| 1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\ |
| 2 | * This is GNU Go, a Go program. Contact gnugo@gnu.org, or see * |
| 3 | * http://www.gnu.org/software/gnugo/ for more information. * |
| 4 | * * |
| 5 | * Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, * |
| 6 | * 2008 and 2009 by the Free Software Foundation. * |
| 7 | * * |
| 8 | * This program is free software; you can redistribute it and/or * |
| 9 | * modify it under the terms of the GNU General Public License as * |
| 10 | * published by the Free Software Foundation - version 3 or * |
| 11 | * (at your option) any later version. * |
| 12 | * * |
| 13 | * This program is distributed in the hope that it will be useful, * |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
| 16 | * GNU General Public License in file COPYING for more details. * |
| 17 | * * |
| 18 | * You should have received a copy of the GNU General Public * |
| 19 | * License along with this program; if not, write to the Free * |
| 20 | * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * |
| 21 | * Boston, MA 02111, USA. * |
| 22 | \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
| 23 | |
| 24 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
| 25 | * * * * * * * * fast pattern matching with DFA version 2.9 * * * |
| 26 | * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
| 27 | |
| 28 | #include "liberty.h" |
| 29 | #include "patterns.h" |
| 30 | #include "dfa-mkpat.h" |
| 31 | #include "random.h" |
| 32 | |
| 33 | #include <assert.h> |
| 34 | #include <stdlib.h> |
| 35 | |
| 36 | #ifdef HAVE_CONFIG_H |
| 37 | #include <config.h> |
| 38 | #endif |
| 39 | |
| 40 | #ifdef HAVE_UNISTD_H |
| 41 | #include <unistd.h> |
| 42 | #endif |
| 43 | |
| 44 | |
| 45 | /********************* |
| 46 | * Public data * |
| 47 | *********************/ |
| 48 | |
| 49 | /* If > 0 more detailed information is given */ |
| 50 | int dfa_verbose = 0; |
| 51 | |
| 52 | |
| 53 | /********************* |
| 54 | * Private data * |
| 55 | *********************/ |
| 56 | |
| 57 | /* auxiliary dfa's for high level functions */ |
| 58 | #define DFA_BINS 33 /* Number of temporary bins used to store intermediate DFAs */ |
| 59 | static dfa_t aux_dfa[DFA_BINS]; /* used to store intermediate DFAs */ |
| 60 | static dfa_t aux_temp; /* used to store temporary DFAs */ |
| 61 | |
| 62 | /* To be sure that everything was well initialized */ |
| 63 | static int dfa_was_initialized = 0; |
| 64 | static int aux_count = 0; |
| 65 | |
| 66 | |
| 67 | /* convert ATT_* values to the corresponding expected values on the board */ |
| 68 | static const char att2val[8] = { |
| 69 | '.', 'X', 'O', 'x', 'o', ',', 'a', '!' |
| 70 | }; |
| 71 | |
| 72 | #define EXPECTED_VAL(att_val) att2val[att_val] |
| 73 | |
| 74 | |
| 75 | /************************************************ |
| 76 | * forward declaration of private functions * |
| 77 | ************************************************/ |
| 78 | static void clean_dfa(dfa_t *pdfa); |
| 79 | static void resize_dfa(dfa_t *pdfa, int max_states, int max_indexes); |
| 80 | static void create_dfa(dfa_t *pdfa, const char *str, int att_val); |
| 81 | static void do_sync_product(int l, int r); |
| 82 | static void sync_product(dfa_t *pout, dfa_t *pleft, dfa_t *pright); |
| 83 | |
| 84 | static void dfa_prepare_rotation_data(void); |
| 85 | |
| 86 | |
| 87 | /******************************** |
| 88 | * manipulating attributes list * |
| 89 | ********************************/ |
| 90 | |
| 91 | /* |
| 92 | * Test if val is member of the attributes set att |
| 93 | */ |
| 94 | |
| 95 | static int |
| 96 | member_att(dfa_t *pdfa, int att, int val) |
| 97 | { |
| 98 | while (att != 0) { |
| 99 | if (pdfa->indexes[att].val == val) |
| 100 | return 1; |
| 101 | |
| 102 | att = pdfa->indexes[att].next; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * return the union of two attribute sets att1 & att2 |
| 110 | * repectively from dfa1 and dfa2 into |
| 111 | * att in dfa. |
| 112 | */ |
| 113 | |
| 114 | static int |
| 115 | union_att(dfa_t *pdfa, dfa_t *pdfa1, int att1, dfa_t *pdfa2, int att2) |
| 116 | { |
| 117 | int att; |
| 118 | int att_aux; |
| 119 | |
| 120 | /* copy att1 in att */ |
| 121 | att = 0; |
| 122 | while (att1 != 0) { |
| 123 | pdfa->last_index++; |
| 124 | if (pdfa->last_index >= pdfa->max_indexes) |
| 125 | resize_dfa(pdfa, pdfa->max_states, pdfa->max_indexes + DFA_RESIZE_STEP); |
| 126 | att_aux = pdfa->last_index; |
| 127 | |
| 128 | pdfa->indexes[att_aux].val = pdfa1->indexes[att1].val; |
| 129 | pdfa->indexes[att_aux].next = att; |
| 130 | att = att_aux; |
| 131 | att1 = pdfa1->indexes[att1].next; |
| 132 | } |
| 133 | |
| 134 | /* add to att the new elements of att2 */ |
| 135 | while (att2 != 0) { |
| 136 | if (!member_att(pdfa, att, pdfa2->indexes[att2].val)) { |
| 137 | pdfa->last_index++; |
| 138 | if (pdfa->last_index >= pdfa->max_indexes) |
| 139 | resize_dfa(pdfa, pdfa->max_states, pdfa->max_indexes + DFA_RESIZE_STEP); |
| 140 | att_aux = pdfa->last_index; |
| 141 | |
| 142 | pdfa->indexes[att_aux].val = pdfa2->indexes[att2].val; |
| 143 | pdfa->indexes[att_aux].next = att; |
| 144 | att = att_aux; |
| 145 | } |
| 146 | att2 = pdfa2->indexes[att2].next; |
| 147 | } |
| 148 | |
| 149 | return att; |
| 150 | } |
| 151 | |
| 152 | |
| 153 | /* Remove all attribute entry repetitions from a dfa. |
| 154 | */ |
| 155 | static void |
| 156 | compactify_att(dfa_t *pdfa) |
| 157 | { |
| 158 | int k; |
| 159 | int last = 0; |
| 160 | int save_last = pdfa->last_index; |
| 161 | int *map; |
| 162 | int *search_first; |
| 163 | int *search_next; |
| 164 | int size = (save_last + 1) * sizeof(int); |
| 165 | |
| 166 | map = malloc(size); |
| 167 | map[0] = 0; |
| 168 | search_first = malloc(size); |
| 169 | memset(search_first, 0, size); |
| 170 | search_next = malloc(size); |
| 171 | memset(search_next, 0, size); |
| 172 | |
| 173 | for (k = 1; k <= save_last; k++) { |
| 174 | int i = search_first[pdfa->indexes[k].val]; |
| 175 | |
| 176 | if (i) { |
| 177 | while (pdfa->indexes[i].next != pdfa->indexes[k].next) { |
| 178 | if (!search_next[i]) { |
| 179 | search_next[i] = ++last; |
| 180 | i = 0; |
| 181 | break; |
| 182 | } |
| 183 | |
| 184 | i = search_next[i]; |
| 185 | } |
| 186 | } |
| 187 | else |
| 188 | search_first[pdfa->indexes[k].val] = ++last; |
| 189 | |
| 190 | if (i) |
| 191 | map[k] = i; |
| 192 | else { |
| 193 | map[k] = last; |
| 194 | pdfa->indexes[last] = pdfa->indexes[k]; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | free(search_first); |
| 199 | free(search_next); |
| 200 | |
| 201 | if (last < save_last) { |
| 202 | pdfa->last_index = last; |
| 203 | for (k = 0; k <= pdfa->last_index; k++) |
| 204 | pdfa->indexes[k].next = map[pdfa->indexes[k].next]; |
| 205 | |
| 206 | for (k = 0; k <= pdfa->last_state; k++) |
| 207 | pdfa->states[k].att = map[pdfa->states[k].att]; |
| 208 | |
| 209 | if (0) |
| 210 | fprintf(stderr, "compactified: %d attributes left of %d\n", |
| 211 | last, save_last); |
| 212 | |
| 213 | compactify_att(pdfa); |
| 214 | } |
| 215 | |
| 216 | free(map); |
| 217 | } |
| 218 | |
| 219 | |
| 220 | /********************** |
| 221 | * manipulating dfa's * |
| 222 | **********************/ |
| 223 | |
| 224 | |
| 225 | /* |
| 226 | * return the effective size of a dfa in kB. |
| 227 | */ |
| 228 | |
| 229 | int |
| 230 | dfa_size(dfa_t *pdfa) |
| 231 | { |
| 232 | int states_size, indexes_size; |
| 233 | |
| 234 | states_size = (pdfa->last_state + 1) * sizeof(state_rt_t); |
| 235 | indexes_size = (pdfa->last_index + 1) * sizeof(attrib_rt_t); |
| 236 | |
| 237 | return (states_size + indexes_size + sizeof(dfa_rt_t)) / 1024; |
| 238 | } |
| 239 | |
| 240 | |
| 241 | /* |
| 242 | * resize memory for a dfa |
| 243 | */ |
| 244 | |
| 245 | static void |
| 246 | resize_dfa(dfa_t *pdfa, int max_states, int max_indexes) |
| 247 | { |
| 248 | state_t *pBuf; |
| 249 | attrib_t *pBuf2; |
| 250 | int i; |
| 251 | |
| 252 | if (dfa_verbose > 1) |
| 253 | fprintf(stderr, "Resizing dfa %s\n", pdfa->name); |
| 254 | |
| 255 | assert(pdfa->last_state <= pdfa->max_states); |
