| 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <string.h> |
| 4 | |
| 5 | #include "tweak.h" |
| 6 | |
| 7 | static DFA dfa = NULL; |
| 8 | static char *tmp = NULL; |
| 9 | static int dfa_size = 0, dfa_len = 0; |
| 10 | |
| 11 | DFA build_dfa (char *pattern, int len) { |
| 12 | int i, j, k, b; |
| 13 | |
| 14 | if (dfa_size < len) { |
| 15 | dfa_size = len; |
| 16 | dfa = (dfa ? realloc(dfa, dfa_size * sizeof(*dfa)) : |
| 17 | malloc(dfa_size * sizeof(*dfa))); |
| 18 | if (!dfa) |
| 19 | return NULL; |
| 20 | tmp = (tmp ? realloc(tmp, dfa_size) : malloc(dfa_size)); |
| 21 | if (!tmp) |
| 22 | return NULL; |
| 23 | } |
| 24 | |
| 25 | memcpy (tmp, pattern, len); |
| 26 | |
| 27 | for (i=len; i-- ;) { |
| 28 | j = i+1; |
| 29 | for (b=0; b<256; b++) { |
| 30 | dfa[i][b] = 0; |
| 31 | if (memchr(pattern, b, len)) { |
| 32 | tmp[j-1] = b; |
| 33 | for (k=1; k<=j; k++) |
| 34 | if (!memcmp(tmp+j-k, pattern, k)) |
| 35 | dfa[i][b] = k; |
| 36 | } |
| 37 | } |
| 38 | } |
| 39 | dfa_len = len; |
| 40 | return dfa; |
| 41 | } |
| 42 | |
| 43 | DFA last_dfa (void) { |
| 44 | return dfa; |
| 45 | } |
| 46 | |
| 47 | int last_len (void) { |
| 48 | return dfa_len; |
| 49 | } |