1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 # Use of this source code is governed by a BSD-style license that can be
3 # found in the LICENSE file.
5 from metrics import power
6 from telemetry.page import page_measurement
9 class ImageDecoding(page_measurement.PageMeasurement):
11 super(ImageDecoding, self).__init__()
12 self._power_metric = power.PowerMetric()
14 def CustomizeBrowserOptions(self, options):
15 options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
16 power.PowerMetric.CustomizeBrowserOptions(options)
18 def WillNavigateToPage(self, page, tab):
19 tab.ExecuteJavaScript("""
21 chrome.gpuBenchmarking &&
22 chrome.gpuBenchmarking.clearImageCache) {
23 chrome.gpuBenchmarking.clearImageCache();
27 def DidNavigateToPage(self, page, tab):
28 self._power_metric.Start(page, tab)
29 tab.StartTimelineRecording()
31 def StopBrowserAfterPage(self, browser, page):
32 return not browser.tabs[0].ExecuteJavaScript("""
34 chrome.gpuBenchmarking &&
35 chrome.gpuBenchmarking.clearImageCache;
38 def MeasurePage(self, page, tab, results):
39 tab.StopTimelineRecording()
40 self._power_metric.Stop(page, tab)
41 self._power_metric.AddResults(tab, results)
44 return tab.EvaluateJavaScript('isDone')
46 decode_image_events = \
47 tab.timeline_model.GetAllEventsOfName('DecodeImage')
49 # If it is a real image page, then store only the last-minIterations
52 'image_decoding_measurement_limit_results_to_min_iterations') and
53 page.image_decoding_measurement_limit_results_to_min_iterations):
55 min_iterations = tab.EvaluateJavaScript('minIterations')
56 decode_image_events = decode_image_events[-min_iterations:]
58 durations = [d.duration for d in decode_image_events]
61 image_decoding_avg = sum(durations) / len(durations)
62 results.Add('ImageDecoding_avg', 'ms', image_decoding_avg)
63 results.Add('ImageLoading_avg', 'ms',
64 tab.EvaluateJavaScript('averageLoadingTimeMs()'))