/*
* FSE : Finite State Entropy decoder
* Copyright (C) 2013-2015, 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.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation. This program is dual-licensed; you may select
* either version 2 of the GNU General Public License ("GPL") or BSD license
* ("BSD").
*
* You can contact the author at :
* - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
*/
/* **************************************************************
* Compiler specifics
****************************************************************/
#define FORCE_INLINE static __always_inline
/* **************************************************************
* Includes
****************************************************************/
#include "bitstream.h"
#include "fse.h"
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/string.h> /* memcpy, memset */
/* **************************************************************
* Error Management
****************************************************************/
#define FSE_isError ERR_isError
#define FSE_STATIC_ASSERT(c) \
{ \
enum { FSE_static_assert = 1 / (int)(!!(c)) }; \
} /* use only *after* variable declarations */
/* check and forward error code */
#define CHECK_F(f) \
{ \
size_t const e = f; \
if (FSE_isError(e)) \
return e; \
}
/* **************************************************************
* 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)
/* Function templates */
size_t FSE_buildDTable_wksp(FSE_DTable *dt, const short *normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void *workspace, size_t workspaceSize)
{
void *const tdPtr = dt + 1; /* because *dt is unsigned, 32-bits aligned on 32-bits */
FSE_DECODE_TYPE *const tableDecode = (FSE_DECODE_TYPE *)(tdPtr);
U16 *symbolNext = (U16 *)workspace;
U32 const maxSV1 = maxSymbolValue + 1;
U32 const tableSize = 1 << tableLog;
U32 highThreshold = tableSize - 1;
/* Sanity Checks */
if (workspaceSize < sizeof(U16) * (FSE_MAX_SYMBOL_VALUE + 1))
return ERROR(tableLog_tooLarge);
if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE)
return ERROR(maxSymbolValue_tooLarge);
if (tableLog > FSE_MAX_TABLELOG)
return ERROR(tableLog_tooLarge);
/* Init, lay down lowprob symbols */
{
FSE_DTableHeader DTableH;
DTableH.tableLog = (U16)tableLog;
DTableH.fastMode = 1;
{
S16 const largeLimit = (S16)(1 << (tableLog - 1));
U32 s;
for (s = 0; s < maxSV1; s++) {
if (normalizedCounter[s] == -1) {
tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
symbolNext[s] = 1;
} else {
if (normalizedCounter[s] >= largeLimit)
DTableH.fastMode = 0;
symbolNext[s] = normalizedCounter[s];
}
}
}
memcpy(dt, &DTableH, sizeof(DTableH));
}
/* Spread symbols */
{
U32 const tableMask = tableSize - 1;
U32 const step = FSE_TABLESTEP(tableSize);
U32 s, position = 0;
for (s = 0; s < maxSV1; 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 ERROR(GENERIC); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
}
/* Build Decoding table */
{
U32 u;
for (u = 0; u < tableSize; u++) {
FSE_FUNCTION_TYPE const symbol = (FSE_FUNCTION_TYPE)(tableDecode[u].symbol);
U16 nextState = symbolNext[symbol]++;
tableDecode[u].nbBits = (BYTE)(tableLog - BIT_highbit32((U32)nextState));
tableDecode[u].newState = (U16)((nextState << tableDecode[u].nbBits) - tableSize);
}
}
return 0;
}
/*-*******************************************************
* Decompression (Byte symbols)
*********************************************************/
size_t FSE_buildDTable_rle(FSE_DTable *dt, BYTE symbolValue)
{
void *ptr = dt;
FSE_DTableHeader *const DTableH = (FSE_DTableHeader *)ptr;
void *dPtr = dt + 1;
FSE_decode_t *const cell = (FSE_decode_t *)dPtr;
DTableH->tableLog = 0;
