src/tools/telemetry/telemetry/web_perf/metrics/smoothness.py

   1 # Copyright 2014 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.web_perf.metrics import timeline_based_metric
   6 from telemetry.web_perf.metrics import rendering_stats
   7 from telemetry.page.perf_tests_helper import FlattenList
   8 from telemetry.util import statistics
   9
  10
  11 class SmoothnessMetric(timeline_based_metric.TimelineBasedMetric):
  12   def __init__(self):
  13     super(SmoothnessMetric, self).__init__()
  14
  15   def AddResults(self, model, renderer_thread, interaction_records, results):
  16     renderer_process = renderer_thread.parent
  17     stats = rendering_stats.RenderingStats(
  18       renderer_process, model.browser_process,
  19       [r.GetBounds() for r in interaction_records])
  20     if stats.mouse_wheel_scroll_latency:
  21       mean_mouse_wheel_scroll_latency = statistics.ArithmeticMean(
  22         stats.mouse_wheel_scroll_latency)
  23       mouse_wheel_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
  24         stats.mouse_wheel_scroll_latency)
  25       results.Add('mean_mouse_wheel_scroll_latency', 'ms',
  26                   round(mean_mouse_wheel_scroll_latency, 3))
  27       results.Add('mouse_wheel_scroll_latency_discrepancy', 'ms',
  28                   round(mouse_wheel_scroll_latency_discrepancy, 4))
  29
  30     if stats.touch_scroll_latency:
  31       mean_touch_scroll_latency = statistics.ArithmeticMean(
  32         stats.touch_scroll_latency)
  33       touch_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
  34         stats.touch_scroll_latency)
  35       results.Add('mean_touch_scroll_latency', 'ms',
  36                   round(mean_touch_scroll_latency, 3))
  37       results.Add('touch_scroll_latency_discrepancy', 'ms',
  38                   round(touch_scroll_latency_discrepancy, 4))
  39
  40     if stats.js_touch_scroll_latency:
  41       mean_js_touch_scroll_latency = statistics.ArithmeticMean(
  42         stats.js_touch_scroll_latency)
  43       js_touch_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
  44         stats.js_touch_scroll_latency)
  45       results.Add('mean_js_touch_scroll_latency', 'ms',
  46                   round(mean_js_touch_scroll_latency, 3))
  47       results.Add('js_touch_scroll_latency_discrepancy', 'ms',
  48                   round(js_touch_scroll_latency_discrepancy, 4))
  49
  50     # List of raw frame times.
  51     frame_times = FlattenList(stats.frame_times)
  52     results.Add('frame_times', 'ms', frame_times)
  53
  54     # Arithmetic mean of frame times.
  55     mean_frame_time = statistics.ArithmeticMean(frame_times)
  56     results.Add('mean_frame_time', 'ms', round(mean_frame_time, 3))
  57
  58     # Absolute discrepancy of frame time stamps.
  59     frame_discrepancy = statistics.TimestampsDiscrepancy(
  60       stats.frame_timestamps)
  61     results.Add('jank', 'ms', round(frame_discrepancy, 4))
  62
  63     # Are we hitting 60 fps for 95 percent of all frames?
  64     # We use 19ms as a somewhat looser threshold, instead of 1000.0/60.0.
  65     percentile_95 = statistics.Percentile(frame_times, 95.0)
  66     results.Add('mostly_smooth', 'score', 1.0 if percentile_95 < 19.0 else 0.0)
  67
  68     # Mean percentage of pixels approximated (missing tiles, low resolution
  69     # tiles, non-ideal resolution tiles)
  70     results.Add('mean_pixels_approximated', 'percent',
  71                 round(statistics.ArithmeticMean(
  72                     FlattenList(stats.approximated_pixel_percentages)), 3))