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- Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
- Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
- PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
/cache/classes/ -> helper.php (source)
Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402]
1 <?php 2 // This file is part of Moodle - http://moodle.org/ 3 // 4 // Moodle is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // Moodle is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU General Public License for more details. 13 // 14 // You should have received a copy of the GNU General Public License 15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>. 16 17 /** 18 * Cache helper class 19 * 20 * This file is part of Moodle's cache API, affectionately called MUC. 21 * It contains the components that are requried in order to use caching. 22 * 23 * @package core 24 * @category cache 25 * @copyright 2012 Sam Hemelryk 26 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 27 */ 28 29 defined('MOODLE_INTERNAL') || die(); 30 31 /** 32 * The cache helper class. 33 * 34 * The cache helper class provides common functionality to the cache API and is useful to developers within to interact with 35 * the cache API in a general way. 36 * 37 * @package core 38 * @category cache 39 * @copyright 2012 Sam Hemelryk 40 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 41 */ 42 class cache_helper { 43 44 /** 45 * Statistics gathered by the cache API during its operation will be used here. 46 * @static 47 * @var array 48 */ 49 protected static $stats = array(); 50 51 /** 52 * The instance of the cache helper. 53 * @var cache_helper 54 */ 55 protected static $instance; 56 57 /** 58 * The site identifier used by the cache. 59 * Set the first time get_site_identifier is called. 60 * @var string 61 */ 62 protected static $siteidentifier = null; 63 64 /** 65 * Returns true if the cache API can be initialised before Moodle has finished initialising itself. 66 * 67 * This check is essential when trying to cache the likes of configuration information. It checks to make sure that the cache 68 * configuration file has been created which allows use to set up caching when ever is required. 69 * 70 * @return bool 71 */ 72 public static function ready_for_early_init() { 73 return cache_config::config_file_exists(); 74 } 75 76 /** 77 * Returns an instance of the cache_helper. 78 * 79 * This is designed for internal use only and acts as a static store. 80 * @staticvar null $instance 81 * @return cache_helper 82 */ 83 protected static function instance() { 84 if (is_null(self::$instance)) { 85 self::$instance = new cache_helper(); 86 } 87 return self::$instance; 88 } 89 90 /** 91 * Constructs an instance of the cache_helper class. Again for internal use only. 92 */ 93 protected function __construct() { 94 // Nothing to do here, just making sure you can't get an instance of this. 95 } 96 97 /** 98 * Used as a data store for initialised definitions. 99 * @var array 100 */ 101 protected $definitions = array(); 102 103 /** 104 * Used as a data store for initialised cache stores 105 * We use this because we want to avoid establishing multiple instances of a single store. 106 * @var array 107 */ 108 protected $stores = array(); 109 110 /** 111 * Returns the class for use as a cache loader for the given mode. 112 * 113 * @param int $mode One of cache_store::MODE_ 114 * @return string 115 * @throws coding_exception 116 */ 117 public static function get_class_for_mode($mode) { 118 switch ($mode) { 119 case cache_store::MODE_APPLICATION : 120 return 'cache_application'; 121 case cache_store::MODE_REQUEST : 122 return 'cache_request'; 123 case cache_store::MODE_SESSION : 124 return 'cache_session'; 125 } 126 throw new coding_exception('Unknown cache mode passed. Must be one of cache_store::MODE_*'); 127 } 128 129 /** 130 * Returns the cache stores to be used with the given definition. 