You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
106 lines
3.6 KiB
106 lines
3.6 KiB
<?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 = []; |
|
|
|
|
|
/** |
|
* 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) { |
|
$hash = $this->generateReusableHash(); |
|
if (!array_key_exists($hash, self::$_reusableData)) { |
|
self::$_reusableData[$hash] = $this->generateDependencyData($cache); |
|
} |
|
$this->data = self::$_reusableData[$hash]; |
|
} else { |
|
$this->data = $this->generateDependencyData($cache); |
|
} |
|
} |
|
|
|
/** |
|
* 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) { |
|
$hash = $this->generateReusableHash(); |
|
if (!array_key_exists($hash, self::$_reusableData)) { |
|
self::$_reusableData[$hash] = $this->generateDependencyData($cache); |
|
} |
|
$data = self::$_reusableData[$hash]; |
|
} else { |
|
$data = $this->generateDependencyData($cache); |
|
} |
|
return $data !== $this->data; |
|
} |
|
|
|
/** |
|
* Resets all cached data for reusable dependencies. |
|
*/ |
|
public static function resetReusableData() |
|
{ |
|
self::$_reusableData = []; |
|
} |
|
|
|
/** |
|
* Generates a unique hash that can be used for retrieving reusable dependency data. |
|
* @return string a unique hash value for this cache dependency. |
|
* @see reusable |
|
*/ |
|
protected function generateReusableHash() |
|
{ |
|
$data = $this->data; |
|
$this->data = null; // https://github.com/yiisoft/yii2/issues/3052 |
|
$key = sha1(serialize($this)); |
|
$this->data = $data; |
|
return $key; |
|
} |
|
|
|
/** |
|
* 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); |
|
}
|
|
|