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![Gustavo A. R. Silva](/assets/img/avatar_default.png)
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple break statements instead of letting the code fall through to the next case, and by replacing a number of /* fall through */ comments with the new pseudo-keyword macro fallthrough. Notice that Clang doesn't recognize /* Fall through */ comments as implicit fall-through markings. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
773 lines
26 KiB
C
773 lines
26 KiB
C
/*
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* Huffman encoder, part of New Generation Entropy library
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* Copyright (C) 2013-2016, Yann Collet.
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*
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* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This program is free software; you can redistribute it and/or modify it under
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* the terms of the GNU General Public License version 2 as published by the
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* Free Software Foundation. This program is dual-licensed; you may select
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* either version 2 of the GNU General Public License ("GPL") or BSD license
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* ("BSD").
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*
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* You can contact the author at :
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* - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
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*/
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/* **************************************************************
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* Includes
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****************************************************************/
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#include "bitstream.h"
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#include "fse.h" /* header compression */
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#include "huf.h"
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#include <linux/kernel.h>
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#include <linux/string.h> /* memcpy, memset */
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/* **************************************************************
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* Error Management
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****************************************************************/
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#define HUF_STATIC_ASSERT(c) \
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{ \
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enum { HUF_static_assert = 1 / (int)(!!(c)) }; \
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} /* use only *after* variable declarations */
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#define CHECK_V_F(e, f) \
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size_t const e = f; \
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if (ERR_isError(e)) \
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return f
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#define CHECK_F(f) \
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{ \
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CHECK_V_F(_var_err__, f); \
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}
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/* **************************************************************
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* Utils
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****************************************************************/
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unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)
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{
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return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1);
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}
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/* *******************************************************
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* HUF : Huffman block compression
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*********************************************************/
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/* HUF_compressWeights() :
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* Same as FSE_compress(), but dedicated to huff0's weights compression.
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* The use case needs much less stack memory.
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* Note : all elements within weightTable are supposed to be <= HUF_TABLELOG_MAX.
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*/
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#define MAX_FSE_TABLELOG_FOR_HUFF_HEADER 6
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size_t HUF_compressWeights_wksp(void *dst, size_t dstSize, const void *weightTable, size_t wtSize, void *workspace, size_t workspaceSize)
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{
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BYTE *const ostart = (BYTE *)dst;
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BYTE *op = ostart;
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BYTE *const oend = ostart + dstSize;
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U32 maxSymbolValue = HUF_TABLELOG_MAX;
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U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;
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FSE_CTable *CTable;
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U32 *count;
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S16 *norm;
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size_t spaceUsed32 = 0;
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HUF_STATIC_ASSERT(sizeof(FSE_CTable) == sizeof(U32));
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CTable = (FSE_CTable *)((U32 *)workspace + spaceUsed32);
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spaceUsed32 += FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX);
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count = (U32 *)workspace + spaceUsed32;
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spaceUsed32 += HUF_TABLELOG_MAX + 1;
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norm = (S16 *)((U32 *)workspace + spaceUsed32);
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spaceUsed32 += ALIGN(sizeof(S16) * (HUF_TABLELOG_MAX + 1), sizeof(U32)) >> 2;
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if ((spaceUsed32 << 2) > workspaceSize)
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return ERROR(tableLog_tooLarge);
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workspace = (U32 *)workspace + spaceUsed32;
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workspaceSize -= (spaceUsed32 << 2);
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/* init conditions */
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if (wtSize <= 1)
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return 0; /* Not compressible */
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/* Scan input and build symbol stats */
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{
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CHECK_V_F(maxCount, FSE_count_simple(count, &maxSymbolValue, weightTable, wtSize));
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if (maxCount == wtSize)
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return 1; /* only a single symbol in src : rle */
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if (maxCount == 1)
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return 0; /* each symbol present maximum once => not compressible */
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}
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tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
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CHECK_F(FSE_normalizeCount(norm, tableLog, count, wtSize, maxSymbolValue));
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/* Write table description header */
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{
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CHECK_V_F(hSize, FSE_writeNCount(op, oend - op, norm, maxSymbolValue, tableLog));
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op += hSize;
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}
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/* Compress */
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CHECK_F(FSE_buildCTable_wksp(CTable, norm, maxSymbolValue, tableLog, workspace, workspaceSize));
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{
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CHECK_V_F(cSize, FSE_compress_usingCTable(op, oend - op, weightTable, wtSize, CTable));
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if (cSize == 0)
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return 0; /* not enough space for compressed data */
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op += cSize;
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}
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return op - ostart;
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}
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struct HUF_CElt_s {
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U16 val;
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BYTE nbBits;
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}; /* typedef'd to HUF_CElt within "huf.h" */
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/*! HUF_writeCTable_wksp() :
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`CTable` : Huffman tree to save, using huf representation.
