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<?php
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// This file is part of Moodle - http://moodle.org/
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//
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// Moodle is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// Moodle is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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/**
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* Cache loaders
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*
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* This file is part of Moodle's cache API, affectionately called MUC.
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* It contains the components that are required in order to use caching.
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*
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* @package core
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* @category cache
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* @copyright 2012 Sam Hemelryk
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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defined('MOODLE_INTERNAL') || die();
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/**
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* The main cache class.
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*
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* This class if the first class that any end developer will interact with.
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* In order to create an instance of a cache that they can work with they must call one of the static make methods belonging
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* to this class.
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*
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* @package core
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* @category cache
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* @copyright 2012 Sam Hemelryk
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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class cache implements cache_loader {
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/**
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* @var int Constant for cache entries that do not have a version number
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*/
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const VERSION_NONE = -1;
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/**
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* We need a timestamp to use within the cache API.
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* This stamp needs to be used for all ttl and time based operations to ensure that we don't end up with
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* timing issues.
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* @var int
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*/
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protected static $now;
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/**
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* A purge token used to distinguish between multiple cache purges in the same second.
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* This is in the format <microtime>-<random string>.
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*
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* @var string
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*/
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protected static $purgetoken;
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/**
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* The definition used when loading this cache if there was one.
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* @var cache_definition
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*/
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private $definition = false;
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/**
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* The cache store that this loader will make use of.
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* @var cache_store
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*/
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private $store;
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/**
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* The next cache loader in the chain if there is one.
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* If a cache request misses for the store belonging to this loader then the loader
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* stored here will be checked next.
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* If there is a loader here then $datasource must be false.
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* @var cache_loader|false
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*/
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private $loader = false;
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/**
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* The data source to use if we need to load data (because if doesn't exist in the cache store).
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* If there is a data source here then $loader above must be false.
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* @var cache_data_source|false
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*/
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private $datasource = false;
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/**
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* Used to quickly check if the store supports key awareness.
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* This is set when the cache is initialised and is used to speed up processing.
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* @var bool
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*/
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private $supportskeyawareness = null;
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/**
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* Used to quickly check if the store supports ttl natively.
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* This is set when the cache is initialised and is used to speed up processing.
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* @var bool
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*/
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private $supportsnativettl = null;
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/**
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* Gets set to true if the cache is going to be using a static array for acceleration.
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* The array statically caches items used during the lifetime of the request. This greatly speeds up interaction
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* with the cache in areas where it will be repetitively hit for the same information such as with strings.
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* There are several other variables to control how this static acceleration array works.
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* @var bool
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*/
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private $staticacceleration = false;
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/**
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* The static acceleration array.
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* Items will be stored in this cache as they were provided. This ensure there is no unnecessary processing taking place.
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* @var array
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*/
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private $staticaccelerationarray = array();
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/**
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* The number of items in the static acceleration array. Avoids count calls like you wouldn't believe.
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* @var int
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*/
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private $staticaccelerationcount = 0;
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/**
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* An array containing just the keys being used in the static acceleration array.
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* This seems redundant perhaps but is used when managing the size of the static acceleration array.
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* Items are added to the end of the array and the when we need to reduce the size of the cache we use the
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* key that is first on this array.
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* @var array
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*/
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private $staticaccelerationkeys = array();
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/**
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* The maximum size of the static acceleration array.
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*
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* If set to false there is no max size.
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* Caches that make use of static acceleration should seriously consider setting this to something reasonably small, but
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* still large enough to offset repetitive calls.
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*
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* @var int|false
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*/
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private $staticaccelerationsize = false;
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/**
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* Gets set to true during initialisation if the definition is making use of a ttl.
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* Used to speed up processing.
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* @var bool
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*/
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private $hasattl = false;
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/**
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* Gets set to the class name of the store during initialisation. This is used several times in the cache class internally
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* and having it here helps speed up processing.
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* @var strubg
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*/
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protected $storetype = 'unknown';
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/**
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* Gets set to true if we want to collect performance information about the cache API.
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* @var bool
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*/
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protected $perfdebug = false;
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/**
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* Determines if this loader is a sub loader, not the top of the chain.
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* @var bool
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*/
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protected $subloader = false;
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/**
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* Gets set to true if the cache writes (set|delete) must have a manual lock created first.
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* @var bool
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*/
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protected $requirelockingbeforewrite = false;
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/**
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* Gets set to true if the cache's primary store natively supports locking.
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* If it does then we use that, otherwise we need to instantiate a second store to use for locking.
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* @var cache_store|null
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*/
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protected $nativelocking = null;
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/**
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* Creates a new cache instance for a pre-defined definition.
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*
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* @param string $component The component for the definition
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* @param string $area The area for the definition
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* @param array $identifiers Any additional identifiers that should be provided to the definition.
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* @param string $unused Used to be datasourceaggregate but that was removed and this is now unused.
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* @return cache_application|cache_session|cache_store
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*/
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public static function make($component, $area, array $identifiers = array(), $unused = null) {
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$factory = cache_factory::instance();
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return $factory->create_cache_from_definition($component, $area, $identifiers);
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}
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/**
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* Creates a new cache instance based upon the given params.
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*
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* @param int $mode One of cache_store::MODE_*
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* @param string $component The component this cache relates to.
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* @param string $area The area this cache relates to.
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* @param array $identifiers Any additional identifiers that should be provided to the definition.
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* @param array $options An array of options, available options are:
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* - simplekeys : Set to true if the keys you will use are a-zA-Z0-9_
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* - simpledata : Set to true if the type of the data you are going to store is scalar, or an array of scalar vars
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* - staticacceleration : If set to true the cache will hold onto data passing through it.
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* - staticaccelerationsize : The max size for the static acceleration array.
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* @return cache_application|cache_session|cache_request
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*/
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public static function make_from_params($mode, $component, $area, array $identifiers = array(), array $options = array()) {
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$factory = cache_factory::instance();
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return $factory->create_cache_from_params($mode, $component, $area, $identifiers, $options);
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}
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/**
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* Constructs a new cache instance.
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*
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* You should not call this method from your code, instead you should use the cache::make methods.
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*
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* This method is public so that the cache_factory is able to instantiate cache instances.
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* Ideally we would make this method protected and expose its construction to the factory method internally somehow.
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* The factory class is responsible for this in order to centralise the storage of instances once created. This way if needed
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* we can force a reset of the cache API (used during unit testing).
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*
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* @param cache_definition $definition The definition for the cache instance.
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* @param cache_store $store The store that cache should use.
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* @param cache_loader|cache_data_source $loader The next loader in the chain or the data source if there is one and there
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* are no other cache_loaders in the chain.
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*/
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public function __construct(cache_definition $definition, cache_store $store, $loader = null) {
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global $CFG;
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$this->definition = $definition;
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$this->store = $store;
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$this->storetype = get_class($store);
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$this->perfdebug = (!empty($CFG->perfdebug) and $CFG->perfdebug > 7);
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if ($loader instanceof cache_loader) {
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$this->set_loader($loader);
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} else if ($loader instanceof cache_data_source) {
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$this->set_data_source($loader);
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}
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$this->definition->generate_definition_hash();
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$this->staticacceleration = $this->definition->use_static_acceleration();
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if ($this->staticacceleration) {
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$this->staticaccelerationsize = $this->definition->get_static_acceleration_size();
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}
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$this->hasattl = ($this->definition->get_ttl() > 0);
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}
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/**
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* Set the loader for this cache.
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*
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* @param cache_loader $loader
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*/
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protected function set_loader(cache_loader $loader): void {
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$this->loader = $loader;
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// Mark the loader as a sub (chained) loader.
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$this->loader->set_is_sub_loader(true);
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}
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/**
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* Set the data source for this cache.
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*
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* @param cache_data_source $datasource
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*/
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protected function set_data_source(cache_data_source $datasource): void {
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$this->datasource = $datasource;
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}
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/**
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* Used to inform the loader of its state as a sub loader, or as the top of the chain.
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*
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* This is important as it ensures that we do not have more than one loader keeping static acceleration data.
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* Subloaders need to be "pure" loaders in the sense that they are used to store and retrieve information from stores or the
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* next loader/data source in the chain.
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* Nothing fancy, nothing flash.
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*
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* @param bool $setting
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*/
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protected function set_is_sub_loader($setting = true) {
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if ($setting) {
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$this->subloader = true;
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// Subloaders should not keep static acceleration data.
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$this->staticacceleration = false;
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$this->staticaccelerationsize = false;
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} else {
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$this->subloader = true;
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$this->staticacceleration = $this->definition->use_static_acceleration();
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if ($this->staticacceleration) {
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$this->staticaccelerationsize = $this->definition->get_static_acceleration_size();
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}
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}
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}
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/**
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* Alters the identifiers that have been provided to the definition.
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*
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* This is an advanced method and should not be used unless really needed.
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* It allows the developer to slightly alter the definition without having to re-establish the cache.
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* It will cause more processing as the definition will need to clear and reprepare some of its properties.
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*
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* @param array $identifiers
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*/
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public function set_identifiers(array $identifiers) {
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if ($this->definition->set_identifiers($identifiers)) {
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// As static acceleration uses input keys and not parsed keys
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// it much be cleared when the identifier set is changed.
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$this->staticaccelerationarray = array();
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if ($this->staticaccelerationsize !== false) {
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$this->staticaccelerationkeys = array();
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$this->staticaccelerationcount = 0;
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}
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}
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}
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/**
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* Process any outstanding invalidation events for the cache we are registering,
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*
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* Identifiers and event invalidation are not compatible with each other at this time.
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* As a result the cache does not need to consider identifiers when working out what to invalidate.
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*/
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protected function handle_invalidation_events() {
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if (!$this->definition->has_invalidation_events()) {
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return;
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}
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// Each cache stores the current 'lastinvalidation' value within the cache itself.
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$lastinvalidation = $this->get('lastinvalidation');
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if ($lastinvalidation === false) {
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// There is currently no value for the lastinvalidation token, therefore the token is not set, and there
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// can be nothing to invalidate.
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// Set the lastinvalidation value to the current purge token and return early.
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$this->set('lastinvalidation', self::get_purge_token());
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return;
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} else if ($lastinvalidation == self::get_purge_token()) {
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// The current purge request has already been fully handled by this cache.
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return;
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}
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/*
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* Now that the whole cache check is complete, we check the meaning of any specific cache invalidation events.
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* These are stored in the core/eventinvalidation cache as an multi-dimensinoal array in the form:
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* [
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* eventname => [
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352 |
* keyname => purgetoken,
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* ]
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* ]
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|
|
355 |
*
|
|
|
356 |
* The 'keyname' value is used to delete a specific key in the cache.
|
|
|
357 |
* If the keyname is set to the special value 'purged', then the whole cache is purged instead.
|
|
|
358 |
*
|
|
|
359 |
* The 'purgetoken' is the token that this key was last purged.
|
|
|
360 |
* a) If the purgetoken matches the last invalidation, then the key/cache is not purged.
|
|
|
361 |
* b) If the purgetoken is newer than the last invalidation, then the key/cache is not purged.
|
|
|
362 |
* c) If the purge token is older than the last invalidation, or it has a different token component, then the
|
|
|
363 |
* cache is purged.
|
|
|
364 |
*
|
|
|
365 |
* Option b should not happen under normal operation, but may happen in race condition whereby a long-running
|
|
|
366 |
* request's cache is cleared in another process during that request, and prior to that long-running request
|
|
|
367 |
* creating the cache. In such a condition, it would be incorrect to clear that cache.
|
|
|
368 |
*/
|
|
|
369 |
$cache = self::make('core', 'eventinvalidation');
|
|
|
370 |
$events = $cache->get_many($this->definition->get_invalidation_events());
|
|
|
371 |
$todelete = array();
|
|
|
372 |
$purgeall = false;
|
|
|
373 |
|
|
|
374 |
// Iterate the returned data for the events.
|
|
|
375 |
foreach ($events as $event => $keys) {
|
|
|
376 |
if ($keys === false) {
|
|
|
377 |
// No data to be invalidated yet.
|
|
|
378 |
continue;
|
|
|
379 |
}
|
|
|
380 |
|
|
|
381 |
// Look at each key and check the timestamp.
|
|
|
382 |
foreach ($keys as $key => $purgetoken) {
|
|
|
383 |
// If the timestamp of the event is more than or equal to the last invalidation (happened between the last
|
|
|
384 |
// invalidation and now), then we need to invaliate the key.
|
|
|
385 |
if (self::compare_purge_tokens($purgetoken, $lastinvalidation) > 0) {
|
|
|
386 |
if ($key === 'purged') {
|
|
|
387 |
$purgeall = true;
|
|
|
388 |
break;
|
|
|
389 |
} else {
|
|
|
390 |
$todelete[] = $key;
|
|
|
391 |
}
|
|
|
392 |
}
|
|
|
393 |
}
|
|
|
394 |
}
|
|
|
395 |
if ($purgeall) {
|
|
|
396 |
$this->purge();
|
|
|
397 |
} else if (!empty($todelete)) {
|
|
|
398 |
$todelete = array_unique($todelete);
|
|
|
399 |
$this->delete_many($todelete);
|
|
|
400 |
}
|
|
|
401 |
// Set the time of the last invalidation.
|
|
|
402 |
if ($purgeall || !empty($todelete)) {
|
|
|
403 |
$this->set('lastinvalidation', self::get_purge_token(true));
|
|
|
404 |
}
|
|
|
405 |
}
|
|
|
406 |
|
|
|
407 |
/**
|
|
|
408 |
* Retrieves the value for the given key from the cache.
|
|
|
409 |
*
|
|
|
410 |
* @param string|int $key The key for the data being requested.
|
|
|
411 |
* It can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
412 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
413 |
* @param int $strictness One of IGNORE_MISSING | MUST_EXIST
|
|
|
414 |
* @return mixed|false The data from the cache or false if the key did not exist within the cache.
|
|
|
415 |
* @throws coding_exception
|
|
|
416 |
*/
|
|
|
417 |
public function get($key, $strictness = IGNORE_MISSING) {
|
|
|
418 |
return $this->get_implementation($key, self::VERSION_NONE, $strictness);
|
|
|
419 |
}
|
|
|
420 |
|
|
|
421 |
/**
|
|
|
422 |
* Retrieves the value and actual version for the given key, with at least the required version.
|
|
|
423 |
*
|
|
|
424 |
* If there is no value for the key, or there is a value but it doesn't have the required
|
|
|
425 |
* version, then this function will return null (or throw an exception if you set strictness
|
|
|
426 |
* to MUST_EXIST).
|
|
|
427 |
*
|
|
|
428 |
* This function can be used to make it easier to support localisable caches (where the cache
|
|
|
429 |
* could be stored on a local server as well as a shared cache). Specifying the version means
|
|
|
430 |
* that it will automatically retrieve the correct version if available, either from the local
|
|
|
431 |
* server or [if that has an older version] from the shared server.
|
|
|
432 |
*
|
|
|
433 |
* If the cached version is newer than specified version, it will be returned regardless. For
|
|
|
434 |
* example, if you request version 4, but the locally cached version is 5, it will be returned.
|
|
|
435 |
* If you request version 6, and the locally cached version is 5, then the system will look in
|
|
|
436 |
* higher-level caches (if any); if there still isn't a version 6 or greater, it will return
|
|
|
437 |
* null.
|
|
|
438 |
*
|
|
|
439 |
* You must use this function if you use set_versioned.
|
|
|
440 |
*
|
|
|
441 |
* @param string|int $key The key for the data being requested.
|
|
|
442 |
* @param int $requiredversion Minimum required version of the data
|
|
|
443 |
* @param int $strictness One of IGNORE_MISSING or MUST_EXIST.
