diff --git a/NEWS b/NEWS
index df7895e4..06f6721b 100644
--- a/NEWS
+++ b/NEWS
@@ -21,7 +21,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 # New compact syntax for AttrDef objects that can be used to instantiate
   new objects via make()
 # Definitions (esp. HTMLDefinition) are now cached for a significant
-  performance boost
+  performance boost. You can disable caching by setting %Core.DefinitionCache
+  to null.
 ! HTML Purifier now works in PHP 4.3.2.
 ! Configuration form-editing API makes tweaking HTMLPurifier_Config a
   breeze!
diff --git a/library/HTMLPurifier/Config.php b/library/HTMLPurifier/Config.php
index ab2e98d4..5f862ab6 100644
--- a/library/HTMLPurifier/Config.php
+++ b/library/HTMLPurifier/Config.php
@@ -6,7 +6,7 @@ require_once 'HTMLPurifier/ConfigSchema.php';
 require_once 'HTMLPurifier/HTMLDefinition.php';
 require_once 'HTMLPurifier/CSSDefinition.php';
 require_once 'HTMLPurifier/Doctype.php';
-require_once 'HTMLPurifier/DefinitionCache.php';
+require_once 'HTMLPurifier/DefinitionCacheFactory.php';
 
 // accomodations for versions earlier than 4.3.10 and 5.0.2
 // borrowed from PHP_Compat, LGPL licensed, by Aidan Lister <aidan@php.net>
@@ -76,6 +76,12 @@ class HTMLPurifier_Config
      */
     var $autoFinalize = true;
     
+    /**
+     * Namespace indexed array of serials for specific namespaces (see
+     * getSerial for more info).
+     */
+    var $serials = array();
+    
     /**
      * @param $definition HTMLPurifier_ConfigSchema that defines what directives
      *                    are allowed.
@@ -149,6 +155,18 @@ class HTMLPurifier_Config
         return $this->conf[$namespace];
     }
     
+    /**
+     * Returns a md5 signature of a segment of the configuration object
+     * that uniquely identifies that particular configuration
+     * @param $namespace Namespace to get serial for
+     */
+    function getBatchSerial($namespace) {
+        if (empty($this->serials[$namespace])) {
+            $this->serials[$namespace] = md5(serialize($this->getBatch($namespace)));
+        }
+        return $this->serials[$namespace];
+    }
+    
     /**
      * Retrieves all directives, organized by namespace
      */
@@ -210,6 +228,8 @@ class HTMLPurifier_Config
         if ($namespace == 'HTML' || $namespace == 'CSS') {
             $this->definitions[$namespace] = null;
         }
+        
+        $this->serials[$namespace] = false;
     }
     