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@return : size of saved CTable */
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size_t HUF_writeCTable_wksp(void *dst, size_t maxDstSize, const HUF_CElt *CTable, U32 maxSymbolValue, U32 huffLog, void *workspace, size_t workspaceSize)
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{
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BYTE *op = (BYTE *)dst;
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U32 n;
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BYTE *bitsToWeight;
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BYTE *huffWeight;
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size_t spaceUsed32 = 0;
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bitsToWeight = (BYTE *)((U32 *)workspace + spaceUsed32);
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spaceUsed32 += ALIGN(HUF_TABLELOG_MAX + 1, sizeof(U32)) >> 2;
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huffWeight = (BYTE *)((U32 *)workspace + spaceUsed32);
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spaceUsed32 += ALIGN(HUF_SYMBOLVALUE_MAX, sizeof(U32)) >> 2;
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if ((spaceUsed32 << 2) > workspaceSize)
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return ERROR(tableLog_tooLarge);
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workspace = (U32 *)workspace + spaceUsed32;
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workspaceSize -= (spaceUsed32 << 2);
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/* check conditions */
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if (maxSymbolValue > HUF_SYMBOLVALUE_MAX)
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return ERROR(maxSymbolValue_tooLarge);
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/* convert to weight */
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bitsToWeight[0] = 0;
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for (n = 1; n < huffLog + 1; n++)
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bitsToWeight[n] = (BYTE)(huffLog + 1 - n);
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for (n = 0; n < maxSymbolValue; n++)
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huffWeight[n] = bitsToWeight[CTable[n].nbBits];
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/* attempt weights compression by FSE */
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{
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CHECK_V_F(hSize, HUF_compressWeights_wksp(op + 1, maxDstSize - 1, huffWeight, maxSymbolValue, workspace, workspaceSize));
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if ((hSize > 1) & (hSize < maxSymbolValue / 2)) { /* FSE compressed */
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op[0] = (BYTE)hSize;
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return hSize + 1;
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}
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}
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/* write raw values as 4-bits (max : 15) */
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if (maxSymbolValue > (256 - 128))
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return ERROR(GENERIC); /* should not happen : likely means source cannot be compressed */
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if (((maxSymbolValue + 1) / 2) + 1 > maxDstSize)
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return ERROR(dstSize_tooSmall); /* not enough space within dst buffer */
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op[0] = (BYTE)(128 /*special case*/ + (maxSymbolValue - 1));
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huffWeight[maxSymbolValue] = 0; /* to be sure it doesn't cause msan issue in final combination */
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for (n = 0; n < maxSymbolValue; n += 2)
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op[(n / 2) + 1] = (BYTE)((huffWeight[n] << 4) + huffWeight[n + 1]);
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return ((maxSymbolValue + 1) / 2) + 1;
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}
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size_t HUF_readCTable_wksp(HUF_CElt *CTable, U32 maxSymbolValue, const void *src, size_t srcSize, void *workspace, size_t workspaceSize)
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{
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U32 *rankVal;
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BYTE *huffWeight;
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U32 tableLog = 0;
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U32 nbSymbols = 0;
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size_t readSize;
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size_t spaceUsed32 = 0;
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rankVal = (U32 *)workspace + spaceUsed32;
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spaceUsed32 += HUF_TABLELOG_ABSOLUTEMAX + 1;
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huffWeight = (BYTE *)((U32 *)workspace + spaceUsed32);
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spaceUsed32 += ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
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if ((spaceUsed32 << 2) > workspaceSize)
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return ERROR(tableLog_tooLarge);
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workspace = (U32 *)workspace + spaceUsed32;
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workspaceSize -= (spaceUsed32 << 2);
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/* get symbol weights */
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readSize = HUF_readStats_wksp(huffWeight, HUF_SYMBOLVALUE_MAX + 1, rankVal, &nbSymbols, &tableLog, src, srcSize, workspace, workspaceSize);
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if (ERR_isError(readSize))
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return readSize;
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/* check result */
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if (tableLog > HUF_TABLELOG_MAX)
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return ERROR(tableLog_tooLarge);
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if (nbSymbols > maxSymbolValue + 1)
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return ERROR(maxSymbolValue_tooSmall);
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/* Prepare base value per rank */
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{
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U32 n, nextRankStart = 0;