| 256 | assert(pdfa->last_index <= pdfa->max_indexes); |
| 257 | |
| 258 | pBuf = realloc(pdfa->states, max_states * sizeof(*pBuf)); |
| 259 | pBuf2 = realloc(pdfa->indexes, max_indexes * sizeof(*pBuf2)); |
| 260 | if (pBuf == NULL || pBuf2 == NULL) { |
| 261 | fprintf(stderr, "No memory left for dfa: %s", pdfa->name); |
| 262 | exit(EXIT_FAILURE); |
| 263 | } |
| 264 | |
| 265 | for (i = pdfa->max_states; i < max_states; i++) |
| 266 | memset(pBuf + i, 0, sizeof(state_t)); |
| 267 | for (i = pdfa->max_indexes; i < max_indexes; i++) |
| 268 | memset(pBuf2 + i, 0, sizeof(attrib_t)); |
| 269 | |
| 270 | pdfa->states = pBuf; |
| 271 | pdfa->max_states = max_states; |
| 272 | pdfa->indexes = pBuf2; |
| 273 | pdfa->max_indexes = max_indexes; |
| 274 | } |
| 275 | |
| 276 | |
| 277 | |
| 278 | /* |
| 279 | * dump a dfa (debugging purpose). |
| 280 | */ |
| 281 | |
| 282 | static const char *line = |
| 283 | "----------------------------------------------------\n"; |
| 284 | |
| 285 | void |
| 286 | dump_dfa(FILE *f, dfa_t *pdfa) |
| 287 | { |
| 288 | int i; |
| 289 | int att, k; |
| 290 | |
| 291 | fprintf(f, line); |
| 292 | fprintf(f, " name : %s\n", pdfa->name); |
| 293 | fprintf(f, " Nb states : %7d, max= %d\n", pdfa->last_state + 1, |
| 294 | pdfa->max_states); |
| 295 | fprintf(f, " Nb Indexes : %7d, max= %d\n", pdfa->last_index, |
| 296 | pdfa->max_indexes); |
| 297 | fprintf(f, " memory needed : %d Mb\n", dfa_size(pdfa) / 1024); |
| 298 | fprintf(f, line); |
| 299 | |
| 300 | if (dfa_size(pdfa) > 10000) /* change this value if needed */ |
| 301 | return; |
| 302 | fprintf(f, " state | . | O | X | # | att \n"); |
| 303 | fprintf(f, line); |
| 304 | for (i = 1; i != pdfa->last_state + 1; i++) { |
| 305 | int *pnext = pdfa->states[i].next; |
| 306 | fprintf(f, " %6d |", i); |
| 307 | fprintf(f, " %6d | %6d | %6d |", pnext[0], pnext[1], pnext[2]); |
| 308 | fprintf(f, " %6d |", pnext[OUT_BOARD]); |
| 309 | att = pdfa->states[i].att; |
| 310 | k = 0; |
| 311 | fprintf(f, " %5d:", att); |
| 312 | while (att != 0 && k < 10) { |
| 313 | fprintf(f, " %4d", pdfa->indexes[att].val); |
| 314 | att = pdfa->indexes[att].next; |
| 315 | k++; |
| 316 | } |
| 317 | if (att != 0) |
| 318 | fprintf(f, " ..."); |
| 319 | fprintf(f, "\n"); |
| 320 | } |
| 321 | fprintf(f, line); |
| 322 | fflush(f); |
| 323 | } |
| 324 | |
| 325 | |
| 326 | /* |
| 327 | * Reset a dfa |
| 328 | */ |
| 329 | |
| 330 | static void |
| 331 | clean_dfa(dfa_t *pdfa) |
| 332 | { |
| 333 | memset(pdfa->states, 0, pdfa->max_states * sizeof(state_t)); |
| 334 | memset(pdfa->indexes, 0, pdfa->max_indexes * sizeof(attrib_t)); |
| 335 | pdfa->last_state = 1; /* initial state */ |
| 336 | pdfa->last_index = 0; |
| 337 | pdfa->indexes[0].val = -1; |
| 338 | } |
| 339 | |
| 340 | |
| 341 | /* |
| 342 | * allocate memory for a new dfa |
| 343 | */ |
| 344 | |
| 345 | void |
| 346 | new_dfa(dfa_t *pdfa, const char *name) |
| 347 | { |
| 348 | memset(pdfa, 0, sizeof(dfa_t)); |
| 349 | resize_dfa(pdfa, DFA_INIT_SIZE, DFA_INIT_SIZE); |
| 350 | clean_dfa(pdfa); |
| 351 | if (name != NULL) |
| 352 | strcpy(pdfa->name, name); |
| 353 | else |
| 354 | strcpy(pdfa->name, "noname "); |
| 355 | |
| 356 | if (dfa_verbose > 1) |
| 357 | fprintf(stderr, "dfa %s is born :)\n", pdfa->name); |
| 358 | |
| 359 | } |
| 360 | |
| 361 | /* |
| 362 | * free memory used by a dfa |
| 363 | */ |
| 364 | |
| 365 | void |
| 366 | kill_dfa(dfa_t *pdfa) |
| 367 | { |
| 368 | free(pdfa->states); |
| 369 | free(pdfa->indexes); |
| 370 | if (dfa_verbose > 1) |
| 371 | fprintf(stderr, "dfa %s is dead :(\n", pdfa->name); |
| 372 | |
| 373 | memset(pdfa, 0, sizeof(dfa_t)); |
| 374 | } |
| 375 | |
| 376 | |
| 377 | /* |
| 378 | * Copy a dfa and resize the destination dfa if necessary. |
| 379 | */ |
| 380 | |
| 381 | void |
| 382 | copy_dfa(dfa_t *p_to, dfa_t *p_from) |
| 383 | { |
| 384 | assert(p_to != p_from); |
| 385 | |
| 386 | if (p_to->max_states < p_from->last_state) |
| 387 | resize_dfa(p_to, p_from->max_states, p_to->max_indexes); |
| 388 | |
| 389 | if (p_to->max_indexes < p_from->last_index) |
| 390 | resize_dfa(p_to, p_to->max_states, p_from->max_indexes); |
| 391 | |
| 392 | clean_dfa(p_to); |
| 393 | |
| 394 | memcpy(p_to->states, p_from->states, |
| 395 | sizeof(state_t) * (p_from->last_state + 1)); |
| 396 | memcpy(p_to->indexes, p_from->indexes, |
| 397 | sizeof(attrib_t) * (p_from->last_index + 1)); |
| 398 | |
| 399 | p_to->last_state = p_from->last_state; |
| 400 | p_to->last_index = p_from->last_index; |
| 401 | } |
| 402 | |
| 403 | |
| 404 | /* |
| 405 | * print c dfa: |
| 406 | * print the dfa in c format. |
| 407 | */ |
| 408 | |
| 409 | void |
| 410 | print_c_dfa(FILE *of, const char *name, dfa_t *pdfa) |
| 411 | { |
| 412 | int i; |
| 413 | |
| 414 | if (sizeof(unsigned short) < 2) { |
| 415 | fprintf(of, "#error shorts too short"); |
| 416 | fprintf(stderr, "Error: shorts are expected to be at least 2 bytes long.\n"); |
| 417 | exit(EXIT_FAILURE); |
| 418 | } |
| 419 | |
| 420 | assert(dfa_minmax_delta(pdfa, -1, 1) > -32768); |
| 421 | if (dfa_minmax_delta(pdfa, -1, 0) > 32768) { |
| 422 | fprintf(of, "#error too many states"); |
| 423 | fprintf(stderr, "Error: The dfa states are too disperse. Can't fit delta into a short.\n"); |
| 424 | exit(EXIT_FAILURE); |
| 425 | } |
| 426 | |
| 427 | if (pdfa->last_index + 1 > 65535) { |
| 428 | fprintf(of, "#error too many states"); |
| 429 | fprintf(stderr, "Error: Too many index entries. Can't fit delta into a short.\n"); |
| 430 | exit(EXIT_FAILURE); |
| 431 | } |
| 432 | |
| 433 | |
| 434 | fprintf(of, "\n#include \"dfa-mkpat.h\"\n"); |
| 435 | |
| 436 | fprintf(of, "static const state_rt_t state_%s[%d] = {\n", |
| 437 | name, pdfa->last_state + 1); |
| 438 | for (i = 0; i != pdfa->last_state + 1; i++) { |
| 439 | int j; |
| 440 | fprintf(of, "{{"); |
| 441 | for (j = 0; j < 4; j++) { |
| 442 | int n = pdfa->states[i].next[j]; |
| 443 | assert((n == 0) || (abs(n - i) < 32768)); |
| 444 | fprintf(of, "%d", n ? n - i : 0); |
| 445 | if (j != 3) |
| 446 | fprintf(of, ","); |
| 447 | } |
| 448 | fprintf(of, "}, %d},%s", pdfa->states[i].att, ((i+1)%3 ? "\t" : "\n")); |
| 449 | } |
| 450 | fprintf(of, "};\n\n"); |
| 451 | |
| 452 | |
| 453 | fprintf(of, "static const attrib_rt_t idx_%s[%d] = {\n", |
| 454 | name, pdfa->last_index + 1); |
| 455 | for (i = 0; i != pdfa->last_index + 1; i++) |
| 456 | fprintf(of, "{%d,%d},%s", pdfa->indexes[i].val, pdfa->indexes[i].next, |
| 457 | ((i+1)%4 ? "\t" : "\n")); |
| 458 | fprintf(of, "};\n\n"); |
| 459 | |
| 460 | fprintf(of, "static dfa_rt_t dfa_%s = {\n", name); |
| 461 | fprintf(of, " \"%s\",\n", name); |
| 462 | fprintf(of, "state_%s,\n", name); |
| 463 | fprintf(of, "idx_%s", name); |
| 464 | fprintf(of, "};\n"); |
| 465 | } |
| 466 | |
| 467 | |
| 468 | /* |
| 469 | * Create a linear dfa from a string and an attributes value |
| 470 | * and resize the dfa if needed. |
| 471 | * |
| 472 | * For example: |
| 473 | * create_dfa(pdfa, "Oo?.", 2001) |
| 474 | * gives: |
| 475 | * |
| 476 | * 1 0,1 0,1,2 0 |
| 477 | * (1,{}) -------> (2,{}) -------> (3,{}) -------> (4,{}) ------> (5,{2001}) |
| 478 | * |
| 479 | * An empty string force a junk pattern : The scanner will always |
| 480 | * consider this pattern as active. |
| 481 | * |
| 482 | * The possible input symbols are : |
| 483 | * |
| 484 | * '.', ',', '*', '!' for EMPTY expected. |
| 485 | * 'X' for BLACK expected. |
| 486 | * 'O' for WHITE expected. |
| 487 | * 'x' for BLACK|EMPTY expected. |
| 488 | * 'o' for WHITE|EMPTY expected. |
| 489 | * '#', '+', '-', '|' for OUT_BOARD expected. |
| 490 | * '?' for EMPTY|BLACK|WHITE expected. |
| 491 | * '$' for EMPTY|BLACK|WHITE|OUT_BOARD expected. |
| 492 | */ |
| 493 | |
| 494 | static void |
| 495 | create_dfa(dfa_t *pdfa, const char *str, int att_val) |
| 496 | { |
| 497 | int new_state; |
| 498 | |
| 499 | if (dfa_verbose > 1) |
| 500 | fprintf(stderr, "linear dfa in %s with string: %s\n", pdfa->name, str); |
| 501 | |
| 502 | assert(str != NULL); |
| 503 | assert(pdfa->max_states > 1); |
| 504 | assert(pdfa->max_indexes > 1); |
| 505 | |
| 506 | clean_dfa(pdfa); |
| 507 | new_state = 1; |
