1 /*- 2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/time.h> 32 33 #include <assert.h> 34 #include <stdlib.h> 35 #include <string.h> 36 37 #include "cachelib.h" 38 #include "debug.h" 39 40 #define INITIAL_ENTRIES_CAPACITY 32 41 #define ENTRIES_CAPACITY_STEP 32 42 43 #define STRING_SIMPLE_HASH_BODY(in_var, var, a, M) \ 44 for ((var) = 0; *(in_var) != '\0'; ++(in_var)) \ 45 (var) = ((a)*(var) + *(in_var)) % (M) 46 47 #define STRING_SIMPLE_MP2_HASH_BODY(in_var, var, a, M) \ 48 for ((var) = 0; *(in_var) != 0; ++(in_var)) \ 49 (var) = ((a)*(var) + *(in_var)) & (M - 1) 50 51 static int cache_elemsize_common_continue_func(struct cache_common_entry_ *, 52 struct cache_policy_item_ *); 53 static int cache_lifetime_common_continue_func(struct cache_common_entry_ *, 54 struct cache_policy_item_ *); 55 static void clear_cache_entry(struct cache_entry_ *); 56 static void destroy_cache_entry(struct cache_entry_ *); 57 static void destroy_cache_mp_read_session(struct cache_mp_read_session_ *); 58 static void destroy_cache_mp_write_session(struct cache_mp_write_session_ *); 59 static int entries_bsearch_cmp_func(const void *, const void *); 60 static int entries_qsort_cmp_func(const void *, const void *); 61 static struct cache_entry_ ** find_cache_entry_p(struct cache_ *, 62 const char *); 63 static void flush_cache_entry(struct cache_entry_ *); 64 static void flush_cache_policy(struct cache_common_entry_ *, 65 struct cache_policy_ *, struct cache_policy_ *, 66 int (*)(struct cache_common_entry_ *, 67 struct cache_policy_item_ *)); 68 static int ht_items_cmp_func(const void *, const void *); 69 static int ht_items_fixed_size_left_cmp_func(const void *, const void *); 70 static hashtable_index_t ht_item_hash_func(const void *, size_t); 71 72 /* 73 * Hashing and comparing routines, that are used with the hash tables 74 */ 75 static int 76 ht_items_cmp_func(const void *p1, const void *p2) 77 { 78 struct cache_ht_item_data_ *hp1, *hp2; 79 size_t min_size; 80 int result; 81 82 hp1 = (struct cache_ht_item_data_ *)p1; 83 hp2 = (struct cache_ht_item_data_ *)p2; 84 85 assert(hp1->key != NULL); 86 assert(hp2->key != NULL); 87 88 if (hp1->key_size != hp2->key_size) { 89 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size : 90 hp2->key_size; 91 result = memcmp(hp1->key, hp2->key, min_size); 92 93 if (result == 0) 94 return ((hp1->key_size < hp2->key_size) ? -1 : 1); 95 else 96 return (result); 97 } else 98 return (memcmp(hp1->key, hp2->key, hp1->key_size)); 99 } 100 101 static int 102 ht_items_fixed_size_left_cmp_func(const void *p1, const void *p2) 103 { 104 struct cache_ht_item_data_ *hp1, *hp2; 105 size_t min_size; 106 int result; 107 108 hp1 = (struct cache_ht_item_data_ *)p1; 109 hp2 = (struct cache_ht_item_data_ *)p2; 110 111 assert(hp1->key != NULL); 112 assert(hp2->key != NULL); 113 114 if (hp1->key_size != hp2->key_size) { 115 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size : 116 hp2->key_size; 117 result = memcmp(hp1->key, hp2->key, min_size); 118 119 if (result == 0) 120 if (min_size == hp1->key_size) 121 return (0); 122 else 123 return ((hp1->key_size < hp2->key_size) ? -1 : 1); 124 else 125 return (result); 126 } else 127 return (memcmp(hp1->key, hp2->key, hp1->key_size)); 128 } 129 130 static hashtable_index_t 131 ht_item_hash_func(const void *p, size_t cache_entries_size) 132 { 133 struct cache_ht_item_data_ *hp; 134 size_t i; 135 136 hashtable_index_t retval; 137 138 hp = (struct cache_ht_item_data_ *)p; 139 assert(hp->key != NULL); 140 141 retval = 0; 142 for (i = 0; i < hp->key_size; ++i) 143 retval = (127 * retval + (unsigned char)hp->key[i]) % 144 cache_entries_size; 145 146 return retval; 147 } 148 149 HASHTABLE_PROTOTYPE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_); 150 HASHTABLE_GENERATE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_, data, 151 ht_item_hash_func, ht_items_cmp_func); 152 153 /* 154 * Routines to sort and search the entries by name 155 */ 156 static int 157 entries_bsearch_cmp_func(const void *key, const void *ent) 158 { 159 160 assert(key != NULL); 161 assert(ent != NULL); 162 163 return (strcmp((char const *)key, 164 (*(struct cache_entry_ const **)ent)->name)); 165 } 166 167 static int 168 entries_qsort_cmp_func(const void *e1, const void *e2) 169 { 170 171 assert(e1 != NULL); 172 assert(e2 != NULL); 173 174 return (strcmp((*(struct cache_entry_ const **)e1)->name, 175 (*(struct cache_entry_ const **)e2)->name)); 176 } 177 178 static struct cache_entry_ ** 179 find_cache_entry_p(struct cache_ *the_cache, const char *entry_name) 