|
|
|
444 |
* @param mixed $actualversion If specified, will be set to the actual version number retrieved
|
|
|
445 |
* @return mixed Data from the cache, or false if the key did not exist or was too old
|
|
|
446 |
* @throws \coding_exception If you call get_versioned on a non-versioned cache key
|
|
|
447 |
*/
|
|
|
448 |
public function get_versioned($key, int $requiredversion, int $strictness = IGNORE_MISSING, &$actualversion = null) {
|
|
|
449 |
return $this->get_implementation($key, $requiredversion, $strictness, $actualversion);
|
|
|
450 |
}
|
|
|
451 |
|
|
|
452 |
/**
|
|
|
453 |
* Checks returned data to see if it matches the specified version number.
|
|
|
454 |
*
|
|
|
455 |
* For versioned data, this returns the version_wrapper object (or false). For other
|
|
|
456 |
* data, it returns the actual data (or false).
|
|
|
457 |
*
|
|
|
458 |
* @param mixed $result Result data
|
|
|
459 |
* @param int $requiredversion Required version number or VERSION_NONE if there must be no version
|
|
|
460 |
* @return bool True if version is current, false if not (or if result is false)
|
|
|
461 |
* @throws \coding_exception If unexpected type of data (versioned vs non-versioned) is found
|
|
|
462 |
*/
|
|
|
463 |
protected static function check_version($result, int $requiredversion): bool {
|
|
|
464 |
if ($requiredversion === self::VERSION_NONE) {
|
|
|
465 |
if ($result instanceof \core_cache\version_wrapper) {
|
|
|
466 |
throw new \coding_exception('Unexpectedly found versioned cache entry');
|
|
|
467 |
} else {
|
|
|
468 |
// No version checks, so version is always correct.
|
|
|
469 |
return true;
|
|
|
470 |
}
|
|
|
471 |
} else {
|
|
|
472 |
// If there's no result, obviously it doesn't meet the required version.
|
|
|
473 |
if (!cache_helper::result_found($result)) {
|
|
|
474 |
return false;
|
|
|
475 |
}
|
|
|
476 |
if (!($result instanceof \core_cache\version_wrapper)) {
|
|
|
477 |
throw new \coding_exception('Unexpectedly found non-versioned cache entry');
|
|
|
478 |
}
|
|
|
479 |
// If the result doesn't match the required version tag, return false.
|
|
|
480 |
if ($result->version < $requiredversion) {
|
|
|
481 |
return false;
|
|
|
482 |
}
|
|
|
483 |
// The version meets the requirement.
|
|
|
484 |
return true;
|
|
|
485 |
}
|
|
|
486 |
}
|
|
|
487 |
|
|
|
488 |
/**
|
|
|
489 |
* Retrieves the value for the given key from the cache.
|
|
|
490 |
*
|
|
|
491 |
* @param string|int $key The key for the data being requested.
|
|
|
492 |
* It can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
493 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
494 |
* @param int $requiredversion Minimum required version of the data or cache::VERSION_NONE
|
|
|
495 |
* @param int $strictness One of IGNORE_MISSING | MUST_EXIST
|
|
|
496 |
* @param mixed $actualversion If specified, will be set to the actual version number retrieved
|
|
|
497 |
* @return mixed|false The data from the cache or false if the key did not exist within the cache.
|
|
|
498 |
* @throws coding_exception
|
|
|
499 |
*/
|
|
|
500 |
protected function get_implementation($key, int $requiredversion, int $strictness, &$actualversion = null) {
|
|
|
501 |
// 1. Get it from the static acceleration array if we can (only when it is enabled and it has already been requested/set).
|
|
|
502 |
$usesstaticacceleration = $this->use_static_acceleration();
|
|
|
503 |
|
|
|
504 |
if ($usesstaticacceleration) {
|
|
|
505 |
$result = $this->static_acceleration_get($key);
|
|
|
506 |
if (cache_helper::result_found($result) && self::check_version($result, $requiredversion)) {
|
|
|
507 |
if ($requiredversion === self::VERSION_NONE) {
|
|
|
508 |
return $result;
|
|
|
509 |
} else {
|
|
|
510 |
$actualversion = $result->version;
|
|
|
511 |
return $result->data;
|
|
|
512 |
}
|
|
|
513 |
}
|
|
|
514 |
}
|
|
|
515 |
|
|
|
516 |
// 2. Parse the key.
|
|
|
517 |
$parsedkey = $this->parse_key($key);
|
|
|
518 |
|
|
|
519 |
// 3. Get it from the store. Obviously wasn't in the static acceleration array.
|
|
|
520 |
$result = $this->store->get($parsedkey);
|
|
|
521 |
if (cache_helper::result_found($result)) {
|
|
|
522 |
// Check the result has at least the required version.
|
|
|
523 |
try {
|
|
|
524 |
$validversion = self::check_version($result, $requiredversion);
|
|
|
525 |
} catch (\coding_exception $e) {
|
|
|
526 |
// In certain circumstances this could happen before users are taken to the upgrade
|
|
|
527 |
// screen when upgrading from an earlier Moodle version that didn't use a versioned
|
|
|
528 |
// cache for this item, so redirect instead of showing error if that's the case.
|
|
|
529 |
redirect_if_major_upgrade_required();
|
|
|
530 |
|
|
|
531 |
// If we still get an exception because there is incorrect data in the cache (not
|
|
|
532 |
// versioned when it ought to be), delete it so this exception goes away next time.
|
|
|
533 |
// The exception should only happen if there is a code bug (which is why we still
|
|
|
534 |
// throw it) but there are unusual scenarios in development where it might happen
|
|
|
535 |
// and that would be annoying if it doesn't fix itself.
|
|
|
536 |
$this->store->delete($parsedkey);
|
|
|
537 |
throw $e;
|
|
|
538 |
}
|
|
|
539 |
|
|
|
540 |
if (!$validversion) {
|
|
|
541 |
// If the result was too old, don't use it.
|
|
|
542 |
$result = false;
|
|
|
543 |
|
|
|
544 |
// Also delete it immediately. This improves performance in the
|
|
|
545 |
// case when the cache item is large and there may be multiple clients simultaneously
|
|
|
546 |
// requesting it - they won't all have to do a megabyte of IO just in order to find
|
|
|
547 |
// that it's out of date.
|
|
|
548 |
$this->store->delete($parsedkey);
|
|
|
549 |
}
|
|
|
550 |
}
|
|
|
551 |
if (cache_helper::result_found($result)) {
|
|
|
552 |
// Look to see if there's a TTL wrapper. It might be inside a version wrapper.
|
|
|
553 |
if ($requiredversion !== self::VERSION_NONE) {
|
|
|
554 |
$ttlconsider = $result->data;
|
|
|
555 |
} else {
|
|
|
556 |
$ttlconsider = $result;
|
|
|
557 |
}
|
|
|
558 |
if ($ttlconsider instanceof cache_ttl_wrapper) {
|
|
|
559 |
if ($ttlconsider->has_expired()) {
|
|
|
560 |
$this->store->delete($parsedkey);
|
|
|
561 |
$result = false;
|
|
|
562 |
} else if ($requiredversion === self::VERSION_NONE) {
|
|
|
563 |
// Use the data inside the TTL wrapper as the result.
|
|
|
564 |
$result = $ttlconsider->data;
|
|
|
565 |
} else {
|
|
|
566 |
// Put the data from the TTL wrapper directly inside the version wrapper.
|
|
|
567 |
$result->data = $ttlconsider->data;
|
|
|
568 |
}
|
|
|
569 |
}
|
|
|
570 |
if ($usesstaticacceleration) {
|
|
|
571 |
$this->static_acceleration_set($key, $result);
|
|
|
572 |
}
|
|
|
573 |
// Remove version wrapper if necessary.
|
|
|
574 |
if ($requiredversion !== self::VERSION_NONE) {
|
|
|
575 |
$actualversion = $result->version;
|
|
|
576 |
$result = $result->data;
|
|
|
577 |
}
|
|
|
578 |
if ($result instanceof cache_cached_object) {
|
|
|
579 |
$result = $result->restore_object();
|
|
|
580 |
}
|
|
|
581 |
}
|
|
|
582 |
|
|
|
583 |
// 4. Load if from the loader/datasource if we don't already have it.
|
|
|
584 |
$setaftervalidation = false;
|
|
|
585 |
if (!cache_helper::result_found($result)) {
|
|
|
586 |
if ($this->perfdebug) {
|
|
|
587 |
cache_helper::record_cache_miss($this->store, $this->definition);
|
|
|
588 |
}
|
|
|
589 |
if ($this->loader !== false) {
|
|
|
590 |
// We must pass the original (unparsed) key to the next loader in the chain.
|
|
|
591 |
// The next loader will parse the key as it sees fit. It may be parsed differently
|
|
|
592 |
// depending upon the capabilities of the store associated with the loader.
|
|
|
593 |
if ($requiredversion === self::VERSION_NONE) {
|
|
|
594 |
$result = $this->loader->get($key);
|
|
|
595 |
} else {
|
|
|
596 |
$result = $this->loader->get_versioned($key, $requiredversion, IGNORE_MISSING, $actualversion);
|
|
|
597 |
}
|
|
|
598 |
} else if ($this->datasource !== false) {
|
|
|
599 |
if ($requiredversion === self::VERSION_NONE) {
|
|
|
600 |
$result = $this->datasource->load_for_cache($key);
|
|
|
601 |
} else {
|
|
|
602 |
if (!$this->datasource instanceof cache_data_source_versionable) {
|
|
|
603 |
throw new \coding_exception('Data source is not versionable');
|
|
|
604 |
}
|
|
|
605 |
$result = $this->datasource->load_for_cache_versioned($key, $requiredversion, $actualversion);
|
|
|
606 |
if ($result && $actualversion < $requiredversion) {
|
|
|
607 |
throw new \coding_exception('Data source returned outdated version');
|
|
|
608 |
}
|
|
|
609 |
}
|
|
|
610 |
}
|
|
|
611 |
$setaftervalidation = (cache_helper::result_found($result));
|
|
|
612 |
} else if ($this->perfdebug) {
|
|
|
613 |
$readbytes = $this->store->get_last_io_bytes();
|
|
|
614 |
cache_helper::record_cache_hit($this->store, $this->definition, 1, $readbytes);
|
|
|
615 |
}
|
|
|
616 |
// 5. Validate strictness.
|
|
|
617 |
if ($strictness === MUST_EXIST && !cache_helper::result_found($result)) {
|
|
|
618 |
throw new coding_exception('Requested key did not exist in any cache stores and could not be loaded.');
|
|
|
619 |
}
|
|
|
620 |
// 6. Set it to the store if we got it from the loader/datasource. Only set to this direct
|
|
|
621 |
// store; parent method will have set it to all stores if needed.
|
|
|
622 |
if ($setaftervalidation) {
|
|
|
623 |
$lock = false;
|
|
|
624 |
try {
|
|
|
625 |
// Only try to acquire a lock for this cache if we do not already have one.
|
|
|
626 |
if (!empty($this->requirelockingbeforewrite) && !$this->check_lock_state($key)) {
|
|
|
627 |
$this->acquire_lock($key);
|
|
|
628 |
$lock = true;
|
|
|
629 |
}
|
|
|
630 |
if ($requiredversion === self::VERSION_NONE) {
|
|
|
631 |
$this->set_implementation($key, self::VERSION_NONE, $result, false);
|
|
|
632 |
} else {
|
|
|
633 |
$this->set_implementation($key, $actualversion, $result, false);
|
|
|
634 |
}
|
|
|
635 |
} finally {
|
|
|
636 |
if ($lock) {
|
|
|
637 |
$this->release_lock($key);
|
|
|
638 |
}
|
|
|
639 |
}
|
|
|
640 |
}
|
|
|
641 |
// 7. Make sure we don't pass back anything that could be a reference.
|
|
|
642 |
// We don't want people modifying the data in the cache.
|
|
|
643 |
if (!$this->store->supports_dereferencing_objects() && !is_scalar($result)) {
|
|
|
644 |
// If data is an object it will be a reference.
|
|
|
645 |
// If data is an array if may contain references.
|
|
|
646 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
647 |
// Call the function to unreference it (in the best way possible).
|
|
|
648 |
$result = $this->unref($result);
|
|
|
649 |
}
|
|
|
650 |
return $result;
|
|
|
651 |
}
|
|
|
652 |
|
|
|
653 |
/**
|
|
|
654 |
* Retrieves an array of values for an array of keys.
|
|
|
655 |
*
|
|
|
656 |
* Using this function comes with potential performance implications.
|
|
|
657 |
* Not all cache stores will support get_many/set_many operations and in order to replicate this functionality will call
|
|
|
658 |
* the equivalent singular method for each item provided.
|
|
|
659 |
* This should not deter you from using this function as there is a performance benefit in situations where the cache store
|
|
|
660 |
* does support it, but you should be aware of this fact.
|
|
|
661 |
*
|
|
|
662 |
* @param array $keys The keys of the data being requested.
|
|
|
663 |
* Each key can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
664 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
665 |
* @param int $strictness One of IGNORE_MISSING or MUST_EXIST.
|
|
|
666 |
* @return array An array of key value pairs for the items that could be retrieved from the cache.
|
|
|
667 |
* If MUST_EXIST was used and not all keys existed within the cache then an exception will be thrown.
|
|
|
668 |
* Otherwise any key that did not exist will have a data value of false within the results.
|
|
|
669 |
* @throws coding_exception
|
|
|
670 |
*/
|
|
|
671 |
public function get_many(array $keys, $strictness = IGNORE_MISSING) {
|
|
|
672 |
|
|
|
673 |
$keysparsed = array();
|
|
|
674 |
$parsedkeys = array();
|
|
|
675 |
$resultpersist = array();
|
|
|
676 |
$resultstore = array();
|
|
|
677 |
$keystofind = array();
|
|
|
678 |
$readbytes = cache_store::IO_BYTES_NOT_SUPPORTED;
|
|
|
679 |
|
|
|
680 |
// First up check the persist cache for each key.
|
|
|
681 |
$isusingpersist = $this->use_static_acceleration();
|
|
|
682 |
foreach ($keys as $key) {
|
|
|
683 |
$pkey = $this->parse_key($key);
|
|
|
684 |
if (is_array($pkey)) {
|
|
|
685 |
$pkey = $pkey['key'];
|
|
|
686 |
}
|
|
|
687 |
$keysparsed[$key] = $pkey;
|
|
|
688 |
$parsedkeys[$pkey] = $key;
|
|
|
689 |
$keystofind[$pkey] = $key;
|
|
|
690 |
if ($isusingpersist) {
|
|
|
691 |
$value = $this->static_acceleration_get($key);
|
|
|
692 |
if ($value !== false) {
|
|
|
693 |
$resultpersist[$pkey] = $value;
|
|
|
694 |
unset($keystofind[$pkey]);
|
|
|
695 |
}
|
|
|
696 |
}
|
|
|
697 |
}
|
|
|
698 |
|
|
|
699 |
// Next assuming we didn't find all of the keys in the persist cache try loading them from the store.
|
|
|
700 |
if (count($keystofind)) {
|
|
|
701 |
$resultstore = $this->store->get_many(array_keys($keystofind));
|
|
|
702 |
if ($this->perfdebug) {
|
|
|
703 |
$readbytes = $this->store->get_last_io_bytes();
|
|
|
704 |
}
|
|
|
705 |
// Process each item in the result to "unwrap" it.
|
|
|
706 |
foreach ($resultstore as $key => $value) {
|
|
|
707 |
if ($value instanceof cache_ttl_wrapper) {
|
|
|
708 |
if ($value->has_expired()) {
|
|
|
709 |
$value = false;
|
|
|
710 |
} else {
|
|
|
711 |
$value = $value->data;
|
|
|
712 |
}
|
|
|
713 |
}
|
|
|
714 |
if ($value !== false && $this->use_static_acceleration()) {
|
|
|
715 |
$this->static_acceleration_set($keystofind[$key], $value);
|
|
|
716 |
}
|
|
|
717 |
if ($value instanceof cache_cached_object) {
|
|
|
718 |
$value = $value->restore_object();
|
|
|
719 |
}
|
|
|
720 |
$resultstore[$key] = $value;
|
|
|
721 |
}
|
|
|
722 |
}
|
|
|
723 |
|
|
|
724 |
// Merge the result from the persis cache with the results from the store load.