| 508 | for (; *str != '\0' && strchr("$#+-|OoXx.?,!a*", *str); str++) { |
| 509 | memset(pdfa->states[new_state].next, 0, 4 * sizeof(int)); |
| 510 | if (strchr("$?.ox,a!*", *str)) |
| 511 | pdfa->states[new_state].next[0] = new_state + 1; |
| 512 | if (strchr("$?Oo", *str)) |
| 513 | pdfa->states[new_state].next[1] = new_state + 1; |
| 514 | if (strchr("$?Xx", *str)) |
| 515 | pdfa->states[new_state].next[2] = new_state + 1; |
| 516 | if (strchr("$#+-|", *str)) |
| 517 | pdfa->states[new_state].next[OUT_BOARD] = new_state + 1; |
| 518 | new_state++; |
| 519 | if (new_state >= pdfa->max_states) |
| 520 | resize_dfa(pdfa, pdfa->max_states + DFA_RESIZE_STEP, |
| 521 | pdfa->max_indexes); |
| 522 | } |
| 523 | memset(pdfa->states[new_state].next, 0, 4 * sizeof(int)); |
| 524 | |
| 525 | pdfa->last_index++; |
| 526 | if (pdfa->last_index >= pdfa->max_indexes) |
| 527 | resize_dfa(pdfa, pdfa->max_states, |
| 528 | pdfa->max_indexes + DFA_RESIZE_STEP); |
| 529 | |
| 530 | memset(&(pdfa->indexes[pdfa->last_index]), 0, sizeof(attrib_t)); |
| 531 | pdfa->states[new_state].att = pdfa->last_index; |
| 532 | |
| 533 | pdfa->indexes[pdfa->states[new_state].att].val = att_val; |
| 534 | pdfa->indexes[pdfa->states[new_state].att].next = 0; |
| 535 | pdfa->last_state = new_state; |
| 536 | } |
| 537 | |
| 538 | |
| 539 | /************************** |
| 540 | * Test array with a * |
| 541 | * hash table * |
| 542 | **************************/ |
| 543 | /* used by sync_product * |
| 544 | * to store visited states* |
| 545 | **************************/ |
| 546 | |
| 547 | #define MAX_HASH_VALUE 4096 |
| 548 | |
| 549 | typedef struct entry { |
| 550 | int l, r; /* key */ |
| 551 | int val; /* value */ |
| 552 | struct entry *pnext; /* NULL if end of list */ |
| 553 | } entry_t; |
| 554 | |
| 555 | typedef struct test_array { |
| 556 | entry_t *hash[MAX_HASH_VALUE]; |
| 557 | } test_array_t; |
| 558 | |
| 559 | |
| 560 | /* initialize empty lists */ |
| 561 | static void |
| 562 | new_test_array(test_array_t *pta) |
| 563 | { |
| 564 | int h; |
| 565 | |
| 566 | for (h = 0; h != MAX_HASH_VALUE ; h++) |
| 567 | pta->hash[h] = NULL; |
| 568 | } |
| 569 | |
| 570 | /* Searh for (l, r) in the linked list plist */ |
| 571 | static int |
| 572 | get_from_entry_list(entry_t *plist, int l, int r) |
| 573 | { |
| 574 | int val = 0; |
| 575 | |
| 576 | while (plist != NULL) { |
| 577 | if (plist->l == l && plist->r == r) |
| 578 | val = plist->val; |
| 579 | plist = plist->pnext; |
| 580 | } |
| 581 | return val; |
| 582 | } |
| 583 | |
| 584 | /* get the value associated with (l, r) or 0 if none */ |
| 585 | static int |
| 586 | get_from_test_array(test_array_t *pta, int l, int r) |
| 587 | { |
| 588 | return get_from_entry_list(pta->hash[(l+r) % MAX_HASH_VALUE], l, r); |
| 589 | } |
| 590 | |
| 591 | |
| 592 | /* insert a new entry at the beginning of the linked list pplist */ |
| 593 | static void |
| 594 | add_to_entry_list(entry_t **pplist, int l, int r, int val) |
| 595 | { |
| 596 | entry_t *new_entry; |
| 597 | |
| 598 | /* make sure val > 0: val = 0 is used in get_from_entry_list */ |
| 599 | assert(val > 0); |
| 600 | assert(!get_from_entry_list(*pplist, l, r)); |
| 601 | |
| 602 | new_entry = malloc(sizeof(*new_entry)); |
| 603 | if (new_entry == NULL) { |
| 604 | fprintf(stderr, "No memory left for new entry\n"); |
| 605 | exit(EXIT_FAILURE); |
| 606 | } |
| 607 | new_entry->pnext = *pplist; |
| 608 | new_entry->l = l; |
| 609 | new_entry->r = r; |
| 610 | new_entry->val = val; |
| 611 | *pplist = new_entry; |
| 612 | } |
| 613 | |
| 614 | |
| 615 | /* add a value at (l, r) */ |
| 616 | static void |
| 617 | add_to_test_array(test_array_t *pta, int l, int r, int val) |
| 618 | { |
| 619 | add_to_entry_list(&(pta->hash[(l+r) % MAX_HASH_VALUE]), l, r, val); |
| 620 | } |
| 621 | |
| 622 | /* free the elements of the linked list plist */ |
| 623 | static void |
| 624 | free_entry_list(entry_t *plist) |
| 625 | { |
| 626 | entry_t *pentry; |
| 627 | |
| 628 | while (plist != NULL) { |
| 629 | pentry = plist; |
| 630 | plist = plist->pnext; |
| 631 | free(pentry); |
| 632 | } |
| 633 | } |
| 634 | |
| 635 | /* free allocated memory */ |
| 636 | static void |
| 637 | free_test_array(test_array_t *pta) |
| 638 | { |
| 639 | int h; |
| 640 | |
| 641 | for (h = 0; h != MAX_HASH_VALUE; h++) { |
| 642 | free_entry_list(pta->hash[h]); |
| 643 | pta->hash[h] = NULL; |
| 644 | } |
| 645 | } |
| 646 | |
| 647 | |
| 648 | /* |
| 649 | * Synchronization product between two automata. |
| 650 | * |
| 651 | * L(A) is the set of patterns recognized by the automaton A. |
| 652 | * |
| 653 | * A syncronized product betwenn two acyclic deterministic automata |
| 654 | * A1 and A2 is an acyclic deterministic classifier A1xA2 that |
| 655 | * recognize and classify the languages |
| 656 | * L(A1), L(A2), L(A1 Union A2) and L(A1 Inter A2). |
| 657 | * |
| 658 | * This algorithm do the product and the reduction at the same time. |
| 659 | * |
| 660 | * See Hopcroft & Ullman "The design and analysis of computer algorithms" |
| 661 | * Ed. Addison-Wesley, Reading MA, 1974 |
| 662 | * For the theorical aspects. |
| 663 | */ |
| 664 | |
| 665 | /* globals used to improve readability */ |
| 666 | static dfa_t *gpout, *gpleft, *gpright; |
| 667 | |
| 668 | /* Hash table used to test if a state has already been |
| 669 | visited and then give its position in the new automaton. */ |
| 670 | static test_array_t gtest; |
| 671 | |
| 672 | static void |
| 673 | do_sync_product(int l, int r) |
| 674 | { |
| 675 | int c; |
| 676 | int nextl, nextr; |
| 677 | int state; |
| 678 | |
| 679 | state = gpout->last_state; |
| 680 | |
| 681 | /* unify the attributes of states l and r */ |
| 682 | gpout->states[state].att = union_att(gpout, gpleft, gpleft->states[l].att, |
| 683 | gpright, gpright->states[r].att); |
| 684 | |
| 685 | /* scan each possible out-transition */ |
| 686 | for (c = 0; c != 4; c++) { |
| 687 | nextl = gpleft->states[l].next[c]; |
| 688 | nextr = gpright->states[r].next[c]; |
| 689 | assert(nextl < gpleft->last_state + 1); |
| 690 | assert(nextr < gpright->last_state + 1); |
| 691 | |
| 692 | /* transition to (0,0) mean no transition at all */ |
| 693 | if (nextl != 0 || nextr != 0) { |
| 694 | /* if the out-state doesn't already exist */ |
| 695 | if (get_from_test_array(>est, nextl, nextr) == 0) { |
| 696 | /* create it! */ |
| 697 | gpout->last_state++; |
| 698 | if (gpout->last_state >= gpout->max_states) |
| 699 | resize_dfa(gpout, gpout->max_states + DFA_RESIZE_STEP, |
| 700 | gpout->max_indexes); |
| 701 | |
| 702 | add_to_test_array(>est, nextl, nextr, gpout->last_state); |
| 703 | |
| 704 | /* link it */ |
| 705 | gpout->states[state].next[c] = gpout->last_state; |
| 706 | |
| 707 | /* create also its sub-automaton */ |
| 708 | do_sync_product(nextl, nextr); |
| 709 | } |
| 710 | else { |
| 711 | /* link it */ |
| 712 | gpout->states[state].next[c] = |
| 713 | get_from_test_array(>est, nextl, nextr); |
| 714 | } |
| 715 | } |
| 716 | else { |
| 717 | /* no output by c from the actual state */ |
| 718 | gpout->states[state].next[c] = 0; |
| 719 | } |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | static void |
| 724 | sync_product(dfa_t *pout, dfa_t *pleft, dfa_t *pright) |
| 725 | { |
| 726 | pout->last_index = 0; |
| 727 | |
| 728 | if (dfa_verbose > 2) { |
| 729 | fprintf(stderr, "Product between %s and %s\n", pleft->name, pright->name); |
| 730 | fprintf(stderr, "result in %s\n", pout->name); |
| 731 | } |
| 732 | |
| 733 | |
| 734 | gpout = pout; |
| 735 | gpleft = pleft; |
| 736 | gpright = pright; |
| 737 | new_test_array(>est); |
| 738 | add_to_test_array(>est, 1, 1, 1); |
| 739 | pout->last_state = 1; |
| 740 | |
| 741 | do_sync_product(1, 1); |
| 742 | |
| 743 | free_test_array(>est); |
| 744 | } |
| 745 | |
| 746 | /* |
| 747 | * Init/end functions |
| 748 | */ |
| 749 | |
| 750 | void |
| 751 | dfa_init(void) |
| 752 | { |
| 753 | int j; |
| 754 | |
| 755 | if (dfa_verbose > 1) |
| 756 | fprintf(stderr, "dfa: init\n"); |
| 757 | dfa_was_initialized++; |
| 758 | |
| 759 | build_spiral_order(); |
