--- /dev/null
+/*
+ * 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 */
+}
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