perf(WTF): extracted scopes to separate file, add documentation

Closes #1361

Author: mhevery

benchmark/web/wtf.dart

@@ -1,11 +1,11 @@
 library wtf_test_app;
 
-import 'package:angular/wtf.dart';
+import 'package:angular/tracing.dart';
 import 'dart:html';
 import 'dart:js' show context;
 
 main() {
-  traceInit(context);
+  traceDetectWTF(context);
   var _main = traceCreateScope('main()');
   var _querySelector = traceCreateScope('Node#querySelector()');
   var _DivElement = traceCreateScope('DivElement()');
@@ -21,7 +21,7 @@ main() {
     traceLeave(s);
 
     s = traceEnter(_ElementText);
-    div.text = 'Hello WTF! (enabled: ${wtfEnabled})';
+    div.text = 'Hello WTF! (enabled: ${traceEnabled})';
     traceLeave(s);
 
     s = traceEnter(_NodeAppend);

lib/angular.dart

@@ -5,6 +5,7 @@ export 'package:angular/application.dart';
 export 'package:angular/core/module.dart';
 export 'package:angular/directive/module.dart';
 export 'package:angular/core/annotation.dart';
+export 'package:angular/tracing.dart';
 export 'package:angular/introspection.dart' hide
     elementExpando, publishToJavaScript;
 export 'package:angular/formatter/module.dart';

lib/application.dart

@@ -82,7 +82,7 @@ import 'package:angular/directive/module.dart';
 import 'package:angular/formatter/module_internal.dart';
 import 'package:angular/routing/module.dart';
 import 'package:angular/introspection.dart';
-import 'package:angular/wtf.dart';
+import 'package:angular/ng_tracing.dart';
 
 import 'package:angular/core_dom/static_keys.dart';
 import 'package:angular/core_dom/directive_injector.dart';
@@ -130,7 +130,6 @@ class AngularModule extends Module {
  * applicationFactory to bootstrap your Angular application.
  *
  */
-var _Application_run = traceCreateScope('Application#run()');
 abstract class Application {
   static _find(String selector, [dom.Element defaultElement]) {
     var element = dom.document.querySelector(selector);
@@ -152,7 +151,7 @@ abstract class Application {
   dom.Element selector(String selector) => element = _find(selector);
 
   Application(): element = _find('[ng-app]', dom.window.document.documentElement) {
-    traceInit(context);
+    traceDetectWTF(context);
     modules.add(ngModule);
     ngModule..bind(VmTurnZone, toValue: zone)
             ..bind(Application, toValue: this)
@@ -175,7 +174,7 @@ abstract class Application {
   }
 
   Injector run() {
-    var scope = traceEnter(_Application_run);
+    var scope = traceEnter(Application_bootstrap);
     try {
       publishToJavaScript();
       return zone.run(() {

lib/change_detection/watch_group.dart

@@ -2,18 +2,12 @@ library angular.watch_group;
 
 import 'package:angular/change_detection/change_detection.dart';
 import 'dart:collection';
-import 'package:angular/wtf.dart';
+import 'package:angular/ng_tracing.dart';
 
 part 'linked_list.dart';
 part 'ast.dart';
 part 'prototype_map.dart';
 
-var _WatchGroup_detect = traceCreateScope('WatchGroup#detect()');
-var _WatchGroup_fields = traceCreateScope('WatchGroup#field()');
-var _WatchGroup_field_handler = traceCreateScope('WatchGroup#field_handler()');
-var _WatchGroup_eval = traceCreateScope('WatchGroup#eval()');
-var _WatchGroup_reaction = traceCreateScope('WatchGroup#reaction()');
-
 /**
  * A function that is notified of changes to the model.
  *
@@ -399,29 +393,27 @@ class RootWatchGroup extends WatchGroup {
                       AvgStopwatch evalStopwatch,
                       AvgStopwatch processStopwatch}) {
     // Process the Records from the change detector
-    var sDetect = traceEnter(_WatchGroup_detect);
-    var s = traceEnter(_WatchGroup_fields);
+    var sDetect = traceEnter(ChangeDetector_check);
+    var sFields = traceEnter(ChangeDetector_fields);
     Iterator<Record<_Handler>> changedRecordIterator =
         (_changeDetector as ChangeDetector<_Handler>).collectChanges(
             exceptionHandler:exceptionHandler,
             stopwatch: fieldStopwatch);
-    traceLeave(s);
     if (processStopwatch != null) processStopwatch.start();
-    s = traceEnter(_WatchGroup_field_handler);
     while (changedRecordIterator.moveNext()) {
       var record = changedRecordIterator.current;
       if (changeLog != null) changeLog(record.handler.expression,
                                        record.currentValue,
                                        record.previousValue);
       record.handler.onChange(record);
     }
-    traceLeave(s);
+    traceLeave(sFields);
     if (processStopwatch != null) processStopwatch.stop();
 