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for (n = 1; n <= tableLog; n++) {
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U32 curr = nextRankStart;
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nextRankStart += (rankVal[n] << (n - 1));
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rankVal[n] = curr;
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}
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}
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/* fill nbBits */
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{
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U32 n;
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for (n = 0; n < nbSymbols; n++) {
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const U32 w = huffWeight[n];
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CTable[n].nbBits = (BYTE)(tableLog + 1 - w);
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}
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}
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/* fill val */
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{
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U16 nbPerRank[HUF_TABLELOG_MAX + 2] = {0}; /* support w=0=>n=tableLog+1 */
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U16 valPerRank[HUF_TABLELOG_MAX + 2] = {0};
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{
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U32 n;
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for (n = 0; n < nbSymbols; n++)
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nbPerRank[CTable[n].nbBits]++;
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}
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/* determine stating value per rank */
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valPerRank[tableLog + 1] = 0; /* for w==0 */
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{
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U16 min = 0;
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U32 n;
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for (n = tableLog; n > 0; n--) { /* start at n=tablelog <-> w=1 */
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valPerRank[n] = min; /* get starting value within each rank */
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min += nbPerRank[n];
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min >>= 1;
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}
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}
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/* assign value within rank, symbol order */
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{
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U32 n;
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for (n = 0; n <= maxSymbolValue; n++)
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CTable[n].val = valPerRank[CTable[n].nbBits]++;
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}
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}
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return readSize;
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}
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typedef struct nodeElt_s {
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U32 count;
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U16 parent;
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BYTE byte;
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BYTE nbBits;
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} nodeElt;
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static U32 HUF_setMaxHeight(nodeElt *huffNode, U32 lastNonNull, U32 maxNbBits)
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{
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const U32 largestBits = huffNode[lastNonNull].nbBits;
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if (largestBits <= maxNbBits)
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return largestBits; /* early exit : no elt > maxNbBits */
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/* there are several too large elements (at least >= 2) */
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{
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int totalCost = 0;
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const U32 baseCost = 1 << (largestBits - maxNbBits);
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U32 n = lastNonNull;
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while (huffNode[n].nbBits > maxNbBits) {
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totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits));
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huffNode[n].nbBits = (BYTE)maxNbBits;
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n--;
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} /* n stops at huffNode[n].nbBits <= maxNbBits */
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while (huffNode[n].nbBits == maxNbBits)
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n--; /* n end at index of smallest symbol using < maxNbBits */
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/* renorm totalCost */
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totalCost >>= (largestBits - maxNbBits); /* note : totalCost is necessarily a multiple of baseCost */
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/* repay normalized cost */
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{
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U32 const noSymbol = 0xF0F0F0F0;
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U32 rankLast[HUF_TABLELOG_MAX + 2];
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int pos;
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/* Get pos of last (smallest) symbol per rank */
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memset(rankLast, 0xF0, sizeof(rankLast));
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{
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U32 currNbBits = maxNbBits;
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for (pos = n; pos >= 0; pos--) {
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if (huffNode[pos].nbBits >= currNbBits)
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continue;
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currNbBits = huffNode[pos].nbBits; /* < maxNbBits */
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rankLast[maxNbBits - currNbBits] = pos;
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}
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}
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while (totalCost > 0) {
