tools/perf/measurements/image_decoding.py

   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.
   4
   5 from metrics import power
   6 from telemetry.page import page_measurement
   7
   8
   9 class ImageDecoding(page_measurement.PageMeasurement):
  10   def __init__(self):
  11     super(ImageDecoding, self).__init__()
  12     self._power_metric = power.PowerMetric()
  13
  14   def CustomizeBrowserOptions(self, options):
  15     options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
  16     power.PowerMetric.CustomizeBrowserOptions(options)
  17
  18   def WillNavigateToPage(self, page, tab):
  19     tab.ExecuteJavaScript("""
  20         if (window.chrome &&
  21             chrome.gpuBenchmarking &&
  22             chrome.gpuBenchmarking.clearImageCache) {
  23           chrome.gpuBenchmarking.clearImageCache();
  24         }
  25     """)
  26
  27   def DidNavigateToPage(self, page, tab):
  28     self._power_metric.Start(page, tab)
  29     tab.StartTimelineRecording()
  30
  31   def StopBrowserAfterPage(self, browser, page):
  32     return not browser.tabs[0].ExecuteJavaScript("""
  33         window.chrome &&
  34             chrome.gpuBenchmarking &&
  35             chrome.gpuBenchmarking.clearImageCache;
  36     """)
  37
  38   def MeasurePage(self, page, tab, results):
  39     tab.StopTimelineRecording()
  40     self._power_metric.Stop(page, tab)
  41     self._power_metric.AddResults(tab, results)
  42
  43     def _IsDone():
  44       return tab.EvaluateJavaScript('isDone')
  45
  46     decode_image_events = \
  47         tab.timeline_model.GetAllEventsOfName('DecodeImage')
  48
  49     # If it is a real image page, then store only the last-minIterations
  50     # decode tasks.
  51     if (hasattr(page,
  52                'image_decoding_measurement_limit_results_to_min_iterations') and
  53         page.image_decoding_measurement_limit_results_to_min_iterations):
  54       assert _IsDone()
  55       min_iterations = tab.EvaluateJavaScript('minIterations')
  56       decode_image_events = decode_image_events[-min_iterations:]
  57
  58     durations = [d.duration for d in decode_image_events]
  59     if not durations:
  60       return
  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()'))