|
|
|
725 |
$result = $resultpersist + $resultstore;
|
|
|
726 |
unset($resultpersist);
|
|
|
727 |
unset($resultstore);
|
|
|
728 |
|
|
|
729 |
// Next we need to find any missing values and load them from the loader/datasource next in the chain.
|
|
|
730 |
$usingloader = ($this->loader !== false);
|
|
|
731 |
$usingsource = (!$usingloader && ($this->datasource !== false));
|
|
|
732 |
if ($usingloader || $usingsource) {
|
|
|
733 |
$missingkeys = array();
|
|
|
734 |
foreach ($result as $key => $value) {
|
|
|
735 |
if ($value === false) {
|
|
|
736 |
$missingkeys[] = $parsedkeys[$key];
|
|
|
737 |
}
|
|
|
738 |
}
|
|
|
739 |
if (!empty($missingkeys)) {
|
|
|
740 |
if ($usingloader) {
|
|
|
741 |
$resultmissing = $this->loader->get_many($missingkeys);
|
|
|
742 |
} else {
|
|
|
743 |
$resultmissing = $this->datasource->load_many_for_cache($missingkeys);
|
|
|
744 |
}
|
|
|
745 |
foreach ($resultmissing as $key => $value) {
|
|
|
746 |
$result[$keysparsed[$key]] = $value;
|
|
|
747 |
$lock = false;
|
|
|
748 |
try {
|
|
|
749 |
if (!empty($this->requirelockingbeforewrite)) {
|
|
|
750 |
$this->acquire_lock($key);
|
|
|
751 |
$lock = true;
|
|
|
752 |
}
|
|
|
753 |
if ($value !== false) {
|
|
|
754 |
$this->set($key, $value);
|
|
|
755 |
}
|
|
|
756 |
} finally {
|
|
|
757 |
if ($lock) {
|
|
|
758 |
$this->release_lock($key);
|
|
|
759 |
}
|
|
|
760 |
}
|
|
|
761 |
}
|
|
|
762 |
unset($resultmissing);
|
|
|
763 |
}
|
|
|
764 |
unset($missingkeys);
|
|
|
765 |
}
|
|
|
766 |
|
|
|
767 |
// Create an array with the original keys and the found values. This will be what we return.
|
|
|
768 |
$fullresult = array();
|
|
|
769 |
foreach ($result as $key => $value) {
|
|
|
770 |
if (!is_scalar($value)) {
|
|
|
771 |
// If data is an object it will be a reference.
|
|
|
772 |
// If data is an array if may contain references.
|
|
|
773 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
774 |
// Call the function to unreference it (in the best way possible).
|
|
|
775 |
$value = $this->unref($value);
|
|
|
776 |
}
|
|
|
777 |
$fullresult[$parsedkeys[$key]] = $value;
|
|
|
778 |
}
|
|
|
779 |
unset($result);
|
|
|
780 |
|
|
|
781 |
// Final step is to check strictness.
|
|
|
782 |
if ($strictness === MUST_EXIST) {
|
|
|
783 |
foreach ($keys as $key) {
|
|
|
784 |
if (!array_key_exists($key, $fullresult)) {
|
|
|
785 |
throw new coding_exception('Not all the requested keys existed within the cache stores.');
|
|
|
786 |
}
|
|
|
787 |
}
|
|
|
788 |
}
|
|
|
789 |
|
|
|
790 |
if ($this->perfdebug) {
|
|
|
791 |
$hits = 0;
|
|
|
792 |
$misses = 0;
|
|
|
793 |
foreach ($fullresult as $value) {
|
|
|
794 |
if ($value === false) {
|
|
|
795 |
$misses++;
|
|
|
796 |
} else {
|
|
|
797 |
$hits++;
|
|
|
798 |
}
|
|
|
799 |
}
|
|
|
800 |
cache_helper::record_cache_hit($this->store, $this->definition, $hits, $readbytes);
|
|
|
801 |
cache_helper::record_cache_miss($this->store, $this->definition, $misses);
|
|
|
802 |
}
|
|
|
803 |
|
|
|
804 |
// Return the result. Phew!
|
|
|
805 |
return $fullresult;
|
|
|
806 |
}
|
|
|
807 |
|
|
|
808 |
/**
|
|
|
809 |
* Sends a key => value pair to the cache.
|
|
|
810 |
*
|
|
|
811 |
* <code>
|
|
|
812 |
* // This code will add four entries to the cache, one for each url.
|
|
|
813 |
* $cache->set('main', 'http://moodle.org');
|
|
|
814 |
* $cache->set('docs', 'http://docs.moodle.org');
|
|
|
815 |
* $cache->set('tracker', 'http://tracker.moodle.org');
|
|
|
816 |
* $cache->set('qa', 'http://qa.moodle.net');
|
|
|
817 |
* </code>
|
|
|
818 |
*
|
|
|
819 |
* @param string|int $key The key for the data being requested.
|
|
|
820 |
* It can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
821 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
822 |
* @param mixed $data The data to set against the key.
|
|
|
823 |
* @return bool True on success, false otherwise.
|
|
|
824 |
*/
|
|
|
825 |
public function set($key, $data) {
|
|
|
826 |
return $this->set_implementation($key, self::VERSION_NONE, $data);
|
|
|
827 |
}
|
|
|
828 |
|
|
|
829 |
/**
|
|
|
830 |
* Sets the value for the given key with the given version.
|
|
|
831 |
*
|
|
|
832 |
* The cache does not store multiple versions - any existing version will be overwritten with
|
|
|
833 |
* this one. This function should only be used if there is a known 'current version' (e.g.
|
|
|
834 |
* stored in a database table). It only ensures that the cache does not return outdated data.
|
|
|
835 |
*
|
|
|
836 |
* This function can be used to help implement localisable caches (where the cache could be
|
|
|
837 |
* stored on a local server as well as a shared cache). The version will be recorded alongside
|
|
|
838 |
* the item and get_versioned will always return the correct version.
|
|
|
839 |
*
|
|
|
840 |
* The version number must be an integer that always increases. This could be based on the
|
|
|
841 |
* current time, or a stored value that increases by 1 each time it changes, etc.
|
|
|
842 |
*
|
|
|
843 |
* If you use this function you must use get_versioned to retrieve the data.
|
|
|
844 |
*
|
|
|
845 |
* @param string|int $key The key for the data being set.
|
|
|
846 |
* @param int $version Integer for the version of the data
|
|
|
847 |
* @param mixed $data The data to set against the key.
|
|
|
848 |
* @return bool True on success, false otherwise.
|
|
|
849 |
*/
|
|
|
850 |
public function set_versioned($key, int $version, $data): bool {
|
|
|
851 |
return $this->set_implementation($key, $version, $data);
|
|
|
852 |
}
|
|
|
853 |
|
|
|
854 |
/**
|
|
|
855 |
* Sets the value for the given key, optionally with a version tag.
|
|
|
856 |
*
|
|
|
857 |
* @param string|int $key The key for the data being set.
|
|
|
858 |
* @param int $version Version number for the data or cache::VERSION_NONE if none
|
|
|
859 |
* @param mixed $data The data to set against the key.
|
|
|
860 |
* @param bool $setparents If true, sets all parent loaders, otherwise only this one
|
|
|
861 |
* @return bool True on success, false otherwise.
|
|
|
862 |
*/
|
|
|
863 |
protected function set_implementation($key, int $version, $data, bool $setparents = true): bool {
|
|
|
864 |
if ($this->loader !== false && $setparents) {
|
|
|
865 |
// We have a loader available set it there as well.
|
|
|
866 |
// We have to let the loader do its own parsing of data as it may be unique.
|
|
|
867 |
if ($version === self::VERSION_NONE) {
|
|
|
868 |
$this->loader->set($key, $data);
|
|
|
869 |
} else {
|
|
|
870 |
$this->loader->set_versioned($key, $version, $data);
|
|
|
871 |
}
|
|
|
872 |
}
|
|
|
873 |
$usestaticacceleration = $this->use_static_acceleration();
|
|
|
874 |
|
|
|
875 |
if (is_object($data) && $data instanceof cacheable_object) {
|
|
|
876 |
$data = new cache_cached_object($data);
|
|
|
877 |
} else if (!$this->store->supports_dereferencing_objects() && !is_scalar($data)) {
|
|
|
878 |
// If data is an object it will be a reference.
|
|
|
879 |
// If data is an array if may contain references.
|
|
|
880 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
881 |
// Call the function to unreference it (in the best way possible).
|
|
|
882 |
$data = $this->unref($data);
|
|
|
883 |
}
|
|
|
884 |
|
|
|
885 |
if ($usestaticacceleration) {
|
|
|
886 |
// Static acceleration cache should include the cache version wrapper, but not TTL.
|
|
|
887 |
if ($version === self::VERSION_NONE) {
|
|
|
888 |
$this->static_acceleration_set($key, $data);
|
|
|
889 |
} else {
|
|
|
890 |
$this->static_acceleration_set($key, new \core_cache\version_wrapper($data, $version));
|
|
|
891 |
}
|
|
|
892 |
}
|
|
|
893 |
|
|
|
894 |
if ($this->has_a_ttl() && !$this->store_supports_native_ttl()) {
|
|
|
895 |
$data = new cache_ttl_wrapper($data, $this->definition->get_ttl());
|
|
|
896 |
}
|
|
|
897 |
$parsedkey = $this->parse_key($key);
|
|
|
898 |
|
|
|
899 |
if ($version !== self::VERSION_NONE) {
|
|
|
900 |
$data = new \core_cache\version_wrapper($data, $version);
|
|
|
901 |
}
|
|
|
902 |
|
|
|
903 |
$success = $this->store->set($parsedkey, $data);
|
|
|
904 |
if ($this->perfdebug) {
|
|
|
905 |
cache_helper::record_cache_set($this->store, $this->definition, 1,
|
|
|
906 |
$this->store->get_last_io_bytes());
|
|
|
907 |
}
|
|
|
908 |
return $success;
|
|
|
909 |
}
|
|
|
910 |
|
|
|
911 |
/**
|
|
|
912 |
* Removes references where required.
|
|
|
913 |
*
|
|
|
914 |
* @param stdClass|array $data
|
|
|
915 |
* @return mixed What ever was put in but without any references.
|
|
|
916 |
*/
|
|
|
917 |
protected function unref($data) {
|
|
|
918 |
if ($this->definition->uses_simple_data()) {
|
|
|
919 |
return $data;
|
|
|
920 |
}
|
|
|
921 |
// Check if it requires serialisation in order to produce a reference free copy.
|
|
|
922 |
if ($this->requires_serialisation($data)) {
|
|
|
923 |
// Damn, its going to have to be serialise.
|
|
|
924 |
$data = serialize($data);
|
|
|
925 |
// We unserialise immediately so that we don't have to do it every time on get.
|
|
|
926 |
$data = unserialize($data);
|
|
|
927 |
} else if (!is_scalar($data)) {
|
|
|
928 |
// Its safe to clone, lets do it, its going to beat the pants of serialisation.
|
|
|
929 |
$data = $this->deep_clone($data);
|
|
|
930 |
}
|
|
|
931 |
return $data;
|
|
|
932 |
}
|
|
|
933 |
|
|
|
934 |
/**
|
|
|
935 |
* Checks to see if a var requires serialisation.
|
|
|
936 |
*
|
|
|
937 |
* @param mixed $value The value to check.
|
|
|
938 |
* @param int $depth Used to ensure we don't enter an endless loop (think recursion).
|
|
|
939 |
* @return bool Returns true if the value is going to require serialisation in order to ensure a reference free copy
|
|
|
940 |
* or false if its safe to clone.
|
|
|
941 |
*/
|
|
|
942 |
protected function requires_serialisation($value, $depth = 1) {
|
|
|
943 |
if (is_scalar($value)) {
|
|
|
944 |
return false;
|
|
|
945 |
} else if (is_array($value) || $value instanceof stdClass || $value instanceof Traversable) {
|
|
|
946 |
if ($depth > 5) {
|
|
|
947 |
// Skrew it, mega-deep object, developer you suck, we're just going to serialise.
|
|
|
948 |
return true;
|
|
|
949 |
}
|
|
|
950 |
foreach ($value as $key => $subvalue) {
|
|
|
951 |
if ($this->requires_serialisation($subvalue, $depth++)) {
|
|
|
952 |
return true;
|
|
|
953 |
}
|
|
|
954 |
}
|
|
|
955 |
}
|
|
|
956 |
// Its not scalar, array, or stdClass so we'll need to serialise.
|
|
|
957 |
return true;
|
|
|
958 |
}
|
|
|
959 |
|
|
|
960 |
/**
|
|
|
961 |
* Creates a reference free clone of the given value.
|
|
|
962 |
*
|
|
|
963 |
* @param mixed $value
|
|
|
964 |
* @return mixed
|
|
|
965 |
*/
|
|
|
966 |
protected function deep_clone($value) {
|
|
|
967 |
if (is_object($value)) {
|
|
|
968 |
// Objects must be cloned to begin with.
|
|
|
969 |
$value = clone $value;
|
|
|
970 |
}
|
|
|
971 |
if (is_array($value) || is_object($value)) {
|
|
|
972 |
foreach ($value as $key => $subvalue) {
|
|
|
973 |
$value[$key] = $this->deep_clone($subvalue);
|
|
|
974 |
}
|
|
|
975 |
}
|
|
|
976 |
return $value;
|
|
|
977 |
}
|
|
|
978 |
|
|
|
979 |
/**
|
|
|
980 |
* Sends several key => value pairs to the cache.
|
|
|
981 |
*
|
|
|
982 |
* Using this function comes with potential performance implications.
|
|
|
983 |
* Not all cache stores will support get_many/set_many operations and in order to replicate this functionality will call
|
|
|
984 |
* the equivalent singular method for each item provided.
|
|
|
985 |
* This should not deter you from using this function as there is a performance benefit in situations where the cache store
|
|
|
986 |
* does support it, but you should be aware of this fact.
|
|
|
987 |
*
|
|
|
988 |
* <code>
|
|
|
989 |
* // This code will add four entries to the cache, one for each url.
|
|
|
990 |
* $cache->set_many(array(
|
|
|
991 |
* 'main' => 'http://moodle.org',
|
|
|
992 |
* 'docs' => 'http://docs.moodle.org',
|
|
|
993 |
* 'tracker' => 'http://tracker.moodle.org',
|
|
|
994 |
* 'qa' => ''http://qa.moodle.net'
|
|
|
995 |
* ));
|
|
|
996 |
* </code>
|
|
|
997 |
*
|
|
|
998 |
* @param array $keyvaluearray An array of key => value pairs to send to the cache.
|
|
|
999 |
* @return int The number of items successfully set. It is up to the developer to check this matches the number of items.
|
|
|
1000 |
* ... if they care that is.
|
|
|
1001 |
*/
|
|
|
1002 |
public function set_many(array $keyvaluearray) {
|
|
|
1003 |
if ($this->loader !== false) {
|
|
|
1004 |
// We have a loader available set it there as well.
|
|
|
1005 |
// We have to let the loader do its own parsing of data as it may be unique.
|
|
|
1006 |
$this->loader->set_many($keyvaluearray);
|
|
|
1007 |
}
|
|
|
1008 |
$data = array();
|
|
|
1009 |
$simulatettl = $this->has_a_ttl() && !$this->store_supports_native_ttl();
|
|
|
1010 |
$usestaticaccelerationarray = $this->use_static_acceleration();
|
|
|
1011 |
$needsdereferencing = !$this->store->supports_dereferencing_objects();
|
|
|
1012 |
foreach ($keyvaluearray as $key => $value) {
|
|
|
1013 |
if (is_object($value) && $value instanceof cacheable_object) {
|
|
|
1014 |
$value = new cache_cached_object($value);
|
|
|
1015 |
} else if ($needsdereferencing && !is_scalar($value)) {
|
|
|
1016 |
// If data is an object it will be a reference.
|
|
|
1017 |
// If data is an array if may contain references.