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U32 nBitsToDecrease = BIT_highbit32(totalCost) + 1;
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for (; nBitsToDecrease > 1; nBitsToDecrease--) {
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U32 highPos = rankLast[nBitsToDecrease];
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U32 lowPos = rankLast[nBitsToDecrease - 1];
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if (highPos == noSymbol)
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continue;
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if (lowPos == noSymbol)
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break;
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{
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U32 const highTotal = huffNode[highPos].count;
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U32 const lowTotal = 2 * huffNode[lowPos].count;
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if (highTotal <= lowTotal)
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break;
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}
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}
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/* only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) */
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/* HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary */
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while ((nBitsToDecrease <= HUF_TABLELOG_MAX) && (rankLast[nBitsToDecrease] == noSymbol))
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nBitsToDecrease++;
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totalCost -= 1 << (nBitsToDecrease - 1);
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if (rankLast[nBitsToDecrease - 1] == noSymbol)
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rankLast[nBitsToDecrease - 1] = rankLast[nBitsToDecrease]; /* this rank is no longer empty */
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huffNode[rankLast[nBitsToDecrease]].nbBits++;
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if (rankLast[nBitsToDecrease] == 0) /* special case, reached largest symbol */
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rankLast[nBitsToDecrease] = noSymbol;
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else {
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rankLast[nBitsToDecrease]--;
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if (huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits - nBitsToDecrease)
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rankLast[nBitsToDecrease] = noSymbol; /* this rank is now empty */
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}
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} /* while (totalCost > 0) */
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while (totalCost < 0) { /* Sometimes, cost correction overshoot */
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if (rankLast[1] == noSymbol) { /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0
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(using maxNbBits) */
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while (huffNode[n].nbBits == maxNbBits)
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n--;
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huffNode[n + 1].nbBits--;
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rankLast[1] = n + 1;
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totalCost++;
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continue;
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}
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huffNode[rankLast[1] + 1].nbBits--;
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rankLast[1]++;
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totalCost++;
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}
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}
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} /* there are several too large elements (at least >= 2) */
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return maxNbBits;
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}
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typedef struct {
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U32 base;
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U32 curr;
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} rankPos;
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static void HUF_sort(nodeElt *huffNode, const U32 *count, U32 maxSymbolValue)
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{
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rankPos rank[32];
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U32 n;
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memset(rank, 0, sizeof(rank));
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for (n = 0; n <= maxSymbolValue; n++) {
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U32 r = BIT_highbit32(count[n] + 1);
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rank[r].base++;
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}
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for (n = 30; n > 0; n--)
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rank[n - 1].base += rank[n].base;
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for (n = 0; n < 32; n++)
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rank[n].curr = rank[n].base;
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for (n = 0; n <= maxSymbolValue; n++) {
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U32 const c = count[n];
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U32 const r = BIT_highbit32(c + 1) + 1;
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U32 pos = rank[r].curr++;
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while ((pos > rank[r].base) && (c > huffNode[pos - 1].count))
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huffNode[pos] = huffNode[pos - 1], pos--;
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huffNode[pos].count = c;
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huffNode[pos].byte = (BYTE)n;
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}
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}
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/** HUF_buildCTable_wksp() :
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* Same as HUF_buildCTable(), but using externally allocated scratch buffer.
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* `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as a table of 1024 unsigned.