180 { 181 182 return ((struct cache_entry_ **)(bsearch(entry_name, the_cache->entries, 183 the_cache->entries_size, sizeof(struct cache_entry_ *), 184 entries_bsearch_cmp_func))); 185 } 186 187 static void 188 destroy_cache_mp_write_session(struct cache_mp_write_session_ *ws) 189 { 190 191 struct cache_mp_data_item_ *data_item; 192 193 TRACE_IN(destroy_cache_mp_write_session); 194 assert(ws != NULL); 195 while (!TAILQ_EMPTY(&ws->items)) { 196 data_item = TAILQ_FIRST(&ws->items); 197 TAILQ_REMOVE(&ws->items, data_item, entries); 198 free(data_item->value); 199 free(data_item); 200 } 201 202 free(ws); 203 TRACE_OUT(destroy_cache_mp_write_session); 204 } 205 206 static void 207 destroy_cache_mp_read_session(struct cache_mp_read_session_ *rs) 208 { 209 210 TRACE_IN(destroy_cache_mp_read_session); 211 assert(rs != NULL); 212 free(rs); 213 TRACE_OUT(destroy_cache_mp_read_session); 214 } 215 216 static void 217 destroy_cache_entry(struct cache_entry_ *entry) 218 { 219 struct cache_common_entry_ *common_entry; 220 struct cache_mp_entry_ *mp_entry; 221 struct cache_mp_read_session_ *rs; 222 struct cache_mp_write_session_ *ws; 223 struct cache_ht_item_ *ht_item; 224 struct cache_ht_item_data_ *ht_item_data; 225 226 TRACE_IN(destroy_cache_entry); 227 assert(entry != NULL); 228 229 if (entry->params->entry_type == CET_COMMON) { 230 common_entry = (struct cache_common_entry_ *)entry; 231 232 HASHTABLE_FOREACH(&(common_entry->items), ht_item) { 233 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data) 234 { 235 free(ht_item_data->key); 236 free(ht_item_data->value); 237 } 238 HASHTABLE_ENTRY_CLEAR(ht_item, data); 239 } 240 241 HASHTABLE_DESTROY(&(common_entry->items), data); 242 243 /* FIFO policy is always first */ 244 destroy_cache_fifo_policy(common_entry->policies[0]); 245 switch (common_entry->common_params.policy) { 246 case CPT_LRU: 247 destroy_cache_lru_policy(common_entry->policies[1]); 248 break; 249 case CPT_LFU: 250 destroy_cache_lfu_policy(common_entry->policies[1]); 251 break; 252 default: 253 break; 254 } 255 free(common_entry->policies); 256 } else { 257 mp_entry = (struct cache_mp_entry_ *)entry; 258 259 while (!TAILQ_EMPTY(&mp_entry->ws_head)) { 260 ws = TAILQ_FIRST(&mp_entry->ws_head); 261 TAILQ_REMOVE(&mp_entry->ws_head, ws, entries); 262 destroy_cache_mp_write_session(ws); 263 } 264 265 while (!TAILQ_EMPTY(&mp_entry->rs_head)) { 266 rs = TAILQ_FIRST(&mp_entry->rs_head); 267 TAILQ_REMOVE(&mp_entry->rs_head, rs, entries); 268 destroy_cache_mp_read_session(rs); 269 } 270 271 if (mp_entry->completed_write_session != NULL) 272 destroy_cache_mp_write_session( 273 mp_entry->completed_write_session); 274 275 if (mp_entry->pending_write_session != NULL) 276 destroy_cache_mp_write_session( 277 mp_entry->pending_write_session); 278 } 279 280 free(entry->name); 281 free(entry); 282 TRACE_OUT(destroy_cache_entry); 283 } 284 285 static void 286 clear_cache_entry(struct cache_entry_ *entry) 287 { 288 struct cache_mp_entry_ *mp_entry; 289 struct cache_common_entry_ *common_entry; 290 struct cache_ht_item_ *ht_item; 291 struct cache_ht_item_data_ *ht_item_data; 292 struct cache_policy_ *policy; 293 struct cache_policy_item_ *item, *next_item; 294 size_t entry_size; 295 unsigned int i; 296 297 if (entry->params->entry_type == CET_COMMON) { 298 common_entry = (struct cache_common_entry_ *)entry; 299 300 entry_size = 0; 301 HASHTABLE_FOREACH(&(common_entry->items), ht_item) { 302 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data) 303 { 304 free(ht_item_data->key); 305 free(ht_item_data->value); 306 } 307 entry_size += HASHTABLE_ENTRY_SIZE(ht_item, data); 308 HASHTABLE_ENTRY_CLEAR(ht_item, data); 309 } 310 311 common_entry->items_size -= entry_size; 312 for (i = 0; i < common_entry->policies_size; ++i) { 313 policy = common_entry->policies[i]; 314 315 next_item = NULL; 316 item = policy->get_first_item_func(policy); 317 while (item != NULL) { 318 next_item = policy->get_next_item_func(policy, 319 item); 320 policy->remove_item_func(policy, item); 321 policy->destroy_item_func(item); 322 item = next_item; 323 } 324 } 325 } else { 326 mp_entry = (struct cache_mp_entry_ *)entry; 327 328 if (mp_entry->rs_size == 0) { 329 if (mp_entry->completed_write_session != NULL) { 330 destroy_cache_mp_write_session( 331 mp_entry->completed_write_session); 332 mp_entry->completed_write_session = NULL; 333 } 334 335 memset(&mp_entry->creation_time, 0, 336 sizeof(struct timeval)); 337 memset(&mp_entry->last_request_time, 0, 338 sizeof(struct timeval)); 339 } 340 } 341 } 342 343 /* 344 * When passed to the flush_cache_policy, ensures that all old elements are 345 * deleted. 