Implement Object.getNotifier() and remove Object.notify()

src/object-observe.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 16 matching lines @@
 
 "use strict";
 
 var InternalObjectIsFrozen = $Object.isFrozen;
 var InternalObjectFreeze = $Object.freeze;
 
 var observationState = %GetObservationState();
 if (IS_UNDEFINED(observationState.observerInfoMap)) {
   observationState.observerInfoMap = %CreateObjectHashTable();
   observationState.objectInfoMap = %CreateObjectHashTable();
+  observationState.notifierTargetMap = %CreateObjectHashTable();
   observationState.activeObservers = new InternalArray;
   observationState.observerPriority = 0;
 }
 
 function InternalObjectHashTable(tableName) {
   this.tableName = tableName;
 }
 
 InternalObjectHashTable.prototype = {
   get: function(key) {
     return %ObjectHashTableGet(observationState[this.tableName], key);
   },
   set: function(key, value) {
     observationState[this.tableName] =
         %ObjectHashTableSet(observationState[this.tableName], key, value);
   },
   has: function(key) {
     return %ObjectHashTableHas(observationState[this.tableName], key);
   }
 };
 
 var observerInfoMap = new InternalObjectHashTable('observerInfoMap');
 var objectInfoMap = new InternalObjectHashTable('objectInfoMap');
+var notifierTargetMap = new InternalObjectHashTable('notifierTargetMap');
+
+function CreateObjectInfo(object) {
+  var info = {
+    changeObservers: new InternalArray,
+    notifier: null,
+  };
+  objectInfoMap.set(object, info);
+  return info;
+}
 
 function ObjectObserve(object, callback) {
   if (!IS_SPEC_OBJECT(object))
     throw MakeTypeError("observe_non_object", ["observe"]);
   if (!IS_SPEC_FUNCTION(callback))
     throw MakeTypeError("observe_non_function", ["observe"]);
   if (InternalObjectIsFrozen(callback))
     throw MakeTypeError("observe_callback_frozen");
 
   if (!observerInfoMap.has(callback)) {
     observerInfoMap.set(callback, {
       pendingChangeRecords: null,
       priority: observationState.observerPriority++,
     });
   }
 
   var objectInfo = objectInfoMap.get(object);
   if (IS_UNDEFINED(objectInfo)) {
-    // TODO: setup objectInfo.notifier
-    objectInfo = {
-      changeObservers: new InternalArray(callback)
-    };
-    objectInfoMap.set(object, objectInfo);
+    objectInfo = CreateObjectInfo(object);
     %SetIsObserved(object, true);
-    return;
   }
 
   var changeObservers = objectInfo.changeObservers;
   if (changeObservers.indexOf(callback) >= 0)
     return;
 
   changeObservers.push(callback);
 }
 
 function ObjectUnobserve(object, callback) {
@@ skipping 28 matching lines @@
 
 function NotifyChange(type, object, name, oldValue) {
   var objectInfo = objectInfoMap.get(object);
   var changeRecord = (arguments.length < 4) ?
       { type: type, object: object, name: name } :
       { type: type, object: object, name: name, oldValue: oldValue };
   InternalObjectFreeze(changeRecord);
   EnqueueChangeRecord(changeRecord, objectInfo.changeObservers);
 }
 
-function ObjectNotify(object, changeRecord) {
-  // TODO: notifier needs to be [[THIS]]
+var notifierPrototype = {};
+
+function ObjectNotifierNotify(changeRecord) {
+  if (!IS_SPEC_OBJECT(this))
+    throw MakeTypeError("called_on_non_object", ["notify"]);
+
+  var target = notifierTargetMap.get(this);
+  if (IS_UNDEFINED(target))
+    throw MakeTypeError("observe_notify_non_notifier");
+
   if (!IS_STRING(changeRecord.type))
     throw MakeTypeError("observe_type_non_string");
 
-  var objectInfo = objectInfoMap.get(object);
+  var objectInfo = objectInfoMap.get(target);
   if (IS_UNDEFINED(objectInfo))
     return;
 
+  if (!objectInfo.changeObservers.length)
+    return;
+
   var newRecord = {
-    object: object  // TODO: Needs to be 'object' retrieved from notifier
+    object: target
   };
   for (var prop in changeRecord) {
     if (prop === 'object')
       continue;
     newRecord[prop] = changeRecord[prop];
   }
   InternalObjectFreeze(newRecord);
 
   EnqueueChangeRecord(newRecord, objectInfo.changeObservers);
 }
 
+function ObjectGetNotifier(object) {
+  if (!IS_SPEC_OBJECT(object))
+    throw MakeTypeError("observe_non_object", ["getNotifier"]);
+
+  if (InternalObjectIsFrozen(object))
+    return null;
+
+  var objectInfo = objectInfoMap.get(object);
+  if (IS_UNDEFINED(objectInfo))
+    objectInfo = CreateObjectInfo(object);
+
+  if (IS_NULL(objectInfo.notifier)) {
+    objectInfo.notifier = {
+      __proto__: notifierPrototype
+    };
+    notifierTargetMap.set(objectInfo.notifier, object);
+  }
+
+  return objectInfo.notifier;
+}
+
 function DeliverChangeRecordsForObserver(observer) {
   var observerInfo = observerInfoMap.get(observer);
   if (IS_UNDEFINED(observerInfo))
     return;
 
   var pendingChangeRecords = observerInfo.pendingChangeRecords;
   if (IS_NULL(pendingChangeRecords))
     return;
 
   observerInfo.pendingChangeRecords = null;
@@ skipping 18 matching lines @@
     for (var i in activeObservers) {
       DeliverChangeRecordsForObserver(activeObservers[i]);
     }
   }
 }
 
 function SetupObjectObserve() {
   %CheckIsBootstrapping();
   InstallFunctions($Object, DONT_ENUM, $Array(
     "deliverChangeRecords", ObjectDeliverChangeRecords,
-    "notify", ObjectNotify,  // TODO: Remove when getNotifier is implemented.
+    "getNotifier", ObjectGetNotifier,
     "observe", ObjectObserve,
     "unobserve", ObjectUnobserve
   ));
+  InstallFunctions(notifierPrototype, DONT_ENUM, $Array(
+    "notify", ObjectNotifierNotify
+  ));
 }
 
 SetupObjectObserve();