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*/
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#define STARTNODE (HUF_SYMBOLVALUE_MAX + 1)
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typedef nodeElt huffNodeTable[2 * HUF_SYMBOLVALUE_MAX + 1 + 1];
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size_t HUF_buildCTable_wksp(HUF_CElt *tree, const U32 *count, U32 maxSymbolValue, U32 maxNbBits, void *workSpace, size_t wkspSize)
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{
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nodeElt *const huffNode0 = (nodeElt *)workSpace;
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nodeElt *const huffNode = huffNode0 + 1;
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U32 n, nonNullRank;
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int lowS, lowN;
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U16 nodeNb = STARTNODE;
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U32 nodeRoot;
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/* safety checks */
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if (wkspSize < sizeof(huffNodeTable))
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return ERROR(GENERIC); /* workSpace is not large enough */
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if (maxNbBits == 0)
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maxNbBits = HUF_TABLELOG_DEFAULT;
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if (maxSymbolValue > HUF_SYMBOLVALUE_MAX)
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return ERROR(GENERIC);
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memset(huffNode0, 0, sizeof(huffNodeTable));
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/* sort, decreasing order */
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HUF_sort(huffNode, count, maxSymbolValue);
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/* init for parents */
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nonNullRank = maxSymbolValue;
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while (huffNode[nonNullRank].count == 0)
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nonNullRank--;
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lowS = nonNullRank;
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nodeRoot = nodeNb + lowS - 1;
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lowN = nodeNb;
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huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS - 1].count;
|
|
huffNode[lowS].parent = huffNode[lowS - 1].parent = nodeNb;
|
|
nodeNb++;
|
|
lowS -= 2;
|
|
for (n = nodeNb; n <= nodeRoot; n++)
|
|
huffNode[n].count = (U32)(1U << 30);
|
|
huffNode0[0].count = (U32)(1U << 31); /* fake entry, strong barrier */
|
|
|
|
/* create parents */
|
|
while (nodeNb <= nodeRoot) {
|
|
U32 n1 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
|
|
U32 n2 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
|
|
huffNode[nodeNb].count = huffNode[n1].count + huffNode[n2].count;
|
|
huffNode[n1].parent = huffNode[n2].parent = nodeNb;
|
|
nodeNb++;
|
|
}
|
|
|
|
/* distribute weights (unlimited tree height) */
|
|
huffNode[nodeRoot].nbBits = 0;
|
|
for (n = nodeRoot - 1; n >= STARTNODE; n--)
|
|
huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1;
|
|
for (n = 0; n <= nonNullRank; n++)
|
|
huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1;
|
|
|
|
/* enforce maxTableLog */
|
|
