49 lines
1.2 KiB
C
49 lines
1.2 KiB
C
#include "memory.h"
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void memcpy(void *dest, const void *src, u32 size)
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{
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u8 *destc = (u8 *)dest;
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const u8 *srcc = (const u8 *)src;
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for(u32 i = 0; i < size; i++)
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destc[i] = srcc[i];
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}
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int memcmp(const void *buf1, const void *buf2, u32 size)
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{
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const u8 *buf1c = (const u8 *)buf1,
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*buf2c = (const u8 *)buf2;
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for(u32 i = 0; i < size; i++)
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{
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int cmp = buf1c[i] - buf2c[i];
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if(cmp != 0) return cmp;
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}
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return 0;
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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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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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} |