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<?php
/**
* TEACache class file
*
* @author Dario rigolin <drigolin@e-portaltech.it>
* @link https://github.com/pradosoft/prado
* @copyright Copyright © 2005-2015 The PRADO Group
* @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
* @package System.Caching
*/
/**
* TEACache class
*
* TEACache implements a cache application module based on {@link http://eaccelerator.net/ eAccelerator}.
*
* By definition, cache does not ensure the existence of a value
* even if it never expires. Cache is not meant to be an persistent storage.
*
* To use this module, the eAccelerator PHP extension must be loaded and enabled
*
* Please note that as of v0.9.6, eAccelerator no longer supports data caching.
* This means if you still want to use this component, your eAccelerator should be of 0.9.5.x or lower version.
*
* Some usage examples of TEACache are as follows,
* <code>
* $cache=new TEACache; // TEACache may also be loaded as a Prado application module
* $cache->init(null);
* $cache->add('object',$object);
* $object2=$cache->get('object');
* </code>
*
* If loaded, TEACache will register itself with {@link TApplication} as the
* cache module. It can be accessed via {@link TApplication::getCache()}.
*
* TEACache may be configured in application configuration file as follows
* <code>
* <module id="cache" class="System.Caching.TEACache" />
* </code>
*
* @author Dario Rigolin <drigolin@e-portaltech.it>
* @package System.Caching
* @since 3.2.2
*/
class TEACache extends TCache
{
/**
* Initializes this module.
* This method is required by the IModule interface.
* @param TXmlElement configuration for this module, can be null
* @throws TConfigurationException if eaccelerator extension is not installed or not started, check your php.ini
*/
public function init($config)
{
if(!function_exists('eaccelerator_get'))
throw new TConfigurationException('eacceleratorcache_extension_required');
parent::init($config);
}
/**
* Retrieves a value from cache with a specified key.
* This is the implementation of the method declared in the parent class.
* @param string a unique key identifying the cached value
* @return string the value stored in cache, false if the value is not in the cache or expired.
*/
protected function getValue($key)
{
$value = eaccelerator_get($key);
return ($value === null) ? false : $value;
}
/**
* Stores a value identified by a key in cache.
* This is the implementation of the method declared in the parent class.
*
* @param string the key identifying the value to be cached
* @param string the value to be cached
* @param integer the number of seconds in which the cached value will expire. 0 means never expire.
* @return boolean true if the value is successfully stored into cache, false otherwise
*/
protected function setValue($key,$value,$expire)
{
return eaccelerator_put($key,$value,$expire);
}
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* This is the implementation of the method declared in the parent class.
*
* @param string the key identifying the value to be cached
* @param string the value to be cached
* @param integer the number of seconds in which the cached value will expire. 0 means never expire.
* @return boolean true if the value is successfully stored into cache, false otherwise
*/
protected function addValue($key,$value,$expire)
{
return (null === eaccelerator_get($key)) ? $this->setValue($key,$value,$expire) : false;
}
/**
* Deletes a value with the specified key from cache
* This is the implementation of the method declared in the parent class.
* @param string the key of the value to be deleted
* @return boolean if no error happens during deletion
*/
protected function deleteValue($key)
{
return eaccelerator_rm($key);
}
/**
* Deletes all values from cache.
* Be careful of performing this operation if the cache is shared by multiple applications.
*/
public function flush()
{
// first, remove expired content from cache
eaccelerator_gc();
// now, remove leftover cache-keys
$keys = eaccelerator_list_keys();
foreach($keys as $key)
$this->deleteValue(substr($key['name'], 1));
return true;
}
}
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