maxNbBits = HUF_setMaxHeight(huffNode, nonNullRank, maxNbBits);
|
|
|
|
/* fill result into tree (val, nbBits) */
|
|
{
|
|
U16 nbPerRank[HUF_TABLELOG_MAX + 1] = {0};
|
|
U16 valPerRank[HUF_TABLELOG_MAX + 1] = {0};
|
|
if (maxNbBits > HUF_TABLELOG_MAX)
|
|
return ERROR(GENERIC); /* check fit into table */
|
|
for (n = 0; n <= nonNullRank; n++)
|
|
nbPerRank[huffNode[n].nbBits]++;
|
|
/* determine stating value per rank */
|
|
{
|
|
U16 min = 0;
|
|
for (n = maxNbBits; n > 0; n--) {
|
|
valPerRank[n] = min; /* get starting value within each rank */
|
|
min += nbPerRank[n];
|
|
min >>= 1;
|
|
}
|
|
}
|
|
for (n = 0; n <= maxSymbolValue; n++)
|
|
tree[huffNode[n].byte].nbBits = huffNode[n].nbBits; /* push nbBits per symbol, symbol order */
|
|
for (n = 0; n <= maxSymbolValue; n++)
|
|
tree[n].val = valPerRank[tree[n].nbBits]++; /* assign value within rank, symbol order */
|
|
}
|
|
|
|
return maxNbBits;
|
|
}
|
|
|
|
static size_t HUF_estimateCompressedSize(HUF_CElt *CTable, const unsigned *count, unsigned maxSymbolValue)
|
|
{
|
|
size_t nbBits = 0;
|
|
int s;
|
|
for (s = 0; s <= (int)maxSymbolValue; ++s) {
|
|
nbBits += CTable[s].nbBits * count[s];
|
|
}
|
|
return nbBits >> 3;
|
|
}
|
|
|
|
static int HUF_validateCTable(const HUF_CElt *CTable, const unsigned *count, unsigned maxSymbolValue)
|
|
{
|
|
int bad = 0;
|
|
int s;
|
|
for (s = 0; s <= (int)maxSymbolValue; ++s) {
|
|
bad |= (count[s] != 0) & (CTable[s].nbBits == 0);
|
|
}
|
|
return !bad;
|
|
}
|
|
|
|
static void HUF_encodeSymbol(BIT_CStream_t *bitCPtr, U32 symbol, const HUF_CElt *CTable)
|
|
{
|
|
BIT_addBitsFast(bitCPtr, CTable[symbol].val, CTable[symbol].nbBits);
|
|
}
|
|
|
|
size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
|
|
|
|
#define HUF_FLUSHBITS(s) BIT_flushBits(s)
|
|
|
|
#define HUF_FLUSHBITS_1(stream) \
|
|
if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 2 + 7) \
|
|
HUF_FLUSHBITS(stream)
|
|
|
|
#define HUF_FLUSHBITS_2(stream) \
|
|
if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 4 + 7) \
|
|
HUF_FLUSHBITS(stream)
|
|
|
|
size_t HUF_compress1X_usingCTable(void *dst, size_t dstSize, const void *src, size_t srcSize, const HUF_CElt *CTable)
|
|
{
|
|
const BYTE *ip = (const BYTE *)src;
|
|
BYTE *const ostart = (BYTE *)dst;
|
|
BYTE *const oend = ostart + dstSize;
|
|
BYTE *op = ostart;
|
|
size_t n;
|
|
BIT_CStream_t bitC;
|
|
|
|
/* init */
|
|
if (dstSize < 8)
|
|
return 0; /* not enough space to compress */
|
|
{
|
|
size_t const initErr = BIT_initCStream(&bitC, op, oend - op);
|
|
if (HUF_isError(initErr))
|
|
return 0;
|
|
}
|
|
|
|
n = srcSize & ~3; /* join to mod 4 */
|
|
switch (srcSize & 3) {
|
|
case 3: HUF_encodeSymbol(&bitC, ip[n + 2], CTable); HUF_FLUSHBITS_2(&bitC);
|
|
fallthrough;
|
|
case 2: HUF_encodeSymbol(&bitC, ip[n + 1], CTable); HUF_FLUSHBITS_1(&bitC);
|
|
fallthrough;
|
|
case 1: HUF_encodeSymbol(&bitC, ip[n + 0], CTable); HUF_FLUSHBITS(&bitC);
|
|
fallthrough;
|
|
case 0:
|
|
default:;
|
|
}
|
|
|
|
for (; n > 0; n -= 4) { /* note : n&3==0 at this stage */
|
|
HUF_encodeSymbol(&bitC, ip[n - 1], CTable);
|
|
HUF_FLUSHBITS_1(&bitC);
|
|
HUF_encodeSymbol(&bitC, ip[n - 2], CTable);
|
|
HUF_FLUSHBITS_2(&bitC);
|
|
HUF_encodeSymbol(&bitC, ip[n - 3], CTable);
|
|
HUF_FLUSHBITS_1(&bitC);
|
|
HUF_encodeSymbol(&bitC, ip[n - 4], CTable);
|
|
HUF_FLUSHBITS(&bitC);
|
|
}
|
|
|
|
return BIT_closeCStream(&bitC);
|
|
}
|
|
|
|
size_t HUF_compress4X_usingCTable(void *dst, size_t dstSize, const void *src, size_t srcSize, const HUF_CElt *CTable)
|
|
{
|
|