346 */ 347 static int 348 cache_lifetime_common_continue_func(struct cache_common_entry_ *entry, 349 struct cache_policy_item_ *item) 350 { 351 352 return ((item->last_request_time.tv_sec - item->creation_time.tv_sec > 353 entry->common_params.max_lifetime.tv_sec) ? 1: 0); 354 } 355 356 /* 357 * When passed to the flush_cache_policy, ensures that all elements, that 358 * exceed the size limit, are deleted. 359 */ 360 static int 361 cache_elemsize_common_continue_func(struct cache_common_entry_ *entry, 362 struct cache_policy_item_ *item) 363 { 364 365 return ((entry->items_size > entry->common_params.satisf_elemsize) ? 1 366 : 0); 367 } 368 369 /* 370 * Removes the elements from the cache entry, while the continue_func returns 1. 371 */ 372 static void 373 flush_cache_policy(struct cache_common_entry_ *entry, 374 struct cache_policy_ *policy, 375 struct cache_policy_ *connected_policy, 376 int (*continue_func)(struct cache_common_entry_ *, 377 struct cache_policy_item_ *)) 378 { 379 struct cache_policy_item_ *item, *next_item, *connected_item; 380 struct cache_ht_item_ *ht_item; 381 struct cache_ht_item_data_ *ht_item_data, ht_key; 382 hashtable_index_t hash; 383 384 assert(policy != NULL); 385 386 next_item = NULL; 387 item = policy->get_first_item_func(policy); 388 while ((item != NULL) && (continue_func(entry, item) == 1)) { 389 next_item = policy->get_next_item_func(policy, item); 390 391 connected_item = item->connected_item; 392 policy->remove_item_func(policy, item); 393 394 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_)); 395 ht_key.key = item->key; 396 ht_key.key_size = item->key_size; 397 398 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &entry->items, 399 &ht_key); 400 assert(hash < HASHTABLE_ENTRIES_COUNT(&entry->items)); 401 402 ht_item = HASHTABLE_GET_ENTRY(&(entry->items), hash); 403 ht_item_data = HASHTABLE_ENTRY_FIND(cache_ht_, ht_item, 404 &ht_key); 405 assert(ht_item_data != NULL); 406 free(ht_item_data->key); 407 free(ht_item_data->value); 408 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item, ht_item_data); 409 --entry->items_size; 410 411 policy->destroy_item_func(item); 412 413 if (connected_item != NULL) { 414 connected_policy->remove_item_func(connected_policy, 415 connected_item); 416 connected_policy->destroy_item_func(connected_item); 417 } 418 419 item = next_item; 420 } 421 } 422 423 static void 424 flush_cache_entry(struct cache_entry_ *entry) 425 { 426 struct cache_mp_entry_ *mp_entry; 427 struct cache_common_entry_ *common_entry; 428 struct cache_policy_ *policy, *connected_policy; 429 430 connected_policy = NULL; 431 if (entry->params->entry_type == CET_COMMON) { 432 common_entry = (struct cache_common_entry_ *)entry; 433 if ((common_entry->common_params.max_lifetime.tv_sec != 0) || 434 (common_entry->common_params.max_lifetime.tv_usec != 0)) { 435 436 policy = common_entry->policies[0]; 437 if (common_entry->policies_size > 1) 438 connected_policy = common_entry->policies[1]; 439 440 flush_cache_policy(common_entry, policy, 441 connected_policy, 442 cache_lifetime_common_continue_func); 443 } 444 445 446 if ((common_entry->common_params.max_elemsize != 0) && 447 common_entry->items_size > 448 common_entry->common_params.max_elemsize) { 449 450 if (common_entry->policies_size > 1) { 451 policy = common_entry->policies[1]; 452 connected_policy = common_entry->policies[0]; 453 } else { 454 policy = common_entry->policies[0]; 455 connected_policy = NULL; 456 } 457 458 flush_cache_policy(common_entry, policy, 459 connected_policy, 460 cache_elemsize_common_continue_func); 461 } 462 } else { 463 mp_entry = (struct cache_mp_entry_ *)entry; 464 465 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0) 466 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) { 467 468 if (mp_entry->last_request_time.tv_sec - 469 mp_entry->last_request_time.tv_sec > 470 mp_entry->mp_params.max_lifetime.tv_sec) 471 clear_cache_entry(entry); 472 } 473 } 474 } 475 476 struct cache_ * 477 init_cache(struct cache_params const *params) 478 { 479 struct cache_ *retval; 480 481 TRACE_IN(init_cache); 482 assert(params != NULL); 483 484 retval = calloc(1, sizeof(*retval)); 485 assert(retval != NULL); 486 487 assert(params != NULL); 488 memcpy(&retval->params, params, sizeof(struct cache_params)); 489 490 retval->entries = calloc(1, 491 sizeof(*retval->entries) * INITIAL_ENTRIES_CAPACITY); 492 assert(retval->entries != NULL); 493 494 retval->entries_capacity = INITIAL_ENTRIES_CAPACITY; 495 retval->entries_size = 0; 496 497 TRACE_OUT(init_cache); 498 return (retval); 499 } 500 501 void 502 destroy_cache(struct cache_ *the_cache) 503 { 504 505 TRACE_IN(destroy_cache); 506 assert(the_cache != NULL); 507 508 if (the_cache->entries != NULL) { 509 size_t i; 510 for (i = 0; i < the_cache->entries_size; ++i) 511 destroy_cache_entry(the_cache->entries[i]); 512 513 free(the_cache->entries); 514 } 515 516 free(the_cache); 517 TRACE_OUT(destroy_cache); 518 } 519 520 int 521 register_cache_entry(struct cache_ *the_cache, 522 struct cache_entry_params const *params) 523 { 524 int policies_size; 525 size_t entry_name_size; 526 struct cache_common_entry_ *new_common_entry; 527 struct cache_mp_entry_ *new_mp_entry; 528 529 TRACE_IN(register_cache_entry); 530 assert(the_cache != NULL); 531 532 if (find_cache_entry(the_cache, params->entry_name) != NULL) { 533 TRACE_OUT(register_cache_entry); 534 return (-1); 535 } 536 537 if (the_cache->entries_size == the_cache->entries_capacity) { 538 struct cache_entry_ **new_entries; 539 size_t new_capacity; 540 541 new_capacity = the_cache->entries_capacity + 542 ENTRIES_CAPACITY_STEP; 543 new_entries = calloc(1, 544 sizeof(*new_entries) * new_capacity); 545 assert(new_entries != NULL); 546 547 memcpy(new_entries, the_cache->entries, 548 sizeof(struct cache_entry_ *) 549 * the_cache->entries_size); 550 551 free(the_cache->entries); 552 the_cache->entries = new_entries; 553 } 554 555 entry_name_size = strlen(params->entry_name) + 1; 556 switch (params->entry_type) 557 { 558 case CET_COMMON: 559 new_common_entry = calloc(1, 560 sizeof(*new_common_entry)); 561 assert(new_common_entry != NULL); 562 563 memcpy(&new_common_entry->common_params, params, 564 sizeof(struct common_cache_entry_params)); 565 new_common_entry->params = 566 (struct cache_entry_params *)&new_common_entry->common_params; 567 568 new_common_entry->common_params.cep.entry_name = calloc(1, 569 entry_name_size); 570 assert(new_common_entry->common_params.cep.entry_name != NULL); 571 strlcpy(new_common_entry->common_params.cep.entry_name, 572 params->entry_name, entry_name_size); 573 new_common_entry->name = 574 new_common_entry->common_params.cep.entry_name; 575 576 HASHTABLE_INIT(&(new_common_entry->items), 577 struct cache_ht_item_data_, data, 578 new_common_entry->common_params.cache_entries_size); 579 580 if (new_common_entry->common_params.policy == CPT_FIFO) 581 policies_size = 1; 582 else 583 policies_size = 2; 584 585 new_common_entry->policies = calloc(1, 586 sizeof(*new_common_entry->policies) * policies_size); 587 assert(new_common_entry->policies != NULL); 588 589 new_common_entry->policies_size = policies_size; 590 new_common_entry->policies[0] = init_cache_fifo_policy(); 591 592 if (policies_size > 1) { 593 switch (new_common_entry->common_params.policy) { 594 case CPT_LRU: 595 new_common_entry->policies[1] = 596 init_cache_lru_policy(); 597 break; 598 case CPT_LFU: 599 new_common_entry->policies[1] = 600 init_cache_lfu_policy(); 601 break; 602 default: 603 break; 604 } 605 } 606 607 new_common_entry->get_time_func = 608 the_cache->params.get_time_func; 609 the_cache->entries[the_cache->entries_size++] = 610 (struct cache_entry_ *)new_common_entry; 611 break; 612 case CET_MULTIPART: 613 new_mp_entry = calloc(1, 614 sizeof(*new_mp_entry)); 615 assert(new_mp_entry != NULL); 616 617 memcpy(&new_mp_entry->mp_params, params, 618 sizeof(struct mp_cache_entry_params)); 619 new_mp_entry->params = 620 (struct cache_entry_params *)&new_mp_entry->mp_params; 621 622 new_mp_entry->mp_params.cep.entry_name = calloc(1, 623 entry_name_size); 624 assert(new_mp_entry->mp_params.cep.entry_name != NULL); 625 strlcpy(new_mp_entry->mp_params.cep.entry_name, params->entry_name, 626 entry_name_size); 627 new_mp_entry->name = new_mp_entry->mp_params.cep.entry_name; 628 629 TAILQ_INIT(&new_mp_entry->ws_head); 630 TAILQ_INIT(&new_mp_entry->rs_head); 631 632 new_mp_entry->get_time_func = the_cache->params.get_time_func; 633 the_cache->entries[the_cache->entries_size++] = 634 (struct cache_entry_ *)new_mp_entry; 635 break; 636 } 637 638 639 qsort(the_cache->entries, the_cache->entries_size, 640 sizeof(struct cache_entry_ *), entries_qsort_cmp_func); 641 642 TRACE_OUT(register_cache_entry); 643 return (0); 644 } 645 646 int 647 unregister_cache_entry(struct cache_ *the_cache, const char *entry_name) 648 { 649 struct cache_entry_ **del_ent; 650 651 TRACE_IN(unregister_cache_entry); 652 assert(the_cache != NULL); 653 654 del_ent = find_cache_entry_p(the_cache, entry_name); 655 