diff options
Diffstat (limited to 'lib/zstd/fse_decompress.c')
| -rw-r--r-- | lib/zstd/fse_decompress.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/lib/zstd/fse_decompress.c b/lib/zstd/fse_decompress.c new file mode 100644 index 000000000000..a84300e5a013 --- /dev/null +++ b/lib/zstd/fse_decompress.c @@ -0,0 +1,332 @@ +/* + * 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 */ +} |