size_t const segmentSize = (srcSize + 3) / 4; /* first 3 segments */
|
|
const BYTE *ip = (const BYTE *)src;
|
|
const BYTE *const iend = ip + srcSize;
|
|
BYTE *const ostart = (BYTE *)dst;
|
|
BYTE *const oend = ostart + dstSize;
|
|
BYTE *op = ostart;
|
|
|
|
if (dstSize < 6 + 1 + 1 + 1 + 8)
|
|
return 0; /* minimum space to compress successfully */
|
|
if (srcSize < 12)
|
|
return 0; /* no saving possible : too small input */
|
|
op += 6; /* jumpTable */
|
|
|
|
{
|
|
CHECK_V_F(cSize, HUF_compress1X_usingCTable(op, oend - op, ip, segmentSize, CTable));
|
|
if (cSize == 0)
|
|
return 0;
|
|
ZSTD_writeLE16(ostart, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
{
|
|
CHECK_V_F(cSize, HUF_compress1X_usingCTable(op, oend - op, ip, segmentSize, CTable));
|
|
if (cSize == 0)
|
|
return 0;
|
|
ZSTD_writeLE16(ostart + 2, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
{
|
|
CHECK_V_F(cSize, HUF_compress1X_usingCTable(op, oend - op, ip, segmentSize, CTable));
|
|
if (cSize == 0)
|
|
return 0;
|
|
ZSTD_writeLE16(ostart + 4, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
{
|
|
CHECK_V_F(cSize, HUF_compress1X_usingCTable(op, oend - op, ip, iend - ip, CTable));
|
|
if (cSize == 0)
|
|
return 0;
|
|
op += cSize;
|
|
}
|
|
|
|
return op - ostart;
|
|
}
|
|
|
|
static size_t HUF_compressCTable_internal(BYTE *const ostart, BYTE *op, BYTE *const oend, const void *src, size_t srcSize, unsigned singleStream,
|
|
const HUF_CElt *CTable)
|
|
{
|
|
size_t const cSize =
|
|
singleStream ? HUF_compress1X_usingCTable(op, oend - op, src, srcSize, CTable) : HUF_compress4X_usingCTable(op, oend - op, src, srcSize, CTable);
|
|
if (HUF_isError(cSize)) {
|
|
return cSize;
|
|
}
|
|
if (cSize == 0) {
|
|
return 0;
|
|
} /* uncompressible */
|
|
op += cSize;
|
|
/* check compressibility */
|
|
if ((size_t)(op - ostart) >= srcSize - 1) {
|
|
return 0;
|
|
}
|
|
return op - ostart;
|
|
}
|
|
|
|
/* `workSpace` must a table of at least 1024 unsigned */
|
|
static size_t HUF_compress_internal(void *dst, size_t dstSize, const void *src, size_t srcSize, unsigned maxSymbolValue, unsigned huffLog,
|
|
unsigned singleStream, void *workSpace, size_t wkspSize, HUF_CElt *oldHufTable, HUF_repeat *repeat, int preferRepeat)
|
|
{
|
|
BYTE *const ostart = (BYTE *)dst;
|
|
BYTE *const oend = ostart + dstSize;
|
|
BYTE *op = ostart;
|
|
|
|
U32 *count;
|
|
size_t const countSize = sizeof(U32) * (HUF_SYMBOLVALUE_MAX + 1);
|
|
HUF_CElt *CTable;
|
|
size_t const CTableSize = sizeof(HUF_CElt) * (HUF_SYMBOLVALUE_MAX + 1);
|
|
|
|
/* checks & inits */
|
|
if (wkspSize < sizeof(huffNodeTable) + countSize + CTableSize)
|
|
return ERROR(GENERIC);
|
|
if (!srcSize)
|
|
return 0; /* Uncompressed (note : 1 means rle, so first byte must be correct) */
|
|
if (!dstSize)
|
|
return 0; /* cannot fit within dst budget */
|
|
if (srcSize > HUF_BLOCKSIZE_MAX)
|
|
return ERROR(srcSize_wrong); /* curr block size limit */
|
|
if (huffLog > HUF_TABLELOG_MAX)
|
|
return ERROR(tableLog_tooLarge);
|
|
if (!maxSymbolValue)
|
|
maxSymbolValue = HUF_SYMBOLVALUE_MAX;
|
|
if (!huffLog)
|
|
huffLog = HUF_TABLELOG_DEFAULT;
|
|
|
|
count = (U32 *)workSpace;
|
|
workSpace = (BYTE *)workSpace + countSize;
|
|
wkspSize -= countSize;
|
|
CTable = (HUF_CElt *)workSpace;
|
|
workSpace = (BYTE *)workSpace + CTableSize;
|
|
wkspSize -= CTableSize;
|
|
|
|
/* Heuristic : If we don't need to check the validity of the old table use the old table for small inputs */
|
|
if (preferRepeat && repeat && *repeat == HUF_repeat_valid) {