|
|
|
1018 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
1019 |
// Call the function to unreference it (in the best way possible).
|
|
|
1020 |
$value = $this->unref($value);
|
|
|
1021 |
}
|
|
|
1022 |
if ($usestaticaccelerationarray) {
|
|
|
1023 |
$this->static_acceleration_set($key, $value);
|
|
|
1024 |
}
|
|
|
1025 |
if ($simulatettl) {
|
|
|
1026 |
$value = new cache_ttl_wrapper($value, $this->definition->get_ttl());
|
|
|
1027 |
}
|
|
|
1028 |
$data[$key] = array(
|
|
|
1029 |
'key' => $this->parse_key($key),
|
|
|
1030 |
'value' => $value
|
|
|
1031 |
);
|
|
|
1032 |
}
|
|
|
1033 |
$successfullyset = $this->store->set_many($data);
|
|
|
1034 |
if ($this->perfdebug && $successfullyset) {
|
|
|
1035 |
cache_helper::record_cache_set($this->store, $this->definition, $successfullyset,
|
|
|
1036 |
$this->store->get_last_io_bytes());
|
|
|
1037 |
}
|
|
|
1038 |
return $successfullyset;
|
|
|
1039 |
}
|
|
|
1040 |
|
|
|
1041 |
/**
|
|
|
1042 |
* Test is a cache has a key.
|
|
|
1043 |
*
|
|
|
1044 |
* The use of the has methods is strongly discouraged. In a high load environment the cache may well change between the
|
|
|
1045 |
* test and any subsequent action (get, set, delete etc).
|
|
|
1046 |
* Instead it is recommended to write your code in such a way they it performs the following steps:
|
|
|
1047 |
* <ol>
|
|
|
1048 |
* <li>Attempt to retrieve the information.</li>
|
|
|
1049 |
* <li>Generate the information.</li>
|
|
|
1050 |
* <li>Attempt to set the information</li>
|
|
|
1051 |
* </ol>
|
|
|
1052 |
*
|
|
|
1053 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
1054 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
1055 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
1056 |
*
|
|
|
1057 |
* @param string|int $key
|
|
|
1058 |
* @param bool $tryloadifpossible If set to true, the cache doesn't contain the key, and there is another cache loader or
|
|
|
1059 |
* data source then the code will try load the key value from the next item in the chain.
|
|
|
1060 |
* @return bool True if the cache has the requested key, false otherwise.
|
|
|
1061 |
*/
|
|
|
1062 |
public function has($key, $tryloadifpossible = false) {
|
|
|
1063 |
if ($this->static_acceleration_has($key)) {
|
|
|
1064 |
// Hoorah, that was easy. It exists in the static acceleration array so we definitely have it.
|
|
|
1065 |
return true;
|
|
|
1066 |
}
|
|
|
1067 |
$parsedkey = $this->parse_key($key);
|
|
|
1068 |
|
|
|
1069 |
if ($this->has_a_ttl() && !$this->store_supports_native_ttl()) {
|
|
|
1070 |
// The data has a TTL and the store doesn't support it natively.
|
|
|
1071 |
// We must fetch the data and expect a ttl wrapper.
|
|
|
1072 |
$data = $this->store->get($parsedkey);
|
|
|
1073 |
$has = ($data instanceof cache_ttl_wrapper && !$data->has_expired());
|
|
|
1074 |
} else if (!$this->store_supports_key_awareness()) {
|
|
|
1075 |
// The store doesn't support key awareness, get the data and check it manually... puke.
|
|
|
1076 |
// Either no TTL is set of the store supports its handling natively.
|
|
|
1077 |
$data = $this->store->get($parsedkey);
|
|
|
1078 |
$has = ($data !== false);
|
|
|
1079 |
} else {
|
|
|
1080 |
// The store supports key awareness, this is easy!
|
|
|
1081 |
// Either no TTL is set of the store supports its handling natively.
|
|
|
1082 |
$has = $this->store->has($parsedkey);
|
|
|
1083 |
}
|
|
|
1084 |
if (!$has && $tryloadifpossible) {
|
|
|
1085 |
if ($this->loader !== false) {
|
|
|
1086 |
$result = $this->loader->get($parsedkey);
|
|
|
1087 |
} else if ($this->datasource !== null) {
|
|
|
1088 |
$result = $this->datasource->load_for_cache($key);
|
|
|
1089 |
}
|
|
|
1090 |
$has = ($result !== null);
|
|
|
1091 |
if ($has) {
|
|
|
1092 |
$this->set($key, $result);
|
|
|
1093 |
}
|
|
|
1094 |
}
|
|
|
1095 |
return $has;
|
|
|
1096 |
}
|
|
|
1097 |
|
|
|
1098 |
/**
|
|
|
1099 |
* Test is a cache has all of the given keys.
|
|
|
1100 |
*
|
|
|
1101 |
* It is strongly recommended to avoid the use of this function if not absolutely required.
|
|
|
1102 |
* In a high load environment the cache may well change between the test and any subsequent action (get, set, delete etc).
|
|
|
1103 |
*
|
|
|
1104 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
1105 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
1106 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
1107 |
*
|
|
|
1108 |
* @param array $keys
|
|
|
1109 |
* @return bool True if the cache has all of the given keys, false otherwise.
|
|
|
1110 |
*/
|
|
|
1111 |
public function has_all(array $keys) {
|
|
|
1112 |
if (($this->has_a_ttl() && !$this->store_supports_native_ttl()) || !$this->store_supports_key_awareness()) {
|
|
|
1113 |
foreach ($keys as $key) {
|
|
|
1114 |
if (!$this->has($key)) {
|
|
|
1115 |
return false;
|
|
|
1116 |
}
|
|
|
1117 |
}
|
|
|
1118 |
return true;
|
|
|
1119 |
}
|
|
|
1120 |
$parsedkeys = array_map(array($this, 'parse_key'), $keys);
|
|
|
1121 |
return $this->store->has_all($parsedkeys);
|
|
|
1122 |
}
|
|
|
1123 |
|
|
|
1124 |
/**
|
|
|
1125 |
* Test if a cache has at least one of the given keys.
|
|
|
1126 |
*
|
|
|
1127 |
* It is strongly recommended to avoid the use of this function if not absolutely required.
|
|
|
1128 |
* In a high load environment the cache may well change between the test and any subsequent action (get, set, delete etc).
|
|
|
1129 |
*
|
|
|
1130 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
1131 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
1132 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
1133 |
*
|
|
|
1134 |
* @param array $keys
|
|
|
1135 |
* @return bool True if the cache has at least one of the given keys
|
|
|
1136 |
*/
|
|
|
1137 |
public function has_any(array $keys) {
|
|
|
1138 |
if (($this->has_a_ttl() && !$this->store_supports_native_ttl()) || !$this->store_supports_key_awareness()) {
|
|
|
1139 |
foreach ($keys as $key) {
|
|
|
1140 |
if ($this->has($key)) {
|
|
|
1141 |
return true;
|
|
|
1142 |
}
|
|
|
1143 |
}
|
|
|
1144 |
return false;
|
|
|
1145 |
}
|
|
|
1146 |
|
|
|
1147 |
if ($this->use_static_acceleration()) {
|
|
|
1148 |
foreach ($keys as $id => $key) {
|
|
|
1149 |
if ($this->static_acceleration_has($key)) {
|
|
|
1150 |
return true;
|
|
|
1151 |
}
|
|
|
1152 |
}
|
|
|
1153 |
}
|
|
|
1154 |
$parsedkeys = array_map(array($this, 'parse_key'), $keys);
|
|
|
1155 |
return $this->store->has_any($parsedkeys);
|
|
|
1156 |
}
|
|
|
1157 |
|
|
|
1158 |
/**
|
|
|
1159 |
* Delete the given key from the cache.
|
|
|
1160 |
*
|
|
|
1161 |
* @param string|int $key The key to delete.
|
|
|
1162 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
1163 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
1164 |
* @return bool True of success, false otherwise.
|
|
|
1165 |
*/
|
|
|
1166 |
public function delete($key, $recurse = true) {
|
|
|
1167 |
$this->static_acceleration_delete($key);
|
|
|
1168 |
if ($recurse && $this->loader !== false) {
|
|
|
1169 |
// Delete from the bottom of the stack first.
|
|
|
1170 |
$this->loader->delete($key, $recurse);
|
|
|
1171 |
}
|
|
|
1172 |
$parsedkey = $this->parse_key($key);
|
|
|
1173 |
return $this->store->delete($parsedkey);
|
|
|
1174 |
}
|
|
|
1175 |
|
|
|
1176 |
/**
|
|
|
1177 |
* Delete all of the given keys from the cache.
|
|
|
1178 |
*
|
|
|
1179 |
* @param array $keys The key to delete.
|
|
|
1180 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
1181 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
1182 |
* @return int The number of items successfully deleted.
|
|
|
1183 |
*/
|
|
|
1184 |
public function delete_many(array $keys, $recurse = true) {
|
|
|
1185 |
if ($this->use_static_acceleration()) {
|
|
|
1186 |
foreach ($keys as $key) {
|
|
|
1187 |
$this->static_acceleration_delete($key);
|
|
|
1188 |
}
|
|
|
1189 |
}
|
|
|
1190 |
if ($recurse && $this->loader !== false) {
|
|
|
1191 |
// Delete from the bottom of the stack first.
|
|
|
1192 |
$this->loader->delete_many($keys, $recurse);
|
|
|
1193 |
}
|
|
|
1194 |
$parsedkeys = array_map(array($this, 'parse_key'), $keys);
|
|
|
1195 |
return $this->store->delete_many($parsedkeys);
|
|
|
1196 |
}
|
|
|
1197 |
|
|
|
1198 |
/**
|
|
|
1199 |
* Purges the cache store, and loader if there is one.
|
|
|
1200 |
*
|
|
|
1201 |
* @return bool True on success, false otherwise
|
|
|
1202 |
*/
|
|
|
1203 |
public function purge() {
|
|
|
1204 |
// 1. Purge the static acceleration array.
|
|
|
1205 |
$this->static_acceleration_purge();
|
|
|
1206 |
// 2. Purge the store.
|
|
|
1207 |
$this->store->purge();
|
|
|
1208 |
// 3. Optionally pruge any stacked loaders.
|
|
|
1209 |
if ($this->loader) {
|
|
|
1210 |
$this->loader->purge();
|
|
|
1211 |
}
|
|
|
1212 |
return true;
|
|
|
1213 |
}
|
|
|
1214 |
|
|
|
1215 |
/**
|
|
|
1216 |
* Parses the key turning it into a string (or array is required) suitable to be passed to the cache store.
|
|
|
1217 |
*
|
|
|
1218 |
* @param string|int $key As passed to get|set|delete etc.
|
|
|
1219 |
* @return string|array String unless the store supports multi-identifiers in which case an array if returned.
|
|
|
1220 |
*/
|
|
|
1221 |
protected function parse_key($key) {
|
|
|
1222 |
// First up if the store supports multiple keys we'll go with that.
|
|
|
1223 |
if ($this->store->supports_multiple_identifiers()) {
|
|
|
1224 |
$result = $this->definition->generate_multi_key_parts();
|
|
|
1225 |
$result['key'] = $key;
|
|
|
1226 |
return $result;
|
|
|
1227 |
}
|
|
|
1228 |
// If not we need to generate a hash and to for that we use the cache_helper.
|
|
|
1229 |
return cache_helper::hash_key($key, $this->definition);
|
|
|
1230 |
}
|
|
|
1231 |
|
|
|
1232 |
/**
|
|
|
1233 |
* Returns true if the cache is making use of a ttl.
|
|
|
1234 |
* @return bool
|
|
|
1235 |
*/
|
|
|
1236 |
protected function has_a_ttl() {
|
|
|
1237 |
return $this->hasattl;
|
|
|
1238 |
}
|
|
|
1239 |
|
|
|
1240 |
/**
|
|
|
1241 |
* Returns true if the cache store supports native ttl.
|
|
|
1242 |
* @return bool
|
|
|
1243 |
*/
|
|
|
1244 |
protected function store_supports_native_ttl() {
|
|
|
1245 |
if ($this->supportsnativettl === null) {
|
|
|
1246 |
$this->supportsnativettl = ($this->store->supports_native_ttl());
|
|
|
1247 |
}
|
|
|
1248 |
return $this->supportsnativettl;
|
|
|
1249 |
}
|
|
|
1250 |
|
|
|
1251 |
/**
|
|
|
1252 |
* Returns the cache definition.
|
|
|
1253 |
*
|
|
|
1254 |
* @return cache_definition
|
|
|
1255 |
*/
|
|
|
1256 |
protected function get_definition() {
|
|
|
1257 |
return $this->definition;
|
|
|
1258 |
}
|
|
|
1259 |
|
|
|
1260 |
/**
|
|
|
1261 |
* Returns the cache store
|
|
|
1262 |
*
|
|
|
1263 |
* @return cache_store
|
|
|
1264 |
*/
|
|
|
1265 |
protected function get_store() {
|
|
|
1266 |
return $this->store;
|
|
|
1267 |
}
|
|
|
1268 |
|
|
|
1269 |
/**
|
|
|
1270 |
* Returns the loader associated with this instance.
|
|
|
1271 |
*
|
|
|
1272 |
* @since Moodle 2.4.4
|
|
|
1273 |
* @return cache|false
|
|
|
1274 |
*/
|
|
|
1275 |
protected function get_loader() {
|
|
|
1276 |
return $this->loader;
|
|
|
1277 |
}
|
|
|
1278 |
|
|
|
1279 |
/**
|
|
|
1280 |
* Returns the data source associated with this cache.
|
|
|
1281 |
*
|
|
|
1282 |
* @since Moodle 2.4.4
|
|
|
1283 |
* @return cache_data_source|false
|
|
|
1284 |
*/
|
|
|
1285 |
protected function get_datasource() {
|
|
|
1286 |
return $this->datasource;
|
|
|
1287 |
}
|
|
|
1288 |
|
|
|
1289 |
/**
|
|
|
1290 |
* Returns true if the store supports key awareness.
|
|
|
1291 |
*
|
|
|
1292 |
* @return bool
|
|
|
1293 |
*/
|
|
|
1294 |
protected function store_supports_key_awareness() {
|
|
|
1295 |
if ($this->supportskeyawareness === null) {
|
|
|
1296 |
$this->supportskeyawareness = ($this->store instanceof cache_is_key_aware);
|
|
|
1297 |
}
|
|
|
1298 |
return $this->supportskeyawareness;
|
|
|
1299 |
}
|
|
|
1300 |
|
|
|
1301 |
/**
|
|
|
1302 |
* Returns true if the store natively supports locking.
|
|
|
1303 |
*
|
|
|
1304 |
* @return bool
|
|
|
1305 |
*/
|
|
|
1306 |
protected function store_supports_native_locking() {
|
|
|
1307 |
if ($this->nativelocking === null) {
|
|
|
1308 |
$this->nativelocking = ($this->store instanceof cache_is_lockable);
|
|
|
1309 |
}
|
|
|
1310 |
return $this->nativelocking;
|
|
|
1311 |
}
|
|
|
1312 |
|
|
|
1313 |
/**
|
|
|
1314 |
* @deprecated since 2.6
|
|
|
1315 |
* @see cache::use_static_acceleration()
|
|
|
1316 |
*/
|
|
|
1317 |
protected function is_using_persist_cache() {
|
|
|
1318 |
throw new coding_exception('cache::is_using_persist_cache() can not be used anymore.' .
|
|
|
1319 |
' Please use cache::use_static_acceleration() instead.');
|
|
|
1320 |
}
|
|
|
1321 |
|
|
|
1322 |
/**
|
|
|
1323 |
* Returns true if this cache is making use of the static acceleration array.
|
|
|
1324 |
*
|
|
|
1325 |
* @return bool
|
|
|
1326 |
*/
|
|
|
1327 |
protected function use_static_acceleration() {
|
|
|
1328 |
return $this->staticacceleration;
|
|
|
1329 |
}
|
|
|
1330 |
|
|
|
1331 |
/**
|
|
|
1332 |
* @see cache::static_acceleration_has
|
|
|
1333 |
* @deprecated since 2.6
|
|
|
1334 |
*/
|
|
|
1335 |
protected function is_in_persist_cache() {
|
|
|
1336 |
throw new coding_exception('cache::is_in_persist_cache() can not be used anymore.' .
