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 telemetry.page import page_measurement
   6
   7
   8 class ImageDecoding(page_measurement.PageMeasurement):
   9   def CustomizeBrowserOptions(self, options):
  10     options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
  11
  12   def WillNavigateToPage(self, page, tab):
  13     tab.ExecuteJavaScript("""
  14         if (window.chrome &&
  15             chrome.gpuBenchmarking &&
  16             chrome.gpuBenchmarking.clearImageCache) {
  17           chrome.gpuBenchmarking.clearImageCache();
  18         }
  19     """)
  20     tab.StartTimelineRecording()
  21
  22   def NeedsBrowserRestartAfterEachRun(self, tab):
  23     return not tab.ExecuteJavaScript("""
  24         window.chrome &&
  25             chrome.gpuBenchmarking &&
  26             chrome.gpuBenchmarking.clearImageCache;
  27     """)
  28
  29   def MeasurePage(self, page, tab, results):
  30     tab.StopTimelineRecording()
  31     def _IsDone():
  32       return tab.EvaluateJavaScript('isDone')
  33
  34     decode_image_events = \
  35         tab.timeline_model.GetAllEventsOfName('DecodeImage')
  36
  37     # If it is a real image page, then store only the last-minIterations
  38     # decode tasks.
  39     if (hasattr(page,
  40                'image_decoding_measurement_limit_results_to_min_iterations') and
  41         page.image_decoding_measurement_limit_results_to_min_iterations):
  42       assert _IsDone()
  43       min_iterations = tab.EvaluateJavaScript('minIterations')
  44       decode_image_events = decode_image_events[-min_iterations:]
  45
  46     durations = [d.duration for d in decode_image_events]
  47     if not durations:
  48       results.Add('ImageDecoding_avg', 'ms', 'unsupported')
  49       return
  50     image_decoding_avg = sum(durations) / len(durations)
  51     results.Add('ImageDecoding_avg', 'ms', image_decoding_avg)
  52     results.Add('ImageLoading_avg', 'ms',
  53                 tab.EvaluateJavaScript('averageLoadingTimeMs()'))