|
|
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable);
|
|
}
|
|
|
|
/* Scan input and build symbol stats */
|
|
{
|
|
CHECK_V_F(largest, FSE_count_wksp(count, &maxSymbolValue, (const BYTE *)src, srcSize, (U32 *)workSpace));
|
|
if (largest == srcSize) {
|
|
*ostart = ((const BYTE *)src)[0];
|
|
return 1;
|
|
} /* single symbol, rle */
|
|
if (largest <= (srcSize >> 7) + 1)
|
|
return 0; /* Fast heuristic : not compressible enough */
|
|
}
|
|
|
|
/* Check validity of previous table */
|
|
if (repeat && *repeat == HUF_repeat_check && !HUF_validateCTable(oldHufTable, count, maxSymbolValue)) {
|
|
*repeat = HUF_repeat_none;
|
|
}
|
|
/* Heuristic : use existing table for small inputs */
|
|
if (preferRepeat && repeat && *repeat != HUF_repeat_none) {
|
|
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable);
|
|
}
|
|
|
|
/* Build Huffman Tree */
|
|
huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
|
|
{
|
|
CHECK_V_F(maxBits, HUF_buildCTable_wksp(CTable, count, maxSymbolValue, huffLog, workSpace, wkspSize));
|
|
huffLog = (U32)maxBits;
|
|
/* Zero the unused symbols so we can check it for validity */
|
|
memset(CTable + maxSymbolValue + 1, 0, CTableSize - (maxSymbolValue + 1) * sizeof(HUF_CElt));
|
|
}
|
|
|
|
/* Write table description header */
|
|
{
|
|
CHECK_V_F(hSize, HUF_writeCTable_wksp(op, dstSize, CTable, maxSymbolValue, huffLog, workSpace, wkspSize));
|
|
/* Check if using the previous table will be beneficial */
|
|
if (repeat && *repeat != HUF_repeat_none) {
|
|
size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, count, maxSymbolValue);
|
|
size_t const newSize = HUF_estimateCompressedSize(CTable, count, maxSymbolValue);
|
|
if (oldSize <= hSize + newSize || hSize + 12 >= srcSize) {
|
|
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable);
|
|
}
|
|
}
|
|
/* Use the new table */
|
|
if (hSize + 12ul >= srcSize) {
|
|
return 0;
|
|
}
|
|
op += hSize;
|
|
if (repeat) {
|
|
*repeat = HUF_repeat_none;
|
|
}
|
|
if (oldHufTable) {
|
|
memcpy(oldHufTable, CTable, CTableSize);
|
|
} /* Save the new table */
|
|
}
|
|
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, CTable);
|
|
}
|
|
|
|
size_t HUF_compress1X_wksp(void *dst, size_t dstSize, const void *src, size_t srcSize, unsigned maxSymbolValue, unsigned huffLog, void *workSpace,
|
|
size_t wkspSize)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 1 /* single stream */, workSpace, wkspSize, NULL, NULL, 0);
|
|
}
|
|
|
|
size_t HUF_compress1X_repeat(void *dst, size_t dstSize, const void *src, size_t srcSize, unsigned maxSymbolValue, unsigned huffLog, void *workSpace,
|
|
size_t wkspSize, HUF_CElt *hufTable, HUF_repeat *repeat, int preferRepeat)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 1 /* single stream */, workSpace, wkspSize, hufTable, repeat,
|
|
preferRepeat);
|
|
}
|
|
|
|
size_t HUF_compress4X_wksp(void *dst, size_t dstSize, const void *src, size_t srcSize, unsigned maxSymbolValue, unsigned huffLog, void *workSpace,
|
|
size_t wkspSize)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 0 /* 4 streams */, workSpace, wkspSize, NULL, NULL, 0);
|
|
}
|
|
|
|
size_t HUF_compress4X_repeat(void *dst, size_t dstSize, const void *src, size_t srcSize, unsigned maxSymbolValue, unsigned huffLog, void *workSpace,
|
|
size_t wkspSize, HUF_CElt *hufTable, HUF_repeat *repeat, int preferRepeat)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 0 /* 4 streams */, workSpace, wkspSize, hufTable, repeat,
|
|
preferRepeat);
|
|
}
|