framework/caching/ApcCache.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\caching;
use yii\base\InvalidConfigException;
/**
* ApcCache provides APC caching in terms of an application component.
*
* To use this application component, the [APC PHP extension](https://www.php.net/apc) must be loaded.
* Alternatively [APCu PHP extension](https://www.php.net/apcu) could be used via setting `useApcu` to `true`.
* In order to enable APC or APCu for CLI you should add "apc.enable_cli = 1" to your php.ini.
*
* See [[Cache]] for common cache operations that ApcCache supports.
*
* For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class ApcCache extends Cache
{
/**
* @var bool whether to use apcu or apc as the underlying caching extension.
* If true, [apcu](https://pecl.php.net/package/apcu) will be used.
* If false, [apc](https://pecl.php.net/package/apc) will be used.
* Defaults to false.
* @since 2.0.7
*/
public $useApcu = false;
/**
* Initializes this application component.
* It checks if extension required is loaded.
*/
public function init()
{
parent::init();
$extension = $this->useApcu ? 'apcu' : 'apc';
if (!extension_loaded($extension)) {
throw new InvalidConfigException("ApcCache requires PHP $extension extension to be loaded.");
}
}
/**
* Checks whether a specified key exists in the cache.
* This can be faster than getting the value from the cache if the data is big.
* Note that this method does not check whether the dependency associated
* with the cached data, if there is any, has changed. So a call to [[get]]
* may return false while exists returns true.
* @param mixed $key a key identifying the cached value. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @return bool true if a value exists in cache, false if the value is not in the cache or expired.
*/
public function exists($key)
{
$key = $this->buildKey($key);
return $this->useApcu ? apcu_exists($key) : apc_exists($key);
}
/**
* Retrieves a value from cache with a specified key.
* This is the implementation of the method declared in the parent class.
* @param string $key a unique key identifying the cached value
* @return mixed|false the value stored in cache, false if the value is not in the cache or expired.
*/
protected function getValue($key)
{
return $this->useApcu ? apcu_fetch($key) : apc_fetch($key);
}
/**
* Retrieves multiple values from cache with the specified keys.
* @param array $keys a list of keys identifying the cached values
* @return array a list of cached values indexed by the keys
*/
protected function getValues($keys)
{
$values = $this->useApcu ? apcu_fetch($keys) : apc_fetch($keys);
return is_array($values) ? $values : [];
}
/**
* Stores a value identified by a key in cache.
* This is the implementation of the method declared in the parent class.
*
* @param string $key the key identifying the value to be cached
* @param mixed $value the value to be cached. Most often it's a string. If you have disabled [[serializer]],
* it could be something else.
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @return bool true if the value is successfully stored into cache, false otherwise.
*/
protected function setValue($key, $value, $duration)
{
return $this->useApcu ? apcu_store($key, $value, $duration) : apc_store($key, $value, $duration);
}
/**
* Stores multiple key-value pairs in cache.
* @param array $data array where key corresponds to cache key while value
* @param int $duration the number of seconds in which the cached values will expire. 0 means never expire.
* @return array array of failed keys
*/
protected function setValues($data, $duration)
{
$result = $this->useApcu ? apcu_store($data, null, $duration) : apc_store($data, null, $duration);
return is_array($result) ? array_keys($result) : [];
}
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* This is the implementation of the method declared in the parent class.
* @param string $key the key identifying the value to be cached
* @param mixed $value the value to be cached. Most often it's a string. If you have disabled [[serializer]],
* it could be something else.
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @return bool true if the value is successfully stored into cache, false otherwise
*/
protected function addValue($key, $value, $duration)
{
return $this->useApcu ? apcu_add($key, $value, $duration) : apc_add($key, $value, $duration);
}
/**
* Adds multiple key-value pairs to cache.
* @param array $data array where key corresponds to cache key while value is the value stored
* @param int $duration the number of seconds in which the cached values will expire. 0 means never expire.
* @return array array of failed keys
*/
protected function addValues($data, $duration)
{
$result = $this->useApcu ? apcu_add($data, null, $duration) : apc_add($data, null, $duration);
return is_array($result) ? array_keys($result) : [];
}
/**
* Deletes a value with the specified key from cache
* This is the implementation of the method declared in the parent class.
* @param string $key the key of the value to be deleted
* @return bool if no error happens during deletion
*/
protected function deleteValue($key)
{
return $this->useApcu ? apcu_delete($key) : apc_delete($key);
}
/**
* Deletes all values from cache.
* This is the implementation of the method declared in the parent class.
* @return bool whether the flush operation was successful.
*/
protected function flushValues()
{
return $this->useApcu ? apcu_clear_cache() : apc_clear_cache('user');
}
}