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| Source at commit 1158 created 13 years 16 days ago. By azimutz, Match nvidia.c with the one on my branch (Chazi) adding dev id's from issue 99 and Asus G74SX (0DF4, 1251). | |
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| 1 | /*␊ |
| 2 | * memmem.c␊ |
| 3 | *␊ |
| 4 | * Find a byte string inside a longer byte string␊ |
| 5 | *␊ |
| 6 | * This uses the "Not So Naive" algorithm, a very simple but␊ |
| 7 | * usually effective algorithm, see:␊ |
| 8 | *␊ |
| 9 | * http://www-igm.univ-mlv.fr/~lecroq/string/␊ |
| 10 | */␊ |
| 11 | ␊ |
| 12 | #include <string.h>␊ |
| 13 | ␊ |
| 14 | void *memmem(const void *haystack, size_t n, const void *needle, size_t m)␊ |
| 15 | {␊ |
| 16 | ␉const unsigned char *y = (const unsigned char *)haystack;␊ |
| 17 | ␉const unsigned char *x = (const unsigned char *)needle;␊ |
| 18 | ␊ |
| 19 | ␉size_t j, k, l;␊ |
| 20 | ␊ |
| 21 | ␉if (m > n || !m || !n)␊ |
| 22 | ␉␉return NULL;␊ |
| 23 | ␊ |
| 24 | ␉if (1 != m) {␊ |
| 25 | ␉␉if (x[0] == x[1]) {␊ |
| 26 | ␉␉␉k = 2;␊ |
| 27 | ␉␉␉l = 1;␊ |
| 28 | ␉␉} else {␊ |
| 29 | ␉␉␉k = 1;␊ |
| 30 | ␉␉␉l = 2;␊ |
| 31 | ␉␉}␊ |
| 32 | ␊ |
| 33 | ␉␉j = 0;␊ |
| 34 | ␉␉while (j <= n - m) {␊ |
| 35 | ␉␉␉if (x[1] != y[j + 1]) {␊ |
| 36 | ␉␉␉␉j += k;␊ |
| 37 | ␉␉␉} else {␊ |
| 38 | ␉␉␉␉if (!memcmp(x + 2, y + j + 2, m - 2)␊ |
| 39 | ␉␉␉␉ && x[0] == y[j])␊ |
| 40 | ␉␉␉␉␉return (void *)&y[j];␊ |
| 41 | ␉␉␉␉j += l;␊ |
| 42 | ␉␉␉}␊ |
| 43 | ␉␉}␊ |
| 44 | ␉} else␊ |
| 45 | ␉␉do {␊ |
| 46 | ␉␉␉if (*y == *x)␊ |
| 47 | ␉␉␉␉return (void *)y;␊ |
| 48 | ␉␉␉y++;␊ |
| 49 | ␉␉} while (--n);␊ |
| 50 | ␊ |
| 51 | ␉return NULL;␊ |
| 52 | }␊ |
| 53 | |
