Playback benchmark scripts.

tools/playback_benchmark/playback.js

Index: tools/playback_benchmark/playback.js
===================================================================
--- tools/playback_benchmark/playback.js	(revision 0)
+++ tools/playback_benchmark/playback.js	(revision 0)
@@ -0,0 +1,256 @@
+// Copyright 2010 Google Inc. All Rights Reserved.
+
+/**
+ * @fileoverview Playback agent.
+ */
+
+var Benchmark = Benchmark || {};
+
+/**
+ * Playback agent class.
+ * @param {Object} data Test data.
+ * @constructor
+ */
+Benchmark.Agent = function(data) {
+  this.timeline = data.timeline;
+  this.timelinePosition = 0;
+  this.steps = data.steps;
+  this.stepsPosition = 0;
+  this.randoms = data.randoms;
+  this.randomsPosition = 0;
+  this.ticks = data.ticks;
+  this.ticksPosition = 0;
+  this.delayedScriptElements = {};
+  this.callStackDepth = 0;
+  document.cookie = data.cookie;
+  if (window.innerWidth != data.width || window.innerHeight != data.height) {
+    Benchmark.die('Wrong window size: ' +
+                  window.innerWidth + 'x' + window.innerHeight +
+                  ' instead of ' + data.width + 'x' + data.height);
+  }
+  this.startTime = Benchmark.originals.Date.now();
+};
+
+/**
+ * Returns current timeline event.
+ * @return {Object} Event.
+ */
+Benchmark.Agent.prototype.getCurrentEvent = function() {
+  return this.timeline[this.timelinePosition];
+};
+
+/**
+ * Returns next recorded event in timeline. If event is the last event in
+ * timeline, posts test results to driver.
+ * @param {Object} event Event that actually happened, should correspond to
+ * the recorded one (used for debug only).
+ * @return {Object} Recorded event from timeline.
+ */
+Benchmark.Agent.prototype.getNextEvent = function(event) {
+  var recordedEvent = this.getCurrentEvent();
+  this.ensureEqual(event, recordedEvent);
+  if (event.type == 'random' || event.type == 'ticks') {
+    recordedEvent.count -= 1;
+    if (recordedEvent.count == 0) {
+      this.timelinePosition += 1;
+    }
+  } else {
+    this.timelinePosition += 1;
+  }
+  if (this.timelinePosition == this.steps[this.stepsPosition][1]) {
+    var score = Benchmark.originals.Date.now() - this.startTime;
+    Benchmark.reportScore(score);
+  }
+  return recordedEvent;
+};
+
+/**
+ * Checks if two events can be considered equal. Throws exception if events
+ * differ.
+ * @param {Object} event Event that actually happened.
+ * @param {Object} recordedEvent Event taken from timeline.
+ */
+Benchmark.Agent.prototype.ensureEqual = function(event, recordedEvent) {
+  var equal = false;
+  if (event.type == recordedEvent.type &&
+      event.type in Benchmark.eventPropertiesMap) {
+    equal = true;
+    var properties = Benchmark.eventPropertiesMap[event.type];
+    for (var i = 0; i < properties.length && equal; ++i)
+      if (event[properties[i]] != recordedEvent[properties[i]])
+        equal = false;
+  }
+  if (!equal) {
+    Benchmark.die('unexpected event: ' + JSON.stringify(event) +
+                  ' instead of ' + JSON.stringify(recordedEvent));
+  }
+};
+
+/**
+ * Gets next event from timeline and returns it's identifier.
+ * @param {Object} event Object with event information.
+ * @return {number} Event identifier.
+ */
+Benchmark.Agent.prototype.createAsyncEvent = function(event) {
+  return this.getNextEvent(event).id;
+};
+
+/**
+ * Stores callback to be invoked according to timeline order.
+ * @param {number} eventId 'Parent' event identifier.
+ * @param {function} callback Callback.
+ */
+Benchmark.Agent.prototype.fireAsyncEvent = function(eventId, callback) {
+  var event = this.timeline[eventId];
+  if (!event.callbackReference) return;
+  this.timeline[event.callbackReference].callback = callback;
+  this.fireSome();
+};
+
+/**
+ * Ensures that things are happening according to recorded timeline.
+ * @param {number} eventId Identifier of cancelled event.
+ */
+Benchmark.Agent.prototype.cancelAsyncEvent = function(eventId) {
+  this.getNextEvent({type: 'cancel', reference: eventId});
+};
+
+/**
+ * Checks if script isn't going to be executed too early and delays script
+ * execution if necessary.