if (del_ent != NULL) { 656 destroy_cache_entry(*del_ent); 657 --the_cache->entries_size; 658 659 memmove(del_ent, del_ent + 1, 660 (&(the_cache->entries[--the_cache->entries_size]) - 661 del_ent) * sizeof(struct cache_entry_ *)); 662 663 TRACE_OUT(unregister_cache_entry); 664 return (0); 665 } else { 666 TRACE_OUT(unregister_cache_entry); 667 return (-1); 668 } 669 } 670 671 struct cache_entry_ * 672 find_cache_entry(struct cache_ *the_cache, const char *entry_name) 673 { 674 struct cache_entry_ **result; 675 676 TRACE_IN(find_cache_entry); 677 result = find_cache_entry_p(the_cache, entry_name); 678 679 if (result == NULL) { 680 TRACE_OUT(find_cache_entry); 681 return (NULL); 682 } else { 683 TRACE_OUT(find_cache_entry); 684 return (*result); 685 } 686 } 687 688 /* 689 * Tries to read the element with the specified key from the cache. If the 690 * value_size is too small, it will be filled with the proper number, and 691 * the user will need to call cache_read again with the value buffer, that 692 * is large enough. 693 * Function returns 0 on success, -1 on error, and -2 if the value_size is too 694 * small. 695 */ 696 int 697 cache_read(struct cache_entry_ *entry, const char *key, size_t key_size, 698 char *value, size_t *value_size) 699 { 700 struct cache_common_entry_ *common_entry; 701 struct cache_ht_item_data_ item_data, *find_res; 702 struct cache_ht_item_ *item; 703 hashtable_index_t hash; 704 struct cache_policy_item_ *connected_item; 705 706 TRACE_IN(cache_read); 707 assert(entry != NULL); 708 assert(key != NULL); 709 assert(value_size != NULL); 710 assert(entry->params->entry_type == CET_COMMON); 711 712 common_entry = (struct cache_common_entry_ *)entry; 713 714 memset(&item_data, 0, sizeof(struct cache_ht_item_data_)); 715 /* can't avoid the cast here */ 716 item_data.key = (char *)key; 717 item_data.key_size = key_size; 718 719 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items, 720 &item_data); 721 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items)); 722 723 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash); 724 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data); 725 if (find_res == NULL) { 726 TRACE_OUT(cache_read); 727 return (-1); 728 } 729 /* pretend that entry was not found if confidence is below threshold*/ 730 if (find_res->confidence < 731 common_entry->common_params.confidence_threshold) { 732 TRACE_OUT(cache_read); 733 return (-1); 734 } 735 736 if ((common_entry->common_params.max_lifetime.tv_sec != 0) || 737 (common_entry->common_params.max_lifetime.tv_usec != 0)) { 738 739 if (find_res->fifo_policy_item->last_request_time.tv_sec - 740 find_res->fifo_policy_item->creation_time.tv_sec > 741 common_entry->common_params.max_lifetime.tv_sec) { 742 743 free(find_res->key); 744 free(find_res->value); 745 746 connected_item = 747 find_res->fifo_policy_item->connected_item; 748 if (connected_item != NULL) { 749 common_entry->policies[1]->remove_item_func( 750 common_entry->policies[1], 751 connected_item); 752 common_entry->policies[1]->destroy_item_func( 753 connected_item); 754 } 755 756 common_entry->policies[0]->remove_item_func( 757 common_entry->policies[0], 758 find_res->fifo_policy_item); 759 common_entry->policies[0]->destroy_item_func( 760 find_res->fifo_policy_item); 761 762 HASHTABLE_ENTRY_REMOVE(cache_ht_, item, find_res); 763 --common_entry->items_size; 764 } 765 } 766 767 if ((*value_size < find_res->value_size) || (value == NULL)) { 768 *value_size = find_res->value_size; 769 TRACE_OUT(cache_read); 770 return (-2); 771 } 772 773 *value_size = find_res->value_size; 774 memcpy(value, find_res->value, find_res->value_size); 775 776 ++find_res->fifo_policy_item->request_count; 777 common_entry->get_time_func( 778 &find_res->fifo_policy_item->last_request_time); 779 common_entry->policies[0]->update_item_func(common_entry->policies[0], 780 find_res->fifo_policy_item); 781 782 if (find_res->fifo_policy_item->connected_item != NULL) { 783 connected_item = find_res->fifo_policy_item->connected_item; 784 memcpy(&connected_item->last_request_time, 785 &find_res->fifo_policy_item->last_request_time, 786 sizeof(struct timeval)); 787 connected_item->request_count = 788 find_res->fifo_policy_item->request_count; 789 790 common_entry->policies[1]->update_item_func( 791 common_entry->policies[1], connected_item); 792 } 793 794 TRACE_OUT(cache_read); 795 return (0); 796 } 797 798 /* 799 * Writes the value with the specified key into the cache entry. 800 * Functions returns 0 on success, and -1 on error. 