| 760 | dfa_prepare_rotation_data(); |
| 761 | |
| 762 | for (j = 0; j < DFA_BINS; j++) |
| 763 | new_dfa(&(aux_dfa[j]), "binAux "); |
| 764 | new_dfa(&aux_temp, "tempAux "); |
| 765 | } |
| 766 | |
| 767 | void |
| 768 | dfa_end(void) |
| 769 | { |
| 770 | int j; |
| 771 | |
| 772 | if (dfa_verbose > 1) |
| 773 | fprintf(stderr, "dfa: end\n"); |
| 774 | |
| 775 | for (j = 0; j < DFA_BINS; j++) |
| 776 | kill_dfa(&(aux_dfa[j])); |
| 777 | kill_dfa(&aux_temp); |
| 778 | dfa_was_initialized--; |
| 779 | } |
| 780 | |
| 781 | |
| 782 | /* |
| 783 | * Returns max or min jump distance from state to next[next_index] for |
| 784 | * all states. If next_index < 0, then max/min for all for states. |
| 785 | */ |
| 786 | |
| 787 | int |
| 788 | dfa_minmax_delta(dfa_t *pdfa, int next_index, int isMin) |
| 789 | { |
| 790 | |
| 791 | int ret, i, j; |
| 792 | assert(next_index <= 3); |
| 793 | |
| 794 | if (isMin) |
| 795 | ret = 99999; |
| 796 | else |
| 797 | ret = -1; |
| 798 | |
| 799 | for (i = 0; i <= pdfa->last_state; i++) { |
| 800 | for (j = 0; j < 4; j++) { |
| 801 | if (j == next_index || next_index < 0) { |
| 802 | int next = pdfa->states[i].next[j]; |
| 803 | if (!next) |
| 804 | continue; |
| 805 | if (isMin) { |
| 806 | if (ret > next - i) |
| 807 | ret = next - i; |
| 808 | } |
| 809 | else { |
| 810 | if (ret < next - i) |
| 811 | ret = next - i; |
| 812 | } |
| 813 | } |
| 814 | } |
| 815 | } |
| 816 | |
| 817 | return ret; |
| 818 | } |
| 819 | |
| 820 | #define DFA_ALIGN 2 |
| 821 | |
| 822 | /* |
| 823 | * Re-orders DFA into a canonical form, which does a half-hearted |
| 824 | * attempt to reduce the size of jumps for all states entries. |
| 825 | */ |
| 826 | void |
| 827 | dfa_shuffle(dfa_t *pdfa) |
| 828 | { |
| 829 | struct state *old_states; |
| 830 | int *state_to; |
| 831 | int *state_from; |
| 832 | int *queue1; |
| 833 | int *queue2; |
| 834 | int *tempq; |
| 835 | int next_new_state; |
| 836 | int q1p; |
| 837 | int q2p; |
| 838 | int i, j; |
| 839 | |
| 840 | state_to = calloc(pdfa->last_state+1, sizeof(*state_to)); |
| 841 | state_from = calloc(pdfa->last_state+1, sizeof(*state_from)); |
| 842 | |
| 843 | queue1 = malloc((pdfa->last_state+1) * sizeof(*queue1)); |
| 844 | queue2 = malloc((pdfa->last_state+1) * sizeof(*queue2)); |
| 845 | q1p = 1; |
| 846 | q2p = 0; |
| 847 | queue1[0] = 1; /* i.e. start at state 1. */ |
| 848 | state_from[0] = state_to[0] = 0; |
| 849 | state_from[1] = state_to[1] = 1; |
| 850 | next_new_state = 2; |
| 851 | |
| 852 | while (q1p) { |
| 853 | for (i = 0; i < q1p; i++) { |
| 854 | for (j = 0; j < 4; j++) { |
| 855 | int n = pdfa->states[queue1[i]].next[j]; |
| 856 | /* next_new_state = DFA_ALIGN * ((next_new_state-1) / DFA_ALIGN) + 1;*/ |
| 857 | while (n && !state_to[n]) { |
| 858 | state_to[n] = next_new_state; |
| 859 | state_from[next_new_state] = n; |
| 860 | next_new_state++; |
| 861 | queue2[q2p++] = n; |
| 862 | n = pdfa->states[n].next[0]; |
| 863 | } |
| 864 | } |
| 865 | } |
| 866 | tempq = queue1; |
| 867 | queue1 = queue2; |
| 868 | queue2 = tempq; |
| 869 | q1p = q2p; |
| 870 | q2p = 0; |
| 871 | } |
| 872 | |
| 873 | old_states = malloc((pdfa->last_state+1) * sizeof(*old_states)); |
| 874 | for (i = 1; i <= pdfa->last_state; i++) { |
| 875 | for (j = 0; j < 4; j++) { |
| 876 | old_states[i].next[j] = pdfa->states[i].next[j]; |
| 877 | old_states[i].att = pdfa->states[i].att; |
| 878 | } |
| 879 | } |
| 880 | for (i = 1; i <= pdfa->last_state; i++) { |
| 881 | for (j = 0; j < 4; j++) { |
| 882 | assert(state_to[i] > 0); |
| 883 | pdfa->states[i].next[j] = state_to[old_states[state_from[i]].next[j]]; |
| 884 | } |
| 885 | pdfa->states[i].att = old_states[state_from[i]].att; |
| 886 | } |
| 887 | } |
| 888 | |
| 889 | |
| 890 | /* Calculate the maximal number of patterns matched at one point for |
| 891 | * one transformation. Multiplying this number by 8 gives an upper |
| 892 | * bound for the total number of matched patterns for all |
| 893 | * transformation. |
| 894 | */ |
| 895 | int |
| 896 | dfa_calculate_max_matched_patterns(dfa_t *pdfa) |
| 897 | { |
| 898 | int total_max = 0; |
| 899 | int *state_max = calloc(pdfa->last_state + 1, sizeof(int)); |
| 900 | char *queued = calloc(pdfa->last_state + 1, sizeof(char)); |
| 901 | int *queue = malloc(pdfa->last_state * sizeof(int)); |
| 902 | int queue_start = 0; |
| 903 | int queue_end = 1; |
| 904 | |
| 905 | queue[0] = 1; |
| 906 | while (queue_start < queue_end) { |
| 907 | int state = queue[queue_start++]; |
| 908 | int k; |
| 909 | |
| 910 | /* Increment maximal number of matched patterns for each pattern |
| 911 | * matched at current `state'. |
| 912 | */ |
| 913 | for (k = pdfa->states[state].att; k; k = pdfa->indexes[k].next) |
| 914 | state_max[state]++; |
| 915 | |
| 916 | if (total_max < state_max[state]) |
| 917 | total_max = state_max[state]; |
| 918 | |
| 919 | for (k = 0; k < 4; k++) { |
| 920 | int next = pdfa->states[state].next[k]; |
| 921 | |
| 922 | if (next != 0) { |
| 923 | if (!queued[next]) { |
| 924 | queue[queue_end++] = next; |
| 925 | queued[next] = 1; |
| 926 | } |
| 927 | |
| 928 | if (state_max[next] < state_max[state]) |
| 929 | state_max[next] = state_max[state]; |
| 930 | } |
| 931 | } |
| 932 | } |
| 933 | |
| 934 | assert(queue_end == pdfa->last_state); |
| 935 | |
| 936 | free(state_max); |
| 937 | free(queued); |
| 938 | free(queue); |
| 939 | |
| 940 | return total_max; |
| 941 | } |
| 942 | |
| 943 | |
| 944 | /* |
| 945 | * Merges cached dfas into the master DFA |
| 946 | */ |
| 947 | void |
| 948 | dfa_finalize(dfa_t *pdfa) |
| 949 | { |
| 950 | int j; |
| 951 | int next_bin = aux_count; |
| 952 | int last_bin = aux_count + DFA_BINS - 1; |
| 953 | while (next_bin + 1 != last_bin) { |
| 954 | for (j = aux_count + 1; j <= last_bin; j += 2) { |
| 955 | if (j+1 == next_bin) |
| 956 | copy_dfa(&aux_dfa[next_bin % DFA_BINS], &aux_dfa[j % DFA_BINS]); |
| 957 | else |
| 958 | sync_product(&aux_dfa[next_bin % DFA_BINS], |
| 959 | &aux_dfa[j % DFA_BINS], |
| 960 | &aux_dfa[(j+1) % DFA_BINS]); |
| 961 | next_bin++; |
| 962 | } |
| 963 | last_bin = next_bin - 1; |
| 964 | aux_count--; |
| 965 | next_bin = aux_count; |
| 966 | } |
| 967 | copy_dfa(pdfa, &aux_dfa[last_bin % DFA_BINS]); |
| 968 | |
| 969 | compactify_att(pdfa); |
| 970 | } |
| 971 | |
| 972 | /* |
| 973 | * Add a new string with attribute att_val into the dfa. |
| 974 | * if the new size of the dfa respect some size conditions |
| 975 | * return increase in kB or -1 if the pattern was rejected. |
| 976 | * This function never rejects string of length <= 1. |
| 977 | */ |
| 978 | |
| 979 | float |
| 980 | dfa_add_string(dfa_t *pdfa, const char *str, int pattern_index, int ll) |
| 981 | { |
| 982 | dfa_t *new_dfa = &(aux_dfa[aux_count % DFA_BINS]); |
| 983 | dfa_t *old_dfa = &(aux_dfa[(aux_count+1) % DFA_BINS]); |
| 984 | float ratio; |
| 985 | |
| 986 | if (dfa_verbose > 1) { |
| 987 | fprintf(stderr, "Adding to dfa %s the string: %s\n", pdfa->name, str); |
| 988 | fprintf(stderr, " pat_ind: %d; rotation: %d at bin: %d\n", |
| 989 | pattern_index, ll, aux_count); |
| 990 | } |
| 991 | |
| 992 | assert(dfa_was_initialized > 0); |
| 993 | assert(pdfa != NULL); |
| 994 | |
| 995 | create_dfa(&aux_temp, str, pattern_index); |
| 996 | |
| 997 | /* then we do the synchronization product with dfa */ |
| 998 | sync_product(new_dfa, old_dfa, &aux_temp); |
| 999 | aux_count++; |
| 1000 | |
| 1001 | ratio = 1; |
| 1002 | if (dfa_size(old_dfa) > 0) |
| 1003 | ratio = (float) (dfa_size(new_dfa) / dfa_size(old_dfa)); |
| 1004 | |
| 1005 | return ratio; |
| 1006 | } |
| 1007 | |
| 1008 | |
| 1009 | /* Used for quick string rotation. */ |
| 1010 | static int dfa_rotation_data[DFA_BASE * DFA_BASE]; |
| 1011 | |
| 1012 | static void |
| 1013 | dfa_prepare_rotation_data(void) |
| 1014 | { |
| 1015 | int k; |
| 1016 | |
| 1017 | for (k = 0; k < DFA_MAX_ORDER; k++) |
| 1018 | dfa_rotation_data[DFA_POS(0, 0) + spiral[k][0]] = k; |
| 1019 | } |
| 1020 | |
| 1021 | |
| 1022 | /* Create a transformation of `string' and store it in |
| 1023 | * `rotated_string'. The latter must be of at least DFA_MAX_ORDER |
