DevTools: show progress when retrieving recorded trace events

Source/devtools/front_end/sdk/TracingManager.js

 /*
  * Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * @constructor
  * @extends {WebInspector.Object}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.TracingManager = function()
 {
     WebInspector.Object.call(this);
     this._active = false;
+    this._eventBufferSize = 0;
+    this._eventsRetrieved = 0;
     WebInspector.targetManager.observeTargets(this);
 }
 
 WebInspector.TracingManager.Events = {
+    "RetrieveEventsProgress": "RetrieveEventsProgress",
     "BufferUsage": "BufferUsage",
     "TracingStarted": "TracingStarted",
     "EventsCollected": "EventsCollected",
     "TracingStopped": "TracingStopped",
     "TracingComplete": "TracingComplete"
 }
 
 /** @typedef {!{
         cat: string,
         pid: number,
@@ skipping 33 matching lines @@
 
     /**
      * @return {?WebInspector.Target}
      */
     target: function()
     {
         return this._target;
     },
 
     /**
-     * @param {number} usage
+     * @param {number=} usage
+     * @param {number=} eventCount
+     * @param {number=} percentFull
      */
-    _bufferUsage: function(usage)
+    _bufferUsage: function(usage, eventCount, percentFull)
     {
-        this.dispatchEventToListeners(WebInspector.TracingManager.Events.BufferUsage, usage);
+        this._eventBufferSize = eventCount;
+        this.dispatchEventToListeners(WebInspector.TracingManager.Events.BufferUsage, usage || percentFull);
     },
 
     /**
      * @param {!Array.<!WebInspector.TracingManager.EventPayload>} events
      */
     _eventsCollected: function(events)
     {
         this.dispatchEventToListeners(WebInspector.TracingManager.Events.EventsCollected, events);
+        this._eventsRetrieved += events.length;
+        if (!this._eventBufferSize)
+            return;
+        if (this._eventsRetrieved > this._eventBufferSize)
+            this._eventsRetrieved = this._eventBufferSize;
+        this.dispatchEventToListeners(WebInspector.TracingManager.Events.RetrieveEventsProgress, this._eventsRetrieved / this._eventBufferSize);
     },
 
     _tracingComplete: function()
     {
+        this._eventBufferSize = 0;
+        this._eventsRetrieved = 0;
         this.dispatchEventToListeners(WebInspector.TracingManager.Events.TracingComplete);
     },
 
     /**
      * @param {string} categoryFilter
      * @param {string} options
      * @param {function(?string)=} callback
      */
     start: function(categoryFilter, options, callback)
     {
@@ skipping 30 matching lines @@
  * @implements {TracingAgent.Dispatcher}
  * @param {!WebInspector.TracingManager} tracingManager
  */
 WebInspector.TracingDispatcher = function(tracingManager)
 {
     this._tracingManager = tracingManager;
 }
 
 WebInspector.TracingDispatcher.prototype = {
     /**
-     * @param {number} usage
+     * @param {number=} usage
+     * @param {number=} eventCount
+     * @param {number=} percentFull
      */
-    bufferUsage: function(usage)
+    bufferUsage: function(usage, eventCount, percentFull)
     {
-        this._tracingManager._bufferUsage(usage);
+        this._tracingManager._bufferUsage(usage, eventCount, percentFull);
     },
 
     /**
      * @param {!Array.<!WebInspector.TracingManager.EventPayload>} data
      */
     dataCollected: function(data)
     {
         this._tracingManager._eventsCollected(data);
     },
 
     tracingComplete: function()
     {
         this._tracingManager._tracingComplete();
     }
 }