perf($rootScope): moving internal queues out of the Scope instances

Author: jbedard

src/ng/rootScope.js

@@ -130,12 +130,9 @@ function $RootScopeProvider(){
                      this.$$childHead = this.$$childTail = null;
       this['this'] = this.$root =  this;
       this.$$destroyed = false;
-      this.$$asyncQueue = [];
-      this.$$postDigestQueue = [];
       this.$$listeners = {};
       this.$$listenerCount = {};
       this.$$isolateBindings = null;
-      this.$$applyAsyncQueue = [];
     }
 
     /**
@@ -193,9 +190,6 @@ function $RootScopeProvider(){
         if (isolate) {
           child = new Scope();
           child.$root = this.$root;
-          // ensure that there is just one async queue per $rootScope and its children
-          child.$$asyncQueue = this.$$asyncQueue;
-          child.$$postDigestQueue = this.$$postDigestQueue;
         } else {
           // Only create a child scope class if somebody asks for one,
           // but cache it to allow the VM to optimize lookups.
@@ -695,8 +689,6 @@ function $RootScopeProvider(){
       $digest: function() {
         var watch, value, last,
             watchers,
-            asyncQueue = this.$$asyncQueue,
-            postDigestQueue = this.$$postDigestQueue,
             length,
             dirty, ttl = TTL,
             next, current, target = this,
@@ -861,6 +853,10 @@ function $RootScopeProvider(){
         if (this.$$prevSibling) this.$$prevSibling.$$nextSibling = this.$$nextSibling;
         if (this.$$nextSibling) this.$$nextSibling.$$prevSibling = this.$$prevSibling;
 
+        // Disable listeners, watchers and apply/digest methods
+        this.$destroy = this.$digest = this.$apply = this.$evalAsync = this.$applyAsync = noop;
+        this.$on = this.$watch = this.$watchGroup = function() { return noop; };
+        this.$$listeners = {};
 
         // All of the code below is bogus code that works around V8's memory leak via optimized code
         // and inline caches.
@@ -871,15 +867,7 @@ function $RootScopeProvider(){
         // - https://github.com/angular/angular.js/issues/1313#issuecomment-10378451
 
         this.$parent = this.$$nextSibling = this.$$prevSibling = this.$$childHead =
-            this.$$childTail = this.$root = null;
-
-        // don't reset these to null in case some async task tries to register a listener/watch/task
-        this.$$listeners = {};
-        this.$$watchers = this.$$asyncQueue = this.$$postDigestQueue = [];
-
-        // prevent NPEs since these methods have references to properties we nulled out
-        this.$destroy = this.$digest = this.$apply = noop;
-        this.$on = this.$watch = this.$watchGroup = function() { return noop; };
+            this.$$childTail = this.$root = this.$$watchers = null;
       },
 
       /**
@@ -946,19 +934,19 @@ function $RootScopeProvider(){
       $evalAsync: function(expr) {
         // if we are outside of an $digest loop and this is the first time we are scheduling async
         // task also schedule async auto-flush
-        if (!$rootScope.$$phase && !$rootScope.$$asyncQueue.length) {
+        if (!$rootScope.$$phase && !asyncQueue.length) {
           $browser.defer(function() {
-            if ($rootScope.$$asyncQueue.length) {
+            if (asyncQueue.length) {
               $rootScope.$digest();
             }
           });
         }
 
-        this.$$asyncQueue.push({scope: this, expression: expr});
+        asyncQueue.push({scope: this, expression: expr});
       },
 
       $$postDigest : function(fn) {
-        this.$$postDigestQueue.push(fn);
+        postDigestQueue.push(fn);
       },
 
       /**
@@ -1042,7 +1030,7 @@ function $RootScopeProvider(){
        */
       $applyAsync: function(expr) {
         var scope = this;
-        expr && $rootScope.$$applyAsyncQueue.push($applyAsyncExpression);
+        expr && applyAsyncQueue.push($applyAsyncExpression);
         scheduleApplyAsync();
 
         function $applyAsyncExpression() {
@@ -1251,6 +1239,11 @@ function $RootScopeProvider(){
 
     var $rootScope = new Scope();
 
+    //The internal queues. Expose them on the $rootScope for debugging/testing purposes.
+    var asyncQueue = $rootScope.$$asyncQueue = [];
+    var postDigestQueue = $rootScope.$$postDigestQueue = [];
+    var applyAsyncQueue = $rootScope.$$applyAsyncQueue = [];
+
     return $rootScope;
 
 
@@ -1284,10 +1277,9 @@ function $RootScopeProvider(){
     function initWatchVal() {}
 
     function flushApplyAsync() {
-      var queue = $rootScope.$$applyAsyncQueue;
-      while (queue.length) {
+      while (applyAsyncQueue.length) {
         try {
-          queue.shift()();
+          applyAsyncQueue.shift()();
         } catch(e) {
           $exceptionHandler(e);
         }

test/ng/directive/ngBindSpec.js

@@ -160,13 +160,13 @@ describe('ngBind*', function() {
       it('should NOT set html for untrusted values', inject(function($rootScope, $compile) {
         element = $compile('<div ng-bind-html="html"></div>')($rootScope);
         $rootScope.html = '<div onclick="">hello</div>';
-        expect($rootScope.$digest).toThrow();
+        expect(function() { $rootScope.$digest(); }).toThrow();
       }));
 
       it('should NOT set html for wrongly typed values', inject(function($rootScope, $compile, $sce) {
         element = $compile('<div ng-bind-html="html"></div>')($rootScope);
         $rootScope.html = $sce.trustAsCss('<div onclick="">hello</div>');
-        expect($rootScope.$digest).toThrow();
+        expect(function() { $rootScope.$digest(); }).toThrow();
       }));
 
       it('should set html for trusted values', inject(function($rootScope, $compile, $sce) {

test/ng/rootScopeSpec.js

@@ -1038,6 +1038,33 @@ describe('Scope', function() {
       expect(fn).toBe(noop);
     }));
 
+    it("should do nothing when $apply()ing after parent's destruction", inject(function($rootScope) {
+      var parent = $rootScope.$new(),
+          child = parent.$new();
+
+      parent.$destroy();
+
+      var called = false;
+      function applyFunc() { called = true; }
+      child.$apply(applyFunc);
+
+      expect(called).toBe(false);
+    }));
+
+    it("should do nothing when $evalAsync()ing after parent's destruction", inject(function($rootScope, $timeout) {
+      var parent = $rootScope.$new(),
+          child = parent.$new();
+
+      parent.$destroy();
+
+      var called = false;
+      function applyFunc() { called = true; }
+      child.$evalAsync(applyFunc);
+
+      $timeout.verifyNoPendingTasks();
+      expect(called).toBe(false);
+    }));
+
 
     it("should preserve all (own and inherited) model properties on a destroyed scope",
         inject(function($rootScope) {
@@ -1204,15 +1231,14 @@ describe('Scope', function() {
       isolateScope.$evalAsync('isolateExpression');
 
       expect(childScope.$$asyncQueue).toBe($rootScope.$$asyncQueue);
-      expect(isolateScope.$$asyncQueue).toBe($rootScope.$$asyncQueue);
+      expect(isolateScope.$$asyncQueue).toBeUndefined();
       expect($rootScope.$$asyncQueue).toEqual([
         {scope: $rootScope, expression: 'rootExpression'},
         {scope: childScope, expression: 'childExpression'},
         {scope: isolateScope, expression: 'isolateExpression'}
       ]);
     }));
 
-
     describe('auto-flushing when queueing outside of an $apply', function() {
       var log, $rootScope, $browser;