| 1024 | * characters in length. */ |
| 1025 | void |
| 1026 | dfa_rotate_string(char *rotated_string, const char *string, int transformation) |
| 1027 | { |
| 1028 | if (transformation > 0) { |
| 1029 | int k; |
| 1030 | int length = strlen(string); |
| 1031 | int new_length = 0; |
| 1032 | |
| 1033 | memset(rotated_string, '$', DFA_MAX_ORDER); |
| 1034 | |
| 1035 | for (k = 0; k < length; k++) { |
| 1036 | if (string[k] != '$') { |
| 1037 | int string_position = dfa_rotation_data[DFA_POS(0, 0) |
| 1038 | + spiral[k][transformation]]; |
| 1039 | rotated_string[string_position] = string[k]; |
| 1040 | if (string_position + 1 > new_length) |
| 1041 | new_length = string_position + 1; |
| 1042 | } |
| 1043 | } |
| 1044 | |
| 1045 | rotated_string[new_length] = 0; |
| 1046 | } |
| 1047 | else |
| 1048 | strcpy(rotated_string, string); |
| 1049 | } |
| 1050 | |
| 1051 | |
| 1052 | /* |
| 1053 | * Build a pattern string from a pattern. `str' must refer a buffer |
| 1054 | * of size greater than DFA_MAX_ORDER. |
| 1055 | */ |
| 1056 | void |
| 1057 | pattern_2_string(struct pattern *pat, struct patval_b *elements, |
| 1058 | char *str, int ci, int cj) |
| 1059 | { |
| 1060 | char work_space[DFA_MAX_BOARD * 4][DFA_MAX_BOARD * 4]; |
| 1061 | int m, n; /* anchor position */ |
| 1062 | int edges, borders, to_test; |
| 1063 | int i, j, k; |
| 1064 | char c; |
| 1065 | |
| 1066 | m = DFA_MAX_BOARD * 2 + ci; |
| 1067 | n = DFA_MAX_BOARD * 2 + cj; /* position of the anchor */ |
| 1068 | |
| 1069 | assert(dfa_was_initialized); |
| 1070 | memset(str, 0, DFA_MAX_ORDER); |
| 1071 | memset(work_space, '#', sizeof(work_space)); |
| 1072 | |
| 1073 | if (dfa_verbose > 0) |
| 1074 | fprintf(stderr, "converting pattern into string.\n"); |
| 1075 | |
| 1076 | /* basic edge constraints */ |
| 1077 | for (i = DFA_MAX_BOARD; i != DFA_MAX_BOARD * 3; i++) |
| 1078 | for (j = DFA_MAX_BOARD; j != DFA_MAX_BOARD * 3; j++) |
| 1079 | work_space[i][j] = '$'; |
| 1080 | |
| 1081 | /* pattern mask */ |
| 1082 | for (i = pat->mini + m; i != pat->maxi + m + 1; i++) |
| 1083 | for (j = pat->minj + n; j != pat->maxj + n + 1; j++) |
| 1084 | work_space[i][j] = '?'; |
| 1085 | |
| 1086 | /* more advanced edge constraints */ |
| 1087 | |
| 1088 | /* South constraint */ |
| 1089 | if (pat->edge_constraints & SOUTH_EDGE) { |
| 1090 | for (i = m + pat->maxi + 1; i != DFA_MAX_BOARD * 3; i++) |
| 1091 | for (j = 0; j != DFA_MAX_BOARD * 3; j++) |
| 1092 | work_space[i][j] = '-'; |
| 1093 | } |
| 1094 | |
| 1095 | /* East constraint */ |
| 1096 | if (pat->edge_constraints & EAST_EDGE) { |
| 1097 | for (i = 0; i != DFA_MAX_BOARD * 3; i++) |
| 1098 | for (j = n + pat->maxj + 1; j != DFA_MAX_BOARD * 3; j++) |
| 1099 | work_space[i][j] = '|'; |
| 1100 | } |
| 1101 | |
| 1102 | /* North constraint */ |
| 1103 | if (pat->edge_constraints & NORTH_EDGE) { |
| 1104 | for (i = 0; i != m + pat->mini; i++) |
| 1105 | for (j = 0; j != DFA_MAX_BOARD * 4; j++) |
| 1106 | work_space[i][j] = '-'; |
| 1107 | } |
| 1108 | |
| 1109 | /* West constraint */ |
| 1110 | if (pat->edge_constraints & WEST_EDGE) { |
| 1111 | /* take care not to erase the south edge constraint */ |
| 1112 | for (i = 0; i != m + pat->maxi + 1; i++) |
| 1113 | for (j = 0; j != n + pat->minj; j++) |
| 1114 | work_space[i][j] = '|'; |
| 1115 | |
| 1116 | /* complete the last corner only if necessary */ |
| 1117 | if (!(pat->edge_constraints & SOUTH_EDGE)) { |
| 1118 | for (i = m + pat->maxi + 1; i != DFA_MAX_BOARD * 3; i++) |
| 1119 | for (j = 0; j != n + pat->minj; j++) |
| 1120 | work_space[i][j] = '|'; |
| 1121 | } |
| 1122 | } |
| 1123 | |
| 1124 | /* dump */ |
| 1125 | if (dfa_verbose > 4) { |
| 1126 | for (i = DFA_MAX_BOARD - 1; i != DFA_MAX_BOARD * 3 + 1; i++) { |
| 1127 | for (j = DFA_MAX_BOARD - 1; j != DFA_MAX_BOARD * 3 + 1; j++) { |
| 1128 | if (i == m && j == n) |
| 1129 | fprintf(stderr, "s"); /* mark the anchor */ |
| 1130 | else |
| 1131 | fprintf(stderr, "%c", work_space[i][j]); |
| 1132 | } |
| 1133 | fprintf(stderr, "\n"); |
| 1134 | } |
| 1135 | fprintf(stderr, "\n"); |
| 1136 | } |
| 1137 | |
| 1138 | /* pattern representation on the work space */ |
| 1139 | for (k = 0; k != pat->patlen; k++) { |
| 1140 | c = EXPECTED_VAL(elements[k].att); |
| 1141 | assert(work_space[m + elements[k].x - ci][n + elements[k].y - cj] == '?'); |
| 1142 | work_space[m + elements[k].x - ci][n + elements[k].y - cj] = c; |
| 1143 | } |
| 1144 | |
| 1145 | /* dump */ |
| 1146 | if (dfa_verbose > 3) { |
| 1147 | for (i = DFA_MAX_BOARD - 1; i != DFA_MAX_BOARD * 3 + 1; i++) { |
| 1148 | for (j = DFA_MAX_BOARD - 1; j != DFA_MAX_BOARD * 3 + 1; j++) { |
| 1149 | if (i == m && j == n) |
| 1150 | fprintf(stderr, "s"); /* mark the anchor */ |
| 1151 | else |
| 1152 | fprintf(stderr, "%c", work_space[i][j]); |
| 1153 | } |
| 1154 | fprintf(stderr, "\n"); |
| 1155 | } |
| 1156 | fprintf(stderr, "\n"); |
| 1157 | } |
| 1158 | |
| 1159 | /* Now we can build the smallest pattern string possible |
| 1160 | * from the anchor */ |
| 1161 | |
| 1162 | to_test = pat->patlen; /* How many positions left to test ? */ |
| 1163 | edges = pat->edge_constraints; /* how many constraint tested ? */ |
| 1164 | borders = 0xF; |
| 1165 | /* we must test at least one intersection by border for |
| 1166 | * patterns like |
| 1167 | * |
| 1168 | * ??? |
| 1169 | * O.O |
| 1170 | * ??? |
| 1171 | * |
| 1172 | * To ensure edge position. |
| 1173 | */ |
| 1174 | |
| 1175 | for (k = 0; |
| 1176 | (k != DFA_MAX_ORDER - 1) && ((borders > 0) || edges || to_test > 0); |
| 1177 | k++) { |
| 1178 | j = spiral[k][0] % DFA_BASE; |
| 1179 | if (j >= DFA_MAX_BOARD) |
| 1180 | j -= DFA_BASE; |
| 1181 | if (j <= -DFA_MAX_BOARD) |
| 1182 | j += DFA_BASE; |
| 1183 | i = (spiral[k][0] - j) / DFA_BASE; |
| 1184 | |
| 1185 | if (i == pat->maxi) |
| 1186 | borders &= ~SOUTH_EDGE; |
| 1187 | if (i == pat->mini) |
| 1188 | borders &= ~NORTH_EDGE; |
| 1189 | if (j == pat->maxj) |
| 1190 | borders &= ~EAST_EDGE; |
| 1191 | if (j == pat->minj) |
| 1192 | borders &= ~WEST_EDGE; |
| 1193 | |
| 1194 | assert(m + i < DFA_MAX_BOARD * 3 && m + i < DFA_MAX_BOARD * 3); |
| 1195 | str[k] = work_space[m + i][n + j]; |
| 1196 | assert(strchr("XOxo.,a!?$#|-+", str[k])); |
| 1197 | |
| 1198 | if (strchr("XOxo.,a!", str[k])) |
| 1199 | to_test--; |
| 1200 | if (strchr("#|-+", str[k])) { |
| 1201 | if (i > pat->maxi) |
| 1202 | edges &= ~SOUTH_EDGE; |
| 1203 | if (i < pat->mini) |
| 1204 | edges &= ~NORTH_EDGE; |
| 1205 | if (j > pat->maxj) |
| 1206 | edges &= ~EAST_EDGE; |
| 1207 | if (j < pat->minj) |
| 1208 | edges &= ~WEST_EDGE; |
| 1209 | } |
| 1210 | } |
| 1211 | |
| 1212 | assert(k < DFA_MAX_ORDER); |
| 1213 | str[k] = '\0'; /* end of string */ |
| 1214 | |
| 1215 | if (0 && dfa_verbose > 0) |
| 1216 | fprintf(stderr, "converted pattern %s into string: %s\n", pat->name, str); |
| 1217 | } |
| 1218 | |
| 1219 | |
| 1220 | /************************************** |
| 1221 | * Experimental DFA builder * |
| 1222 | **************************************/ |
| 1223 | |
| 1224 | /* This builder differs from the one above in that it builds the whole dfa |
| 1225 | * at once. That is, it must have all the patterns to build and cannot add |
| 1226 | * pattern by pattern. Currently, it is only used in DFA size optimization |
| 1227 | * (it seems to be significantly faster). |
| 1228 | */ |
| 1229 | |
| 1230 | |
| 1231 | /* Allocate a new dfa_attrib structure from a dynamic array. */ |
| 1232 | static dfa_attrib * |
| 1233 | dfa_attrib_new(dfa_attrib_array *array, int string_index) |
| 1234 | { |
| 1235 | dfa_attrib *attribute; |
| 1236 | |
| 1237 | if (array->allocated == DFA_ATTRIB_BLOCK_SIZE) { |
| 1238 | dfa_attrib_block *new_block = malloc(sizeof(*new_block)); |
| 1239 | assert(new_block); |
| 1240 | |
| 1241 | new_block->previous = array->last_block; |
| 1242 | array->last_block = new_block; |
| 1243 | array->allocated = 0; |
| 1244 | } |
| 1245 | |
| 1246 | attribute = &(array->last_block->attrib[array->allocated++]); |
| 1247 | attribute->next = NULL; |
| 1248 | attribute->string_index = string_index; |
| 1249 | |
| 1250 | return attribute; |
| 1251 | } |
