mirror of
https://github.com/yiisoft/yii2.git
synced 2025-11-04 06:37:55 +08:00
100 lines
3.1 KiB
PHP
100 lines
3.1 KiB
PHP
<?php
|
|
/**
|
|
* @link http://www.yiiframework.com/
|
|
* @copyright Copyright (c) 2008 Yii Software LLC
|
|
* @license http://www.yiiframework.com/license/
|
|
*/
|
|
|
|
namespace yii\caching;
|
|
|
|
/**
|
|
* Dependency is the base class for cache dependency classes.
|
|
*
|
|
* Child classes should override its [[generateDependencyData()]] for generating
|
|
* the actual dependency data.
|
|
*
|
|
* @author Qiang Xue <qiang.xue@gmail.com>
|
|
* @since 2.0
|
|
*/
|
|
abstract class Dependency extends \yii\base\Object
|
|
{
|
|
/**
|
|
* @var mixed the dependency data that is saved in cache and later is compared with the
|
|
* latest dependency data.
|
|
*/
|
|
public $data;
|
|
/**
|
|
* @var boolean whether this dependency is reusable or not. True value means that dependent
|
|
* data for this cache dependency will be generated only once per request. This allows you
|
|
* to use the same cache dependency for multiple separate cache calls while generating the same
|
|
* page without an overhead of re-evaluating dependency data each time. Defaults to false.
|
|
*/
|
|
public $reusable = false;
|
|
|
|
/**
|
|
* @var array static storage of cached data for reusable dependencies.
|
|
*/
|
|
private static $_reusableData = [];
|
|
/**
|
|
* @var string a unique hash value for this cache dependency.
|
|
*/
|
|
private $_hash;
|
|
|
|
|
|
/**
|
|
* Evaluates the dependency by generating and saving the data related with dependency.
|
|
* This method is invoked by cache before writing data into it.
|
|
* @param Cache $cache the cache component that is currently evaluating this dependency
|
|
*/
|
|
public function evaluateDependency($cache)
|
|
{
|
|
if (!$this->reusable) {
|
|
$this->data = $this->generateDependencyData($cache);
|
|
} else {
|
|
if ($this->_hash === null) {
|
|
$this->_hash = sha1(serialize($this));
|
|
}
|
|
if (!array_key_exists($this->_hash, self::$_reusableData)) {
|
|
self::$_reusableData[$this->_hash] = $this->generateDependencyData($cache);
|
|
}
|
|
$this->data = self::$_reusableData[$this->_hash];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns a value indicating whether the dependency has changed.
|
|
* @param Cache $cache the cache component that is currently evaluating this dependency
|
|
* @return boolean whether the dependency has changed.
|
|
*/
|
|
public function getHasChanged($cache)
|
|
{
|
|
if (!$this->reusable) {
|
|
return $this->generateDependencyData($cache) !== $this->data;
|
|
} else {
|
|
if ($this->_hash === null) {
|
|
$this->_hash = sha1(serialize($this));
|
|
}
|
|
if (!array_key_exists($this->_hash, self::$_reusableData)) {
|
|
self::$_reusableData[$this->_hash] = $this->generateDependencyData($cache);
|
|
}
|
|
return self::$_reusableData[$this->_hash] !== $this->data;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Resets all cached data for reusable dependencies.
|
|
*/
|
|
public static function resetReusableData()
|
|
{
|
|
self::$_reusableData = [];
|
|
}
|
|
|
|
/**
|
|
* Generates the data needed to determine if dependency has been changed.
|
|
* Derived classes should override this method to generate the actual dependency data.
|
|
* @param Cache $cache the cache component that is currently evaluating this dependency
|
|
* @return mixed the data needed to determine if dependency has been changed.
|
|
*/
|
|
abstract protected function generateDependencyData($cache);
|
|
}
|