[1.7.0] Add DefinitionCache decorators, implement Memory decorator

- Move serialization responsibility to Config
- Create DefinitionCacheFactory
- Implement Null definition cache

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1117 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/DefinitionCache.php

@@ -1,11 +1,13 @@
 <?php
 
 require_once 'HTMLPurifier/DefinitionCache/Serializer.php';
+require_once 'HTMLPurifier/DefinitionCache/Null.php';
+
+require_once 'HTMLPurifier/DefinitionCache/Decorator.php';
 
 /**
  * Abstract class representing Definition cache managers that implements
  * useful common methods and is a factory.
- * @note The configuration object is transformed into the key used by the cache
  * @todo Get some sort of versioning variable so the library can easily
  *       invalidate the cache with a new version
  * @todo Make the test runner cache aware and allow the user to easily
@@ -33,9 +35,9 @@ class HTMLPurifier_DefinitionCache
      * @param Instance of HTMLPurifier_Config
      */
     function generateKey($config) {
-        $version  = $config->version;
-        $revision = $config->revision;
-        return $version . '-' . $revision . '-' . md5(serialize($config->getBatch($this->type)));
+        return $config->version . '-' . // possibly replace with function calls
+               $config->revision . '-' .
+               $config->getBatchSerial($this->type);
     }
     
     /**
@@ -52,17 +54,6 @@ class HTMLPurifier_DefinitionCache
         return true;
     }
     
-    /**
-     * Factory method that creates a cache object based on configuration
-     * @param $name Name of definitions handled by cache
-     * @param $config Instance of HTMLPurifier_Config
-     */
-    function create($name, $config) {
-        // only one implementation as for right now, $config will
-        // be used to determine implementation
-        return new HTMLPurifier_DefinitionCache_Serializer($name);
-    }
-    
     /**
      * Checks if a definition's type jives with the cache's type
      * @note Throws an error on failure