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 } 729 730 if ((common_entry->common_params.max_lifetime.tv_sec != 0) || 731 (common_entry->common_params.max_lifetime.tv_usec != 0)) { 732 733 if (find_res->fifo_policy_item->last_request_time.tv_sec - 734 find_res->fifo_policy_item->creation_time.tv_sec > 735 common_entry->common_params.max_lifetime.tv_sec) { 736 737 free(find_res->key); 738 free(find_res->value); 739 740 connected_item = 741 find_res->fifo_policy_item->connected_item; 742 if (connected_item != NULL) { 743 common_entry->policies[1]->remove_item_func( 744 common_entry->policies[1], 745 connected_item); 746 common_entry->policies[1]->destroy_item_func( 747 connected_item); 748 } 749 750 common_entry->policies[0]->remove_item_func( 751 common_entry->policies[0], 752 find_res->fifo_policy_item); 753 common_entry->policies[0]->destroy_item_func( 754 find_res->fifo_policy_item); 755 756 HASHTABLE_ENTRY_REMOVE(cache_ht_, item, find_res); 757 --common_entry->items_size; 758 } 759 } 760 761 if ((*value_size < find_res->value_size) || (value == NULL)) { 762 *value_size = find_res->value_size; 763 TRACE_OUT(cache_read); 764 return (-2); 765 } 766 767 *value_size = find_res->value_size; 768 memcpy(value, find_res->value, find_res->value_size); 769 770 ++find_res->fifo_policy_item->request_count; 771 common_entry->get_time_func( 772 &find_res->fifo_policy_item->last_request_time); 773 common_entry->policies[0]->update_item_func(common_entry->policies[0], 774 find_res->fifo_policy_item); 775 776 if (find_res->fifo_policy_item->connected_item != NULL) { 777 connected_item = find_res->fifo_policy_item->connected_item; 778 memcpy(&connected_item->last_request_time, 779 &find_res->fifo_policy_item->last_request_time, 780 sizeof(struct timeval)); 781 connected_item->request_count = 782 find_res->fifo_policy_item->request_count; 783 784 common_entry->policies[1]->update_item_func( 785 common_entry->policies[1], connected_item); 786 } 787 788 TRACE_OUT(cache_read); 789 return (0); 790 } 791 792 /* 793 * Writes the value with the specified key into the cache entry. 794 * Functions returns 0 on success, and -1 on error. 795 */ 796 int 797 cache_write(struct cache_entry_ *entry, const char *key, size_t key_size, 798 char const *value, size_t value_size) 799 { 800 struct cache_common_entry_ *common_entry; 801 struct cache_ht_item_data_ item_data, *find_res; 802 struct cache_ht_item_ *item; 803 hashtable_index_t hash; 804 805 struct cache_policy_ *policy, *connected_policy; 806 struct cache_policy_item_ *policy_item; 807 struct cache_policy_item_ *connected_policy_item; 808 809 TRACE_IN(cache_write); 810 assert(entry != NULL); 811 assert(key != NULL); 812 assert(value != NULL); 813 assert(entry->params->entry_type == CET_COMMON); 814 815 common_entry = (struct cache_common_entry_ *)entry; 816 817 memset(&item_data, 0, sizeof(struct cache_ht_item_data_)); 818 /* can't avoid the cast here */ 819 item_data.key = (char *)key; 820 item_data.key_size = key_size; 821 822 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items, 823 &item_data); 824 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items)); 825 826 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash); 827 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data); 828 if (find_res != NULL) { 829 TRACE_OUT(cache_write); 830 return (-1); 831 } 832 833 item_data.key = malloc(key_size); 834 memcpy(item_data.key, key, key_size); 835 836 item_data.value = malloc(value_size); 837 assert(item_data.value != NULL); 838 839 memcpy(item_data.value, value, value_size); 840 item_data.value_size = value_size; 841 842 policy_item = common_entry->policies[0]->create_item_func(); 843 policy_item->key = item_data.key; 844 policy_item->key_size = item_data.key_size; 