|
|
|
1337 |
' Please use cache::static_acceleration_has() instead.');
|
|
|
1338 |
}
|
|
|
1339 |
|
|
|
1340 |
/**
|
|
|
1341 |
* Returns true if the requested key exists within the static acceleration array.
|
|
|
1342 |
*
|
|
|
1343 |
* @param string $key The parsed key
|
|
|
1344 |
* @return bool
|
|
|
1345 |
*/
|
|
|
1346 |
protected function static_acceleration_has($key) {
|
|
|
1347 |
// This could be written as a single line, however it has been split because the ttl check is faster than the instanceof
|
|
|
1348 |
// and has_expired calls.
|
|
|
1349 |
if (!$this->staticacceleration || !isset($this->staticaccelerationarray[$key])) {
|
|
|
1350 |
return false;
|
|
|
1351 |
}
|
|
|
1352 |
return true;
|
|
|
1353 |
}
|
|
|
1354 |
|
|
|
1355 |
/**
|
|
|
1356 |
* @deprecated since 2.6
|
|
|
1357 |
* @see cache::static_acceleration_get
|
|
|
1358 |
*/
|
|
|
1359 |
protected function get_from_persist_cache() {
|
|
|
1360 |
throw new coding_exception('cache::get_from_persist_cache() can not be used anymore.' .
|
|
|
1361 |
' Please use cache::static_acceleration_get() instead.');
|
|
|
1362 |
}
|
|
|
1363 |
|
|
|
1364 |
/**
|
|
|
1365 |
* Returns the item from the static acceleration array if it exists there.
|
|
|
1366 |
*
|
|
|
1367 |
* @param string $key The parsed key
|
|
|
1368 |
* @return mixed|false Dereferenced data from the static acceleration array or false if it wasn't there.
|
|
|
1369 |
*/
|
|
|
1370 |
protected function static_acceleration_get($key) {
|
|
|
1371 |
if (!$this->staticacceleration || !isset($this->staticaccelerationarray[$key])) {
|
|
|
1372 |
$result = false;
|
|
|
1373 |
} else {
|
|
|
1374 |
$data = $this->staticaccelerationarray[$key]['data'];
|
|
|
1375 |
|
|
|
1376 |
if ($data instanceof cache_cached_object) {
|
|
|
1377 |
$result = $data->restore_object();
|
|
|
1378 |
} else if ($this->staticaccelerationarray[$key]['serialized']) {
|
|
|
1379 |
$result = unserialize($data);
|
|
|
1380 |
} else {
|
|
|
1381 |
$result = $data;
|
|
|
1382 |
}
|
|
|
1383 |
}
|
|
|
1384 |
if (cache_helper::result_found($result)) {
|
|
|
1385 |
if ($this->perfdebug) {
|
|
|
1386 |
cache_helper::record_cache_hit(cache_store::STATIC_ACCEL, $this->definition);
|
|
|
1387 |
}
|
|
|
1388 |
if ($this->staticaccelerationsize > 1 && $this->staticaccelerationcount > 1) {
|
|
|
1389 |
// Check to see if this is the last item on the static acceleration keys array.
|
|
|
1390 |
if (end($this->staticaccelerationkeys) !== $key) {
|
|
|
1391 |
// It isn't the last item.
|
|
|
1392 |
// Move the item to the end of the array so that it is last to be removed.
|
|
|
1393 |
unset($this->staticaccelerationkeys[$key]);
|
|
|
1394 |
$this->staticaccelerationkeys[$key] = $key;
|
|
|
1395 |
}
|
|
|
1396 |
}
|
|
|
1397 |
return $result;
|
|
|
1398 |
} else {
|
|
|
1399 |
if ($this->perfdebug) {
|
|
|
1400 |
cache_helper::record_cache_miss(cache_store::STATIC_ACCEL, $this->definition);
|
|
|
1401 |
}
|
|
|
1402 |
return false;
|
|
|
1403 |
}
|
|
|
1404 |
}
|
|
|
1405 |
|
|
|
1406 |
/**
|
|
|
1407 |
* @deprecated since 2.6
|
|
|
1408 |
* @see cache::static_acceleration_set
|
|
|
1409 |
*/
|
|
|
1410 |
protected function set_in_persist_cache() {
|
|
|
1411 |
throw new coding_exception('cache::set_in_persist_cache() can not be used anymore.' .
|
|
|
1412 |
' Please use cache::static_acceleration_set() instead.');
|
|
|
1413 |
}
|
|
|
1414 |
|
|
|
1415 |
/**
|
|
|
1416 |
* Sets a key value pair into the static acceleration array.
|
|
|
1417 |
*
|
|
|
1418 |
* @param string $key The parsed key
|
|
|
1419 |
* @param mixed $data
|
|
|
1420 |
* @return bool
|
|
|
1421 |
*/
|
|
|
1422 |
protected function static_acceleration_set($key, $data) {
|
|
|
1423 |
if ($this->staticaccelerationsize !== false && isset($this->staticaccelerationkeys[$key])) {
|
|
|
1424 |
$this->staticaccelerationcount--;
|
|
|
1425 |
unset($this->staticaccelerationkeys[$key]);
|
|
|
1426 |
}
|
|
|
1427 |
|
|
|
1428 |
// We serialize anything that's not;
|
|
|
1429 |
// 1. A known scalar safe value.
|
|
|
1430 |
// 2. A definition that says it's simpledata. We trust it that it doesn't contain dangerous references.
|
|
|
1431 |
// 3. An object that handles dereferencing by itself.
|
|
|
1432 |
if (is_scalar($data) || $this->definition->uses_simple_data()
|
|
|
1433 |
|| $data instanceof cache_cached_object) {
|
|
|
1434 |
$this->staticaccelerationarray[$key]['data'] = $data;
|
|
|
1435 |
$this->staticaccelerationarray[$key]['serialized'] = false;
|
|
|
1436 |
} else {
|
|
|
1437 |
$this->staticaccelerationarray[$key]['data'] = serialize($data);
|
|
|
1438 |
$this->staticaccelerationarray[$key]['serialized'] = true;
|
|
|
1439 |
}
|
|
|
1440 |
if ($this->staticaccelerationsize !== false) {
|
|
|
1441 |
$this->staticaccelerationcount++;
|
|
|
1442 |
$this->staticaccelerationkeys[$key] = $key;
|
|
|
1443 |
if ($this->staticaccelerationcount > $this->staticaccelerationsize) {
|
|
|
1444 |
$dropkey = array_shift($this->staticaccelerationkeys);
|
|
|
1445 |
unset($this->staticaccelerationarray[$dropkey]);
|
|
|
1446 |
$this->staticaccelerationcount--;
|
|
|
1447 |
}
|
|
|
1448 |
}
|
|
|
1449 |
return true;
|
|
|
1450 |
}
|
|
|
1451 |
|
|
|
1452 |
/**
|
|
|
1453 |
* @deprecated since 2.6
|
|
|
1454 |
* @see cache::static_acceleration_delete()
|
|
|
1455 |
*/
|
|
|
1456 |
protected function delete_from_persist_cache() {
|
|
|
1457 |
throw new coding_exception('cache::delete_from_persist_cache() can not be used anymore.' .
|
|
|
1458 |
' Please use cache::static_acceleration_delete() instead.');
|
|
|
1459 |
}
|
|
|
1460 |
|
|
|
1461 |
/**
|
|
|
1462 |
* Deletes an item from the static acceleration array.
|
|
|
1463 |
*
|
|
|
1464 |
* @param string|int $key As given to get|set|delete
|
|
|
1465 |
* @return bool True on success, false otherwise.
|
|
|
1466 |
*/
|
|
|
1467 |
protected function static_acceleration_delete($key) {
|
|
|
1468 |
unset($this->staticaccelerationarray[$key]);
|
|
|
1469 |
if ($this->staticaccelerationsize !== false && isset($this->staticaccelerationkeys[$key])) {
|
|
|
1470 |
unset($this->staticaccelerationkeys[$key]);
|
|
|
1471 |
$this->staticaccelerationcount--;
|
|
|
1472 |
}
|
|
|
1473 |
return true;
|
|
|
1474 |
}
|
|
|
1475 |
|
|
|
1476 |
/**
|
|
|
1477 |
* Purge the static acceleration cache.
|
|
|
1478 |
*/
|
|
|
1479 |
protected function static_acceleration_purge() {
|
|
|
1480 |
$this->staticaccelerationarray = array();
|
|
|
1481 |
if ($this->staticaccelerationsize !== false) {
|
|
|
1482 |
$this->staticaccelerationkeys = array();
|
|
|
1483 |
$this->staticaccelerationcount = 0;
|
|
|
1484 |
}
|
|
|
1485 |
}
|
|
|
1486 |
|
|
|
1487 |
/**
|
|
|
1488 |
* Returns the timestamp from the first request for the time from the cache API.
|
|
|
1489 |
*
|
|
|
1490 |
* This stamp needs to be used for all ttl and time based operations to ensure that we don't end up with
|
|
|
1491 |
* timing issues.
|
|
|
1492 |
*
|
|
|
1493 |
* @param bool $float Whether to use floating precision accuracy.
|
|
|
1494 |
* @return int|float
|
|
|
1495 |
*/
|
|
|
1496 |
public static function now($float = false) {
|
|
|
1497 |
if (self::$now === null) {
|
|
|
1498 |
self::$now = microtime(true);
|
|
|
1499 |
}
|
|
|
1500 |
|
|
|
1501 |
if ($float) {
|
|
|
1502 |
return self::$now;
|
|
|
1503 |
} else {
|
|
|
1504 |
return (int) self::$now;
|
|
|
1505 |
}
|
|
|
1506 |
}
|
|
|
1507 |
|
|
|
1508 |
/**
|
|
|
1509 |
* Get a 'purge' token used for cache invalidation handling.
|
|
|
1510 |
*
|
|
|
1511 |
* Note: This function is intended for use from within the Cache API only and not by plugins, or cache stores.
|
|
|
1512 |
*
|
|
|
1513 |
* @param bool $reset Whether to reset the token and generate a new one.
|
|
|
1514 |
* @return string
|
|
|
1515 |
*/
|
|
|
1516 |
public static function get_purge_token($reset = false) {
|
|
|
1517 |
if (self::$purgetoken === null || $reset) {
|
|
|
1518 |
self::$now = null;
|
|
|
1519 |
self::$purgetoken = self::now(true) . '-' . uniqid('', true);
|
|
|
1520 |
}
|
|
|
1521 |
|
|
|
1522 |
return self::$purgetoken;
|
|
|
1523 |
}
|
|
|
1524 |
|
|
|
1525 |
/**
|
|
|
1526 |
* Compare a pair of purge tokens.
|
|
|
1527 |
*
|
|
|
1528 |
* If the two tokens are identical, then the return value is 0.
|
|
|
1529 |
* If the time component of token A is newer than token B, then a positive value is returned.
|
|
|
1530 |
* If the time component of token B is newer than token A, then a negative value is returned.
|
|
|
1531 |
*
|
|
|
1532 |
* Note: This function is intended for use from within the Cache API only and not by plugins, or cache stores.
|
|
|
1533 |
*
|
|
|
1534 |
* @param string $tokena
|
|
|
1535 |
* @param string $tokenb
|
|
|
1536 |
* @return int
|
|
|
1537 |
*/
|
|
|
1538 |
public static function compare_purge_tokens($tokena, $tokenb) {
|
|
|
1539 |
if ($tokena === $tokenb) {
|
|
|
1540 |
// There is an exact match.
|
|
|
1541 |
return 0;
|
|
|
1542 |
}
|
|
|
1543 |
|
|
|
1544 |
// The token for when the cache was last invalidated.
|
|
|
1545 |
list($atime) = explode('-', "{$tokena}-", 2);
|
|
|
1546 |
|
|
|
1547 |
// The token for this cache.
|
|
|
1548 |
list($btime) = explode('-', "{$tokenb}-", 2);
|
|
|
1549 |
|
|
|
1550 |
if ($atime >= $btime) {
|
|
|
1551 |
// Token A is newer.
|
|
|
1552 |
return 1;
|
|
|
1553 |
} else {
|
|
|
1554 |
// Token A is older.
|
|
|
1555 |
return -1;
|
|
|
1556 |
}
|
|
|
1557 |
}
|
|
|
1558 |
|
|
|
1559 |
/**
|
|
|
1560 |
* Subclasses may support purging cache of all data belonging to the
|
|
|
1561 |
* current user.
|
|
|
1562 |
*/
|
|
|
1563 |
public function purge_current_user() {
|
|
|
1564 |
}
|
|
|
1565 |
}
|
|
|
1566 |
|
|
|
1567 |
/**
|
|
|
1568 |
* An application cache.
|
|
|
1569 |
*
|
|
|
1570 |
* This class is used for application caches returned by the cache::make methods.
|
|
|
1571 |
* On top of the standard functionality it also allows locking to be required and or manually operated.
|
|
|
1572 |
*
|
|
|
1573 |
* This cache class should never be interacted with directly. Instead you should always use the cache::make methods.
|
|
|
1574 |
* It is technically possible to call those methods through this class however there is no guarantee that you will get an
|
|
|
1575 |
* instance of this class back again.
|
|
|
1576 |
*
|
|
|
1577 |
* @internal don't use me directly.
|
|
|
1578 |
*
|
|
|
1579 |
* @package core
|
|
|
1580 |
* @category cache
|
|
|
1581 |
* @copyright 2012 Sam Hemelryk
|
|
|
1582 |
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
|
|
|
1583 |
*/
|
|
|
1584 |
class cache_application extends cache implements cache_loader_with_locking {
|
|
|
1585 |
|
|
|
1586 |
/**
|
|
|
1587 |
* Lock identifier.
|
|
|
1588 |
* This is used to ensure the lock belongs to the cache instance + definition + user.
|
|
|
1589 |
* @var string
|
|
|
1590 |
*/
|
|
|
1591 |
protected $lockidentifier;
|
|
|
1592 |
|
|
|
1593 |
/**
|
|
|
1594 |
* Gets set to true if the cache's primary store natively supports locking.
|
|
|
1595 |
* If it does then we use that, otherwise we need to instantiate a second store to use for locking.
|
|
|
1596 |
* @var cache_store
|
|
|
1597 |
*/
|
|
|
1598 |
protected $nativelocking = null;
|
|
|
1599 |
|
|
|
1600 |
/**
|
|
|
1601 |
* Gets set to true if the cache is going to be using locking.
|
|
|
1602 |
* This isn't a requirement, it doesn't need to use locking (most won't) and this bool is used to quickly check things.
|
|
|
1603 |
* If required then locking will be forced for the get|set|delete operation.
|
|
|
1604 |
* @var bool
|
|
|
1605 |
*/
|
|
|
1606 |
protected $requirelocking = false;
|
|
|
1607 |
|
|
|
1608 |
/**
|
|
|
1609 |
* Gets set to true if the cache writes (set|delete) must have a manual lock created first
|
|
|
1610 |
* @var bool
|
|
|
1611 |
*/
|
|
|
1612 |
protected $requirelockingbeforewrite = false;
|
|
|
1613 |
|
|
|
1614 |
/**
|
|
|
1615 |
* Gets set to a cache_store to use for locking if the caches primary store doesn't support locking natively.
|
|
|
1616 |
* @var cache_lock_interface
|
|
|
1617 |
*/
|
|
|
1618 |
protected $cachelockinstance;
|
|
|
1619 |
|
|
|
1620 |
/**
|
|
|
1621 |
* Store a list of locks acquired by this process.
|
|
|
1622 |
* @var array
|
|
|
1623 |
*/
|
|
|
1624 |
protected $locks;
|
|
|
1625 |
|
|
|
1626 |
/**
|
|
|
1627 |
* Overrides the cache construct method.