     /**
@@ -235,7 +255,8 @@ class HTMLPurifier_Config
      */
     function &getDefinition($type, $raw = false) {
         if (!$this->finalized && $this->autoFinalize) $this->finalize();
-        $cache = HTMLPurifier_DefinitionCache::create($type, $this);
+        $factory = HTMLPurifier_DefinitionCacheFactory::instance();
+        $cache = $factory->create($type, $this);
         if (!$raw) {
             // see if we can quickly supply a definition
             if (!empty($this->definitions[$type])) {
diff --git a/library/HTMLPurifier/DefinitionCache.php b/library/HTMLPurifier/DefinitionCache.php
index b2212256..da84682e 100644
--- a/library/HTMLPurifier/DefinitionCache.php
+++ b/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
diff --git a/library/HTMLPurifier/DefinitionCache/Decorator.php b/library/HTMLPurifier/DefinitionCache/Decorator.php
new file mode 100644
index 00000000..ca2e53aa
--- /dev/null
+++ b/library/HTMLPurifier/DefinitionCache/Decorator.php
@@ -0,0 +1,62 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCache.php';
+
+require_once 'HTMLPurifier/DefinitionCache/Decorator/Memory.php';
+
+class HTMLPurifier_DefinitionCache_Decorator extends HTMLPurifier_DefinitionCache
+{
+    
+    /**
+     * Cache object we are decorating
+     */
+    var $cache;
+    
+    function HTMLPurifier_DefinitionCache_Decorator() {}
+    
+    /**
+     * Lazy decorator function
+     * @param $cache Reference to cache object to decorate
+     */
+    function decorate(&$cache) {
+        $decorator = $this->copy();
+        // reference is necessary for mocks in PHP 4
+        $decorator->cache =& $cache;
+        $decorator->type  = $cache->type;
+        return $decorator;
+    }
+    
+    /**
+     * Cross-compatible clone substitute
+     */
+    function copy() {
+        return new HTMLPurifier_DefinitionCache_Decorator();
+    }
+    
+    function add($def, $config) {
+        return $this->cache->add($def, $config);
+    }
+    
+    function set($def, $config) {
+        return $this->cache->set($def, $config);
+    }
+    
+    function replace($def, $config) {
+        return $this->cache->replace($def, $config);
+    }
+    
+    function get($config) {
+        return $this->cache->get($config);
+    }
+    
+    function flush() {
+        return $this->cache->flush();
+    }
+    
+    function cleanup($config) {
+        return $this->cache->cleanup($config);
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/DefinitionCache/Decorator/Memory.php b/library/HTMLPurifier/DefinitionCache/Decorator/Memory.php
new file mode 100644
index 00000000..44908293
--- /dev/null
+++ b/library/HTMLPurifier/DefinitionCache/Decorator/Memory.php
@@ -0,0 +1,47 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCache/Decorator.php';
+
+/**
+ * Definition cache decorator class that saves all cache retrievals
+ * to PHP's memory; good for unit tests or circumstances where 
+ * there are lots of configuration objects floating around.
+ */
+class HTMLPurifier_DefinitionCache_Decorator_Memory extends
+      HTMLPurifier_DefinitionCache_Decorator
+{
+    
+    var $definitions;
+    
+    function copy() {
+        return new HTMLPurifier_DefinitionCache_Decorator_Memory();
+    }
+    
+    function add($def, $config) {
+        $status = parent::add($def, $config);
+        if ($status) $this->definitions[$this->generateKey($config)] = $def;
+        return $status;
+    }
+    
+    function set($def, $config) {
+        $status = parent::set($def, $config);
+        if ($status) $this->definitions[$this->generateKey($config)] = $def;
+        return $status;
+    }
+    
+    function replace($def, $config) {
+        $status = parent::replace($def, $config);
+        if ($status) $this->definitions[$this->generateKey($config)] = $def;
+        return $status;
+    }
+    
+    function get($config) {
+        $key = $this->generateKey($config);
+        if (isset($this->definitions[$key])) return $this->definitions[$key];
+        $this->definitions[$key] = parent::get($config);
+        return $this->definitions[$key];
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/DefinitionCache/Decorator/Template.php.in b/library/HTMLPurifier/DefinitionCache/Decorator/Template.php.in
new file mode 100644
index 00000000..6bf4a63d
--- /dev/null
+++ b/library/HTMLPurifier/DefinitionCache/Decorator/Template.php.in
@@ -0,0 +1,46 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCache/Decorator.php';
+
+/**
+ * Definition cache decorator template.
+ */
+class HTMLPurifier_DefinitionCache_Decorator_Template extends
+      HTMLPurifier_DefinitionCache_Decorator
+{
+    
+    // must be defined!!!
+    
+    function copy() {
+        return new HTMLPurifier_DefinitionCache_Decorator_Template();
+    }
+    