845 common_entry->get_time_func(&policy_item->creation_time); 846 847 if (common_entry->policies_size > 1) { 848 connected_policy_item = 849 common_entry->policies[1]->create_item_func(); 850 memcpy(&connected_policy_item->creation_time, 851 &policy_item->creation_time, 852 sizeof(struct timeval)); 853 connected_policy_item->key = policy_item->key; 854 connected_policy_item->key_size = policy_item->key_size; 855 856 connected_policy_item->connected_item = policy_item; 857 policy_item->connected_item = connected_policy_item; 858 } 859 860 item_data.fifo_policy_item = policy_item; 861 862 common_entry->policies[0]->add_item_func(common_entry->policies[0], 863 policy_item); 864 if (common_entry->policies_size > 1) 865 common_entry->policies[1]->add_item_func( 866 common_entry->policies[1], connected_policy_item); 867 868 HASHTABLE_ENTRY_STORE(cache_ht_, item, &item_data); 869 ++common_entry->items_size; 870 871 if ((common_entry->common_params.max_elemsize != 0) && 872 (common_entry->items_size > 873 common_entry->common_params.max_elemsize)) { 874 if (common_entry->policies_size > 1) { 875 policy = common_entry->policies[1]; 876 connected_policy = common_entry->policies[0]; 877 } else { 878 policy = common_entry->policies[0]; 879 connected_policy = NULL; 880 } 881 882 flush_cache_policy(common_entry, policy, connected_policy, 883 cache_elemsize_common_continue_func); 884 } 885 886 TRACE_OUT(cache_write); 887 return (0); 888 } 889 890 /* 891 * Initializes the write session for the specified multipart entry. This 892 * session then should be filled with data either committed or abandoned by 893 * using close_cache_mp_write_session or abandon_cache_mp_write_session 894 * respectively. 895 * Returns NULL on errors (when there are too many opened write sessions for 896 * the entry). 897 */ 898 struct cache_mp_write_session_ * 899 open_cache_mp_write_session(struct cache_entry_ *entry) 900 { 901 struct cache_mp_entry_ *mp_entry; 902 struct cache_mp_write_session_ *retval; 903 904 TRACE_IN(open_cache_mp_write_session); 905 assert(entry != NULL); 906 assert(entry->params->entry_type == CET_MULTIPART); 907 mp_entry = (struct cache_mp_entry_ *)entry; 908 909 if ((mp_entry->mp_params.max_sessions > 0) && 910 (mp_entry->ws_size == mp_entry->mp_params.max_sessions)) { 911 TRACE_OUT(open_cache_mp_write_session); 912 return (NULL); 913 } 914 915 retval = calloc(1, 916 sizeof(*retval)); 917 assert(retval != NULL); 918 919 TAILQ_INIT(&retval->items); 920 retval->parent_entry = mp_entry; 921 922 TAILQ_INSERT_HEAD(&mp_entry->ws_head, retval, entries); 923 ++mp_entry->ws_size; 924 925 TRACE_OUT(open_cache_mp_write_session); 926 return (retval); 927 } 928 929 /* 930 * Writes data to the specified session. Return 0 on success and -1 on errors 931 * (when write session size limit is exceeded). 932 */ 933 int 934 cache_mp_write(struct cache_mp_write_session_ *ws, char *data, 935 size_t data_size) 936 { 937 struct cache_mp_data_item_ *new_item; 938 939 TRACE_IN(cache_mp_write); 940 assert(ws != NULL); 941 assert(ws->parent_entry != NULL); 942 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 943 944 if ((ws->parent_entry->mp_params.max_elemsize > 0) && 945 (ws->parent_entry->mp_params.max_elemsize == ws->items_size)) { 946 TRACE_OUT(cache_mp_write); 947 return (-1); 948 } 949 950 new_item = calloc(1, 951 sizeof(*new_item)); 952 assert(new_item != NULL); 953 954 new_item->value = malloc(data_size); 955 assert(new_item->value != NULL); 956 memcpy(new_item->value, data, data_size); 957 new_item->value_size = data_size; 958 959 TAILQ_INSERT_TAIL(&ws->items, new_item, entries); 960 ++ws->items_size; 961 962 TRACE_OUT(cache_mp_write); 963 return (0); 964 } 965 966 /* 967 * Abandons the write session and frees all the connected resources. 