From 66758500e65804ec2f40186b6f25e6498eff0b97 Mon Sep 17 00:00:00 2001
From: Mike Gerwitz <mike@mikegerwitz.com>
Date: Mon, 14 Mar 2011 23:43:56 -0400
Subject: [PATCH] Class metadata is now stored in class object (first step in
 working with GC)

---
 lib/class.js              | 49 ++++++++++++++++++---------------------
 test/test-class-parent.js | 18 --------------
 2 files changed, 23 insertions(+), 44 deletions(-)

diff --git a/lib/class.js b/lib/class.js
index 08f6a84..8ec561d 100644
--- a/lib/class.js
+++ b/lib/class.js
@@ -27,14 +27,6 @@ var util           = require( './util' ),
     propobj        = require( './propobj' )
 ;
 
-/**
- * Stores class metadata internally (ensures data is encapsulated)
- *
- * The data in this object is hashed a class id.
- *
- * @type  {Object.<number, { implemented: Array.<string> }>}
- */
-var class_meta = {};
 
 /**
  * Stores class instance visibility object
@@ -217,7 +209,7 @@ module.exports.isInstanceOf = function( type, instance )
 
     // if no metadata is available, then our remaining checks cannot be
     // performed
-    if ( !instance.__cid || !( meta = getMeta( instance.__cid ) ) )
+    if ( !instance.__cid || !( meta = getMeta( instance ) ) )
     {
         return false;
     }
@@ -450,7 +442,7 @@ var extend = ( function( extending )
             members    = member_builder.initMembers( prototype ),
 
             abstract_methods =
-                util.clone( getMeta( base.__cid ).abstractMethods )
+                util.clone( getMeta( base ).abstractMethods )
                 || { __length: 0 }
         ;
 
@@ -543,7 +535,7 @@ var extend = ( function( extending )
         } );
 
         // reference to the parent prototype (for more experienced users)
-        prototype.parent = base.prototype;
+        prototype.___$$parent$$ = base.prototype;
 
         // set up the new class
         var new_class = createCtor( cname, abstract_methods, members );
@@ -556,15 +548,15 @@ var extend = ( function( extending )
         // important: call after setting prototype
         setupProps( new_class, abstract_methods, class_id );
 
+        // create internal metadata for the new class
+        var meta = createMeta( new_class, base );
+        meta.abstractMethods = abstract_methods;
+        meta.name            = cname;
+
         // lock down the new class (if supported) to ensure that we can't add
         // members at runtime
         util.freeze( new_class );
 
-        // create internal metadata for the new class
-        var meta = createMeta( new_class, base.prototype.__cid );
-        meta.abstractMethods = abstract_methods;
-        meta.name            = cname;
-
         // we're done with the extension process
         extending = false;
 
@@ -724,7 +716,7 @@ var implement = function()
 
     // create a new class with the implemented abstract methods
     var class_new = module.exports.extend( base, dest );
-    getMeta( class_new.__cid ).implemented = implemented;
+    getMeta( class_new ).implemented = implemented;
 
     return class_new;
 }
@@ -801,7 +793,7 @@ function attachPropInit( prototype, properties, members, cid )
 
         // first initialize the parent's properties, so that ours will overwrite
         // them
-        var parent_init = prototype.parent.__initProps;
+        var parent_init = prototype.___$$parent$$.__initProps;
         if ( parent_init instanceof Function )
         {
             // call the parent prop_init, letting it know that it's been
@@ -952,29 +944,34 @@ function attachInstanceOf( instance )
 /**
  * Initializes class metadata for the given class
  *
- * @param  {Class}  func  class to initialize metadata for
+ * @param  {Class}  func     class to initialize metadata for
+ * @param  {Class}  cparent  class parent
  *
  * @return  {undefined}
  */
-function createMeta( func, parent_id )
+function createMeta( func, cparent )
 {
     var id          = func.__cid,
-        parent_meta = ( ( parent_id ) ? getMeta( parent_id ) : undefined );
+        parent_meta = ( ( cparent.__cid ) ? getMeta( cparent ) : undefined );
 
     // copy the parent prototype's metadata if it exists (inherit metadata)
     if ( parent_meta )
     {
-        class_meta[ id ] = util.clone( parent_meta, true );
+        func.___$$meta$$ = util.clone( parent_meta, true );
     }
     else
     {
         // create empty
-        class_meta[ id ] = {
+        func.___$$meta$$ = {
             implemented: [],
         };
     }
 
-    return class_meta[ id ];
+    // store the metadata in the prototype as well (inconsiderable overhead;
+    // it's just a reference)
+    func.prototype.___$$meta$$ = func.___$$meta$$;
+
+    return func.___$$meta$$;
 }
 
 
@@ -988,9 +985,9 @@ function createMeta( func, parent_id )
  *
  * @return  {Object}
  */
-function getMeta( id )
+function getMeta( cls )
 {
-    return class_meta[ id ] || {};
+    return cls.___$$meta$$ || {};
 }
 
 
diff --git a/test/test-class-parent.js b/test/test-class-parent.js
index 1efd5f2..6ef8d64 100644
--- a/test/test-class-parent.js
+++ b/test/test-class-parent.js
@@ -60,11 +60,6 @@ var common = require( './common' ),
         {
             return this.__super( arg );
         },
-
-        callParentAlt: function()
-        {
-            return this.parent.myMethod2.apply( this, arguments );
-        },
     }),
 
     foo     = new Foo(),
@@ -109,19 +104,6 @@ assert.equal(
     "Arguments should be passed to super method via _super argument list"
 );
 
-assert.deepEqual(
-    SubFoo.prototype.parent,
-    Foo.prototype,
-    "Parent property should represent parent prototype"
-);
-
-sub_foo.callParentAlt( arg = 'moo' );
-assert.equal(
-    method2Arg,
-    arg,
-    "The parent property may also be used to invoke parent methods"
-);
-
 assert.throws( function()
 {
     Foo.extend(