+ * @param {number} scriptId Unique script identifier.
+ * @param {HTMLElement} doc Document element.
+ * @param {boolean} inlined Indicates whether script is a text block in the page
+ * or resides in a separate file.
+ * @param {string} src Script url (if script is not inlined).
+ */
+Benchmark.Agent.prototype.readyToExecuteScript = function(scriptId, doc,
+                                                          inlined, src) {
+  var event = this.getCurrentEvent();
+  if (event.type == 'willExecuteScript' && event.scriptId == scriptId) {
+    this.timelinePosition += 1;
+    return true;
+  }
+  var element;
+  var elements = doc.getElementsByTagName('script');
+  for (var i = 0, el; (el = elements[i]) && !element; ++i) {
+    if (inlined) {
+      if (el.src) continue;
+      var text = el.textContent;
+      if (scriptId == text.substring(2, text.indexOf("*/")))
+        element = elements[i];
+    } else {
+      if (!el.src) continue;
+      if (el.src.indexOf(src) != -1 || src.indexOf(el.src) != -1) {
+        element = el;
+      }
+    }
+  }
+  if (!element) {
+    Benchmark.die('script element not found', scriptId, src);
+  }
+  for (var el2 = element; el2; el2 = el2.parentElement) {
+    if (el2.onload) {
+      console.log('found', el2);
+    }
+  }
+  this.delayedScriptElements[scriptId] = element;
+  return false;
+};
+
+/**
+ * Ensures that things are happening according to recorded timeline.
+ * @param {Object} event Object with event information.
+ */
+Benchmark.Agent.prototype.didExecuteScript = function(scriptId ) {
+  this.getNextEvent({type: 'didExecuteScript', scriptId: scriptId});
+  this.fireSome();
+};
+
+/**
+ * Invokes async events' callbacks according to timeline order.
+ */
+Benchmark.Agent.prototype.fireSome = function() {
+  while (this.timelinePosition < this.timeline.length) {
+    var event = this.getCurrentEvent();
+    if (event.type == 'willFire') {
+      if(!event.callback) break;
+      this.timelinePosition += 1;
+      this.callStackDepth += 1;
+      event.callback();
+      this.callStackDepth -= 1;
+      this.getNextEvent({type: 'didFire', reference: event.reference});
+    } else if (event.type == 'willExecuteScript') {
+      if (event.scriptId in this.delayedScriptElements) {
+        var element = this.delayedScriptElements[event.scriptId];
+        var parent = element.parentElement;
+        var cloneElement = element.cloneNode();
+        delete this.delayedScriptElements[event.scriptId];
+        parent.replaceChild(cloneElement, element);
+      }
+      break;
+    } else if (this.callStackDepth > 0) {
+      break;
+    } else {
+      Benchmark.die('unexpected event in fireSome:' + JSON.stringify(event));
+    }
+  }
+};
+
+/**
+ * Returns recorded random.
+ * @return {number} Recorded random.
+ */
+Benchmark.Agent.prototype.random = function() {
+  this.getNextEvent({type: 'random'});
+  return this.randoms[this.randomsPosition++];
+};
+
+/**
+ * Returns recorded ticks.
+ * @return {number} Recorded ticks.
+ */
+Benchmark.Agent.prototype.dateNow = function(event) {
+  this.getNextEvent({type: 'ticks'});
+  return this.ticks[this.ticksPosition++];
+};
+
+/**
+ * Event type -> property list mapping used for matching events.
+ * @const
+ */
+Benchmark.eventPropertiesMap = {
+  'timeout': ['timeout'],
+  'request': ['url'],
+  'addEventListener': ['eventType'],
+  'script load': ['src'],
+  'willExecuteScript': ['scriptId'],
+  'didExecuteScript': ['scriptId'],
+  'willFire': ['reference'],
+  'didFire': ['reference'],
+  'cancel': ['reference'],
+  'random': [],
+  'ticks': []
+};
+
+/**
+ * Agent used by native window functions wrappers.
+ */
+Benchmark.agent = new Benchmark.Agent(Benchmark.data);
+
+/**
+ * Playback flag.
+ * @const
+ */
+Benchmark.playback = true;
+
+Benchmark.reportScore = function(score) {
+  Benchmark.score = score;
+};
+
+Benchmark.originals.addEventListenerToWindow.call(
+    window, 'message', function(event) {
+      if (Benchmark.score) {
+        event.source.postMessage(Benchmark.score, event.origin);
+      }
+    }, false);