131 * @param cache_definition $definition 132 * @return array 133 */ 134 public static function get_cache_stores(cache_definition $definition) { 135 $instance = cache_config::instance(); 136 $stores = $instance->get_stores_for_definition($definition); 137 $stores = self::initialise_cachestore_instances($stores, $definition); 138 return $stores; 139 } 140 141 /** 142 * Internal function for initialising an array of stores against a given cache definition. 143 * 144 * @param array $stores 145 * @param cache_definition $definition 146 * @return cache_store[] 147 */ 148 protected static function initialise_cachestore_instances(array $stores, cache_definition $definition) { 149 $return = array(); 150 $factory = cache_factory::instance(); 151 foreach ($stores as $name => $details) { 152 $store = $factory->create_store_from_config($name, $details, $definition); 153 if ($store !== false) { 154 $return[] = $store; 155 } 156 } 157 return $return; 158 } 159 160 /** 161 * Returns a cache_lock instance suitable for use with the store. 162 * 163 * @param cache_store $store 164 * @return cache_lock_interface 165 */ 166 public static function get_cachelock_for_store(cache_store $store) { 167 $instance = cache_config::instance(); 168 $lockconf = $instance->get_lock_for_store($store->my_name()); 169 $factory = cache_factory::instance(); 170 return $factory->create_lock_instance($lockconf); 171 } 172 173 /** 174 * Returns an array of plugins without using core methods. 175 * 176 * This function explicitly does NOT use core functions as it will in some circumstances be called before Moodle has 177 * finished initialising. This happens when loading configuration for instance. 178 * 179 * @return array 180 */ 181 public static function early_get_cache_plugins() { 182 global $CFG; 183 $result = array(); 184 $ignored = array('CVS', '_vti_cnf', 'simpletest', 'db', 'yui', 'tests'); 185 $fulldir = $CFG->dirroot.'/cache/stores'; 186 $items = new DirectoryIterator($fulldir); 187 foreach ($items as $item) { 188 if ($item->isDot() or !$item->isDir()) { 189 continue; 190 } 191 $pluginname = $item->getFilename(); 192 if (in_array($pluginname, $ignored)) { 193 continue; 194 } 195 if (!is_valid_plugin_name($pluginname)) { 196 // Better ignore plugins with problematic names here. 197 continue; 198 } 199 $result[$pluginname] = $fulldir.'/'.$pluginname; 200 unset($item); 201 } 202 unset($items); 203 return $result; 204 } 205 206 /** 207 * Invalidates a given set of keys from a given definition. 208 * 209 * @todo Invalidating by definition should also add to the event cache so that sessions can be invalidated (when required). 210 * 211 * @param string $component 212 * @param string $area 213 * @param array $identifiers 214 * @param array|string|int $keys 215 * @return boolean 216 * @throws coding_exception 217 */ 218 public static function invalidate_by_definition($component, $area, array $identifiers = array(), $keys = array()) { 219 $cache = cache::make($component, $area, $identifiers); 220 if (is_array($keys)) { 221 $cache->delete_many($keys); 222 } else if (is_scalar($keys)) { 223 $cache->delete($keys); 224 } else { 225 throw new coding_exception('cache_helper::invalidate_by_definition only accepts $keys as array, or scalar.'); 226 } 227 return true; 228 } 229 230 /** 231 * Invalidates a given set of keys by means of an event. 232 * 233 * Events cannot determine what identifiers might need to be cleared. Event based purge and invalidation 234 * are only supported on caches without identifiers. 235 * 236 * @param string $event 237 * @param array $keys 238 */ 239 public static function invalidate_by_event($event, array $keys) { 240 $instance = cache_config::instance(); 241 $invalidationeventset = false; 242 $factory = cache_factory::instance(); 243 $inuse = $factory->get_caches_in_use(); 244 $purgetoken = null; 245 foreach ($instance->get_definitions() as $name => $definitionarr) { 246 $definition = cache_definition::load($name, $definitionarr); 247 if ($definition->invalidates_on_event($event)) { 248 // First up check if there is a cache loader for this definition already. 