
* Header bitstream management
****************************************************************/
static size_t FSE_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 (size_t)-FSE_ERROR_srcSize_wrong;
bitStream = FSE_readLE32(ip);
nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG; /* extract tableLog */
if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return (size_t)-FSE_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 = FSE_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 (size_t)-FSE_ERROR_maxSymbolValue_tooSmall;
while (charnum < n0) normalizedCounter[charnum++] = 0;
if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
{
ip += bitCount>>3;
bitCount &= 7;
bitStream = FSE_readLE32(ip) >> bitCount;
}
else
bitStream >>= 2;
}
{
const short 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 -= FSE_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 = FSE_readLE32(ip) >> (bitCount & 31);
}
}
}
if (remaining != 1) return (size_t)-FSE_ERROR_GENERIC;
*maxSVPtr = charnum-1;
ip += (bitCount+7)>>3;
if ((size_t)(ip-istart) > hbSize) return (size_t)-FSE_ERROR_srcSize_wrong;
return ip-istart;
}
/*********************************************************
* Decompression (Byte symbols)
*********************************************************/
static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
{
void* ptr = dt;
FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1; /* because dt is unsigned */
DTableH->tableLog = 0;
DTableH->fastMode = 0;
cell->newState = 0;
cell->symbol = symbolValue;
cell->nbBits = 0;
return 0;
}
static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
{
void* ptr = dt;
FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1; /* because dt is unsigned */
const unsigned tableSize = 1 << nbBits;
const unsigned tableMask = tableSize - 1;
const unsigned maxSymbolValue = tableMask;
unsigned s;
/* Sanity checks */
if (nbBits < 1) return (size_t)-FSE_ERROR_GENERIC; /* min size */
/* Build Decoding Table */
DTableH->tableLog = (U16)nbBits;
DTableH->fastMode = 1;
for (s=0; s<=maxSymbolValue; s++)
{
dinfo[s].newState = 0;
dinfo[s].symbol = (BYTE)s;
dinfo[s].nbBits = (BYTE)nbBits;
}
return 0;
}
/* FSE_initDStream
* Initialize a FSE_DStream_t.
* srcBuffer must point at the beginning of an FSE block.
* The function result is the size of the FSE_block (== srcSize).
* If srcSize is too small, the function will return an errorCode;
*/
static size_t FSE_initDStream(FSE_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
{
if (srcSize < 1) return (size_t)-FSE_ERROR_srcSize_wrong;
if (srcSize >= sizeof(size_t))
{
U32 contain32;
bitD->start = (const char*)srcBuffer;
bitD->ptr = (const char*)srcBuffer + srcSize - sizeof(size_t);
bitD->bitContainer = FSE_readLEST(bitD->ptr);
contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC; /* stop bit not present */
bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
}
else
{
U32 contain32;
bitD->start = (const char*)srcBuffer;
bitD->ptr = bitD->start;
bitD->bitContainer = *(const BYTE*)(bitD->start);
switch(srcSize)
{
case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
/* fallthrough */
case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
/* fallthrough */
case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
/* fallthrough */
case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
/* fallthrough */
case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
/* fallthrough */
case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) << 8;
/* fallthrough */
default:;
}
contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC; /* stop bit not present */
bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
}
return srcSize;
}
/*!FSE_lookBits
* Provides next n bits from the bitContainer.
* bitContainer is not modified (bits are still present for next read/look)
* On 32-bits, maxNbBits==25
* On 64-bits, maxNbBits==57
* return : value extracted.
*/
static size_t FSE_lookBits(FSE_DStream_t* bitD, U32 nbBits)
{
const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
}
static size_t FSE_lookBitsFast(FSE_DStream_t* bitD, U32 nbBits) /* only if nbBits >= 1 !! */
{
const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
}
static void FSE_skipBits(FSE_DStream_t* bitD, U32 nbBits)
{
bitD->bitsConsumed += nbBits;
}
/*!FSE_readBits
* Read next n bits from the bitContainer.
* On 32-bits, don't read more than maxNbBits==25
* On 64-bits, don't read more than maxNbBits==57
* Use the fast variant *only* if n >= 1.
* return : value extracted.