|
|
|
1628 |
*
|
|
|
1629 |
* You should not call this method from your code, instead you should use the cache::make methods.
|
|
|
1630 |
*
|
|
|
1631 |
* @param cache_definition $definition
|
|
|
1632 |
* @param cache_store $store
|
|
|
1633 |
* @param cache_loader|cache_data_source $loader
|
|
|
1634 |
*/
|
|
|
1635 |
public function __construct(cache_definition $definition, cache_store $store, $loader = null) {
|
|
|
1636 |
parent::__construct($definition, $store, $loader);
|
|
|
1637 |
$this->nativelocking = $this->store_supports_native_locking();
|
|
|
1638 |
if ($definition->require_locking()) {
|
|
|
1639 |
$this->requirelocking = true;
|
|
|
1640 |
$this->requirelockingbeforewrite = $definition->require_locking_before_write();
|
|
|
1641 |
}
|
|
|
1642 |
|
|
|
1643 |
$this->handle_invalidation_events();
|
|
|
1644 |
}
|
|
|
1645 |
|
|
|
1646 |
/**
|
|
|
1647 |
* Returns the identifier to use
|
|
|
1648 |
*
|
|
|
1649 |
* @staticvar int $instances Counts the number of instances. Used as part of the lock identifier.
|
|
|
1650 |
* @return string
|
|
|
1651 |
*/
|
|
|
1652 |
public function get_identifier() {
|
|
|
1653 |
static $instances = 0;
|
|
|
1654 |
if ($this->lockidentifier === null) {
|
|
|
1655 |
$this->lockidentifier = md5(
|
|
|
1656 |
$this->get_definition()->generate_definition_hash() .
|
|
|
1657 |
sesskey() .
|
|
|
1658 |
$instances++ .
|
|
|
1659 |
'cache_application'
|
|
|
1660 |
);
|
|
|
1661 |
}
|
|
|
1662 |
return $this->lockidentifier;
|
|
|
1663 |
}
|
|
|
1664 |
|
|
|
1665 |
/**
|
|
|
1666 |
* Fixes the instance up after a clone.
|
|
|
1667 |
*/
|
|
|
1668 |
public function __clone() {
|
|
|
1669 |
// Force a new idenfitier.
|
|
|
1670 |
$this->lockidentifier = null;
|
|
|
1671 |
}
|
|
|
1672 |
|
|
|
1673 |
/**
|
|
|
1674 |
* Acquires a lock on the given key.
|
|
|
1675 |
*
|
|
|
1676 |
* This is done automatically if the definition requires it.
|
|
|
1677 |
* It is recommended to use a definition if you want to have locking although it is possible to do locking without having
|
|
|
1678 |
* it required by the definition.
|
|
|
1679 |
* The problem with such an approach is that you cannot ensure that code will consistently use locking. You will need to
|
|
|
1680 |
* rely on the integrators review skills.
|
|
|
1681 |
*
|
|
|
1682 |
* @param string|int $key The key as given to get|set|delete
|
|
|
1683 |
* @return bool Always returns true
|
|
|
1684 |
* @throws moodle_exception If the lock cannot be obtained
|
|
|
1685 |
*/
|
|
|
1686 |
public function acquire_lock($key) {
|
|
|
1687 |
$releaseparent = false;
|
|
|
1688 |
try {
|
|
|
1689 |
if ($this->get_loader() !== false) {
|
|
|
1690 |
$this->get_loader()->acquire_lock($key);
|
|
|
1691 |
// We need to release this lock later if the lock is not successful.
|
|
|
1692 |
$releaseparent = true;
|
|
|
1693 |
}
|
|
|
1694 |
$hashedkey = cache_helper::hash_key($key, $this->get_definition());
|
|
|
1695 |
$before = microtime(true);
|
|
|
1696 |
if ($this->nativelocking) {
|
|
|
1697 |
$lock = $this->get_store()->acquire_lock($hashedkey, $this->get_identifier());
|
|
|
1698 |
} else {
|
|
|
1699 |
$this->ensure_cachelock_available();
|
|
|
1700 |
$lock = $this->cachelockinstance->lock($hashedkey, $this->get_identifier());
|
|
|
1701 |
}
|
|
|
1702 |
$after = microtime(true);
|
|
|
1703 |
if ($lock) {
|
|
|
1704 |
$this->locks[$hashedkey] = $lock;
|
|
|
1705 |
if (MDL_PERF || $this->perfdebug) {
|
|
|
1706 |
\core\lock\timing_wrapper_lock_factory::record_lock_data($after, $before,
|
|
|
1707 |
$this->get_definition()->get_id(), $hashedkey, $lock, $this->get_identifier() . $hashedkey);
|
|
|
1708 |
}
|
|
|
1709 |
$releaseparent = false;
|
|
|
1710 |
return true;
|
|
|
1711 |
} else {
|
|
|
1712 |
throw new moodle_exception('ex_unabletolock', 'cache', '', null,
|
|
|
1713 |
'store: ' . get_class($this->get_store()) . ', lock: ' . $hashedkey);
|
|
|
1714 |
}
|
|
|
1715 |
} finally {
|
|
|
1716 |
// Release the parent lock if we acquired it, then threw an exception.
|
|
|
1717 |
if ($releaseparent) {
|
|
|
1718 |
$this->get_loader()->release_lock($key);
|
|
|
1719 |
}
|
|
|
1720 |
}
|
|
|
1721 |
}
|
|
|
1722 |
|
|
|
1723 |
/**
|
|
|
1724 |
* Checks if this cache has a lock on the given key.
|
|
|
1725 |
*
|
|
|
1726 |
* @param string|int $key The key as given to get|set|delete
|
|
|
1727 |
* @return bool|null Returns true if there is a lock and this cache has it, null if no one has a lock on that key, false if
|
|
|
1728 |
* someone else has the lock.
|
|
|
1729 |
*/
|
|
|
1730 |
public function check_lock_state($key) {
|
|
|
1731 |
$key = cache_helper::hash_key($key, $this->get_definition());
|
|
|
1732 |
if (!empty($this->locks[$key])) {
|
|
|
1733 |
return true; // Shortcut to save having to make a call to the cache store if the lock is held by this process.
|
|
|
1734 |
}
|
|
|
1735 |
if ($this->nativelocking) {
|
|
|
1736 |
return $this->get_store()->check_lock_state($key, $this->get_identifier());
|
|
|
1737 |
} else {
|
|
|
1738 |
$this->ensure_cachelock_available();
|
|
|
1739 |
return $this->cachelockinstance->check_state($key, $this->get_identifier());
|
|
|
1740 |
}
|
|
|
1741 |
}
|
|
|
1742 |
|
|
|
1743 |
/**
|
|
|
1744 |
* Releases the lock this cache has on the given key
|
|
|
1745 |
*
|
|
|
1746 |
* @param string|int $key
|
|
|
1747 |
* @return bool True if the operation succeeded, false otherwise.
|
|
|
1748 |
*/
|
|
|
1749 |
public function release_lock($key) {
|
|
|
1750 |
$loaderkey = $key;
|
|
|
1751 |
$key = cache_helper::hash_key($key, $this->get_definition());
|
|
|
1752 |
if ($this->nativelocking) {
|
|
|
1753 |
$released = $this->get_store()->release_lock($key, $this->get_identifier());
|
|
|
1754 |
} else {
|
|
|
1755 |
$this->ensure_cachelock_available();
|
|
|
1756 |
$released = $this->cachelockinstance->unlock($key, $this->get_identifier());
|
|
|
1757 |
}
|
|
|
1758 |
if ($released && array_key_exists($key, $this->locks)) {
|
|
|
1759 |
unset($this->locks[$key]);
|
|
|
1760 |
if (MDL_PERF || $this->perfdebug) {
|
|
|
1761 |
\core\lock\timing_wrapper_lock_factory::record_lock_released_data($this->get_identifier() . $key);
|
|
|
1762 |
}
|
|
|
1763 |
}
|
|
|
1764 |
if ($this->get_loader() !== false) {
|
|
|
1765 |
$this->get_loader()->release_lock($loaderkey);
|
|
|
1766 |
}
|
|
|
1767 |
return $released;
|
|
|
1768 |
}
|
|
|
1769 |
|
|
|
1770 |
/**
|
|
|
1771 |
* Ensure that the dedicated lock store is ready to go.
|
|
|
1772 |
*
|
|
|
1773 |
* This should only happen if the cache store doesn't natively support it.
|
|
|
1774 |
*/
|
|
|
1775 |
protected function ensure_cachelock_available() {
|
|
|
1776 |
if ($this->cachelockinstance === null) {
|
|
|
1777 |
$this->cachelockinstance = cache_helper::get_cachelock_for_store($this->get_store());
|
|
|
1778 |
}
|
|
|
1779 |
}
|
|
|
1780 |
|
|
|
1781 |
/**
|
|
|
1782 |
* Sends a key => value pair to the cache.
|
|
|
1783 |
*
|
|
|
1784 |
* <code>
|
|
|
1785 |
* // This code will add four entries to the cache, one for each url.
|
|
|
1786 |
* $cache->set('main', 'http://moodle.org');
|
|
|
1787 |
* $cache->set('docs', 'http://docs.moodle.org');
|
|
|
1788 |
* $cache->set('tracker', 'http://tracker.moodle.org');
|
|
|
1789 |
* $cache->set('qa', 'http://qa.moodle.net');
|
|
|
1790 |
* </code>
|
|
|
1791 |
*
|
|
|
1792 |
* @param string|int $key The key for the data being requested.
|
|
|
1793 |
* @param int $version Version number
|
|
|
1794 |
* @param mixed $data The data to set against the key.
|
|
|
1795 |
* @param bool $setparents If true, sets all parent loaders, otherwise only this one
|
|
|
1796 |
* @return bool True on success, false otherwise.
|
|
|
1797 |
* @throws coding_exception If a required lock has not beeen acquired
|
|
|
1798 |
*/
|
|
|
1799 |
protected function set_implementation($key, int $version, $data, bool $setparents = true): bool {
|
|
|
1800 |
if ($this->requirelockingbeforewrite && !$this->check_lock_state($key)) {
|
|
|
1801 |
throw new coding_exception('Attempted to set cache key "' . $key . '" without a lock. '
|
|
|
1802 |
. 'Locking before writes is required for ' . $this->get_definition()->get_id());
|
|
|
1803 |
}
|
|
|
1804 |
return parent::set_implementation($key, $version, $data, $setparents);
|
|
|
1805 |
}
|
|
|
1806 |
|
|
|
1807 |
/**
|
|
|
1808 |
* Sends several key => value pairs to the cache.
|
|
|
1809 |
*
|
|
|
1810 |
* Using this function comes with potential performance implications.
|
|
|
1811 |
* Not all cache stores will support get_many/set_many operations and in order to replicate this functionality will call
|
|
|
1812 |
* the equivalent singular method for each item provided.
|
|
|
1813 |
* This should not deter you from using this function as there is a performance benefit in situations where the cache store
|
|
|
1814 |
* does support it, but you should be aware of this fact.
|
|
|
1815 |
*
|
|
|
1816 |
* <code>
|
|
|
1817 |
* // This code will add four entries to the cache, one for each url.
|
|
|
1818 |
* $cache->set_many(array(
|
|
|
1819 |
* 'main' => 'http://moodle.org',
|
|
|
1820 |
* 'docs' => 'http://docs.moodle.org',
|
|
|
1821 |
* 'tracker' => 'http://tracker.moodle.org',
|
|
|
1822 |
* 'qa' => ''http://qa.moodle.net'
|
|
|
1823 |
* ));
|
|
|
1824 |
* </code>
|
|
|
1825 |
*
|
|
|
1826 |
* @param array $keyvaluearray An array of key => value pairs to send to the cache.
|
|
|
1827 |
* @return int The number of items successfully set. It is up to the developer to check this matches the number of items.
|
|
|
1828 |
* ... if they care that is.
|
|
|
1829 |
* @throws coding_exception If a required lock has not beeen acquired
|
|
|
1830 |
*/
|
|
|
1831 |
public function set_many(array $keyvaluearray) {
|
|
|
1832 |
if ($this->requirelockingbeforewrite) {
|
|
|
1833 |
foreach ($keyvaluearray as $key => $value) {
|
|
|
1834 |
if (!$this->check_lock_state($key)) {
|
|
|
1835 |
throw new coding_exception('Attempted to set cache key "' . $key . '" without a lock. '
|
|
|
1836 |
. 'Locking before writes is required for ' . $this->get_definition()->get_id());
|
|
|
1837 |
}
|
|
|
1838 |
}
|
|
|
1839 |
}
|
|
|
1840 |
return parent::set_many($keyvaluearray);
|
|
|
1841 |
}
|
|
|
1842 |
|
|
|
1843 |
/**
|
|
|
1844 |
* Delete the given key from the cache.
|
|
|
1845 |
*
|
|
|
1846 |
* @param string|int $key The key to delete.
|
|
|
1847 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
1848 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
1849 |
* @return bool True of success, false otherwise.
|
|
|
1850 |
* @throws coding_exception If a required lock has not beeen acquired
|
|
|
1851 |
*/
|
|
|
1852 |
public function delete($key, $recurse = true) {
|
|
|
1853 |
if ($this->requirelockingbeforewrite && !$this->check_lock_state($key)) {
|
|
|
1854 |
throw new coding_exception('Attempted to delete cache key "' . $key . '" without a lock. '
|
|
|
1855 |
. 'Locking before writes is required for ' . $this->get_definition()->get_id());
|
|
|
1856 |
}
|
|
|
1857 |
return parent::delete($key, $recurse);
|
|
|
1858 |
}
|
|
|
1859 |
|
|
|
1860 |
/**
|
|
|
1861 |
* Delete all of the given keys from the cache.
|
|
|
1862 |
*
|
|
|
1863 |
* @param array $keys The key to delete.
|
|
|
1864 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
1865 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
1866 |
* @return int The number of items successfully deleted.
|
|
|
1867 |
* @throws coding_exception If a required lock has not beeen acquired
|
|
|
1868 |
*/
|
|
|
1869 |
public function delete_many(array $keys, $recurse = true) {
|
|
|
1870 |
if ($this->requirelockingbeforewrite) {
|
|
|
1871 |
foreach ($keys as $key) {
|
|
|
1872 |
if (!$this->check_lock_state($key)) {
|
|
|
1873 |
throw new coding_exception('Attempted to delete cache key "' . $key . '" without a lock. '
|
|
|
1874 |
. 'Locking before writes is required for ' . $this->get_definition()->get_id());
|
|
|
1875 |
}
|
|
|
1876 |
}
|
|
|
1877 |
}
|
|
|
1878 |
return parent::delete_many($keys, $recurse);
|
|
|
1879 |
}
|
|
|
1880 |
}
|
|
|
1881 |
|
|
|
1882 |
/**
|
|
|
1883 |
* A session cache.
|
|
|
1884 |
*
|
|
|
1885 |
* This class is used for session caches returned by the cache::make methods.
|
|
|
1886 |
*
|
|
|
1887 |
* It differs from the application loader in a couple of noteable ways:
|
|
|
1888 |
* 1. Sessions are always expected to exist.
|
|
|
1889 |
* Because of this we don't ever use the static acceleration array.
|
|
|
1890 |
* 2. Session data for a loader instance (store + definition) is consolidate into a
|
|
|
1891 |
* single array for storage within the store.
|
|
|
1892 |
* Along with this we embed a lastaccessed time with the data. This way we can
|
|
|
1893 |
* check sessions for a last access time.
|
|
|
1894 |
* 3. Session stores are required to support key searching and must
|
|
|
1895 |
* implement cache_is_searchable. This ensures stores used for the cache can be
|
|
|
1896 |
* targetted for garbage collection of session data.
|
|
|
1897 |
*
|
|
|
1898 |
* This cache class should never be interacted with directly. Instead you should always use the cache::make methods.
|
|
|
1899 |
* It is technically possible to call those methods through this class however there is no guarantee that you will get an
|
|
|
1900 |
* instance of this class back again.