249 // If there is we need to invalidate the keys from there. 250 $definitionkey = $definition->get_component().'/'.$definition->get_area(); 251 if (isset($inuse[$definitionkey])) { 252 $inuse[$definitionkey]->delete_many($keys); 253 } 254 255 // We should only log events for application and session caches. 256 // Request caches shouldn't have events as all data is lost at the end of the request. 257 // Events should only be logged once of course and likely several definitions are watching so we 258 // track its logging with $invalidationeventset. 259 $logevent = ($invalidationeventset === false && $definition->get_mode() !== cache_store::MODE_REQUEST); 260 261 if ($logevent) { 262 // Get the event invalidation cache. 263 $cache = cache::make('core', 'eventinvalidation'); 264 // Get any existing invalidated keys for this cache. 265 $data = $cache->get($event); 266 if ($data === false) { 267 // There are none. 268 $data = array(); 269 } 270 // Add our keys to them with the current cache timestamp. 271 if (null === $purgetoken) { 272 $purgetoken = cache::get_purge_token(true); 273 } 274 foreach ($keys as $key) { 275 $data[$key] = $purgetoken; 276 } 277 // Set that data back to the cache. 278 $cache->set($event, $data); 279 // This only needs to occur once. 280 $invalidationeventset = true; 281 } 282 } 283 } 284 } 285 286 /** 287 * Purges the cache for a specific definition. 288 * 289 * @param string $component 290 * @param string $area 291 * @param array $identifiers 292 * @return bool 293 */ 294 public static function purge_by_definition($component, $area, array $identifiers = array()) { 295 // Create the cache. 296 $cache = cache::make($component, $area, $identifiers); 297 // Initialise, in case of a store. 298 if ($cache instanceof cache_store) { 299 $factory = cache_factory::instance(); 300 $definition = $factory->create_definition($component, $area, null); 301 $cacheddefinition = clone $definition; 302 $cacheddefinition->set_identifiers($identifiers); 303 $cache->initialise($cacheddefinition); 304 } 305 // Purge baby, purge. 306 $cache->purge(); 307 return true; 308 } 309 310 /** 311 * Purges a cache of all information on a given event. 312 * 313 * Events cannot determine what identifiers might need to be cleared. Event based purge and invalidation 314 * are only supported on caches without identifiers. 315 * 316 * @param string $event 317 */ 318 public static function purge_by_event($event) { 319 $instance = cache_config::instance(); 320 $invalidationeventset = false; 321 $factory = cache_factory::instance(); 322 $inuse = $factory->get_caches_in_use(); 323 $purgetoken = null; 324 foreach ($instance->get_definitions() as $name => $definitionarr) { 325 $definition = cache_definition::load($name, $definitionarr); 326 if ($definition->invalidates_on_event($event)) { 327 // First up check if there is a cache loader for this definition already. 328 // If there is we need to invalidate the keys from there. 329 $definitionkey = $definition->get_component().'/'.$definition->get_area(); 330 if (isset($inuse[$definitionkey])) { 331 $inuse[$definitionkey]->purge(); 332 } else { 333 cache::make($definition->get_component(), $definition->get_area())->purge(); 334 } 335 336 // We should only log events for application and session caches. 337 // Request caches shouldn't have events as all data is lost at the end of the request. 338 // Events should only be logged once of course and likely several definitions are watching so we 339 // track its logging with $invalidationeventset. 340 $logevent = ($invalidationeventset === false && $definition->get_mode() !== cache_store::MODE_REQUEST); 341 342 // We need to flag the event in the "Event invalidation" cache if it hasn't already happened. 343 if ($logevent && $invalidationeventset === false) { 344 // Get the event invalidation cache. 