Admin Control Panel v2.0

✎ Editing: DefinitionCache.php ← Back

<?php

/**

* Abstract class representing Definition cache managers that implements

* useful common methods and is a factory.

* @todo Create a separate maintenance file advanced users can use to

*       cache their custom HTMLDefinition, which can be loaded

*       via a configuration directive

* @todo Implement memcached

abstract class HTMLPurifier_DefinitionCache

{

/**

* @type string

public $type;

/**

* @param string $type Type of definition objects this instance of the

*      cache will handle.

public function __construct($type)

{

$this->type = $type;

}

/**

* Generates a unique identifier for a particular configuration

* @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config

* @return string

public function generateKey($config)

{

return $config->version . ',' . // possibly replace with function calls

$config->getBatchSerial($this->type) . ',' .

$config->get($this->type . '.DefinitionRev');

}

/**

* Tests whether or not a key is old with respect to the configuration's

* version and revision number.

* @param string $key Key to test

* @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config to test against

* @return bool

public function isOld($key, $config)

{

if (substr_count($key, ',') < 2) {

return true;

}

list($version, $hash, $revision) = explode(',', $key, 3);

$compare = version_compare($version, $config->version);

// version mismatch, is always old

if ($compare != 0) {

return true;

}

// versions match, ids match, check revision number

if ($hash == $config->getBatchSerial($this->type) &&

$revision < $config->get($this->type . '.DefinitionRev')) {

return true;

}

return false;

}

/**

* Checks if a definition's type jives with the cache's type

* @note Throws an error on failure

* @param HTMLPurifier_Definition $def Definition object to check

* @return bool true if good, false if not

public function checkDefType($def)

{

if ($def->type !== $this->type) {

trigger_error("Cannot use definition of type {$def->type} in cache for {$this->type}");

return false;

}

return true;

}

/**

* Adds a definition object to the cache

* @param HTMLPurifier_Definition $def

* @param HTMLPurifier_Config $config

abstract public function add($def, $config);

/**

* Unconditionally saves a definition object to the cache

* @param HTMLPurifier_Definition $def

* @param HTMLPurifier_Config $config

abstract public function set($def, $config);

/**

* Replace an object in the cache

* @param HTMLPurifier_Definition $def

* @param HTMLPurifier_Config $config

abstract public function replace($def, $config);

/**

* Retrieves a definition object from the cache

* @param HTMLPurifier_Config $config

abstract public function get($config);

/**

* Removes a definition object to the cache

* @param HTMLPurifier_Config $config

abstract public function remove($config);

/**

* Clears all objects from cache

* @param HTMLPurifier_Config $config

abstract public function flush($config);

/**

* Clears all expired (older version or revision) objects from cache

* @note Be carefuly implementing this method as flush. Flush must

*       not interfere with other Definition types, and cleanup()

*       should not be repeatedly called by userland code.

* @param HTMLPurifier_Config $config

abstract public function cleanup($config);

}

// vim: et sw=4 sts=4

Cancel