801 */ 802 int 803 cache_write(struct cache_entry_ *entry, const char *key, size_t key_size, 804 char const *value, size_t value_size) 805 { 806 struct cache_common_entry_ *common_entry; 807 struct cache_ht_item_data_ item_data, *find_res; 808 struct cache_ht_item_ *item; 809 hashtable_index_t hash; 810 811 struct cache_policy_ *policy, *connected_policy; 812 struct cache_policy_item_ *policy_item; 813 struct cache_policy_item_ *connected_policy_item; 814 815 TRACE_IN(cache_write); 816 assert(entry != NULL); 817 assert(key != NULL); 818 assert(value != NULL); 819 assert(entry->params->entry_type == CET_COMMON); 820 821 common_entry = (struct cache_common_entry_ *)entry; 822 823 memset(&item_data, 0, sizeof(struct cache_ht_item_data_)); 824 /* can't avoid the cast here */ 825 item_data.key = (char *)key; 826 item_data.key_size = key_size; 827 828 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items, 829 &item_data); 830 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items)); 831 832 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash); 833 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data); 834 if (find_res != NULL) { 835 if (find_res->confidence < common_entry->common_params.confidence_threshold) { 836 /* duplicate entry is no error, if confidence is low */ 837 if ((find_res->value_size == value_size) && 838 (memcmp(find_res->value, value, value_size) == 0)) { 839 /* increase confidence on exact match (key and values) */ 840 find_res->confidence++; 841 } else { 842 /* create new entry with low confidence, if value changed */ 843 free(item_data.value); 844 item_data.value = malloc(value_size); 845 assert(item_data.value != NULL); 846 memcpy(item_data.value, value, value_size); 847 item_data.value_size = value_size; 848 find_res->confidence = 1; 849 } 850 TRACE_OUT(cache_write); 851 return (0); 852 } 853 TRACE_OUT(cache_write); 854 return (-1); 855 } 856 857 item_data.key = malloc(key_size); 858 memcpy(item_data.key, key, key_size); 859 860 item_data.value = malloc(value_size); 861 assert(item_data.value != NULL); 862 863 memcpy(item_data.value, value, value_size); 864 item_data.value_size = value_size; 865 866 item_data.confidence = 1; 867 868 policy_item = common_entry->policies[0]->create_item_func(); 869 policy_item->key = item_data.key; 870 policy_item->key_size = item_data.key_size; 871 common_entry->get_time_func(&policy_item->creation_time); 872 873 if (common_entry->policies_size > 1) { 874 connected_policy_item = 875 common_entry->policies[1]->create_item_func(); 876 memcpy(&connected_policy_item->creation_time, 877 &policy_item->creation_time, 878 sizeof(struct timeval)); 879 connected_policy_item->key = policy_item->key; 880 connected_policy_item->key_size = policy_item->key_size; 881 882 connected_policy_item->connected_item = policy_item; 883 policy_item->connected_item = connected_policy_item; 884 } 885 886 item_data.fifo_policy_item = policy_item; 887 888 common_entry->policies[0]->add_item_func(common_entry->policies[0], 889 policy_item); 890 if (common_entry->policies_size > 1) 891 common_entry->policies[1]->add_item_func( 892 common_entry->policies[1], connected_policy_item); 893 894 HASHTABLE_ENTRY_STORE(cache_ht_, item, &item_data); 895 ++common_entry->items_size; 896 897 if ((common_entry->common_params.max_elemsize != 0) && 898 (common_entry->items_size > 899 common_entry->common_params.max_elemsize)) { 900 if (common_entry->policies_size > 1) { 901 policy = common_entry->policies[1]; 902 connected_policy = common_entry->policies[0]; 903 } else { 904 policy = common_entry->policies[0]; 905 connected_policy = NULL; 906 } 907 908 flush_cache_policy(common_entry, policy, connected_policy, 909 cache_elemsize_common_continue_func); 910 } 911 912 TRACE_OUT(cache_write); 913 return (0); 914 } 915 916 /* 917 * Initializes the write session for the specified multipart entry. This 918 * session then should be filled with data either committed or abandoned by 919 * using close_cache_mp_write_session or abandon_cache_mp_write_session 920 * respectively. 921 * Returns NULL on errors (when there are too many opened write sessions for 922 * the entry). 