     if (evalStopwatch != null) evalStopwatch.start();
     // Process our own function evaluations
     _EvalWatchRecord evalRecord = _evalWatchHead;
-    s = traceEnter(_WatchGroup_eval);
+    var sEval = traceEnter(ChangeDetector_eval);
     int evalCount = 0;
     while (evalRecord != null) {
       try {
@@ -437,14 +429,14 @@ class RootWatchGroup extends WatchGroup {
       evalRecord = evalRecord._nextEvalWatch;
     }
 
-    traceLeave(s);
+    traceLeave(sEval);
     traceLeave(sDetect);
     if (evalStopwatch != null) evalStopwatch..stop()..increment(evalCount);
 
     // Because the handler can forward changes between each other synchronously
     // We need to call reaction functions asynchronously. This processes the
     // asynchronous reaction function queue.
-    s = traceEnter(_WatchGroup_reaction);
+    var sReaction = traceEnter(ChangeDetector_reaction);
     int count = 0;
     if (processStopwatch != null) processStopwatch.start();
     Watch dirtyWatch = _dirtyWatchHead;
@@ -468,7 +460,7 @@ class RootWatchGroup extends WatchGroup {
       _dirtyWatchTail = null;
       root._removeCount = 0;
     }
-    traceLeave(s);
+    traceLeaveVal(sReaction, count);
     if (processStopwatch != null) processStopwatch..stop()..increment(count);
     return count;
   }
@@ -514,7 +506,12 @@ class Watch {
   void invoke() {
     if (_deleted || !_dirty) return;
     _dirty = false;
-    reactionFn(_record.currentValue, _record.previousValue);
+    var s = traceEnabled ? traceEnter1(ChangeDetector_invoke, expression) : null;
+    try {
+      reactionFn(_record.currentValue, _record.previousValue);
+    } finally {
+      if (traceEnabled) traceLeave(s);
+    }
   }
 
   void remove() {

lib/core/module_internal.dart

@@ -11,7 +11,7 @@ import 'package:di/annotations.dart';
 import 'package:angular/core/parser/parser.dart';
 import 'package:angular/core/parser/lexer.dart';
 import 'package:angular/utils.dart';
-import 'package:angular/wtf.dart';
+import 'package:angular/ng_tracing.dart';
 
 import 'package:angular/core/annotation_src.dart';
 

lib/core/scope.dart

@@ -3,14 +3,6 @@ part of angular.core_internal;
 typedef EvalFunction0();
 typedef EvalFunction1(context);
 
-var _Scope_apply = traceCreateScope('Scope#apply()');
-var _Scope_digest = traceCreateScope('Scope#digest()');
-var _Scope_flush = traceCreateScope('Scope#flush()');
-var _Scope_domWrite = traceCreateScope('Scope#domWrite()');
-var _Scope_domRead = traceCreateScope('Scope#domRead()');
-var _Scope_assert = traceCreateScope('Scope#assert()');
-var _Scope_runAsync = traceCreateScope('Scope#runAsync()');
-var _Scope_createChild = traceCreateScope('Scope#createChild()');
 /**
  * Injected into the listener function within [Scope.on] to provide event-specific details to the
  * scope listener.
@@ -338,7 +330,7 @@ class Scope {
 