| 1252 | |
| 1253 | |
| 1254 | /* Initialize dfa_attrib_array structure. */ |
| 1255 | static void |
| 1256 | dfa_attrib_array_reset(dfa_attrib_array *array) |
| 1257 | { |
| 1258 | array->last_block = NULL; |
| 1259 | array->allocated = DFA_ATTRIB_BLOCK_SIZE; |
| 1260 | } |
| 1261 | |
| 1262 | |
| 1263 | /* Clear a dynamic array by freeing all blocks befor `cutoff_point'. */ |
| 1264 | static void |
| 1265 | dfa_attrib_array_partially_clear(dfa_attrib_block *cutoff_point) |
| 1266 | { |
| 1267 | if (cutoff_point) { |
| 1268 | dfa_attrib_block *block = cutoff_point->previous; |
| 1269 | |
| 1270 | while (block) { |
| 1271 | dfa_attrib_block *previous = block->previous; |
| 1272 | free(block); |
| 1273 | block = previous; |
| 1274 | } |
| 1275 | |
| 1276 | cutoff_point->previous = NULL; |
| 1277 | } |
| 1278 | } |
| 1279 | |
| 1280 | |
| 1281 | /* Clear a dynamic array completely. All blocks are freed. */ |
| 1282 | static void |
| 1283 | dfa_attrib_array_clear(dfa_attrib_array *array) |
| 1284 | { |
| 1285 | if (array->last_block) { |
| 1286 | dfa_attrib_array_partially_clear(array->last_block); |
| 1287 | free(array->last_block); |
| 1288 | array->last_block = NULL; |
| 1289 | } |
| 1290 | |
| 1291 | array->allocated = DFA_ATTRIB_BLOCK_SIZE; |
| 1292 | } |
| 1293 | |
| 1294 | |
| 1295 | /* Allocate a new dfa_node structure in a DFA graph. */ |
| 1296 | static dfa_node * |
| 1297 | dfa_node_new(dfa_graph *graph) |
| 1298 | { |
| 1299 | dfa_node *node; |
| 1300 | |
| 1301 | if (graph->allocated == DFA_NODE_BLOCK_SIZE) { |
| 1302 | dfa_node_block *new_block = malloc(sizeof(*new_block)); |
| 1303 | assert(new_block); |
| 1304 | |
| 1305 | new_block->previous = graph->last_block; |
| 1306 | graph->last_block = new_block; |
| 1307 | graph->allocated = 0; |
| 1308 | } |
| 1309 | |
| 1310 | graph->num_nodes++; |
| 1311 | node = &(graph->last_block->node[graph->allocated++]); |
| 1312 | memset(node, 0, sizeof(dfa_node)); |
| 1313 | |
| 1314 | return node; |
| 1315 | } |
| 1316 | |
| 1317 | |
| 1318 | /* This is a hash table used to quickly find a DFA node using a linked list |
| 1319 | * of its attributes as a key. |
| 1320 | */ |
| 1321 | static dfa_hash_entry *dfa_hash_table[DFA_HASH_TABLE_SIZE]; |
| 1322 | static dfa_hash_block *dfa_hash_last_block = NULL; |
| 1323 | static int dfa_hash_allocated; |
| 1324 | |
| 1325 | |
| 1326 | /* Allocate a dfa_entry structure dynamically. */ |
| 1327 | static dfa_hash_entry * |
| 1328 | dfa_hash_entry_new(void) |
| 1329 | { |
| 1330 | if (dfa_hash_allocated == DFA_HASH_BLOCK_SIZE) { |
| 1331 | dfa_hash_block *new_block = malloc(sizeof(*new_block)); |
| 1332 | assert(new_block); |
| 1333 | |
| 1334 | new_block->previous = dfa_hash_last_block; |
| 1335 | dfa_hash_last_block = new_block; |
| 1336 | dfa_hash_allocated = 0; |
| 1337 | } |
| 1338 | |
| 1339 | return &(dfa_hash_last_block->entry[dfa_hash_allocated++]); |
| 1340 | } |
| 1341 | |
| 1342 | |
| 1343 | /* Clear the hash table completely. Used after having finished a graph level. */ |
| 1344 | static void |
| 1345 | dfa_hash_clear(void) |
| 1346 | { |
| 1347 | memset(dfa_hash_table, 0, DFA_HASH_TABLE_SIZE * sizeof(dfa_hash_entry *)); |
| 1348 | |
| 1349 | if (dfa_hash_last_block) { |
| 1350 | dfa_hash_block *block = dfa_hash_last_block->previous; |
| 1351 | |
| 1352 | while (block) { |
| 1353 | dfa_hash_block *previous = block->previous; |
| 1354 | free(block); |
| 1355 | block = previous; |
| 1356 | } |
| 1357 | |
| 1358 | dfa_hash_last_block->previous = NULL; |
| 1359 | dfa_hash_allocated = 0; |
| 1360 | } |
| 1361 | else |
| 1362 | dfa_hash_allocated = DFA_HASH_BLOCK_SIZE; |
| 1363 | } |
| 1364 | |
| 1365 | |
| 1366 | /* Compute the hash value of a key (linked list of attributes). */ |
| 1367 | static int |
| 1368 | dfa_hash_value(dfa_attrib *key) |
| 1369 | { |
| 1370 | int hash_value = DFA_HASH_VALUE_1 * key->string_index; |
| 1371 | if (key->next) { |
| 1372 | hash_value += DFA_HASH_VALUE_2 * key->next->string_index; |
| 1373 | if (key->next->next) |
| 1374 | hash_value += DFA_HASH_VALUE_3 * key->next->next->string_index; |
| 1375 | } |
| 1376 | |
| 1377 | return hash_value % DFA_HASH_TABLE_SIZE; |
| 1378 | } |
| 1379 | |
| 1380 | |
| 1381 | /* Search for a node with a given key in the hash table. */ |
| 1382 | static dfa_node * |
| 1383 | dfa_hash_search(dfa_attrib *key) |
| 1384 | { |
| 1385 | int hash_value = dfa_hash_value(key); |
| 1386 | dfa_hash_entry *entry; |
| 1387 | |
| 1388 | for (entry = dfa_hash_table[hash_value]; entry; entry = entry->next) { |
| 1389 | dfa_attrib *left = key; |
| 1390 | dfa_attrib *right = entry->key; |
| 1391 | |
| 1392 | while (left && right) { |
| 1393 | if (left->string_index != right->string_index) |
| 1394 | break; |
| 1395 | |
| 1396 | left = left->next; |
| 1397 | right = right->next; |
| 1398 | } |
| 1399 | |
| 1400 | if (!left && !right) |
| 1401 | return entry->value; |
| 1402 | } |
| 1403 | |
| 1404 | return NULL; |
| 1405 | } |
| 1406 | |
| 1407 | |
| 1408 | /* Add a node to the table. The list of strings which pass through it is used |
| 1409 | * as a key. |
| 1410 | */ |
| 1411 | static void |
| 1412 | dfa_hash_add_node(dfa_node *node) |
| 1413 | { |
| 1414 | int hash_value = dfa_hash_value(node->passing_strings); |
| 1415 | dfa_hash_entry *entry; |
| 1416 | |
| 1417 | entry = dfa_hash_entry_new(); |
| 1418 | entry->next = dfa_hash_table[hash_value]; |
| 1419 | dfa_hash_table[hash_value] = entry; |
| 1420 | |
| 1421 | entry->key = node->passing_strings; |
| 1422 | entry->value = node; |
| 1423 | } |
| 1424 | |
| 1425 | |
| 1426 | /* DFA iterator. Used to walk the array of nodes in backward direction. */ |
| 1427 | static dfa_node_block *dfa_iterator_block; |
| 1428 | static int dfa_iterator_node_num; |
| 1429 | |
| 1430 | |
| 1431 | /* Reset the iterator. The last added node of the specified graph becomes |
| 1432 | * the current node. |
| 1433 | */ |
| 1434 | static dfa_node* |
| 1435 | dfa_iterator_reset(dfa_graph *graph) |
| 1436 | { |
| 1437 | assert(graph->last_block); |
| 1438 | |
| 1439 | if (graph->allocated > 0) { |
| 1440 | dfa_iterator_block = graph->last_block; |
| 1441 | dfa_iterator_node_num = graph->allocated - 1; |
| 1442 | } |
| 1443 | else { |
| 1444 | dfa_iterator_block = graph->last_block->previous; |
| 1445 | assert(dfa_iterator_block); |
| 1446 | dfa_iterator_node_num = DFA_NODE_BLOCK_SIZE - 1; |
| 1447 | } |
| 1448 | |
| 1449 | return &(dfa_iterator_block->node[dfa_iterator_node_num]); |
| 1450 | } |
| 1451 | |
| 1452 | |
| 1453 | /* Shift the current node pointer one node backwards. */ |
| 1454 | static dfa_node* |
| 1455 | dfa_iterate(void) |
| 1456 | { |
| 1457 | dfa_iterator_node_num--; |
| 1458 | if (dfa_iterator_node_num < 0) { |
| 1459 | dfa_iterator_block = dfa_iterator_block->previous; |
| 1460 | assert(dfa_iterator_block); |
| 1461 | dfa_iterator_node_num = DFA_NODE_BLOCK_SIZE - 1; |
| 1462 | } |
| 1463 | |
| 1464 | return &(dfa_iterator_block->node[dfa_iterator_node_num]); |
| 1465 | } |
| 1466 | |
| 1467 | |
| 1468 | /* Initialize a dfa_graph structure. */ |
| 1469 | void |
| 1470 | dfa_graph_reset(dfa_graph *graph) |
| 1471 | { |
| 1472 | graph->num_nodes = 0; |
| 1473 | graph->root = NULL; |
| 1474 | |
| 1475 | graph->last_block = NULL; |
| 1476 | graph->allocated = DFA_NODE_BLOCK_SIZE; |
| 1477 | dfa_attrib_array_reset(&(graph->attributes)); |
| 1478 | } |
| 1479 | |
| 1480 | |
| 1481 | /* Free all resources associated with the specified DFA graph. */ |
| 1482 | static void |
| 1483 | dfa_graph_clear(dfa_graph *graph) |
| 1484 | { |
| 1485 | dfa_node_block *block = graph->last_block; |
| 1486 | graph->num_nodes = 0; |
| 1487 | graph->root = NULL; |
| 1488 | |
| 1489 | while (block) { |
| 1490 | dfa_node_block *previous = block->previous; |
| 1491 | free(block); |
| 1492 | block = previous; |
| 1493 | } |
| 1494 | |
| 1495 | graph->last_block = NULL; |
| 1496 | graph->allocated = DFA_NODE_BLOCK_SIZE; |
| 1497 | |
| 1498 | dfa_attrib_array_clear(&(graph->attributes)); |
| 1499 | } |
| 1500 | |
| 1501 | |
| 1502 | /* dfa_graph_build_level() builds a level of a graph. Level `n' is a set of |
