tools/perf/perf_tools/image_decoding_benchmark.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_benchmark
   6
   7
   8 class ImageDecoding(page_benchmark.PageBenchmark):
   9   def WillNavigateToPage(self, page, tab):
  10     tab.StartTimelineRecording()
  11
  12   def MeasurePage(self, page, tab, results):
  13     tab.StopTimelineRecording()
  14     def _IsDone():
  15       return tab.EvaluateJavaScript('isDone')
  16
  17     decode_image_events = \
  18         tab.timeline_model.GetAllOfName('DecodeImage')
  19
  20     # If it is a real image benchmark, then store only the last-minIterations
  21     # decode tasks.
  22     if (hasattr(page,
  23                'image_decoding_benchmark_limit_results_to_min_iterations') and
  24         page.image_decoding_benchmark_limit_results_to_min_iterations):
  25       assert _IsDone()
  26       min_iterations = tab.EvaluateJavaScript('minIterations')
  27       decode_image_events = decode_image_events[-min_iterations:]
  28
  29     durations = [d.duration_ms for d in decode_image_events]
  30     if not durations:
  31       results.Add('ImageDecoding_avg', 'ms', 'unsupported')
  32       return
  33     image_decoding_avg = sum(durations) / len(durations)
  34     results.Add('ImageDecoding_avg', 'ms', image_decoding_avg)