   /// Creates a child [Scope] with the given [childContext]
   Scope createChild(Object childContext) {
-    var s = traceEnter(_Scope_createChild);
+    var s = traceEnter(Scope_createChild);
     assert(isAttached);
     var child = new Scope(childContext, rootScope, this,
                           _readWriteGroup.newGroup(childContext),
@@ -746,7 +738,7 @@ class RootScope extends Scope {
     try {
       do {
         if (_domWriteHead != null) _stats.domWriteStart();
-        var s = traceEnter(_Scope_domWrite);
+        var s = traceEnter(Scope_domWrite);
         while (_domWriteHead != null) {
           try {
             _domWriteHead.fn();
@@ -766,7 +758,7 @@ class RootScope extends Scope {
               processStopwatch: _scopeStats.processStopwatch);
         }
         if (_domReadHead != null) _stats.domReadStart();
-        s = traceEnter(_Scope_domRead);
+        s = traceEnter(Scope_domRead);
         while (_domReadHead != null) {
           try {
             _domReadHead.fn();
@@ -823,7 +815,7 @@ class RootScope extends Scope {
   }
 
   _runAsyncFns() {
-    var s = traceEnter(_Scope_runAsync);
+    var s = traceEnter(Scope_execAsync);
     var count = 0;
     while (_runAsyncHead != null) {
       try {
@@ -865,10 +857,10 @@ class RootScope extends Scope {
     _state = to;
     if (_state_wtf_scope != null) traceLeave(_state_wtf_scope);
     var wtfScope = null;
-    if (to == STATE_APPLY) wtfScope = _Scope_apply;
-    else if (to == STATE_DIGEST) wtfScope = _Scope_digest;
-    else if (to == STATE_FLUSH) wtfScope = _Scope_flush;
-    else if (to == STATE_FLUSH_ASSERT) wtfScope = _Scope_assert;
+    if (to == STATE_APPLY) wtfScope = Scope_apply;
+    else if (to == STATE_DIGEST) wtfScope = Scope_digest;
+    else if (to == STATE_FLUSH) wtfScope = Scope_flush;
+    else if (to == STATE_FLUSH_ASSERT) wtfScope = Scope_assert;
     _state_wtf_scope = wtfScope == null ? null : traceEnter(wtfScope);
   }
 }

lib/core/zone.dart

@@ -39,9 +39,6 @@ class LongStackTrace {
   }
 }
 
-var _VmTurnZone_onRunBase = traceCreateScope('VmTurnZone#onRun()');
-var _VmTurnZone_onScheduleMicrotask = traceCreateScope('VmTurnZone#onScheduleMicrotask()');
-
 /**
  * A [Zone] wrapper that lets you schedule tasks after its private microtask
  * queue is exhausted but before the next "turn", i.e. event loop iteration.
@@ -93,7 +90,7 @@ class VmTurnZone {
   var _currentlyInTurn = false;
 
   dynamic _onRunBase(async.Zone self, async.ZoneDelegate delegate, async.Zone zone, fn()) {
-    var scope = traceEnter(_VmTurnZone_onRunBase);
+    var scope = traceEnter(VmTurnZone_run);
     _runningInTurn++;
     try {
       if (!_currentlyInTurn) {
@@ -121,7 +118,7 @@ class VmTurnZone {
       _onRunBase(self, delegate, zone, () => delegate.runUnary(zone, fn, args));
 
   void _onScheduleMicrotask(async.Zone self, async.ZoneDelegate delegate, async.Zone zone, fn()) {
-    var s = traceEnter(_VmTurnZone_onScheduleMicrotask);
+    var s = traceEnter(VmTurnZone_scheduleMicrotask);
     try {
       onScheduleMicrotask(() => delegate.run(zone, fn));
       if (_runningInTurn == 0 && !_inFinishTurn)  _finishTurn(zone, delegate);

lib/core_dom/compiler.dart

@@ -1,7 +1,5 @@
 part of angular.core.dom_internal;
 
-var _Compiler_call = traceCreateScope('Compiler#call()');
-var _Compiler_subTemplate = traceCreateScope('Compiler#subTemplate()');
 
 @Injectable()
 class Compiler implements Function {
@@ -11,7 +9,7 @@ class Compiler implements Function {
   Compiler(this._perf, this._expando);
 