923 */ 924 struct cache_mp_write_session_ * 925 open_cache_mp_write_session(struct cache_entry_ *entry) 926 { 927 struct cache_mp_entry_ *mp_entry; 928 struct cache_mp_write_session_ *retval; 929 930 TRACE_IN(open_cache_mp_write_session); 931 assert(entry != NULL); 932 assert(entry->params->entry_type == CET_MULTIPART); 933 mp_entry = (struct cache_mp_entry_ *)entry; 934 935 if ((mp_entry->mp_params.max_sessions > 0) && 936 (mp_entry->ws_size == mp_entry->mp_params.max_sessions)) { 937 TRACE_OUT(open_cache_mp_write_session); 938 return (NULL); 939 } 940 941 retval = calloc(1, 942 sizeof(*retval)); 943 assert(retval != NULL); 944 945 TAILQ_INIT(&retval->items); 946 retval->parent_entry = mp_entry; 947 948 TAILQ_INSERT_HEAD(&mp_entry->ws_head, retval, entries); 949 ++mp_entry->ws_size; 950 951 TRACE_OUT(open_cache_mp_write_session); 952 return (retval); 953 } 954 955 /* 956 * Writes data to the specified session. Return 0 on success and -1 on errors 957 * (when write session size limit is exceeded). 958 */ 959 int 960 cache_mp_write(struct cache_mp_write_session_ *ws, char *data, 961 size_t data_size) 962 { 963 struct cache_mp_data_item_ *new_item; 964 965 TRACE_IN(cache_mp_write); 966 assert(ws != NULL); 967 assert(ws->parent_entry != NULL); 968 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 969 970 if ((ws->parent_entry->mp_params.max_elemsize > 0) && 971 (ws->parent_entry->mp_params.max_elemsize == ws->items_size)) { 972 TRACE_OUT(cache_mp_write); 973 return (-1); 974 } 975 976 new_item = calloc(1, 977 sizeof(*new_item)); 978 assert(new_item != NULL); 979 980 new_item->value = malloc(data_size); 981 assert(new_item->value != NULL); 982 memcpy(new_item->value, data, data_size); 983 new_item->value_size = data_size; 984 985 TAILQ_INSERT_TAIL(&ws->items, new_item, entries); 986 ++ws->items_size; 987 988 TRACE_OUT(cache_mp_write); 989 return (0); 990 } 991 992 /* 993 * Abandons the write session and frees all the connected resources. 994 */ 995 void 996 abandon_cache_mp_write_session(struct cache_mp_write_session_ *ws) 997 { 998 999 TRACE_IN(abandon_cache_mp_write_session); 1000 assert(ws != NULL); 1001 assert(ws->parent_entry != NULL); 1002 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 1003 1004 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries); 1005 --ws->parent_entry->ws_size; 1006 1007 destroy_cache_mp_write_session(ws); 1008 TRACE_OUT(abandon_cache_mp_write_session); 1009 } 1010 1011 /* 1012 * Commits the session to the entry, for which it was created. 1013 */ 1014 void 1015 close_cache_mp_write_session(struct cache_mp_write_session_ *ws) 1016 { 1017 1018 TRACE_IN(close_cache_mp_write_session); 1019 assert(ws != NULL); 1020 assert(ws->parent_entry != NULL); 1021 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 1022 1023 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries); 1024 --ws->parent_entry->ws_size; 1025 1026 if (ws->parent_entry->completed_write_session == NULL) { 1027 /* 1028 * If there is no completed session yet, this will be the one 1029 */ 1030 ws->parent_entry->get_time_func( 1031 &ws->parent_entry->creation_time); 1032 ws->parent_entry->completed_write_session = ws; 1033 } else { 1034 /* 1035 * If there is a completed session, then we'll save our session 1036 * as a pending session. If there is already a pending session, 1037 * it would be destroyed. 1038 */ 1039 if (ws->parent_entry->pending_write_session != NULL) 1040 destroy_cache_mp_write_session( 1041 ws->parent_entry->pending_write_session); 1042 1043 ws->parent_entry->pending_write_session = ws; 1044 } 1045 TRACE_OUT(close_cache_mp_write_session); 1046 } 1047 1048 /* 1049 * Opens read session for the specified entry. Returns NULL on errors (when 1050 * there are no data in the entry, or the data are obsolete). 1051 */ 1052 struct cache_mp_read_session_ * 1053 open_cache_mp_read_session(struct cache_entry_ *entry) 1054 { 1055 struct cache_mp_entry_ *mp_entry; 1056 struct cache_mp_read_session_ *retval; 1057 1058 TRACE_IN(open_cache_mp_read_session); 1059 assert(entry != NULL); 1060 assert(entry->params->entry_type == CET_MULTIPART); 1061 mp_entry = (struct cache_mp_entry_ *)entry; 1062 1063 if (mp_entry->completed_write_session == NULL) { 1064 TRACE_OUT(open_cache_mp_read_session); 1065 return (NULL); 1066 } 1067 1068 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0) 1069 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) { 1070 if (mp_entry->last_request_time.tv_sec - 1071 mp_entry->last_request_time.tv_sec > 1072 mp_entry->mp_params.max_lifetime.tv_sec) { 1073 flush_cache_entry(entry); 1074 TRACE_OUT(open_cache_mp_read_session); 1075 return (NULL); 1076 } 1077 } 1078 1079 retval = calloc(1, 1080 sizeof(*retval)); 1081 assert(retval != NULL); 1082 1083 retval->parent_entry = mp_entry; 1084 retval->current_item = TAILQ_FIRST( 1085 &mp_entry->completed_write_session->items); 1086 1087 TAILQ_INSERT_HEAD(&mp_entry->rs_head, retval, entries); 1088 ++mp_entry->rs_size; 1089 1090 mp_entry->get_time_func(&mp_entry->last_request_time); 1091 TRACE_OUT(open_cache_mp_read_session); 1092 return (retval); 1093 } 1094 1095 /* 1096 * Reads the data from the read session - step by step. 1097 * Returns 0 on success, -1 on error (when there are no more data), and -2 if 1098 * the data_size is too small. In the last case, data_size would be filled 1099 * the proper value. 