968 */ 969 void 970 abandon_cache_mp_write_session(struct cache_mp_write_session_ *ws) 971 { 972 973 TRACE_IN(abandon_cache_mp_write_session); 974 assert(ws != NULL); 975 assert(ws->parent_entry != NULL); 976 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 977 978 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries); 979 --ws->parent_entry->ws_size; 980 981 destroy_cache_mp_write_session(ws); 982 TRACE_OUT(abandon_cache_mp_write_session); 983 } 984 985 /* 986 * Commits the session to the entry, for which it was created. 987 */ 988 void 989 close_cache_mp_write_session(struct cache_mp_write_session_ *ws) 990 { 991 992 TRACE_IN(close_cache_mp_write_session); 993 assert(ws != NULL); 994 assert(ws->parent_entry != NULL); 995 assert(ws->parent_entry->params->entry_type == CET_MULTIPART); 996 997 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries); 998 --ws->parent_entry->ws_size; 999 1000 if (ws->parent_entry->completed_write_session == NULL) { 1001 /* 1002 * If there is no completed session yet, this will be the one 1003 */ 1004 ws->parent_entry->get_time_func( 1005 &ws->parent_entry->creation_time); 1006 ws->parent_entry->completed_write_session = ws; 1007 } else { 1008 /* 1009 * If there is a completed session, then we'll save our session 1010 * as a pending session. If there is already a pending session, 1011 * it would be destroyed. 1012 */ 1013 if (ws->parent_entry->pending_write_session != NULL) 1014 destroy_cache_mp_write_session( 1015 ws->parent_entry->pending_write_session); 1016 1017 ws->parent_entry->pending_write_session = ws; 1018 } 1019 TRACE_OUT(close_cache_mp_write_session); 1020 } 1021 1022 /* 1023 * Opens read session for the specified entry. Returns NULL on errors (when 1024 * there are no data in the entry, or the data are obsolete). 1025 */ 1026 struct cache_mp_read_session_ * 1027 open_cache_mp_read_session(struct cache_entry_ *entry) 1028 { 1029 struct cache_mp_entry_ *mp_entry; 1030 struct cache_mp_read_session_ *retval; 1031 1032 TRACE_IN(open_cache_mp_read_session); 1033 assert(entry != NULL); 1034 assert(entry->params->entry_type == CET_MULTIPART); 1035 mp_entry = (struct cache_mp_entry_ *)entry; 1036 1037 if (mp_entry->completed_write_session == NULL) { 1038 TRACE_OUT(open_cache_mp_read_session); 1039 return (NULL); 1040 } 1041 1042 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0) 1043 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) { 1044 if (mp_entry->last_request_time.tv_sec - 1045 mp_entry->last_request_time.tv_sec > 1046 mp_entry->mp_params.max_lifetime.tv_sec) { 1047 flush_cache_entry(entry); 1048 TRACE_OUT(open_cache_mp_read_session); 1049 return (NULL); 1050 } 1051 } 1052 1053 retval = calloc(1, 1054 sizeof(*retval)); 1055 assert(retval != NULL); 1056 1057 retval->parent_entry = mp_entry; 1058 retval->current_item = TAILQ_FIRST( 1059 &mp_entry->completed_write_session->items); 1060 1061 TAILQ_INSERT_HEAD(&mp_entry->rs_head, retval, entries); 1062 ++mp_entry->rs_size; 1063 1064 mp_entry->get_time_func(&mp_entry->last_request_time); 1065 TRACE_OUT(open_cache_mp_read_session); 1066 return (retval); 1067 } 1068 1069 /* 1070 * Reads the data from the read session - step by step. 1071 * Returns 0 on success, -1 on error (when there are no more data), and -2 if 1072 * the data_size is too small. In the last case, data_size would be filled 1073 * the proper value. 