345 $cache = cache::make('core', 'eventinvalidation'); 346 // Create a key to invalidate all. 347 if (null === $purgetoken) { 348 $purgetoken = cache::get_purge_token(true); 349 } 350 $data = array( 351 'purged' => $purgetoken, 352 ); 353 // Set that data back to the cache. 354 $cache->set($event, $data); 355 // This only needs to occur once. 356 $invalidationeventset = true; 357 } 358 } 359 } 360 } 361 362 /** 363 * Ensure that the stats array is ready to collect information for the given store and definition. 364 * @param string $store 365 * @param string $storeclass 366 * @param string $definition A string that identifies the definition. 367 * @param int $mode One of cache_store::MODE_*. Since 2.9. 368 */ 369 protected static function ensure_ready_for_stats($store, $storeclass, $definition, $mode = cache_store::MODE_APPLICATION) { 370 // This function is performance-sensitive, so exit as quickly as possible 371 // if we do not need to do anything. 372 if (isset(self::$stats[$definition]['stores'][$store])) { 373 return; 374 } 375 376 if (!array_key_exists($definition, self::$stats)) { 377 self::$stats[$definition] = array( 378 'mode' => $mode, 379 'stores' => array( 380 $store => array( 381 'class' => $storeclass, 382 'hits' => 0, 383 'misses' => 0, 384 'sets' => 0, 385 'iobytes' => cache_store::IO_BYTES_NOT_SUPPORTED, 386 'locks' => 0, 387 ) 388 ) 389 ); 390 } else if (!array_key_exists($store, self::$stats[$definition]['stores'])) { 391 self::$stats[$definition]['stores'][$store] = array( 392 'class' => $storeclass, 393 'hits' => 0, 394 'misses' => 0, 395 'sets' => 0, 396 'iobytes' => cache_store::IO_BYTES_NOT_SUPPORTED, 397 'locks' => 0, 398 ); 399 } 400 } 401 402 /** 403 * Returns a string to describe the definition. 404 * 405 * This method supports the definition as a string due to legacy requirements. 406 * It is backwards compatible when a string is passed but is not accurate. 407 * 408 * @since 2.9 409 * @param cache_definition|string $definition 410 * @return string 411 */ 412 protected static function get_definition_stat_id_and_mode($definition) { 413 if (!($definition instanceof cache_definition)) { 414 // All core calls to this method have been updated, this is the legacy state. 415 // We'll use application as the default as that is the most common, really this is not accurate of course but 416 // at this point we can only guess and as it only affects calls to cache stat outside of core (of which there should 417 // be none) I think that is fine. 418 debugging('Please update you cache stat calls to pass the definition rather than just its ID.', DEBUG_DEVELOPER); 419 return array((string)$definition, cache_store::MODE_APPLICATION); 420 } 421 return array($definition->get_id(), $definition->get_mode()); 422 } 423 424 /** 425 * Record a cache hit in the stats for the given store and definition. 426 * 427 * In Moodle 2.9 the $definition argument changed from accepting only a string to accepting a string or a 428 * cache_definition instance. It is preferable to pass a cache definition instance. 429 * 430 * In Moodle 3.9 the first argument changed to also accept a cache_store. 431 * 432 * @internal 433 * @param string|cache_store $store 434 * @param cache_definition $definition You used to be able to pass a string here, however that is deprecated please pass the 435 * actual cache_definition object now. 436 * @param int $hits The number of hits to record (by default 1) 437 * @param int $readbytes Number of bytes read from the cache or cache_store::IO_BYTES_NOT_SUPPORTED 438 */ 439 public static function record_cache_hit($store, $definition, int $hits = 1, int $readbytes = cache_store::IO_BYTES_NOT_SUPPORTED): void { 440 $storeclass = ''; 441 if ($store instanceof cache_store) { 442 $storeclass = get_class($store); 443 $store = $store->my_name(); 444 } 445 list($definitionstr, $mode) = self::get_definition_stat_id_and_mode($definition); 446 self::ensure_ready_for_stats($store, $storeclass, $definitionstr, $mode); 447 self::$stats[$definitionstr]['stores'][$store]['hits'] += $hits; 448 if ($readbytes !