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85 lines
2.8 KiB
PHP
85 lines
2.8 KiB
PHP
<?php
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/**
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* @link https://www.yiiframework.com/
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* @copyright Copyright (c) 2008 Yii Software LLC
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* @license https://www.yiiframework.com/license/
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*/
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namespace yii\caching;
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/**
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* DummyCache is a placeholder cache component.
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*
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* DummyCache does not cache anything. It is provided so that one can always configure
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* a 'cache' application component and save the check of existence of `\Yii::$app->cache`.
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* By replacing DummyCache with some other cache component, one can quickly switch from
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* non-caching mode to caching mode.
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*
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* For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
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*
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* @author Qiang Xue <qiang.xue@gmail.com>
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* @since 2.0
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*/
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class DummyCache extends Cache
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{
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/**
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* Retrieves a value from cache with a specified key.
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* This is the implementation of the method declared in the parent class.
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* @param string $key a unique key identifying the cached value
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* @return mixed|false the value stored in cache, false if the value is not in the cache or expired.
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*/
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protected function getValue($key)
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{
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return false;
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}
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/**
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* Stores a value identified by a key in cache.
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* This is the implementation of the method declared in the parent class.
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*
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* @param string $key the key identifying the value to be cached
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* @param mixed $value the value to be cached
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* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
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* @return bool true if the value is successfully stored into cache, false otherwise
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*/
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protected function setValue($key, $value, $duration)
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{
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return true;
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}
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/**
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* Stores a value identified by a key into cache if the cache does not contain this key.
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* This is the implementation of the method declared in the parent class.
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* @param string $key the key identifying the value to be cached
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* @param mixed $value the value to be cached
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* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
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* @return bool true if the value is successfully stored into cache, false otherwise
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*/
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protected function addValue($key, $value, $duration)
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{
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return true;
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}
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/**
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* Deletes a value with the specified key from cache
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* This is the implementation of the method declared in the parent class.
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* @param string $key the key of the value to be deleted
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* @return bool if no error happens during deletion
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*/
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protected function deleteValue($key)
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{
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return true;
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}
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/**
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* Deletes all values from cache.
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* This is the implementation of the method declared in the parent class.
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* @return bool whether the flush operation was successful.
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*/
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protected function flushValues()
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{
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return true;
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}
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}
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