+    // remove methods you don't need
+    
+    function add($def, $config) {
+        return parent::add($def, $config);
+    }
+    
+    function set($def, $config) {
+        return parent::set($def, $config);
+    }
+    
+    function replace($def, $config) {
+        return parent::replace($def, $config);
+    }
+    
+    function get($config) {
+        return parent::get($config);
+    }
+    
+    function flush() {
+        return parent::flush();
+    }
+    
+    function cleanup($config) {
+        return parent::cleanup($config);
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/DefinitionCache/Null.php b/library/HTMLPurifier/DefinitionCache/Null.php
new file mode 100644
index 00000000..dd505cc3
--- /dev/null
+++ b/library/HTMLPurifier/DefinitionCache/Null.php
@@ -0,0 +1,37 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCache.php';
+
+/**
+ * Null cache object to use when no caching is on.
+ */
+class HTMLPurifier_DefinitionCache_Null extends HTMLPurifier_DefinitionCache
+{
+    
+    function add($def, $config) {
+        return false;
+    }
+    
+    function set($def, $config) {
+        return false;
+    }
+    
+    function replace($def, $config) {
+        return false;
+    }
+    
+    function get($config) {
+        return false;
+    }
+    
+    function flush() {
+        return false;
+    }
+    
+    function cleanup($config) {
+        return false;
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/DefinitionCacheFactory.php b/library/HTMLPurifier/DefinitionCacheFactory.php
new file mode 100644
index 00000000..c68f3135
--- /dev/null
+++ b/library/HTMLPurifier/DefinitionCacheFactory.php
@@ -0,0 +1,82 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCache.php';
+
+HTMLPurifier_ConfigSchema::define(
+    'Core', 'DefinitionCache', 'Serializer', 'string/null', '
+This directive defines which method to use when caching definitions,
+the complex data-type that makes HTML Purifier tick. Set to null
+to disable caching (not recommended, as you will see a definite
+performance degradation). This directive has been available since 1.7.0.
+');
+
+HTMLPurifier_ConfigSchema::defineAllowedValues(
+    'Core', 'DefinitionCache', array('Serializer')
+);
+
+
+/**
+ * Responsible for creating definition caches.
+ */
+class HTMLPurifier_DefinitionCacheFactory
+{
+    
+    var $caches = array('Serializer' => array());
+    var $decorators = array();
+    
+    /**
+     * Retrieves an instance of global definition cache factory.
+     * @static
+     */
+    function &instance($prototype = null) {
+        static $instance;
+        if ($prototype !== null) {
+            $instance = $prototype;
+        } elseif ($instance === null || $prototype === true) {
+            $instance = new HTMLPurifier_DefinitionCacheFactory();
+        }
+        return $instance;
+    }
+    
+    /**
+     * Factory method that creates a cache object based on configuration
+     * @param $name Name of definitions handled by cache
+     * @param $config Instance of HTMLPurifier_Config
+     */
+    function &create($type, $config) {
+        // only one implementation as for right now, $config will
+        // be used to determine implementation
+        $method = $config->get('Core', 'DefinitionCache');
+        if ($method === null) {
+            $null = new HTMLPurifier_DefinitionCache_Null($type);
+            return $null;
+        }
+        if (!empty($this->caches[$method][$type])) {
+            return $this->caches[$method][$type];
+        }
+        $cache = new HTMLPurifier_DefinitionCache_Serializer($type);
+        foreach ($this->decorators as $decorator) {
+            $new_cache = $decorator->decorate($cache);
+            // prevent infinite recursion in PHP 4
+            unset($cache);
+            $cache = $new_cache;
+        }
+        $this->caches[$method][$type] = $cache;
+        return $this->caches[$method][$type];
+    }
+    
+    /**
+     * Registers a decorator to add to all new cache objects
+     * @param 
+     */
+    function addDecorator($decorator) {
+        if (is_string($decorator)) {
+            $class = "HTMLPurifier_DefinitionCache_Decorator_$decorator";
+            $decorator = new $class;
+        }
+        $this->decorators[] = $decorator;
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/DefinitionCache/Decorator/MemoryTest.php b/tests/HTMLPurifier/DefinitionCache/Decorator/MemoryTest.php
new file mode 100644
index 00000000..e715df4e
--- /dev/null
+++ b/tests/HTMLPurifier/DefinitionCache/Decorator/MemoryTest.php
@@ -0,0 +1,79 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCacheHarness.php';
+require_once 'HTMLPurifier/DefinitionCache/Decorator/Memory.php';
+
+generate_mock_once('HTMLPurifier_DefinitionCache');
+