| 1503 | * nodes which correspond to n's element of a string. When matching using a |
| 1504 | * dfa, nodes of level `n' are only checked at (n + 1)'s iteration (root node |
| 1505 | * is considered to be level -1, but is matched at iteration 0). |
| 1506 | */ |
| 1507 | static void |
| 1508 | dfa_graph_build_level(dfa_graph *graph, char **strings, int level, |
| 1509 | dfa_node *terminal_node, |
| 1510 | dfa_attrib_array *passing_strings_array) |
| 1511 | { |
| 1512 | int save_num_nodes = graph->num_nodes; |
| 1513 | dfa_attrib_block *cutoff_point; |
| 1514 | dfa_node *node; |
| 1515 | dfa_node *this_terminal_node = dfa_iterator_reset(graph); |
| 1516 | |
| 1517 | cutoff_point = passing_strings_array->last_block; |
| 1518 | dfa_hash_clear(); |
| 1519 | |
| 1520 | /* Walk through all nodes of the previous level (backwards, but that doesn't |
| 1521 | * matter - it's just because iterator works that way). |
| 1522 | */ |
| 1523 | for (node = this_terminal_node; node != terminal_node; node = dfa_iterate()) { |
| 1524 | int k; |
| 1525 | int num_masks = 0; |
| 1526 | char mask[4]; |
| 1527 | dfa_attrib *passing_string; |
| 1528 | dfa_attrib **link = &(node->attributes); |
| 1529 | dfa_attrib *new_passing_strings[4]; |
| 1530 | dfa_attrib **new_link[4]; |
| 1531 | |
| 1532 | /* Calculate all different masks for subnodes. For instance, if there are |
| 1533 | * three strings passing through a node of level 1, say "X$...", "Xx..." |
| 1534 | * and "XO...", there will be three masks: 8 (stands for '#'), 5 ('X' and |
| 1535 | * '.') and 2 ('O'). String "X$..." will pass further through all three |
| 1536 | * subnodes, "Xx..." - through subnode corresponding to mask 5 and string |
| 1537 | * "XO..." - through subnode corresponding to mask 2. |
| 1538 | */ |
| 1539 | for (passing_string = node->passing_strings; |
| 1540 | passing_string && num_masks < 4; |
| 1541 | passing_string = passing_string->next) { |
| 1542 | int index = passing_string->string_index; |
| 1543 | char string_mask = strings[index][level]; |
| 1544 | |
| 1545 | if (string_mask) { |
| 1546 | int limit = num_masks; |
| 1547 | |
| 1548 | for (k = 0; k < limit; k++) { |
| 1549 | char common_branches = string_mask & mask[k]; |
| 1550 | |
| 1551 | if (common_branches && common_branches != mask[k]) { |
| 1552 | /* Split a mask, since the string passes through a "part" of it. */ |
| 1553 | mask[k] ^= common_branches; |
| 1554 | mask[num_masks++] = common_branches; |
| 1555 | } |
| 1556 | |
| 1557 | string_mask ^= common_branches; |
| 1558 | } |
| 1559 | |
| 1560 | if (string_mask) { |
| 1561 | /* If there is no mask corresponding to a (part) of the string's |
| 1562 | * mask, add it now. |
| 1563 | */ |
| 1564 | mask[num_masks++] = string_mask; |
| 1565 | } |
| 1566 | } |
| 1567 | else { |
| 1568 | /* If the string ends at this level, add its index to the list of |
| 1569 | * matched strings of the current node. Not used at the moment, |
| 1570 | * since this builder isn't used for actual DFA building. |
| 1571 | */ |
| 1572 | *link = dfa_attrib_new(&(graph->attributes), index); |
| 1573 | link = &((*link)->next); |
| 1574 | } |
| 1575 | } |
| 1576 | |
| 1577 | for (k = 0; k < num_masks; k++) |
| 1578 | new_link[k] = &(new_passing_strings[k]); |
| 1579 | |
| 1580 | /* Now, for each mask, create a list of all strings which will follow it |
| 1581 | * (pass through a node corresponding to it). It is possible to merge this |
| 1582 | * loop with the previous one, but it is simplier to keep them separated. |
| 1583 | */ |
| 1584 | for (passing_string = node->passing_strings; passing_string; |
| 1585 | passing_string = passing_string->next) { |
| 1586 | int index = passing_string->string_index; |
| 1587 | |
| 1588 | for (k = 0; k < num_masks; k++) { |
| 1589 | if (strings[index][level] & mask[k]) { |
| 1590 | *(new_link[k]) = dfa_attrib_new(passing_strings_array, index); |
| 1591 | new_link[k] = &((*(new_link[k]))->next); |
| 1592 | } |
| 1593 | } |
| 1594 | } |
| 1595 | |
| 1596 | /* Finally, create new nodes for the masks when necessary. */ |
| 1597 | for (k = 0; k < num_masks; k++) { |
| 1598 | int i; |
| 1599 | |
| 1600 | /* Maybe we have already added such a node? */ |
| 1601 | dfa_node *new_node = dfa_hash_search(new_passing_strings[k]); |
| 1602 | |
| 1603 | if (!new_node) { |
| 1604 | /* If not, create it, save the list of passing strings and add the |
| 1605 | * new node to hash table. |
| 1606 | */ |
| 1607 | new_node = dfa_node_new(graph); |
| 1608 | new_node->passing_strings = new_passing_strings[k]; |
| 1609 | |
| 1610 | dfa_hash_add_node(new_node); |
| 1611 | } |
| 1612 | |
| 1613 | /* At this moment we convert the masks to actual transitions. These are |
| 1614 | * also unused till we use this builder for actual DFA creation. |
| 1615 | */ |
| 1616 | for (i = 0; i < 4; i++) { |
| 1617 | if (mask[k] & (1 << i)) |
| 1618 | node->branch[i] = new_node; |
| 1619 | } |
| 1620 | } |
| 1621 | } |
| 1622 | |
| 1623 | /* Free the lists of passing strings for the previous level. Useful if we |
| 1624 | * building an exceptionally huge DFA. |
| 1625 | */ |
| 1626 | dfa_attrib_array_partially_clear(cutoff_point); |
| 1627 | |
| 1628 | if (graph->num_nodes != save_num_nodes) { |
| 1629 | /* If we have added any nodes, this level is not the last one. */ |
| 1630 | dfa_graph_build_level(graph, strings, level + 1, this_terminal_node, |
| 1631 | passing_strings_array); |
| 1632 | } |
| 1633 | } |
| 1634 | |
| 1635 | |
| 1636 | /* Convert a pattern to a string of masks. */ |
| 1637 | static char * |
| 1638 | dfa_prepare_string(const char *string) |
| 1639 | { |
| 1640 | int k; |
| 1641 | int l = strlen(string); |
| 1642 | char *dfa_string = malloc(l + 1); |
| 1643 | assert(dfa_string); |
| 1644 | |
| 1645 | for (k = 0; k < l; k++) { |
| 1646 | switch (string[k]) { |
| 1647 | case '$': dfa_string[k] = 15; break; /* 1111 */ |
| 1648 | case '-': |
| 1649 | case '|': |
| 1650 | case '+': |
| 1651 | case '#': dfa_string[k] = 8; break; /* 1000 */ |
| 1652 | case '.': |
| 1653 | case ',': |
| 1654 | case '!': |
| 1655 | case 'a': dfa_string[k] = 1; break; /* 0001 */ |
| 1656 | case '?': dfa_string[k] = 7; break; /* 0111 */ |
| 1657 | case 'O': dfa_string[k] = 2; break; /* 0010 */ |
| 1658 | case 'X': dfa_string[k] = 4; break; /* 0100 */ |
| 1659 | case 'o': dfa_string[k] = 3; break; /* 0011 */ |
| 1660 | case 'x': dfa_string[k] = 5; break; /* 0101 */ |
| 1661 | |
| 1662 | default: assert(0); /* Shouldn't happen. */ |
| 1663 | } |
| 1664 | } |
| 1665 | |
| 1666 | dfa_string[l] = 0; |
| 1667 | return dfa_string; |
| 1668 | } |
| 1669 | |
| 1670 | |
| 1671 | /* Initialize a dfa_patterns structure. */ |
| 1672 | void |
| 1673 | dfa_patterns_reset(dfa_patterns *patterns) |
| 1674 | { |
| 1675 | patterns->num_patterns = 0; |
| 1676 | patterns->patterns = NULL; |
| 1677 | patterns->last_pattern = NULL; |
| 1678 | |
| 1679 | dfa_graph_reset(&(patterns->graph)); |
| 1680 | } |
| 1681 | |
| 1682 | |
| 1683 | /* Clear the graph and reset all fields of a dfa_patterns structure. */ |
| 1684 | void |
| 1685 | dfa_patterns_clear(dfa_patterns *patterns) |
| 1686 | { |
| 1687 | dfa_pattern *pattern = patterns->patterns; |
| 1688 | |
| 1689 | while (pattern) { |
| 1690 | int k; |
| 1691 | dfa_pattern *next = pattern->next; |
| 1692 | |
| 1693 | for (k = 0; k < pattern->num_variations; k++) |
| 1694 | free(pattern->variation[k]); |
| 1695 | |
| 1696 | free(pattern); |
| 1697 | pattern = next; |
| 1698 | } |
| 1699 | |
| 1700 | patterns->num_patterns = 0; |
| 1701 | patterns->patterns = NULL; |
| 1702 | patterns->last_pattern = NULL; |
| 1703 | |
| 1704 | dfa_graph_clear(&(patterns->graph)); |
| 1705 | } |
| 1706 | |
| 1707 | |
| 1708 | /* Add a pattern to a list. If `index' is equal to the index of the last |
| 1709 | * added pattern, add a variation to that pattern instead. |
| 1710 | */ |
| 1711 | void |
| 1712 | dfa_patterns_add_pattern(dfa_patterns *patterns, const char *string, int index) |
| 1713 | { |
| 1714 | dfa_pattern *pattern = NULL; |
| 1715 | |
| 1716 | if (index == patterns->num_patterns - 1) { |
| 1717 | assert(patterns->last_pattern); |
| 1718 | assert(patterns->last_pattern->num_variations < 8); |