*/
static size_t FSE_readBits(FSE_DStream_t* bitD, U32 nbBits)
{
size_t value = FSE_lookBits(bitD, nbBits);
FSE_skipBits(bitD, nbBits);
return value;
}
static size_t FSE_readBitsFast(FSE_DStream_t* bitD, U32 nbBits) /* only if nbBits >= 1 !! */
{
size_t value = FSE_lookBitsFast(bitD, nbBits);
FSE_skipBits(bitD, nbBits);
return value;
}
static unsigned FSE_reloadDStream(FSE_DStream_t* bitD)
{
if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8)) /* should never happen */
return FSE_DStream_tooFar;
if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
{
bitD->ptr -= bitD->bitsConsumed >> 3;
bitD->bitsConsumed &= 7;
bitD->bitContainer = FSE_readLEST(bitD->ptr);
return FSE_DStream_unfinished;
}
if (bitD->ptr == bitD->start)
{
if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return FSE_DStream_endOfBuffer;
return FSE_DStream_completed;
}
{
U32 nbBytes = bitD->bitsConsumed >> 3;
U32 result = FSE_DStream_unfinished;
if (bitD->ptr - nbBytes < bitD->start)
{
nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */
result = FSE_DStream_endOfBuffer;
}
bitD->ptr -= nbBytes;
bitD->bitsConsumed -= nbBytes*8;
bitD->bitContainer = FSE_readLEST(bitD->ptr); /* reminder : srcSize > sizeof(bitD) */
return result;
}
}
static void FSE_initDState(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD, const FSE_DTable* dt)
{
const void* ptr = dt;
const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
DStatePtr->state = FSE_readBits(bitD, DTableH->tableLog);
FSE_reloadDStream(bitD);
DStatePtr->table = dt + 1;
}
static BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
{
const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
const U32 nbBits = DInfo.nbBits;
BYTE symbol = DInfo.symbol;
size_t lowBits = FSE_readBits(bitD, nbBits);
DStatePtr->state = DInfo.newState + lowBits;
return symbol;
}
static BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
{
const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
const U32 nbBits = DInfo.nbBits;
BYTE symbol = DInfo.symbol;
size_t lowBits = FSE_readBitsFast(bitD, nbBits);
DStatePtr->state = DInfo.newState + lowBits;
return symbol;
}
/* FSE_endOfDStream
Tells if bitD has reached end of bitStream or not */
static unsigned FSE_endOfDStream(const FSE_DStream_t* bitD)
{
return ((bitD->ptr == bitD->start) && (bitD->bitsConsumed == sizeof(bitD->bitContainer)*8));
}
static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
{
return DStatePtr->state == 0;
}
FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
void* dst, size_t maxDstSize,
const void* cSrc, size_t cSrcSize,
const FSE_DTable* dt, const unsigned fast)
{
BYTE* const ostart = (BYTE*) dst;
BYTE* op = ostart;
BYTE* const omax = op + maxDstSize;
BYTE* const olimit = omax-3;
FSE_DStream_t bitD;
FSE_DState_t state1;
FSE_DState_t state2;
size_t errorCode;
/* Init */
errorCode = FSE_initDStream(&bitD, cSrc, cSrcSize); /* replaced last arg by maxCompressed Size */
if (FSE_isError(errorCode)) return errorCode;
FSE_initDState(&state1, &bitD, dt);
FSE_initDState(&state2, &bitD, dt);
#define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
/* 4 symbols per loop */
for ( ; (FSE_reloadDStream(&bitD)==FSE_DStream_unfinished) && (op<olimit) ; op+=4)
{
op[0] = FSE_GETSYMBOL(&state1);
if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8) /* This test must be static */
FSE_reloadDStream(&bitD);
op[1] = FSE_GETSYMBOL(&state2);
if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8) /* This test must be static */
{ if (FSE_reloadDStream(&bitD) > FSE_DStream_unfinished) { op+=2; break; } }
op[2] = FSE_GETSYMBOL(&state1);
if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8) /* This test must be static */
FSE_reloadDStream(&bitD);
op[3] = FSE_GETSYMBOL(&state2);
}
/* tail */
/* note : FSE_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly FSE_DStream_completed */
while (1)
{
if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
break;
*op++ = FSE_GETSYMBOL(&state1);
if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
break;
*op++ = FSE_GETSYMBOL(&state2);
}
/* end ? */
if (FSE_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
return op-ostart;
if (op==omax) return (size_t)-FSE_ERROR_dstSize_tooSmall; /* dst buffer is full, but cSrc unfinished */
return (size_t)-FSE_ERROR_corruptionDetected;
}
static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
const void* cSrc, size_t cSrcSize,
const FSE_DTable* dt)
{
FSE_DTableHeader DTableH;
memcpy(&DTableH, dt, sizeof(DTableH)); /* memcpy() into local variable, to avoid strict aliasing warning */
/* select fast mode (static) */
if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
}
static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
{
const BYTE* const istart = (const BYTE*)cSrc;
const BYTE* ip = istart;
short counting[FSE_MAX_SYMBOL_VALUE+1];
DTable_max_t dt; /* Static analyzer seems unable to understand this table will be properly initialized later */
unsigned tableLog;
unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
size_t errorCode;
if (cSrcSize<2) return (size_t)-FSE_ERROR_srcSize_wrong; /* too small input size */
/* normal FSE decoding mode */
errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
if (FSE_isError(errorCode)) return errorCode;
if (errorCode >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong; /* too small input size */
ip += errorCode;
cSrcSize -= errorCode;
errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
if (FSE_isError(errorCode)) return errorCode;
/* always return, even if it is an error code */
return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
}
/* *******************************************************
* Huff0 : Huffman block compression
*********************************************************/
#define HUF_MAX_SYMBOL_VALUE 255
#define HUF_DEFAULT_TABLELOG 12 /* used by default, when not specified */
#define HUF_MAX_TABLELOG 12 /* max possible tableLog; for allocation purpose; can be modified */
#define HUF_ABSOLUTEMAX_TABLELOG 16 /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