== cache_store::IO_BYTES_NOT_SUPPORTED) { 449 if (self::$stats[$definitionstr]['stores'][$store]['iobytes'] === cache_store::IO_BYTES_NOT_SUPPORTED) { 450 self::$stats[$definitionstr]['stores'][$store]['iobytes'] = $readbytes; 451 } else { 452 self::$stats[$definitionstr]['stores'][$store]['iobytes'] += $readbytes; 453 } 454 } 455 } 456 457 /** 458 * Record a cache miss in the stats for the given store and definition. 459 * 460 * In Moodle 2.9 the $definition argument changed from accepting only a string to accepting a string or a 461 * cache_definition instance. It is preferable to pass a cache definition instance. 462 * 463 * In Moodle 3.9 the first argument changed to also accept a cache_store. 464 * 465 * @internal 466 * @param string|cache_store $store 467 * @param cache_definition $definition You used to be able to pass a string here, however that is deprecated please pass the 468 * actual cache_definition object now. 469 * @param int $misses The number of misses to record (by default 1) 470 */ 471 public static function record_cache_miss($store, $definition, $misses = 1) { 472 $storeclass = ''; 473 if ($store instanceof cache_store) { 474 $storeclass = get_class($store); 475 $store = $store->my_name(); 476 } 477 list($definitionstr, $mode) = self::get_definition_stat_id_and_mode($definition); 478 self::ensure_ready_for_stats($store, $storeclass, $definitionstr, $mode); 479 self::$stats[$definitionstr]['stores'][$store]['misses'] += $misses; 480 } 481 482 /** 483 * Record a cache set in the stats for the given store and definition. 484 * 485 * In Moodle 2.9 the $definition argument changed from accepting only a string to accepting a string or a 486 * cache_definition instance. It is preferable to pass a cache definition instance. 487 * 488 * In Moodle 3.9 the first argument changed to also accept a cache_store. 489 * 490 * @internal 491 * @param string|cache_store $store 492 * @param cache_definition $definition You used to be able to pass a string here, however that is deprecated please pass the 493 * actual cache_definition object now. 494 * @param int $sets The number of sets to record (by default 1) 495 * @param int $writebytes Number of bytes written to the cache or cache_store::IO_BYTES_NOT_SUPPORTED 496 */ 497 public static function record_cache_set($store, $definition, int $sets = 1, 498 int $writebytes = cache_store::IO_BYTES_NOT_SUPPORTED) { 499 $storeclass = ''; 500 if ($store instanceof cache_store) { 501 $storeclass = get_class($store); 502 $store = $store->my_name(); 503 } 504 list($definitionstr, $mode) = self::get_definition_stat_id_and_mode($definition); 505 self::ensure_ready_for_stats($store, $storeclass, $definitionstr, $mode); 506 self::$stats[$definitionstr]['stores'][$store]['sets'] += $sets; 507 if ($writebytes !== cache_store::IO_BYTES_NOT_SUPPORTED) { 508 if (self::$stats[$definitionstr]['stores'][$store]['iobytes'] === cache_store::IO_BYTES_NOT_SUPPORTED) { 509 self::$stats[$definitionstr]['stores'][$store]['iobytes'] = $writebytes; 510 } else { 511 self::$stats[$definitionstr]['stores'][$store]['iobytes'] += $writebytes; 512 } 513 } 514 } 515 516 /** 517 * Return the stats collected so far. 518 * @return array 519 */ 520 public static function get_stats() { 521 return self::$stats; 522 } 523 524 /** 525 * Purge all of the cache stores of all of their data. 526 * 527 * Think twice before calling this method. It will purge **ALL** caches regardless of whether they have been used recently or 528 * anything. This will involve full setup of the cache + the purge operation. On a site using caching heavily this WILL be 529 * painful. 530 * 531 * @param bool $usewriter If set to true the cache_config_writer class is used. This class is special as it avoids 532 * it is still usable when caches have been disabled. 533 * Please use this option only if you really must. It's purpose is to allow the cache to be purged when it would be 534 * otherwise impossible. 