| 1719 | |
| 1720 | pattern = patterns->last_pattern; |
| 1721 | } |
| 1722 | else { |
| 1723 | assert(patterns->num_patterns <= index); |
| 1724 | |
| 1725 | while (patterns->num_patterns <= index) { |
| 1726 | patterns->num_patterns++; |
| 1727 | pattern = malloc(sizeof(*pattern)); |
| 1728 | pattern->num_variations = 0; |
| 1729 | |
| 1730 | if (patterns->last_pattern) |
| 1731 | patterns->last_pattern->next = pattern; |
| 1732 | else |
| 1733 | patterns->patterns = pattern; |
| 1734 | patterns->last_pattern = pattern; |
| 1735 | } |
| 1736 | |
| 1737 | pattern->current_variation = 0; |
| 1738 | pattern->next = NULL; |
| 1739 | } |
| 1740 | |
| 1741 | pattern->variation[pattern->num_variations++] = dfa_prepare_string(string); |
| 1742 | } |
| 1743 | |
| 1744 | |
| 1745 | /* Set the variation of the last pattern. Can be used in actual DFA building |
| 1746 | * or to set a hint (results of the previous optimization) for optimization. |
| 1747 | */ |
| 1748 | void |
| 1749 | dfa_patterns_set_last_pattern_variation(dfa_patterns *patterns, int variation) |
| 1750 | { |
| 1751 | assert(patterns->last_pattern); |
| 1752 | assert(patterns->last_pattern->num_variations > variation); |
| 1753 | |
| 1754 | patterns->last_pattern->current_variation = variation; |
| 1755 | } |
| 1756 | |
| 1757 | |
| 1758 | /* Make the shortest variation of the last pattern its current variation. It |
| 1759 | * is used as a starting point in DFA optimization process. |
| 1760 | */ |
| 1761 | void |
| 1762 | dfa_patterns_select_shortest_variation(dfa_patterns *patterns) |
| 1763 | { |
| 1764 | int k; |
| 1765 | int min_length; |
| 1766 | dfa_pattern *pattern = patterns->last_pattern; |
| 1767 | assert(pattern); |
| 1768 | |
| 1769 | pattern->current_variation = 0; |
| 1770 | min_length = strlen(pattern->variation[0]); |
| 1771 | for (k = 1; k < pattern->num_variations; k++) { |
| 1772 | int length = strlen(pattern->variation[k]); |
| 1773 | |
| 1774 | if (length < min_length) { |
| 1775 | pattern->current_variation = k; |
| 1776 | min_length = length; |
| 1777 | } |
| 1778 | } |
| 1779 | } |
| 1780 | |
| 1781 | |
| 1782 | /* Build a DFA graph for a list of patterns. */ |
| 1783 | void |
| 1784 | dfa_patterns_build_graph(dfa_patterns *patterns) |
| 1785 | { |
| 1786 | int k = 0; |
| 1787 | char **strings; |
| 1788 | dfa_attrib_array passing_strings_array; |
| 1789 | dfa_attrib **link; |
| 1790 | dfa_node *error_state; |
| 1791 | dfa_graph *graph = &(patterns->graph); |
| 1792 | dfa_pattern *pattern; |
| 1793 | |
| 1794 | strings = malloc(patterns->num_patterns * sizeof(*strings)); |
| 1795 | assert(strings); |
| 1796 | |
| 1797 | dfa_graph_clear(graph); |
| 1798 | dfa_attrib_array_reset(&passing_strings_array); |
| 1799 | |
| 1800 | /* Error state node is used as a terminator for level -1 (root node). */ |
| 1801 | error_state = dfa_node_new(graph); |
| 1802 | graph->root = dfa_node_new(graph); |
| 1803 | |
| 1804 | /* Add all strings as passing through root node (level -1). */ |
| 1805 | link = &(graph->root->passing_strings); |
| 1806 | for (pattern = patterns->patterns; pattern; pattern = pattern->next, k++) { |
| 1807 | if (pattern->num_variations > 0) { |
| 1808 | assert(pattern->current_variation < pattern->num_variations); |
| 1809 | strings[k] = pattern->variation[pattern->current_variation]; |
| 1810 | |
| 1811 | *link = dfa_attrib_new(&passing_strings_array, k); |
| 1812 | link = &((*link)->next); |
| 1813 | } |
| 1814 | else |
| 1815 | strings[k] = NULL; |
| 1816 | } |
| 1817 | |
| 1818 | dfa_graph_build_level(graph, strings, 0, error_state, &passing_strings_array); |
| 1819 | |
| 1820 | free(strings); |
| 1821 | dfa_attrib_array_clear(&passing_strings_array); |
| 1822 | } |
| 1823 | |
| 1824 | |
| 1825 | /* dfa_patterns_optimize_variations() tries to reduce the size of DFA by |
| 1826 | * altering pattern variations (in fact, transformations). The algorithm |
| 1827 | * is to change several patterns' variations and if this happens to give |
| 1828 | * size reduction, to keep the change, otherwise, revert. |
| 1829 | * |
| 1830 | * This function contains many heuristically chosen values for variation |
| 1831 | * changing probability etc. They have been chosen by observing algorithm |
| 1832 | * effectiveness and seem to be very good. |
| 1833 | * |
| 1834 | * Note that we subtract 1 from the number of nodes to be consistent with |
| 1835 | * the standard builder, which doesn't count error state. |
| 1836 | */ |
| 1837 | int * |
| 1838 | dfa_patterns_optimize_variations(dfa_patterns *patterns, int iterations) |
| 1839 | { |
| 1840 | int k = 0; |
| 1841 | int failed_iterations = 0; |
| 1842 | int min_nodes_so_far; |
| 1843 | int num_nodes_original; |
| 1844 | int *best_variations; |
| 1845 | double lower_limit = 2.0 / patterns->num_patterns; |
| 1846 | double upper_limit = 6.0 / patterns->num_patterns; |
| 1847 | double change_probability = 4.0 / patterns->num_patterns; |
| 1848 | dfa_pattern *pattern; |
| 1849 | |
| 1850 | best_variations = malloc(patterns->num_patterns * sizeof(*best_variations)); |
| 1851 | assert(best_variations); |
| 1852 | for (pattern = patterns->patterns; pattern; pattern = pattern->next, k++) |
| 1853 | best_variations[k] = pattern->current_variation; |
| 1854 | |
| 1855 | dfa_patterns_build_graph(patterns); |
| 1856 | num_nodes_original = patterns->graph.num_nodes; |
| 1857 | min_nodes_so_far = num_nodes_original; |
| 1858 | |
| 1859 | fprintf(stderr, "Original number of DFA states: %d\n", min_nodes_so_far - 1); |
| 1860 | fprintf(stderr, "Trying to optimize in %d iterations\n", iterations); |
| 1861 | |
| 1862 | gg_srand(num_nodes_original + patterns->num_patterns); |
| 1863 | |
| 1864 | while (iterations--) { |
| 1865 | int changed_variations = 0; |
| 1866 | int k = 0; |
| 1867 | |
| 1868 | /* Randomly change some variations. */ |
| 1869 | for (pattern = patterns->patterns; pattern; pattern = pattern->next, k++) { |
| 1870 | if (gg_drand() < change_probability && pattern->num_variations > 1) { |
| 1871 | int new_variation = gg_rand() % (pattern->num_variations - 1); |
| 1872 | if (new_variation >= pattern->current_variation) |
| 1873 | new_variation++; |
| 1874 | pattern->current_variation = new_variation; |
| 1875 | changed_variations++; |
| 1876 | } |
| 1877 | else |
| 1878 | pattern->current_variation = best_variations[k]; |
| 1879 | } |
| 1880 | |
| 1881 | if (changed_variations == 0) { |
| 1882 | iterations++; |
| 1883 | continue; |
| 1884 | } |
| 1885 | |
| 1886 | fprintf(stderr, "."); |
| 1887 | dfa_patterns_build_graph(patterns); |
| 1888 | |
| 1889 | if (patterns->graph.num_nodes < min_nodes_so_far) { |
| 1890 | /* If the new set of variations produces smaller dfa, save it. */ |
| 1891 | int k = 0; |
| 1892 | for (pattern = patterns->patterns; pattern; pattern = pattern->next, k++) |
| 1893 | best_variations[k] = pattern->current_variation; |
| 1894 | |
| 1895 | fprintf(stderr, "\nOptimized: %d => %d states (%d iterations left)\n", |
| 1896 | min_nodes_so_far - 1, patterns->graph.num_nodes - 1, iterations); |
| 1897 | min_nodes_so_far = patterns->graph.num_nodes; |
| 1898 | failed_iterations = 0; |
| 1899 | } |
| 1900 | else |
| 1901 | failed_iterations++; |
| 1902 | |
| 1903 | if (failed_iterations >= 30) { |
| 1904 | /* If haven't succeded in 30 last iterations, try to alter variation |
| 1905 | * change probability. |
| 1906 | */ |
| 1907 | double delta = gg_drand() / patterns->num_patterns; |
| 1908 | if (change_probability > upper_limit |
| 1909 | || (change_probability >= lower_limit && gg_rand() % 2 == 0)) |
| 1910 | delta = -delta; |
| 1911 | |
| 1912 | change_probability += delta; |
| 1913 | failed_iterations = 0; |
| 1914 | } |
| 1915 | } |
| 1916 | |
| 1917 | fprintf(stderr, "\nTotal optimization result: %d => %d states\n", |
| 1918 | num_nodes_original - 1, min_nodes_so_far - 1); |
| 1919 | |
| 1920 | dfa_graph_clear(&(patterns->graph)); |
| 1921 | return best_variations; |
| 1922 | } |
| 1923 | |
| 1924 | |
| 1925 | /* |
| 1926 | * Local Variables: |
| 1927 | * tab-width: 8 |
| 1928 | * c-basic-offset: 2 |
| 1929 | * End: |
| 1930 | */ |