   ViewFactory call(List<dom.Node> elements, DirectiveMap directives) {
-    var s = traceEnter(_Compiler_call);
+    var s = traceEnter(Compiler_compile);
     var timerId;
     assert((timerId = _perf.startTimer('ng.compile', _html(elements))) != false);
     final elementBinders = <TaggedElementBinder>[];
@@ -141,7 +139,7 @@ class Compiler implements Function {
       DirectiveRef directiveRef,
       ElementBinder transcludedElementBinder,
       DirectiveMap directives) {
-    var s = traceEnter(_Compiler_subTemplate);
+    var s = traceEnter(Compiler_template);
     var anchorName = directiveRef.annotation.selector +
         (directiveRef.value != null ? '=' + directiveRef.value : '');
 

lib/core_dom/element_binder.dart

@@ -1,7 +1,5 @@
 part of angular.core.dom_internal;
 
-var _ElementBinder_directive = traceCreateScope('ElementBinder#createDirective(ascii name)');
-var _ElementBinder_setupBindings = traceCreateScope('ElementBinder#setupBindings(ascii name)');
 
 class TemplateElementBinder extends ElementBinder {
   final DirectiveRef template;
@@ -193,19 +191,13 @@ class ElementBinder {
     for(var i = 0; i < _usableDirectiveRefs.length; i++) {
       DirectiveRef ref = _usableDirectiveRefs[i];
       var key = ref.typeKey;
-      var wtfArgs = wtfEnabled ? [ref.typeKey.toString()] : null;
+      var directiveName = traceEnabled ? ref.typeKey.toString() : null;
       if (identical(key, TEXT_MUSTACHE_KEY) || identical(key, ATTR_MUSTACHE_KEY)) continue;
 
-      s = traceEnter(_ElementBinder_directive, wtfArgs);
+      s = traceEnter1(Directive_create, directiveName);
       var directive;
       try {
         directive = directiveInjector.getByKey(ref.typeKey);
-      } finally {
-        traceLeave(s);
-      }
-
-      s = traceEnter(_ElementBinder_setupBindings, wtfArgs);
-      try {
         if (ref.annotation is Controller) {
           scope.parentScope.context[(ref.annotation as Controller).publishAs] = directive;
         }

lib/core_dom/http.dart

@@ -445,7 +445,7 @@ class Http {
     cache,
     timeout
   }) {
-    var range = wtfEnabled ? traceAsyncStart('http:$method', url) : null;
+    var range = traceEnabled ? traceAsyncStart('http:$method', url) : null;
     if (timeout != null) {
       throw ['timeout not implemented'];
     }
@@ -545,7 +545,7 @@ class Http {
     var result = chainResult is async.Future
         ? chainResult
         : new async.Future.value(chainResult);
-    if (wtfEnabled) {
+    if (traceEnabled) {
       return new async.Future(() {
         traceAsyncEnd(range);
         return result;

lib/core_dom/module_internal.dart

@@ -22,7 +22,7 @@ export 'package:angular/core_dom/directive_injector.dart' show DirectiveInjector
 import 'package:angular/change_detection/watch_group.dart' show Watch, PrototypeMap;
 import 'package:angular/change_detection/ast_parser.dart';
 import 'package:angular/core/registry.dart';
-import 'package:angular/wtf.dart';
+import 'package:angular/ng_tracing.dart';
 
 import 'package:angular/directive/module.dart' show NgBaseCss;
 import 'dart:collection';

lib/core_dom/shadow_dom_component_factory.dart

@@ -1,7 +1,5 @@
 part of angular.core.dom_internal;
 
-var _ComponentFactory_call = traceCreateScope('ComponentFactory#call()');
-
 abstract class ComponentFactory {
   BoundComponentFactory bind(DirectiveRef ref, directives);
 }
@@ -126,7 +124,7 @@ class BoundShadowDomComponentFactory implements BoundComponentFactory {
   Function call(dom.Element element) {
     return (DirectiveInjector injector, Scope scope, NgBaseCss baseCss,
             EventHandler eventHandler) {
-      var s = traceEnter(_ComponentFactory_call);
+      var s = traceEnter(View_createComponent);
       try {
         var shadowDom = element.createShadowRoot()
           ..applyAuthorStyles = _component.applyAuthorStyles