|
|
|
1901 |
*
|
|
|
1902 |
* @todo we should support locking in the session as well. Should be pretty simple to set up.
|
|
|
1903 |
*
|
|
|
1904 |
* @internal don't use me directly.
|
|
|
1905 |
* @method cache_store|cache_is_searchable get_store() Returns the cache store which must implement both cache_is_searchable.
|
|
|
1906 |
*
|
|
|
1907 |
* @package core
|
|
|
1908 |
* @category cache
|
|
|
1909 |
* @copyright 2012 Sam Hemelryk
|
|
|
1910 |
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
|
|
|
1911 |
*/
|
|
|
1912 |
class cache_session extends cache {
|
|
|
1913 |
/**
|
|
|
1914 |
* The user the session has been established for.
|
|
|
1915 |
* @var int
|
|
|
1916 |
*/
|
|
|
1917 |
protected static $loadeduserid = null;
|
|
|
1918 |
|
|
|
1919 |
/**
|
|
|
1920 |
* The userid this cache is currently using.
|
|
|
1921 |
* @var int
|
|
|
1922 |
*/
|
|
|
1923 |
protected $currentuserid = null;
|
|
|
1924 |
|
|
|
1925 |
/**
|
|
|
1926 |
* The session id we are currently using.
|
|
|
1927 |
* @var array
|
|
|
1928 |
*/
|
|
|
1929 |
protected $sessionid = null;
|
|
|
1930 |
|
|
|
1931 |
/**
|
|
|
1932 |
* The session data for the above session id.
|
|
|
1933 |
* @var array
|
|
|
1934 |
*/
|
|
|
1935 |
protected $session = null;
|
|
|
1936 |
|
|
|
1937 |
/**
|
|
|
1938 |
* Constant used to prefix keys.
|
|
|
1939 |
*/
|
|
|
1940 |
const KEY_PREFIX = 'sess_';
|
|
|
1941 |
|
|
|
1942 |
/**
|
|
|
1943 |
* This is the key used to track last access.
|
|
|
1944 |
*/
|
|
|
1945 |
const LASTACCESS = '__lastaccess__';
|
|
|
1946 |
|
|
|
1947 |
/**
|
|
|
1948 |
* Override the cache::construct method.
|
|
|
1949 |
*
|
|
|
1950 |
* This function gets overriden so that we can process any invalidation events if need be.
|
|
|
1951 |
* If the definition doesn't have any invalidation events then this occurs exactly as it would for the cache class.
|
|
|
1952 |
* Otherwise we look at the last invalidation time and then check the invalidation data for events that have occured
|
|
|
1953 |
* between then now.
|
|
|
1954 |
*
|
|
|
1955 |
* You should not call this method from your code, instead you should use the cache::make methods.
|
|
|
1956 |
*
|
|
|
1957 |
* @param cache_definition $definition
|
|
|
1958 |
* @param cache_store $store
|
|
|
1959 |
* @param cache_loader|cache_data_source $loader
|
|
|
1960 |
*/
|
|
|
1961 |
public function __construct(cache_definition $definition, cache_store $store, $loader = null) {
|
|
|
1962 |
// First up copy the loadeduserid to the current user id.
|
|
|
1963 |
$this->currentuserid = self::$loadeduserid;
|
|
|
1964 |
$this->set_session_id();
|
|
|
1965 |
parent::__construct($definition, $store, $loader);
|
|
|
1966 |
|
|
|
1967 |
// This will trigger check tracked user. If this gets removed a call to that will need to be added here in its place.
|
|
|
1968 |
$this->set(self::LASTACCESS, cache::now());
|
|
|
1969 |
|
|
|
1970 |
$this->handle_invalidation_events();
|
|
|
1971 |
}
|
|
|
1972 |
|
|
|
1973 |
/**
|
|
|
1974 |
* Sets the session id for the loader.
|
|
|
1975 |
*/
|
|
|
1976 |
protected function set_session_id() {
|
|
|
1977 |
$this->sessionid = preg_replace('#[^a-zA-Z0-9_]#', '_', session_id());
|
|
|
1978 |
}
|
|
|
1979 |
|
|
|
1980 |
/**
|
|
|
1981 |
* Returns the prefix used for all keys.
|
|
|
1982 |
* @return string
|
|
|
1983 |
*/
|
|
|
1984 |
protected function get_key_prefix() {
|
|
|
1985 |
return 'u'.$this->currentuserid.'_'.$this->sessionid;
|
|
|
1986 |
}
|
|
|
1987 |
|
|
|
1988 |
/**
|
|
|
1989 |
* Parses the key turning it into a string (or array is required) suitable to be passed to the cache store.
|
|
|
1990 |
*
|
|
|
1991 |
* This function is called for every operation that uses keys. For this reason we use this function to also check
|
|
|
1992 |
* that the current user is the same as the user who last used this cache.
|
|
|
1993 |
*
|
|
|
1994 |
* On top of that if prepends the string 'sess_' to the start of all keys. The _ ensures things are easily identifiable.
|
|
|
1995 |
*
|
|
|
1996 |
* @param string|int $key As passed to get|set|delete etc.
|
|
|
1997 |
* @return string|array String unless the store supports multi-identifiers in which case an array if returned.
|
|
|
1998 |
*/
|
|
|
1999 |
protected function parse_key($key) {
|
|
|
2000 |
$prefix = $this->get_key_prefix();
|
|
|
2001 |
if ($key === self::LASTACCESS) {
|
|
|
2002 |
return $key.$prefix;
|
|
|
2003 |
}
|
|
|
2004 |
return $prefix.'_'.parent::parse_key($key);
|
|
|
2005 |
}
|
|
|
2006 |
|
|
|
2007 |
/**
|
|
|
2008 |
* Check that this cache instance is tracking the current user.
|
|
|
2009 |
*/
|
|
|
2010 |
protected function check_tracked_user() {
|
|
|
2011 |
if (isset($_SESSION['USER']->id) && $_SESSION['USER']->id !== null) {
|
|
|
2012 |
// Get the id of the current user.
|
|
|
2013 |
$new = $_SESSION['USER']->id;
|
|
|
2014 |
} else {
|
|
|
2015 |
// No user set up yet.
|
|
|
2016 |
$new = 0;
|
|
|
2017 |
}
|
|
|
2018 |
if ($new !== self::$loadeduserid) {
|
|
|
2019 |
// The current user doesn't match the tracked userid for this request.
|
|
|
2020 |
if (!is_null(self::$loadeduserid)) {
|
|
|
2021 |
// Purge the data we have for the old user.
|
|
|
2022 |
// This way we don't bloat the session.
|
|
|
2023 |
$this->purge();
|
|
|
2024 |
}
|
|
|
2025 |
self::$loadeduserid = $new;
|
|
|
2026 |
$this->currentuserid = $new;
|
|
|
2027 |
} else if ($new !== $this->currentuserid) {
|
|
|
2028 |
// The current user matches the loaded user but not the user last used by this cache.
|
|
|
2029 |
$this->purge_current_user();
|
|
|
2030 |
$this->currentuserid = $new;
|
|
|
2031 |
}
|
|
|
2032 |
}
|
|
|
2033 |
|
|
|
2034 |
/**
|
|
|
2035 |
* Purges the session cache of all data belonging to the current user.
|
|
|
2036 |
*/
|
|
|
2037 |
public function purge_current_user() {
|
|
|
2038 |
$keys = $this->get_store()->find_by_prefix($this->get_key_prefix());
|
|
|
2039 |
$this->get_store()->delete_many($keys);
|
|
|
2040 |
}
|
|
|
2041 |
|
|
|
2042 |
/**
|
|
|
2043 |
* Retrieves the value for the given key from the cache.
|
|
|
2044 |
*
|
|
|
2045 |
* @param string|int $key The key for the data being requested.
|
|
|
2046 |
* It can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
2047 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
2048 |
* @param int $requiredversion Minimum required version of the data or cache::VERSION_NONE
|
|
|
2049 |
* @param int $strictness One of IGNORE_MISSING | MUST_EXIST
|
|
|
2050 |
* @param mixed &$actualversion If specified, will be set to the actual version number retrieved
|
|
|
2051 |
* @return mixed|false The data from the cache or false if the key did not exist within the cache.
|
|
|
2052 |
* @throws coding_exception
|
|
|
2053 |
*/
|
|
|
2054 |
protected function get_implementation($key, int $requiredversion, int $strictness, &$actualversion = null) {
|
|
|
2055 |
// Check the tracked user.
|
|
|
2056 |
$this->check_tracked_user();
|
|
|
2057 |
|
|
|
2058 |
// Use parent code.
|
|
|
2059 |
return parent::get_implementation($key, $requiredversion, $strictness, $actualversion);
|
|
|
2060 |
}
|
|
|
2061 |
|
|
|
2062 |
/**
|
|
|
2063 |
* Sends a key => value pair to the cache.
|
|
|
2064 |
*
|
|
|
2065 |
* <code>
|
|
|
2066 |
* // This code will add four entries to the cache, one for each url.
|
|
|
2067 |
* $cache->set('main', 'http://moodle.org');
|
|
|
2068 |
* $cache->set('docs', 'http://docs.moodle.org');
|
|
|
2069 |
* $cache->set('tracker', 'http://tracker.moodle.org');
|
|
|
2070 |
* $cache->set('qa', 'http://qa.moodle.net');
|
|
|
2071 |
* </code>
|
|
|
2072 |
*
|
|
|
2073 |
* @param string|int $key The key for the data being requested.
|
|
|
2074 |
* It can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
2075 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
2076 |
* @param mixed $data The data to set against the key.
|
|
|
2077 |
* @return bool True on success, false otherwise.
|
|
|
2078 |
*/
|
|
|
2079 |
public function set($key, $data) {
|
|
|
2080 |
$this->check_tracked_user();
|
|
|
2081 |
$loader = $this->get_loader();
|
|
|
2082 |
if ($loader !== false) {
|
|
|
2083 |
// We have a loader available set it there as well.
|
|
|
2084 |
// We have to let the loader do its own parsing of data as it may be unique.
|
|
|
2085 |
$loader->set($key, $data);
|
|
|
2086 |
}
|
|
|
2087 |
if (is_object($data) && $data instanceof cacheable_object) {
|
|
|
2088 |
$data = new cache_cached_object($data);
|
|
|
2089 |
} else if (!$this->get_store()->supports_dereferencing_objects() && !is_scalar($data)) {
|
|
|
2090 |
// If data is an object it will be a reference.
|
|
|
2091 |
// If data is an array if may contain references.
|
|
|
2092 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
2093 |
// Call the function to unreference it (in the best way possible).
|
|
|
2094 |
$data = $this->unref($data);
|
|
|
2095 |
}
|
|
|
2096 |
// We dont' support native TTL here as we consolidate data for sessions.
|
|
|
2097 |
if ($this->has_a_ttl() && !$this->store_supports_native_ttl()) {
|
|
|
2098 |
$data = new cache_ttl_wrapper($data, $this->get_definition()->get_ttl());
|
|
|
2099 |
}
|
|
|
2100 |
$success = $this->get_store()->set($this->parse_key($key), $data);
|
|
|
2101 |
if ($this->perfdebug) {
|
|
|
2102 |
cache_helper::record_cache_set($this->get_store(), $this->get_definition(), 1,
|
|
|
2103 |
$this->get_store()->get_last_io_bytes());
|
|
|
2104 |
}
|
|
|
2105 |
return $success;
|
|
|
2106 |
}
|
|
|
2107 |
|
|
|
2108 |
/**
|
|
|
2109 |
* Delete the given key from the cache.
|
|
|
2110 |
*
|
|
|
2111 |
* @param string|int $key The key to delete.
|
|
|
2112 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
2113 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
2114 |
* @return bool True of success, false otherwise.
|
|
|
2115 |
*/
|
|
|
2116 |
public function delete($key, $recurse = true) {
|
|
|
2117 |
$parsedkey = $this->parse_key($key);
|
|
|
2118 |
if ($recurse && $this->get_loader() !== false) {
|
|
|
2119 |
// Delete from the bottom of the stack first.
|
|
|
2120 |
$this->get_loader()->delete($key, $recurse);
|
|
|
2121 |
}
|
|
|
2122 |
return $this->get_store()->delete($parsedkey);
|
|
|
2123 |
}
|
|
|
2124 |
|
|
|
2125 |
/**
|
|
|
2126 |
* Retrieves an array of values for an array of keys.
|
|
|
2127 |
*
|
|
|
2128 |
* Using this function comes with potential performance implications.
|
|
|
2129 |
* Not all cache stores will support get_many/set_many operations and in order to replicate this functionality will call
|
|
|
2130 |
* the equivalent singular method for each item provided.
|
|
|
2131 |
* This should not deter you from using this function as there is a performance benefit in situations where the cache store
|
|
|
2132 |
* does support it, but you should be aware of this fact.
|
|
|
2133 |
*
|
|
|
2134 |
* @param array $keys The keys of the data being requested.
|
|
|
2135 |
* Each key can be any structure although using a scalar string or int is recommended in the interests of performance.
|
|
|
2136 |
* In advanced cases an array may be useful such as in situations requiring the multi-key functionality.
|
|
|
2137 |
* @param int $strictness One of IGNORE_MISSING or MUST_EXIST.
|
|
|
2138 |
* @return array An array of key value pairs for the items that could be retrieved from the cache.
|
|
|
2139 |
* If MUST_EXIST was used and not all keys existed within the cache then an exception will be thrown.
|
|
|
2140 |
* Otherwise any key that did not exist will have a data value of false within the results.
|
|
|
2141 |
* @throws coding_exception
|
|
|
2142 |
*/
|
|
|
2143 |
public function get_many(array $keys, $strictness = IGNORE_MISSING) {
|
|
|
2144 |
$this->check_tracked_user();
|
|
|
2145 |
$parsedkeys = array();
|
|
|
2146 |
$keymap = array();
|
|
|
2147 |
foreach ($keys as $key) {
|
|
|
2148 |
$parsedkey = $this->parse_key($key);
|
|
|
2149 |
$parsedkeys[$key] = $parsedkey;
|
|
|
2150 |
$keymap[$parsedkey] = $key;
|
|
|
2151 |
}
|
|
|
2152 |
$result = $this->get_store()->get_many($parsedkeys);
|
|
|
2153 |
if ($this->perfdebug) {
|
|
|
2154 |
$readbytes = $this->get_store()->get_last_io_bytes();
|
|
|
2155 |
}
|
|
|
2156 |
$return = array();
|
|
|
2157 |
$missingkeys = array();
|
|
|
2158 |
$hasmissingkeys = false;
|
|
|
2159 |
foreach ($result as $parsedkey => $value) {
|
|
|
2160 |
$key = $keymap[$parsedkey];
|
|
|
2161 |
if ($value instanceof cache_ttl_wrapper) {
|
|
|
2162 |
/* @var cache_ttl_wrapper $value */
|
|
|
2163 |
if ($value->has_expired()) {
|
|
|
2164 |
$this->delete($keymap[$parsedkey]);
|
|
|
2165 |
$value = false;
|
|
|
2166 |
} else {
|
|
|
2167 |
$value = $value->data;
|
|
|
2168 |
}
|
|
|
2169 |
}
|
|
|
2170 |
if ($value instanceof cache_cached_object) {
|
|
|
2171 |
/* @var cache_cached_object $value */
|
|
|
2172 |
$value = $value->restore_object();
|
|
|
2173 |
} else if (!$this->get_store()->supports_dereferencing_objects() && !is_scalar($value)) {
|
|
|
2174 |
// If data is an object it will be a reference.
|
|
|
2175 |
// If data is an array if may contain references.
|
|
|
2176 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
2177 |
// Call the function to unreference it (in the best way possible).
|
|
|
2178 |
$value = $this->unref($value);
|
|
|
2179 |
}
|
|
|
2180 |
$return[$key] = $value;
|
|
|
2181 |
if ($value === false) {
|
|
|
2182 |
$hasmissingkeys = true;
|
|
|
2183 |
$missingkeys[$parsedkey] = $key;
|
|
|
2184 |
}
|
|
|
2185 |
}
|
|
|
2186 |
if ($hasmissingkeys) {
|
|
|
2187 |
// We've got missing keys - we've got to check any loaders or data sources.