1100 */ 1101 int 1102 cache_mp_read(struct cache_mp_read_session_ *rs, char *data, size_t *data_size) 1103 { 1104 1105 TRACE_IN(cache_mp_read); 1106 assert(rs != NULL); 1107 1108 if (rs->current_item == NULL) { 1109 TRACE_OUT(cache_mp_read); 1110 return (-1); 1111 } 1112 1113 if (rs->current_item->value_size > *data_size) { 1114 *data_size = rs->current_item->value_size; 1115 if (data == NULL) { 1116 TRACE_OUT(cache_mp_read); 1117 return (0); 1118 } 1119 1120 TRACE_OUT(cache_mp_read); 1121 return (-2); 1122 } 1123 1124 *data_size = rs->current_item->value_size; 1125 memcpy(data, rs->current_item->value, rs->current_item->value_size); 1126 rs->current_item = TAILQ_NEXT(rs->current_item, entries); 1127 1128 TRACE_OUT(cache_mp_read); 1129 return (0); 1130 } 1131 1132 /* 1133 * Closes the read session. If there are no more read sessions and there is 1134 * a pending write session, it will be committed and old 1135 * completed_write_session will be destroyed. 1136 */ 1137 void 1138 close_cache_mp_read_session(struct cache_mp_read_session_ *rs) 1139 { 1140 1141 TRACE_IN(close_cache_mp_read_session); 1142 assert(rs != NULL); 1143 assert(rs->parent_entry != NULL); 1144 1145 TAILQ_REMOVE(&rs->parent_entry->rs_head, rs, entries); 1146 --rs->parent_entry->rs_size; 1147 1148 if ((rs->parent_entry->rs_size == 0) && 1149 (rs->parent_entry->pending_write_session != NULL)) { 1150 destroy_cache_mp_write_session( 1151 rs->parent_entry->completed_write_session); 1152 rs->parent_entry->completed_write_session = 1153 rs->parent_entry->pending_write_session; 1154 rs->parent_entry->pending_write_session = NULL; 1155 } 1156 1157 destroy_cache_mp_read_session(rs); 1158 TRACE_OUT(close_cache_mp_read_session); 1159 } 1160 1161 int 1162 transform_cache_entry(struct cache_entry_ *entry, 1163 enum cache_transformation_t transformation) 1164 { 1165 1166 TRACE_IN(transform_cache_entry); 1167 switch (transformation) { 1168 case CTT_CLEAR: 1169 clear_cache_entry(entry); 1170 TRACE_OUT(transform_cache_entry); 1171 return (0); 1172 case CTT_FLUSH: 1173 flush_cache_entry(entry); 1174 TRACE_OUT(transform_cache_entry); 1175 return (0); 1176 default: 1177 TRACE_OUT(transform_cache_entry); 1178 return (-1); 1179 } 1180 } 1181 1182 int 1183 transform_cache_entry_part(struct cache_entry_ *entry, 1184 enum cache_transformation_t transformation, const char *key_part, 1185 size_t key_part_size, enum part_position_t part_position) 1186 { 1187 struct cache_common_entry_ *common_entry; 1188 struct cache_ht_item_ *ht_item; 1189 struct cache_ht_item_data_ *ht_item_data, ht_key; 1190 1191 struct cache_policy_item_ *item, *connected_item; 1192 1193 TRACE_IN(transform_cache_entry_part); 1194 if (entry->params->entry_type != CET_COMMON) { 1195 TRACE_OUT(transform_cache_entry_part); 1196 return (-1); 1197 } 1198 1199 if (transformation != CTT_CLEAR) { 1200 TRACE_OUT(transform_cache_entry_part); 1201 return (-1); 1202 } 1203 1204 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_)); 1205 ht_key.key = (char *)key_part; /* can't avoid casting here */ 1206 ht_key.key_size = key_part_size; 1207 1208 common_entry = (struct cache_common_entry_ *)entry; 1209 HASHTABLE_FOREACH(&(common_entry->items), ht_item) { 1210 do { 1211 ht_item_data = HASHTABLE_ENTRY_FIND_SPECIAL(cache_ht_, 1212 ht_item, &ht_key, 1213 ht_items_fixed_size_left_cmp_func); 1214 1215 if (ht_item_data != NULL) { 1216 item = ht_item_data->fifo_policy_item; 1217 connected_item = item->connected_item; 1218 1219 common_entry->policies[0]->remove_item_func( 1220 common_entry->policies[0], 1221 item); 1222 1223 free(ht_item_data->key); 1224 free(ht_item_data->value); 1225 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item, 1226 ht_item_data); 1227 --common_entry->items_size; 1228 1229 common_entry->policies[0]->destroy_item_func( 1230 item); 1231 if (common_entry->policies_size == 2) { 1232 common_entry->policies[1]->remove_item_func( 1233 common_entry->policies[1], 1234 connected_item); 1235 common_entry->policies[1]->destroy_item_func( 1236 connected_item); 1237 } 1238 } 1239 } while (ht_item_data != NULL); 1240 } 1241 1242 TRACE_OUT(transform_cache_entry_part); 1243 return (0); 1244 } 1245