+class HTMLPurifier_DefinitionCache_Decorator_MemoryTest extends HTMLPurifier_DefinitionCacheHarness
+{
+    
+    function setup() {
+        unset($this->mock);
+        unset($this->cache);
+        $this->mock     =& new HTMLPurifier_DefinitionCacheMock($this);
+        $this->mock->type = 'Test';
+        $this->cache    = new HTMLPurifier_DefinitionCache_Decorator_Memory();
+        $this->cache    = $this->cache->decorate($this->mock);
+        $this->def      = $this->generateDefinition();
+        $this->config   = $this->generateConfigMock();
+    }
+    
+    function test_get() {
+        $this->mock->expectOnce('get', array($this->config)); // only ONE call!
+        $this->mock->setReturnValue('get', $this->def, array($this->config));
+        $this->assertEqual($this->cache->get($this->config), $this->def);
+        $this->assertEqual($this->cache->get($this->config), $this->def);
+    }
+    
+    function setupMockForSuccess($op) {
+        $this->mock->expectOnce($op, array($this->def, $this->config));
+        $this->mock->setReturnValue($op, true, array($this->def, $this->config));
+        $this->mock->expectNever('get');
+    }
+    
+    function setupMockForFailure($op) {
+        $this->mock->expectOnce($op, array($this->def, $this->config));
+        $this->mock->setReturnValue($op, false, array($this->def, $this->config));
+        $this->mock->expectOnce('get', array($this->config));
+    }
+    
+    function test_set() {
+        $this->setupMockForSuccess('set');
+        $this->assertEqual($this->cache->set($this->def, $this->config), true);
+        $this->assertEqual($this->cache->get($this->config), $this->def);
+    }
+    
+    function test_set_failure() {
+        $this->setupMockForFailure('set');
+        $this->assertEqual($this->cache->set($this->def, $this->config), false);
+        $this->cache->get($this->config);
+    }
+    
+    function test_replace() {
+        $this->setupMockForSuccess('replace');
+        $this->assertEqual($this->cache->replace($this->def, $this->config), true);
+        $this->assertEqual($this->cache->get($this->config), $this->def);
+    }
+    
+    function test_replace_failure() {
+        $this->setupMockForFailure('replace');
+        $this->assertEqual($this->cache->replace($this->def, $this->config), false);
+        $this->cache->get($this->config);
+    }
+    
+    function test_add() {
+        $this->setupMockForSuccess('add');
+        $this->assertEqual($this->cache->add($this->def, $this->config), true);
+        $this->assertEqual($this->cache->get($this->config), $this->def);
+    }
+    
+    function test_add_failure() {
+        $this->setupMockForFailure('add');
+        $this->assertEqual($this->cache->add($this->def, $this->config), false);
+        $this->cache->get($this->config);
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/DefinitionCache/DecoratorTest.php b/tests/HTMLPurifier/DefinitionCache/DecoratorTest.php
new file mode 100644
index 00000000..9c4be611
--- /dev/null
+++ b/tests/HTMLPurifier/DefinitionCache/DecoratorTest.php
@@ -0,0 +1,45 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCacheHarness.php';
+require_once 'HTMLPurifier/DefinitionCache/Decorator.php';
+
+class HTMLPurifier_DefinitionCache_DecoratorTest extends HTMLPurifier_DefinitionCacheHarness
+{
+    
+    function test() {
+        
+        generate_mock_once('HTMLPurifier_DefinitionCache');
+        $mock =& new HTMLPurifier_DefinitionCacheMock($this);
+        $mock->type = 'Test';
+        
+        $cache = new HTMLPurifier_DefinitionCache_Decorator();
+        $cache = $cache->decorate($mock);
+        
+        $this->assertIdentical($cache->type, $mock->type);
+        
+        $def = $this->generateDefinition();
+        $config = $this->generateConfigMock();
+        
+        $mock->expectOnce('add', array($def, $config));
+        $cache->add($def, $config);
+        
+        $mock->expectOnce('set', array($def, $config));
+        $cache->set($def, $config);
+        
+        $mock->expectOnce('replace', array($def, $config));
+        $cache->replace($def, $config);
+        
+        $mock->expectOnce('get', array($config));
+        $cache->get($config);
+        
+        $mock->expectOnce('flush', array());
+        $cache->flush();
+        
+        $mock->expectOnce('cleanup', array($config));
+        $cache->cleanup($config);
+        
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/DefinitionCache/SerializerTest.php b/tests/HTMLPurifier/DefinitionCache/SerializerTest.php
index 2da20ef1..9b9f385b 100644
--- a/tests/HTMLPurifier/DefinitionCache/SerializerTest.php
+++ b/tests/HTMLPurifier/DefinitionCache/SerializerTest.php
@@ -3,62 +3,18 @@
 require_once 'HTMLPurifier/DefinitionCacheHarness.php';
 require_once 'HTMLPurifier/DefinitionCache/Serializer.php';
 