|
|
|
2188 |
$loader = $this->get_loader();
|
|
|
2189 |
$datasource = $this->get_datasource();
|
|
|
2190 |
if ($loader !== false) {
|
|
|
2191 |
foreach ($loader->get_many($missingkeys) as $key => $value) {
|
|
|
2192 |
if ($value !== false) {
|
|
|
2193 |
$return[$key] = $value;
|
|
|
2194 |
unset($missingkeys[$parsedkeys[$key]]);
|
|
|
2195 |
}
|
|
|
2196 |
}
|
|
|
2197 |
}
|
|
|
2198 |
$hasmissingkeys = count($missingkeys) > 0;
|
|
|
2199 |
if ($datasource !== false && $hasmissingkeys) {
|
|
|
2200 |
// We're still missing keys but we've got a datasource.
|
|
|
2201 |
foreach ($datasource->load_many_for_cache($missingkeys) as $key => $value) {
|
|
|
2202 |
if ($value !== false) {
|
|
|
2203 |
$return[$key] = $value;
|
|
|
2204 |
unset($missingkeys[$parsedkeys[$key]]);
|
|
|
2205 |
}
|
|
|
2206 |
}
|
|
|
2207 |
$hasmissingkeys = count($missingkeys) > 0;
|
|
|
2208 |
}
|
|
|
2209 |
}
|
|
|
2210 |
if ($hasmissingkeys && $strictness === MUST_EXIST) {
|
|
|
2211 |
throw new coding_exception('Requested key did not exist in any cache stores and could not be loaded.');
|
|
|
2212 |
}
|
|
|
2213 |
if ($this->perfdebug) {
|
|
|
2214 |
$hits = 0;
|
|
|
2215 |
$misses = 0;
|
|
|
2216 |
foreach ($return as $value) {
|
|
|
2217 |
if ($value === false) {
|
|
|
2218 |
$misses++;
|
|
|
2219 |
} else {
|
|
|
2220 |
$hits++;
|
|
|
2221 |
}
|
|
|
2222 |
}
|
|
|
2223 |
cache_helper::record_cache_hit($this->get_store(), $this->get_definition(), $hits, $readbytes);
|
|
|
2224 |
cache_helper::record_cache_miss($this->get_store(), $this->get_definition(), $misses);
|
|
|
2225 |
}
|
|
|
2226 |
return $return;
|
|
|
2227 |
|
|
|
2228 |
}
|
|
|
2229 |
|
|
|
2230 |
/**
|
|
|
2231 |
* Delete all of the given keys from the cache.
|
|
|
2232 |
*
|
|
|
2233 |
* @param array $keys The key to delete.
|
|
|
2234 |
* @param bool $recurse When set to true the key will also be deleted from all stacked cache loaders and their stores.
|
|
|
2235 |
* This happens by default and ensure that all the caches are consistent. It is NOT recommended to change this.
|
|
|
2236 |
* @return int The number of items successfully deleted.
|
|
|
2237 |
*/
|
|
|
2238 |
public function delete_many(array $keys, $recurse = true) {
|
|
|
2239 |
$parsedkeys = array_map(array($this, 'parse_key'), $keys);
|
|
|
2240 |
if ($recurse && $this->get_loader() !== false) {
|
|
|
2241 |
// Delete from the bottom of the stack first.
|
|
|
2242 |
$this->get_loader()->delete_many($keys, $recurse);
|
|
|
2243 |
}
|
|
|
2244 |
return $this->get_store()->delete_many($parsedkeys);
|
|
|
2245 |
}
|
|
|
2246 |
|
|
|
2247 |
/**
|
|
|
2248 |
* Sends several key => value pairs to the cache.
|
|
|
2249 |
*
|
|
|
2250 |
* Using this function comes with potential performance implications.
|
|
|
2251 |
* Not all cache stores will support get_many/set_many operations and in order to replicate this functionality will call
|
|
|
2252 |
* the equivalent singular method for each item provided.
|
|
|
2253 |
* This should not deter you from using this function as there is a performance benefit in situations where the cache store
|
|
|
2254 |
* does support it, but you should be aware of this fact.
|
|
|
2255 |
*
|
|
|
2256 |
* <code>
|
|
|
2257 |
* // This code will add four entries to the cache, one for each url.
|
|
|
2258 |
* $cache->set_many(array(
|
|
|
2259 |
* 'main' => 'http://moodle.org',
|
|
|
2260 |
* 'docs' => 'http://docs.moodle.org',
|
|
|
2261 |
* 'tracker' => 'http://tracker.moodle.org',
|
|
|
2262 |
* 'qa' => ''http://qa.moodle.net'
|
|
|
2263 |
* ));
|
|
|
2264 |
* </code>
|
|
|
2265 |
*
|
|
|
2266 |
* @param array $keyvaluearray An array of key => value pairs to send to the cache.
|
|
|
2267 |
* @return int The number of items successfully set. It is up to the developer to check this matches the number of items.
|
|
|
2268 |
* ... if they care that is.
|
|
|
2269 |
*/
|
|
|
2270 |
public function set_many(array $keyvaluearray) {
|
|
|
2271 |
$this->check_tracked_user();
|
|
|
2272 |
$loader = $this->get_loader();
|
|
|
2273 |
if ($loader !== false) {
|
|
|
2274 |
// We have a loader available set it there as well.
|
|
|
2275 |
// We have to let the loader do its own parsing of data as it may be unique.
|
|
|
2276 |
$loader->set_many($keyvaluearray);
|
|
|
2277 |
}
|
|
|
2278 |
$data = array();
|
|
|
2279 |
$definitionid = $this->get_definition()->get_ttl();
|
|
|
2280 |
$simulatettl = $this->has_a_ttl() && !$this->store_supports_native_ttl();
|
|
|
2281 |
foreach ($keyvaluearray as $key => $value) {
|
|
|
2282 |
if (is_object($value) && $value instanceof cacheable_object) {
|
|
|
2283 |
$value = new cache_cached_object($value);
|
|
|
2284 |
} else if (!$this->get_store()->supports_dereferencing_objects() && !is_scalar($value)) {
|
|
|
2285 |
// If data is an object it will be a reference.
|
|
|
2286 |
// If data is an array if may contain references.
|
|
|
2287 |
// We want to break references so that the cache cannot be modified outside of itself.
|
|
|
2288 |
// Call the function to unreference it (in the best way possible).
|
|
|
2289 |
$value = $this->unref($value);
|
|
|
2290 |
}
|
|
|
2291 |
if ($simulatettl) {
|
|
|
2292 |
$value = new cache_ttl_wrapper($value, $definitionid);
|
|
|
2293 |
}
|
|
|
2294 |
$data[$key] = array(
|
|
|
2295 |
'key' => $this->parse_key($key),
|
|
|
2296 |
'value' => $value
|
|
|
2297 |
);
|
|
|
2298 |
}
|
|
|
2299 |
$successfullyset = $this->get_store()->set_many($data);
|
|
|
2300 |
if ($this->perfdebug && $successfullyset) {
|
|
|
2301 |
cache_helper::record_cache_set($this->get_store(), $this->get_definition(), $successfullyset,
|
|
|
2302 |
$this->get_store()->get_last_io_bytes());
|
|
|
2303 |
}
|
|
|
2304 |
return $successfullyset;
|
|
|
2305 |
}
|
|
|
2306 |
|
|
|
2307 |
/**
|
|
|
2308 |
* Purges the cache store, and loader if there is one.
|
|
|
2309 |
*
|
|
|
2310 |
* @return bool True on success, false otherwise
|
|
|
2311 |
*/
|
|
|
2312 |
public function purge() {
|
|
|
2313 |
$this->get_store()->purge();
|
|
|
2314 |
if ($this->get_loader()) {
|
|
|
2315 |
$this->get_loader()->purge();
|
|
|
2316 |
}
|
|
|
2317 |
return true;
|
|
|
2318 |
}
|
|
|
2319 |
|
|
|
2320 |
/**
|
|
|
2321 |
* Test is a cache has a key.
|
|
|
2322 |
*
|
|
|
2323 |
* The use of the has methods is strongly discouraged. In a high load environment the cache may well change between the
|
|
|
2324 |
* test and any subsequent action (get, set, delete etc).
|
|
|
2325 |
* Instead it is recommended to write your code in such a way they it performs the following steps:
|
|
|
2326 |
* <ol>
|
|
|
2327 |
* <li>Attempt to retrieve the information.</li>
|
|
|
2328 |
* <li>Generate the information.</li>
|
|
|
2329 |
* <li>Attempt to set the information</li>
|
|
|
2330 |
* </ol>
|
|
|
2331 |
*
|
|
|
2332 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
2333 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
2334 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
2335 |
*
|
|
|
2336 |
* @param string|int $key
|
|
|
2337 |
* @param bool $tryloadifpossible If set to true, the cache doesn't contain the key, and there is another cache loader or
|
|
|
2338 |
* data source then the code will try load the key value from the next item in the chain.
|
|
|
2339 |
* @return bool True if the cache has the requested key, false otherwise.
|
|
|
2340 |
*/
|
|
|
2341 |
public function has($key, $tryloadifpossible = false) {
|
|
|
2342 |
$this->check_tracked_user();
|
|
|
2343 |
$parsedkey = $this->parse_key($key);
|
|
|
2344 |
$store = $this->get_store();
|
|
|
2345 |
if ($this->has_a_ttl() && !$this->store_supports_native_ttl()) {
|
|
|
2346 |
// The data has a TTL and the store doesn't support it natively.
|
|
|
2347 |
// We must fetch the data and expect a ttl wrapper.
|
|
|
2348 |
$data = $store->get($parsedkey);
|
|
|
2349 |
$has = ($data instanceof cache_ttl_wrapper && !$data->has_expired());
|
|
|
2350 |
} else if (!$this->store_supports_key_awareness()) {
|
|
|
2351 |
// The store doesn't support key awareness, get the data and check it manually... puke.
|
|
|
2352 |
// Either no TTL is set of the store supports its handling natively.
|
|
|
2353 |
$data = $store->get($parsedkey);
|
|
|
2354 |
$has = ($data !== false);
|
|
|
2355 |
} else {
|
|
|
2356 |
// The store supports key awareness, this is easy!
|
|
|
2357 |
// Either no TTL is set of the store supports its handling natively.
|
|
|
2358 |
/* @var cache_store|cache_is_key_aware $store */
|
|
|
2359 |
$has = $store->has($parsedkey);
|
|
|
2360 |
}
|
|
|
2361 |
if (!$has && $tryloadifpossible) {
|
|
|
2362 |
$result = null;
|
|
|
2363 |
if ($this->get_loader() !== false) {
|
|
|
2364 |
$result = $this->get_loader()->get($parsedkey);
|
|
|
2365 |
} else if ($this->get_datasource() !== null) {
|
|
|
2366 |
$result = $this->get_datasource()->load_for_cache($key);
|
|
|
2367 |
}
|
|
|
2368 |
$has = ($result !== null);
|
|
|
2369 |
if ($has) {
|
|
|
2370 |
$this->set($key, $result);
|
|
|
2371 |
}
|
|
|
2372 |
}
|
|
|
2373 |
return $has;
|
|
|
2374 |
}
|
|
|
2375 |
|
|
|
2376 |
/**
|
|
|
2377 |
* Test is a cache has all of the given keys.
|
|
|
2378 |
*
|
|
|
2379 |
* It is strongly recommended to avoid the use of this function if not absolutely required.
|
|
|
2380 |
* In a high load environment the cache may well change between the test and any subsequent action (get, set, delete etc).
|
|
|
2381 |
*
|
|
|
2382 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
2383 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
2384 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
2385 |
*
|
|
|
2386 |
* @param array $keys
|
|
|
2387 |
* @return bool True if the cache has all of the given keys, false otherwise.
|
|
|
2388 |
*/
|
|
|
2389 |
public function has_all(array $keys) {
|
|
|
2390 |
$this->check_tracked_user();
|
|
|
2391 |
if (($this->has_a_ttl() && !$this->store_supports_native_ttl()) || !$this->store_supports_key_awareness()) {
|
|
|
2392 |
foreach ($keys as $key) {
|
|
|
2393 |
if (!$this->has($key)) {
|
|
|
2394 |
return false;
|
|
|
2395 |
}
|
|
|
2396 |
}
|
|
|
2397 |
return true;
|
|
|
2398 |
}
|
|
|
2399 |
// The cache must be key aware and if support native ttl if it a ttl is set.
|
|
|
2400 |
/* @var cache_store|cache_is_key_aware $store */
|
|
|
2401 |
$store = $this->get_store();
|
|
|
2402 |
return $store->has_all(array_map(array($this, 'parse_key'), $keys));
|
|
|
2403 |
}
|
|
|
2404 |
|
|
|
2405 |
/**
|
|
|
2406 |
* Test if a cache has at least one of the given keys.
|
|
|
2407 |
*
|
|
|
2408 |
* It is strongly recommended to avoid the use of this function if not absolutely required.
|
|
|
2409 |
* In a high load environment the cache may well change between the test and any subsequent action (get, set, delete etc).
|
|
|
2410 |
*
|
|
|
2411 |
* Its also worth mentioning that not all stores support key tests.
|
|
|
2412 |
* For stores that don't support key tests this functionality is mimicked by using the equivalent get method.
|
|
|
2413 |
* Just one more reason you should not use these methods unless you have a very good reason to do so.
|
|
|
2414 |
*
|
|
|
2415 |
* @param array $keys
|
|
|
2416 |
* @return bool True if the cache has at least one of the given keys
|
|
|
2417 |
*/
|
|
|
2418 |
public function has_any(array $keys) {
|
|
|
2419 |
if (($this->has_a_ttl() && !$this->store_supports_native_ttl()) || !$this->store_supports_key_awareness()) {
|
|
|
2420 |
foreach ($keys as $key) {
|
|
|
2421 |
if ($this->has($key)) {
|
|
|
2422 |
return true;
|
|
|
2423 |
}
|
|
|
2424 |
}
|
|
|
2425 |
return false;
|
|
|
2426 |
}
|
|
|
2427 |
/* @var cache_store|cache_is_key_aware $store */
|
|
|
2428 |
$store = $this->get_store();
|
|
|
2429 |
return $store->has_any(array_map(array($this, 'parse_key'), $keys));
|
|
|
2430 |
}
|
|
|
2431 |
|
|
|
2432 |
/**
|
|
|
2433 |
* The session loader never uses static acceleration.
|
|
|
2434 |
* Instead it stores things in the static $session variable. Shared between all session loaders.
|
|
|
2435 |
*
|
|
|
2436 |
* @return bool
|
|
|
2437 |
*/
|
|
|
2438 |
protected function use_static_acceleration() {
|
|
|
2439 |
return false;
|
|
|
2440 |
}
|
|
|
2441 |
}
|
|
|
2442 |
|
|
|
2443 |
/**
|
|
|
2444 |
* An request cache.
|
|
|
2445 |
*
|
|
|
2446 |
* This class is used for request caches returned by the cache::make methods.
|
|
|
2447 |
*
|
|
|
2448 |
* This cache class should never be interacted with directly. Instead you should always use the cache::make methods.
|
|
|
2449 |
* It is technically possible to call those methods through this class however there is no guarantee that you will get an
|
|
|
2450 |
* instance of this class back again.
|
|
|
2451 |
*
|
|
|
2452 |
* @internal don't use me directly.
|
|
|
2453 |
*
|
|
|
2454 |
* @package core
|
|
|
2455 |
* @category cache
|
|
|
2456 |
* @copyright 2012 Sam Hemelryk
|
|
|
2457 |
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
|
|
|
2458 |
*/
|
|
|
2459 |
class cache_request extends cache {
|
|
|
2460 |
// This comment appeases code pre-checker ;) !
|
|
|
2461 |
}
|