DTableH->fastMode = 0;
cell->newState = 0;
cell->symbol = symbolValue;
cell->nbBits = 0;
return 0;
}
size_t FSE_buildDTable_raw(FSE_DTable *dt, unsigned nbBits)
{
void *ptr = dt;
FSE_DTableHeader *const DTableH = (FSE_DTableHeader *)ptr;
void *dPtr = dt + 1;
FSE_decode_t *const dinfo = (FSE_decode_t *)dPtr;
const unsigned tableSize = 1 << nbBits;
const unsigned tableMask = tableSize - 1;
const unsigned maxSV1 = tableMask + 1;
unsigned s;
/* Sanity checks */
if (nbBits < 1)
return ERROR(GENERIC); /* min size */
/* Build Decoding Table */
DTableH->tableLog = (U16)nbBits;
DTableH->fastMode = 1;
for (s = 0; s < maxSV1; s++) {
dinfo[s].newState = 0;
dinfo[s].symbol = (BYTE)s;
dinfo[s].nbBits = (BYTE)nbBits;
}
return 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;
BIT_DStream_t bitD;
FSE_DState_t state1;
FSE_DState_t state2;
/* Init */
CHECK_F(BIT_initDStream(&bitD, cSrc, cSrcSize));
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 (; (BIT_reloadDStream(&bitD) == BIT_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 */
BIT_reloadDStream(&bitD);
op[1] = FSE_GETSYMBOL(&state2);
if (FSE_MAX_TABLELOG * 4 + 7 > sizeof(bitD.bitContainer) * 8) /* This test must be static */
{
if (BIT_reloadDStream(&bitD) > BIT_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 */
BIT_reloadDStream(&bitD);
op[3] = FSE_GETSYMBOL(&state2);
}
/* tail */
/* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
while (1) {
if (op > (omax - 2))
return ERROR(dstSize_tooSmall);
*op++ = FSE_GETSYMBOL(&state1);
if (BIT_reloadDStream(&bitD) == BIT_DStream_overflow) {
*op++ = FSE_GETSYMBOL(&state2);
break;
}
if (op > (omax - 2))
return ERROR(dstSize_tooSmall);
*op++ = FSE_GETSYMBOL(&state2);
if (BIT_reloadDStream(&bitD) == BIT_DStream_overflow) {
*op++ = FSE_GETSYMBOL(&state1);
break;
}
}
return op - ostart;
}
size_t FSE_decompress_usingDTable(void *dst, size_t originalSize, const void *cSrc, size_t cSrcSize, const FSE_DTable *dt)
{
const void *ptr = dt;
const FSE_DTableHeader *DTableH = (const FSE_DTableHeader *)ptr;
const U32 fastMode = DTableH->fastMode;
/* select fast mode (static) */
if (fastMode)
return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
}
size_t FSE_decompress_wksp(void *dst, size_t dstCapacity, const void *cSrc, size_t cSrcSize, unsigned maxLog, void *workspace, size_t workspaceSize)
{
const BYTE *const istart = (const BYTE *)cSrc;
const BYTE *ip = istart;
unsigned tableLog;
unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
size_t NCountLength;
FSE_DTable *dt;
short *counting;
size_t spaceUsed32 = 0;
FSE_STATIC_ASSERT(sizeof(FSE_DTable) == sizeof(U32));
dt = (FSE_DTable *)((U32 *)workspace + spaceUsed32);
spaceUsed32 += FSE_DTABLE_SIZE_U32(maxLog);
counting = (short *)((U32 *)workspace + spaceUsed32);
spaceUsed32 += ALIGN(sizeof(short) * (FSE_MAX_SYMBOL_VALUE + 1), sizeof(U32)) >> 2;
if ((spaceUsed32 << 2) > workspaceSize)
return ERROR(tableLog_tooLarge);
workspace = (U32 *)workspace + spaceUsed32;
workspaceSize -= (spaceUsed32 << 2);
/* normal FSE decoding mode */
NCountLength = FSE_readNCount(counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
if (FSE_isError(NCountLength))
return NCountLength;
// if (NCountLength >= cSrcSize) return ERROR(srcSize_wrong); /* too small input size; supposed to be already checked in NCountLength, only remaining
// case : NCountLength==cSrcSize */
if (tableLog > maxLog)
return ERROR(tableLog_tooLarge);
ip += NCountLength;
cSrcSize -= NCountLength;
CHECK_F(FSE_buildDTable_wksp(dt, counting, maxSymbolValue, tableLog, workspace, workspaceSize));
return FSE_decompress_usingDTable(dst, dstCapacity, ip, cSrcSize, dt); /* always return, even if it is an error code */
}