#if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
# error "HUF_MAX_TABLELOG is too large !"
#endif
typedef struct HUF_CElt_s {
U16 val;
BYTE nbBits;
} HUF_CElt ;
typedef struct nodeElt_s {
U32 count;
U16 parent;
BYTE byte;
BYTE nbBits;
} nodeElt;
/* *******************************************************
* Huff0 : Huffman block decompression
*********************************************************/
typedef struct {
BYTE byte;
BYTE nbBits;
} HUF_DElt;
static size_t HUF_readDTable (U16* DTable, const void* src, size_t srcSize)
{
BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1]; /* large enough for values from 0 to 16 */
U32 weightTotal;
U32 maxBits;
const BYTE* ip = (const BYTE*) src;
size_t iSize;
size_t oSize;
U32 n;
U32 nextRankStart;
void* ptr = DTable+1;
HUF_DElt* const dt = (HUF_DElt*)ptr;
if (!srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
iSize = ip[0];
FSE_STATIC_ASSERT(sizeof(HUF_DElt) == sizeof(U16)); /* if compilation fails here, assertion is false */
//memset(huffWeight, 0, sizeof(huffWeight)); /* should not be necessary, but some analyzer complain ... */
if (iSize >= 128) /* special header */
{
if (iSize >= (242)) /* RLE */
{
static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
oSize = l[iSize-242];
memset(huffWeight, 1, sizeof(huffWeight));
iSize = 0;
}
else /* Incompressible */
{
oSize = iSize - 127;
iSize = ((oSize+1)/2);
if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
ip += 1;
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 (size_t)-FSE_ERROR_srcSize_wrong;
oSize = FSE_decompress(huffWeight, HUF_MAX_SYMBOL_VALUE, ip+1, iSize); /* max 255 values decoded, last one is implied */
if (FSE_isError(oSize)) return oSize;
}
/* collect weight stats */
memset(rankVal, 0, sizeof(rankVal));
weightTotal = 0;
for (n=0; n<oSize; n++)
{
if (huffWeight[n] >= HUF_ABSOLUTEMAX_TABLELOG) return (size_t)-FSE_ERROR_corruptionDetected;
rankVal[huffWeight[n]]++;
weightTotal += (1 << huffWeight[n]) >> 1;
}
if (weightTotal == 0) return (size_t)-FSE_ERROR_corruptionDetected;
/* get last non-null symbol weight (implied, total must be 2^n) */
maxBits = FSE_highbit32(weightTotal) + 1;
if (maxBits > DTable[0]) return (size_t)-FSE_ERROR_tableLog_tooLarge; /* DTable is too small */
DTable[0] = (U16)maxBits;
{
U32 total = 1 << maxBits;
U32 rest = total - weightTotal;
U32 verif = 1 << FSE_highbit32(rest);
U32 lastWeight = FSE_highbit32(rest) + 1;
if (verif != rest) return (size_t)-FSE_ERROR_corruptionDetected; /* last value must be a clean power of 2 */
huffWeight[oSize] = (BYTE)lastWeight;
rankVal[lastWeight]++;
}
/* check tree construction validity */
if ((rankVal[1] < 2) || (rankVal[1] & 1)) return (size_t)-FSE_ERROR_corruptionDetected; /* by construction : at least 2 elts of rank 1, must be even */
/* Prepare ranks */
nextRankStart = 0;
for (n=1; n<=maxBits; n++)
{
U32 current = nextRankStart;