lib/htmlpurifier/HTMLPurifier/DefinitionCacheFactory.php

   1 <?php
   2
   3 require_once 'HTMLPurifier/DefinitionCache.php';
   4 require_once 'HTMLPurifier/DefinitionCache/Serializer.php';
   5
   6 HTMLPurifier_ConfigSchema::define(
   7     'Cache', 'DefinitionImpl', 'Serializer', 'string/null', '
   8 This directive defines which method to use when caching definitions,
   9 the complex data-type that makes HTML Purifier tick. Set to null
  10 to disable caching (not recommended, as you will see a definite
  11 performance degradation). This directive has been available since 2.0.0.
  12 ');
  13
  14 HTMLPurifier_ConfigSchema::defineAlias(
  15     'Core', 'DefinitionCache',
  16     'Cache', 'DefinitionImpl'
  17 );
  18
  19
  20 /**
  21  * Responsible for creating definition caches.
  22  */
  23 class HTMLPurifier_DefinitionCacheFactory
  24 {
  25
  26     var $caches = array('Serializer' => array());
  27     var $implementations = array();
  28     var $decorators = array();
  29
  30     /**
  31      * Initialize default decorators
  32      */
  33     function setup() {
  34         $this->addDecorator('Cleanup');
  35     }
  36
  37     /**
  38      * Retrieves an instance of global definition cache factory.
  39      * @static
  40      */
  41     function &instance($prototype = null) {
  42         static $instance;
  43         if ($prototype !== null) {
  44             $instance = $prototype;
  45         } elseif ($instance === null || $prototype === true) {
  46             $instance = new HTMLPurifier_DefinitionCacheFactory();
  47             $instance->setup();
  48         }
  49         return $instance;
  50     }
  51
  52     /**
  53      * Registers a new definition cache object
  54      * @param $short Short name of cache object, for reference
  55      * @param $long Full class name of cache object, for construction
  56      */
  57     function register($short, $long) {
  58         $this->implementations[$short] = $long;
  59     }
  60
  61     /**
  62      * Factory method that creates a cache object based on configuration
  63      * @param $name Name of definitions handled by cache
  64      * @param $config Instance of HTMLPurifier_Config
  65      */
  66     function &create($type, $config) {
  67         $method = $config->get('Cache', 'DefinitionImpl');
  68         if ($method === null) {
  69             $null = new HTMLPurifier_DefinitionCache_Null($type);
  70             return $null;
  71         }
  72         if (!empty($this->caches[$method][$type])) {
  73             return $this->caches[$method][$type];
  74         }
  75         if (
  76           isset($this->implementations[$method]) &&
  77           class_exists($class = $this->implementations[$method])
  78         ) {
  79             $cache = new $class($type);
  80         } else {
  81             if ($method != 'Serializer') {
  82                 trigger_error("Unrecognized DefinitionCache $method, using Serializer instead", E_USER_WARNING);
  83             }
  84             $cache = new HTMLPurifier_DefinitionCache_Serializer($type);
  85         }
  86         foreach ($this->decorators as $decorator) {
  87             $new_cache = $decorator->decorate($cache);
  88             // prevent infinite recursion in PHP 4
  89             unset($cache);
  90             $cache = $new_cache;
  91         }
  92         $this->caches[$method][$type] = $cache;
  93         return $this->caches[$method][$type];
  94     }
  95
  96     /**
  97      * Registers a decorator to add to all new cache objects
  98      * @param
  99      */
 100     function addDecorator($decorator) {
 101         if (is_string($decorator)) {
 102             $class = "HTMLPurifier_DefinitionCache_Decorator_$decorator";
 103             $decorator = new $class;
 104         }
 105         $this->decorators[$decorator->name] = $decorator;
 106     }
 107
 108 }
 109