| 1 | #include "../git-compat-util.h" |
| 2 | |
| 3 | void *gitmemmem(const void *haystack, size_t haystack_len, |
| 4 | const void *needle, size_t needle_len) |
| 5 | { |
| 6 | const char *begin = haystack; |
| 7 | const char *last_possible = begin + haystack_len - needle_len; |
| 8 | const char *tail = needle; |
| 9 | char point; |
| 10 | |
| 11 | /* |
| 12 | * The first occurrence of the empty string is deemed to occur at |
| 13 | * the beginning of the string. |
| 14 | */ |
| 15 | if (needle_len == 0) |
| 16 | return (void *)begin; |
| 17 | |
| 18 | /* |
| 19 | * Sanity check, otherwise the loop might search through the whole |
| 20 | * memory. |
| 21 | */ |
| 22 | if (haystack_len < needle_len) |
| 23 | return NULL; |
| 24 | |
| 25 | point = *tail++; |
| 26 | for (; begin <= last_possible; begin++) { |
| 27 | if (*begin == point && !memcmp(begin + 1, tail, needle_len - 1)) |
| 28 | return (void *)begin; |
| 29 | } |
| 30 | |
| 31 | return NULL; |
| 32 | } |