lib/htmlpurifier/HTMLPurifier/DefinitionCacheFactory.php

   1 <?php
   2
   3 require_once 'HTMLPurifier/DefinitionCache.php';
   4
   5 HTMLPurifier_ConfigSchema::define(
   6     'Cache', 'DefinitionImpl', 'Serializer', 'string/null', '
   7 This directive defines which method to use when caching definitions,
   8 the complex data-type that makes HTML Purifier tick. Set to null
   9 to disable caching (not recommended, as you will see a definite
  10 performance degradation). This directive has been available since 2.0.0.
  11 ');
  12
  13 HTMLPurifier_ConfigSchema::defineAllowedValues(
  14     'Cache', 'DefinitionImpl', array('Serializer')
  15 );
  16
  17 HTMLPurifier_ConfigSchema::defineAlias(
  18     'Core', 'DefinitionCache',
  19     'Cache', 'DefinitionImpl'
  20 );
  21
  22
  23 /**
  24  * Responsible for creating definition caches.
  25  */
  26 class HTMLPurifier_DefinitionCacheFactory
  27 {
  28
  29     var $caches = array('Serializer' => array());
  30     var $decorators = array();
  31
  32     /**
  33      * Initialize default decorators
  34      */
  35     function setup() {
  36         $this->addDecorator('Cleanup');
  37     }
  38
  39     /**
  40      * Retrieves an instance of global definition cache factory.
  41      * @static
  42      */
  43     function &instance($prototype = null) {
  44         static $instance;
  45         if ($prototype !== null) {
  46             $instance = $prototype;
  47         } elseif ($instance === null || $prototype === true) {
  48             $instance = new HTMLPurifier_DefinitionCacheFactory();
  49             $instance->setup();
  50         }
  51         return $instance;
  52     }
  53
  54     /**
  55      * Factory method that creates a cache object based on configuration
  56      * @param $name Name of definitions handled by cache
  57      * @param $config Instance of HTMLPurifier_Config
  58      */
  59     function &create($type, $config) {
  60         // only one implementation as for right now, $config will
  61         // be used to determine implementation
  62         $method = $config->get('Cache', 'DefinitionImpl');
  63         if ($method === null) {
  64             $null = new HTMLPurifier_DefinitionCache_Null($type);
  65             return $null;
  66         }
  67         if (!empty($this->caches[$method][$type])) {
  68             return $this->caches[$method][$type];
  69         }
  70         $cache = new HTMLPurifier_DefinitionCache_Serializer($type);
  71         foreach ($this->decorators as $decorator) {
  72             $new_cache = $decorator->decorate($cache);
  73             // prevent infinite recursion in PHP 4
  74             unset($cache);
  75             $cache = $new_cache;
  76         }
  77         $this->caches[$method][$type] = $cache;
  78         return $this->caches[$method][$type];
  79     }
  80
  81     /**
  82      * Registers a decorator to add to all new cache objects
  83      * @param
  84      */
  85     function addDecorator($decorator) {
  86         if (is_string($decorator)) {
  87             $class = "HTMLPurifier_DefinitionCache_Decorator_$decorator";
  88             $decorator = new $class;
  89         }
  90         $this->decorators[$decorator->name] = $decorator;
  91     }
  92
  93 }
  94