57 lines
2.1 KiB
C
57 lines
2.1 KiB
C
/*
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* This file is part of Luma3DS
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* Copyright (C) 2016-2020 Aurora Wright, TuxSH
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Additional Terms 7.b and 7.c of GPLv3 apply to this file:
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* * Requiring preservation of specified reasonable legal notices or
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* author attributions in that material or in the Appropriate Legal
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* Notices displayed by works containing it.
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* * Prohibiting misrepresentation of the origin of that material,
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* or requiring that modified versions of such material be marked in
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* reasonable ways as different from the original version.
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*/
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/*
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* Boyer-Moore Horspool algorithm adapted from http://www-igm.univ-mlv.fr/~lecroq/string/node18.html#SECTION00180
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* memcpy, memset and memcmp adapted from https://github.com/mid-kid/CakesForeveryWan/blob/557a8e8605ab3ee173af6497486e8f22c261d0e2/source/memfuncs.c
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*/
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#include "memory.h"
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u8 *memsearch(u8 *startPos, const void *pattern, u32 size, u32 patternSize)
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{
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const u8 *patternc = (const u8 *)pattern;
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u32 table[256];
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//Preprocessing
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for(u32 i = 0; i < 256; i++)
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table[i] = patternSize;
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for(u32 i = 0; i < patternSize - 1; i++)
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table[patternc[i]] = patternSize - i - 1;
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//Searching
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u32 j = 0;
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while(j <= size - patternSize)
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{
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u8 c = startPos[j + patternSize - 1];
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if(patternc[patternSize - 1] == c && memcmp(pattern, startPos + j, patternSize - 1) == 0)
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return startPos + j;
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j += table[c];
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}
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return NULL;
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}
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