1074 */ 1075 int 1076 cache_mp_read(struct cache_mp_read_session_ *rs, char *data, size_t *data_size) 1077 { 1078 1079 TRACE_IN(cache_mp_read); 1080 assert(rs != NULL); 1081 1082 if (rs->current_item == NULL) { 1083 TRACE_OUT(cache_mp_read); 1084 return (-1); 1085 } 1086 1087 if (rs->current_item->value_size > *data_size) { 1088 *data_size = rs->current_item->value_size; 1089 if (data == NULL) { 1090 TRACE_OUT(cache_mp_read); 1091 return (0); 1092 } 1093 1094 TRACE_OUT(cache_mp_read); 1095 return (-2); 1096 } 1097 1098 *data_size = rs->current_item->value_size; 1099 memcpy(data, rs->current_item->value, rs->current_item->value_size); 1100 rs->current_item = TAILQ_NEXT(rs->current_item, entries); 1101 1102 TRACE_OUT(cache_mp_read); 1103 return (0); 1104 } 1105 1106 /* 1107 * Closes the read session. If there are no more read sessions and there is 1108 * a pending write session, it will be committed and old 1109 * completed_write_session will be destroyed. 1110 */ 1111 void 1112 close_cache_mp_read_session(struct cache_mp_read_session_ *rs) 1113 { 1114 1115 TRACE_IN(close_cache_mp_read_session); 1116 assert(rs != NULL); 1117 assert(rs->parent_entry != NULL); 1118 1119 TAILQ_REMOVE(&rs->parent_entry->rs_head, rs, entries); 1120 --rs->parent_entry->rs_size; 1121 1122 if ((rs->parent_entry->rs_size == 0) && 1123 (rs->parent_entry->pending_write_session != NULL)) { 1124 destroy_cache_mp_write_session( 1125 rs->parent_entry->completed_write_session); 1126 rs->parent_entry->completed_write_session = 1127 rs->parent_entry->pending_write_session; 1128 rs->parent_entry->pending_write_session = NULL; 1129 } 1130 1131 destroy_cache_mp_read_session(rs); 1132 TRACE_OUT(close_cache_mp_read_session); 1133 } 1134 1135 int 1136 transform_cache_entry(struct cache_entry_ *entry, 1137 enum cache_transformation_t transformation) 1138 { 1139 1140 TRACE_IN(transform_cache_entry); 1141 switch (transformation) { 1142 case CTT_CLEAR: 1143 clear_cache_entry(entry); 1144 TRACE_OUT(transform_cache_entry); 1145 return (0); 1146 case CTT_FLUSH: 1147 flush_cache_entry(entry); 1148 TRACE_OUT(transform_cache_entry); 1149 return (0); 1150 default: 1151 TRACE_OUT(transform_cache_entry); 1152 return (-1); 1153 } 1154 } 1155 1156 int 1157 transform_cache_entry_part(struct cache_entry_ *entry, 1158 enum cache_transformation_t transformation, const char *key_part, 1159 size_t key_part_size, enum part_position_t part_position) 1160 { 1161 struct cache_common_entry_ *common_entry; 1162 struct cache_ht_item_ *ht_item; 1163 struct cache_ht_item_data_ *ht_item_data, ht_key; 1164 1165 struct cache_policy_item_ *item, *connected_item; 1166 1167 TRACE_IN(transform_cache_entry_part); 1168 if (entry->params->entry_type != CET_COMMON) { 1169 TRACE_OUT(transform_cache_entry_part); 1170 return (-1); 1171 } 1172 1173 if (transformation != CTT_CLEAR) { 1174 TRACE_OUT(transform_cache_entry_part); 1175 return (-1); 1176 } 1177 1178 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_)); 1179 ht_key.key = (char *)key_part; /* can't avoid casting here */ 1180 ht_key.key_size = key_part_size; 1181 1182 common_entry = (struct cache_common_entry_ *)entry; 1183 HASHTABLE_FOREACH(&(common_entry->items), ht_item) { 1184 do { 1185 ht_item_data = HASHTABLE_ENTRY_FIND_SPECIAL(cache_ht_, 1186 ht_item, &ht_key, 1187 ht_items_fixed_size_left_cmp_func); 1188 1189 if (ht_item_data != NULL) { 1190 item = ht_item_data->fifo_policy_item; 1191 connected_item = item->connected_item; 1192 1193 common_entry->policies[0]->remove_item_func( 1194 common_entry->policies[0], 1195 item); 1196 1197 free(ht_item_data->key); 1198 free(ht_item_data->value); 1199 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item, 1200 ht_item_data); 1201 --common_entry->items_size; 1202 1203 common_entry->policies[0]->destroy_item_func( 1204 item); 1205 if (common_entry->policies_size == 2) { 1206 common_entry->policies[1]->remove_item_func( 1207 common_entry->policies[1], 1208 connected_item); 1209 common_entry->policies[1]->destroy_item_func( 1210 connected_item); 1211 } 1212 } 1213 } while (ht_item_data != NULL); 1214 } 1215 1216 TRACE_OUT(transform_cache_entry_part); 1217 return (0); 1218 } 1219