535 */ 536 public static function purge_all($usewriter = false) { 537 $factory = cache_factory::instance(); 538 $config = $factory->create_config_instance($usewriter); 539 foreach ($config->get_all_stores() as $store) { 540 self::purge_store($store['name'], $config); 541 } 542 foreach ($factory->get_adhoc_caches_in_use() as $cache) { 543 $cache->purge(); 544 } 545 } 546 547 /** 548 * Purges a store given its name. 549 * 550 * @param string $storename 551 * @param cache_config $config 552 * @return bool 553 */ 554 public static function purge_store($storename, cache_config $config = null) { 555 if ($config === null) { 556 $config = cache_config::instance(); 557 } 558 559 $stores = $config->get_all_stores(); 560 if (!array_key_exists($storename, $stores)) { 561 // The store does not exist. 562 return false; 563 } 564 565 $store = $stores[$storename]; 566 $class = $store['class']; 567 568 569 // We check are_requirements_met although we expect is_ready is going to check as well. 570 if (!$class::are_requirements_met()) { 571 return false; 572 } 573 // Found the store: is it ready? 574 /* @var cache_store $instance */ 575 $instance = new $class($store['name'], $store['configuration']); 576 if (!$instance->is_ready()) { 577 unset($instance); 578 return false; 579 } 580 foreach ($config->get_definitions_by_store($storename) as $id => $definition) { 581 $definition = cache_definition::load($id, $definition); 582 $definitioninstance = clone($instance); 583 $definitioninstance->initialise($definition); 584 $definitioninstance->purge(); 585 unset($definitioninstance); 586 } 587 588 return true; 589 } 590 591 /** 592 * Purges all of the stores used by a definition. 593 * 594 * Unlike cache_helper::purge_by_definition this purges all of the data from the stores not 595 * just the data relating to the definition. 596 * This function is useful when you must purge a definition that requires setup but you don't 597 * want to set it up. 598 * 599 * @param string $component 600 * @param string $area 601 */ 602 public static function purge_stores_used_by_definition($component, $area) { 603 $factory = cache_factory::instance(); 604 $config = $factory->create_config_instance(); 605 $definition = $factory->create_definition($component, $area); 606 $stores = $config->get_stores_for_definition($definition); 607 foreach ($stores as $store) { 608 self::purge_store($store['name']); 609 } 610 } 611 612 /** 613 * Returns the translated name of the definition. 614 * 615 * @param cache_definition $definition 616 * @return lang_string 617 */ 618 public static function get_definition_name($definition) { 619 if ($definition instanceof cache_definition) { 620 return $definition->get_name(); 621 } 622 $identifier = 'cachedef_'.clean_param($definition['area'], PARAM_STRINGID); 623 $component = $definition['component']; 624 if ($component === 'core') { 625 $component = 'cache'; 626 } 627 return new lang_string($identifier, $component); 628 } 629 630 /** 631 * Hashes a descriptive key to make it shorter and still unique. 632 * @param string|int $key 633 * @param cache_definition $definition 634 * @return string 635 */ 636 public static function hash_key($key, cache_definition $definition) { 637 if ($definition->uses_simple_keys()) { 638 if (debugging() && preg_match('#[^a-zA-Z0-9_]#', $key ?? '')) { 639 throw new coding_exception('Cache definition '.$definition->get_id().' requires simple keys. Invalid key provided.', $key); 640 } 641 // We put the key first so that we can be sure the start of the key changes. 642 return (string)$key . '-' . $definition->generate_single_key_prefix(); 643 } 644 $key = $definition->generate_single_key_prefix() . '-' . $key; 645 return sha1($key); 646 } 647 648 /** 649 * Finds all definitions and updates them within the cache config file. 650 * 651 * @param bool $coreonly If set to true only core definitions will be updated. 652 */ 653 public static function update_definitions($coreonly = false) { 654 global $CFG; 655 // Include locallib. 