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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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namespace core_cache;
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/**
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* Cache Data Source.
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*
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* The cache data source interface can be implemented by any class within Moodle.
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* If implemented then the class can be reference in a cache definition and will be used to load information that cannot be
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* retrieved from the cache. As part of its retrieval that information will also be loaded into the cache.
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*
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* This allows developers to created a complete cache solution that can be used through code ensuring consistent cache
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* interaction and loading. Allowing them in turn to centralise code and help keeps things more easily maintainable.
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*
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* Can be implemented by any class.
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*
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* @package core_cache
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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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interface data_source_interface {
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/**
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* Returns an instance of the data source class that the cache can use for loading data using the other methods
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* specified by this interface.
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*
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* @param definition $definition
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* @return object
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*/
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public static function get_instance_for_cache(definition $definition);
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/**
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* Loads the data for the key provided ready formatted for caching.
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*
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* @param string|int $key The key to load.
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* @return mixed What ever data should be returned, or false if it can't be loaded.
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*/
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public function load_for_cache($key);
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/**
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* Loads several keys for the cache.
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*
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* @param array $keys An array of keys each of which will be string|int.
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* @return array An array of matching data items.
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*/
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public function load_many_for_cache(array $keys);
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}
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// Alias this class to the old name.
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// This file will be autoloaded by the legacyclasses autoload system.
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// In future all uses of this class will be corrected and the legacy references will be removed.
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class_alias(data_source_interface::class, \cache_data_source::class);
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