-class HTMLPurifier_Definition_SerializerMock extends HTMLPurifier_Definition
-{
-    
-    var $_test;
-    var $_expect = false;
-    
-    function HTMLPurifier_Definition_SerializerMock(&$test_case) {
-        $this->_test =& $test_case;
-    }
-    
-    function expectDoSetupOnce() {$this->_expect = true;}
-    
-    function doSetup($config) {
-        if ($this->_expect) {
-            $this->_test->pass();
-        } else {
-            $this->_test->fail('Unexpected call to doSetup');
-        }
-        unset($this->_test, $this->_expect);
-    }
-    
-}
-
 class HTMLPurifier_DefinitionCache_SerializerTest extends HTMLPurifier_DefinitionCacheHarness
 {
     
-    function test__SerializerMock_pass() {
-        $config = 'config';
-        generate_mock_once('UnitTestCase');
-        $test =& new UnitTestCaseMock($this);
-        $test->expectOnce('pass');
-        $mock = new HTMLPurifier_Definition_SerializerMock($test);
-        $mock->expectDoSetupOnce();
-        $mock->doSetup($config);
-    }
-    
-    function test__SerializerMock_fail() {
-        $config = 'config';
-        generate_mock_once('UnitTestCase');
-        $test =& new UnitTestCaseMock($this);
-        $test->expectOnce('fail');
-        $mock = new HTMLPurifier_Definition_SerializerMock($test);
-        $mock->doSetup($config);
-    }
-    
     function test() {
         