656 require_once($CFG->dirroot.'/cache/locallib.php'); 657 // First update definitions 658 cache_config_writer::update_definitions($coreonly); 659 // Second reset anything we have already initialised to ensure we're all up to date. 660 cache_factory::reset(); 661 } 662 663 /** 664 * Update the site identifier stored by the cache API. 665 * 666 * @param string $siteidentifier 667 * @return string The new site identifier. 668 */ 669 public static function update_site_identifier($siteidentifier) { 670 global $CFG; 671 // Include locallib. 672 require_once($CFG->dirroot.'/cache/locallib.php'); 673 $factory = cache_factory::instance(); 674 $factory->updating_started(); 675 $config = $factory->create_config_instance(true); 676 $siteidentifier = $config->update_site_identifier($siteidentifier); 677 $factory->updating_finished(); 678 cache_factory::reset(); 679 return $siteidentifier; 680 } 681 682 /** 683 * Returns the site identifier. 684 * 685 * @return string 686 */ 687 public static function get_site_identifier() { 688 global $CFG; 689 if (!is_null(self::$siteidentifier)) { 690 return self::$siteidentifier; 691 } 692 // If site identifier hasn't been collected yet attempt to get it from the cache config. 693 $factory = cache_factory::instance(); 694 // If the factory is initialising then we don't want to try to get it from the config or we risk 695 // causing the cache to enter an infinite initialisation loop. 696 if (!$factory->is_initialising()) { 697 $config = $factory->create_config_instance(); 698 self::$siteidentifier = $config->get_site_identifier(); 699 } 700 if (is_null(self::$siteidentifier)) { 701 // If the site identifier is still null then config isn't aware of it yet. 702 // We'll see if the CFG is loaded, and if not we will just use unknown. 703 // It's very important here that we don't use get_config. We don't want an endless cache loop! 704 if (!empty($CFG->siteidentifier)) { 705 self::$siteidentifier = self::update_site_identifier($CFG->siteidentifier); 706 } else { 707 // It's not being recorded in MUC's config and the config data hasn't been loaded yet. 708 // Likely we are initialising. 709 return 'unknown'; 710 } 711 } 712 return self::$siteidentifier; 713 } 714 715 /** 716 * Returns the site version. 717 * 718 * @return string 719 */ 720 public static function get_site_version() { 721 global $CFG; 722 return (string)$CFG->version; 723 } 724 725 /** 726 * Runs cron routines for MUC. 727 */ 728 public static function cron() { 729 self::clean_old_session_data(true); 730 } 731 732 /** 733 * Cleans old session data from cache stores used for session based definitions. 734 * 735 * @param bool $output If set to true output will be given. 736 */ 737 public static function clean_old_session_data($output = false) { 738 global $CFG; 739 if ($output) { 740 mtrace('Cleaning up stale session data from cache stores.'); 741 } 742 $factory = cache_factory::instance(); 743 $config = $factory->create_config_instance(); 744 $definitions = $config->get_definitions(); 745 $purgetime = time() - $CFG->sessiontimeout; 746 foreach ($definitions as $definitionarray) { 747 // We are only interested in session caches. 748 if (!($definitionarray['mode'] & cache_store::MODE_SESSION)) { 749 continue; 750 } 751 $definition = $factory->create_definition($definitionarray['component'], $definitionarray['area']); 752 $stores = $config->get_stores_for_definition($definition); 753 // Turn them into store instances. 754 $stores = self::initialise_cachestore_instances($stores, $definition); 755 // Initialise all of the stores used for that definition. 756 foreach ($stores as $store) { 757 // If the store doesn't support searching we can skip it. 758 if (!($store instanceof cache_is_searchable)) { 759 debugging('Cache stores used for session definitions should ideally be searchable.', DEBUG_DEVELOPER); 760 continue; 761 } 762 // Get all of the keys. 763 $keys = $store->find_by_prefix(cache_session::KEY_PREFIX); 764 $todelete = array(); 765 foreach ($store->get_many($keys) as $key => $value) { 766 if (strpos($key, cache_session::KEY_PREFIX) !== 0 || !is_array($value) || !isset($value['lastaccess'])) { 767 continue; 768 } 769 if ((int)$value['lastaccess'] < $purgetime || true) { 770 $todelete[] = $key; 771 } 772 } 773 if (count($todelete)) { 774 $outcome = (int)$store->delete_many($todelete); 775 if ($output) { 776 $strdef = s($definition->get_id()); 777 $strstore = s($store->my_name()); 778 mtrace("- Removed {$outcome} old {$strdef} sessions from the '{$strstore}' cache store."); 779 } 780 } 781 } 782 } 783 } 784 785 /** 786 * Returns an array of stores that would meet the requirements for every definition. 787 * 788 * These stores would be 100% suitable to map as defaults for cache modes. 789 * 790 * @return array[] An array of stores, keys are the store names. 791 */ 792 public static function get_stores_suitable_for_mode_default() { 793 $factory = cache_factory::instance(); 794 $config = $factory->create_config_instance(); 795 $requirements = 0; 796 foreach ($config->get_definitions() as $definition) { 797 $definition = cache_definition::load($definition['component'].'/'.$definition['area'], $definition); 798 $requirements = $requirements | $definition->get_requirements_bin(); 799 } 800 $stores = array(); 801 foreach ($config->get_all_stores() as $name => $store) { 802 if (!empty($store['features']) && ($store['features'] & $requirements)) { 803 $stores[$name] = $store; 804 } 805 } 806 return $stores; 807 } 808 809 /** 810 * Returns stores suitable for use with a given definition. 811 * 812 * @param cache_definition $definition 813 * @return cache_store[] 814 */ 815 public static function get_stores_suitable_for_definition(cache_definition $definition) { 816 $factory = cache_factory::instance(); 817 $stores = array(); 818 if ($factory->is_initialising() || $factory->stores_disabled()) { 819 // No suitable stores here. 820 return $stores; 821 } else { 822 $stores = self::get_cache_stores($definition); 823 // If mappingsonly is set, having 0 stores is ok. 824 if ((count($stores) === 0) && (!$definition->is_for_mappings_only())) { 825 // No suitable stores we found for the definition. We need to come up with a sensible default. 826 // If this has happened we can be sure that the user has mapped custom stores to either the 827 // mode of the definition. The first alternative to try is the system default for the mode. 828 // e.g. the default file store instance for application definitions. 829 $config = $factory->create_config_instance(); 830 foreach ($config->get_stores($definition->get_mode()) as $name => $details) { 831 if (!empty($details['default'])) { 832 $stores[] = $factory->create_store_from_config($name, $details, $definition); 833 break; 834 } 835 } 836 } 837 } 838 return $stores; 839 } 840 841 /** 842 * Returns an array of warnings from the cache API. 843 * 844 * The warning returned here are for things like conflicting store instance configurations etc. 845 * These get shown on the admin notifications page for example. 846 * 847 * @param array|null $stores An array of stores to get warnings for, or null for all. 848 * @return string[] 849 */ 850 public static function warnings(array $stores = null) { 851 global $CFG; 852 if ($stores === null) { 853 require_once($CFG->dirroot.'/cache/locallib.php'); 854 $stores = core_cache\administration_helper::get_store_instance_summaries(); 855 } 856 $warnings = array(); 857 foreach ($stores as $store) { 858 if (!empty($store['warnings'])) { 859 $warnings = array_merge($warnings, $store['warnings']); 860 } 861 } 862 return $warnings; 863 } 864 865 /** 866 * A helper to determine whether a result was found. 867 * 868 * This has been deemed required after people have been confused by the fact that [] == false. 869 * 870 * @param mixed $value 871 * @return bool 872 */ 873 public static function result_found($value): bool { 874 return $value !== false; 875 } 876 }
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