         $cache = new HTMLPurifier_DefinitionCache_Serializer('Test');
         
-        $config_array = array('Foo' => 'Bar');
-        
-        $config = $this->generateConfigMock($config_array);
+        $config = $this->generateConfigMock('serial');
         $config->version = '1.0.0';
         $config->revision = 2;
         
-        $config_md5   = '1.0.0-' . $config->revision . '-' . md5(serialize($config_array));
+        $config_md5   = '1.0.0-' . $config->revision . '-serial';
         
         $file = realpath(
             $rel_file = dirname(__FILE__) .
@@ -114,7 +70,7 @@ class HTMLPurifier_DefinitionCache_SerializerTest extends HTMLPurifier_Definitio
         $def = new HTMLPurifier_Definition();
         $def->setup = true;
         $def->type = 'NotTest';
-        $config = $this->generateConfigMock(array('Test' => 'foo'));
+        $config = $this->generateConfigMock('testfoo');
         
         $this->expectError('Cannot use definition of type NotTest in cache for Test');
         $cache->add($def, $config);
@@ -130,9 +86,9 @@ class HTMLPurifier_DefinitionCache_SerializerTest extends HTMLPurifier_Definitio
         
         $cache = new HTMLPurifier_DefinitionCache_Serializer('Test');
         
-        $config1 = $this->generateConfigMock(array('Test' => 1));
-        $config2 = $this->generateConfigMock(array('Test' => 2));
-        $config3 = $this->generateConfigMock(array('Test' => 3));
+        $config1 = $this->generateConfigMock('test1');
+        $config2 = $this->generateConfigMock('test2');
+        $config3 = $this->generateConfigMock('test3');
         
         $def1 = $this->generateDefinition(array('info_candles' => 1));
         $def2 = $this->generateDefinition(array('info_candles' => 2));
diff --git a/tests/HTMLPurifier/DefinitionCacheFactoryTest.php b/tests/HTMLPurifier/DefinitionCacheFactoryTest.php
new file mode 100644
index 00000000..892f8805
--- /dev/null
+++ b/tests/HTMLPurifier/DefinitionCacheFactoryTest.php
@@ -0,0 +1,65 @@
+<?php
+
+require_once 'HTMLPurifier/DefinitionCacheFactory.php';
+
+class HTMLPurifier_DefinitionCacheFactoryTest extends UnitTestCase
+{
+    
+    var $newFactory;
+    var $oldFactory;
+    
+    function setup() {
+        $new = new HTMLPurifier_DefinitionCacheFactory();
+        $this->oldFactory = HTMLPurifier_DefinitionCacheFactory::instance();
+        HTMLPurifier_DefinitionCacheFactory::instance($new);
+    }
+    
+    function teardown() {
+        HTMLPurifier_DefinitionCacheFactory::instance($this->oldFactory);
+    }
+    
+    function test_create() {
+        $config  = HTMLPurifier_Config::createDefault();
+        $factory = HTMLPurifier_DefinitionCacheFactory::instance();
+        $cache   = $factory->create('Test', $config);
+        $this->assertEqual($cache, new HTMLPurifier_DefinitionCache_Serializer('Test'));
+    }
+    
+    function test_create_withDecorator() {
+        $config  = HTMLPurifier_Config::createDefault();
+        $factory =& HTMLPurifier_DefinitionCacheFactory::instance();
+        $factory->addDecorator('Memory');
+        $cache =& $factory->create('Test', $config);
+        $cache_real = new HTMLPurifier_DefinitionCache_Decorator_Memory();
+        $cache_real = $cache_real->decorate(new HTMLPurifier_DefinitionCache_Serializer('Test'));
+        $this->assertEqual($cache, $cache_real);
+    }
+    
+    function test_create_withDecoratorObject() {
+        $config  = HTMLPurifier_Config::createDefault();
+        $factory =& HTMLPurifier_DefinitionCacheFactory::instance();
+        $factory->addDecorator(new HTMLPurifier_DefinitionCache_Decorator_Memory());
+        $cache =& $factory->create('Test', $config);
+        $cache_real = new HTMLPurifier_DefinitionCache_Decorator_Memory();
+        $cache_real = $cache_real->decorate(new HTMLPurifier_DefinitionCache_Serializer('Test'));
+        $this->assertEqual($cache, $cache_real);
+    }
+    
+    function test_create_recycling() {
+        $config  = HTMLPurifier_Config::createDefault();
+        $factory =& HTMLPurifier_DefinitionCacheFactory::instance();
+        $cache =& $factory->create('Test', $config);
+        $cache2 =& $factory->create('Test', $config);
+        $this->assertReference($cache, $cache2);
+    }
+    
+    function test_null() {
+        $config = HTMLPurifier_Config::create(array('Core.DefinitionCache' => null));
+        $factory =& HTMLPurifier_DefinitionCacheFactory::instance();
+        $cache =& $factory->create('Test', $config);
+        $this->assertEqual($cache, new HTMLPurifier_DefinitionCache_Null('Test'));
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/DefinitionCacheHarness.php b/tests/HTMLPurifier/DefinitionCacheHarness.php
index d43df6bc..ebc15d68 100644
--- a/tests/HTMLPurifier/DefinitionCacheHarness.php
+++ b/tests/HTMLPurifier/DefinitionCacheHarness.php
@@ -8,10 +8,10 @@ class HTMLPurifier_DefinitionCacheHarness extends UnitTestCase
      * to a getBatch() call
      * @param $values Values to return when getBatch is invoked
      */
-    function generateConfigMock($values = array()) {
+    function generateConfigMock($serial = 'defaultserial') {
         generate_mock_once('HTMLPurifier_Config');
         $config = new HTMLPurifier_ConfigMock($this);
-        $config->setReturnValue('getBatch', $values, array('Test'));
+        $config->setReturnValue('getBatchSerial', $serial, array('Test'));
         $config->version = '1.0.0';
         $config->revision = 1;
         return $config;
diff --git a/tests/HTMLPurifier/DefinitionCacheTest.php b/tests/HTMLPurifier/DefinitionCacheTest.php
index b117a282..eb78a11c 100644
--- a/tests/HTMLPurifier/DefinitionCacheTest.php
+++ b/tests/HTMLPurifier/DefinitionCacheTest.php
@@ -4,11 +4,6 @@ require_once 'HTMLPurifier/DefinitionCache.php';
 
 class HTMLPurifier_DefinitionCacheTest extends UnitTestCase
 {
-    function test_create() {
-        $config = HTMLPurifier_Config::createDefault();
-        $cache  = HTMLPurifier_DefinitionCache::create('Test', $config);
-        $this->assertEqual($cache, new HTMLPurifier_DefinitionCache_Serializer('Test'));
-    }
     
     function test_isOld() {
         $cache = new HTMLPurifier_DefinitionCache('Test'); // non-functional
diff --git a/tests/index.php b/tests/index.php
index 543930a4..c10e128c 100644
--- a/tests/index.php
+++ b/tests/index.php
@@ -40,6 +40,10 @@ if ( is_string($GLOBALS['HTMLPurifierTest']['PEAR']) ) {
 // initialize and load HTML Purifier
 require_once '../library/HTMLPurifier.auto.php';
 
+// setup special DefinitionCacheFactory decorator
+$factory =& HTMLPurifier_DefinitionCacheFactory::instance();
+$factory->addDecorator('Memory'); // since we deal with a lot of config objects
+
 // load tests
 $test_files = array();
 require 'test_files.php'; // populates $test_files array
diff --git a/tests/test_files.php b/tests/test_files.php
index 069b4aca..6ecdb3c7 100644
--- a/tests/test_files.php
+++ b/tests/test_files.php
@@ -61,7 +61,10 @@ $test_files[] = 'HTMLPurifier/ChildDef/TableTest.php';
 $test_files[] = 'HTMLPurifier/ConfigSchemaTest.php';
 $test_files[] = 'HTMLPurifier/ConfigTest.php';
 $test_files[] = 'HTMLPurifier/ContextTest.php';
+$test_files[] = 'HTMLPurifier/DefinitionCacheFactoryTest.php';
 $test_files[] = 'HTMLPurifier/DefinitionCacheTest.php';
+$test_files[] = 'HTMLPurifier/DefinitionCache/Decorator/MemoryTest.php';
+$test_files[] = 'HTMLPurifier/DefinitionCache/DecoratorTest.php';
 $test_files[] = 'HTMLPurifier/DefinitionCache/SerializerTest.php';
 $test_files[] = 'HTMLPurifier/DefinitionTest.php';
 $test_files[] = 'HTMLPurifier/DoctypeRegistryTest.php';