tools/perf/metrics/webrtc_stats.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 import json
   6 import logging
   7 import re
   8
   9 from metrics import Metric
  10 from telemetry.core import camel_case
  11 from telemetry.value import list_of_scalar_values
  12
  13 INTERESTING_METRICS = {
  14     'packetsReceived': {
  15         'units': 'packets',
  16         'description': 'Packets received by the peer connection',
  17     },
  18     'packetsSent': {
  19         'units': 'packets',
  20         'description': 'Packets sent by the peer connection',
  21     },
  22     'googDecodeMs': {
  23         'units': 'ms',
  24         'description': 'Time spent decoding.',
  25     },
  26     'googMaxDecodeMs': {
  27         'units': 'ms',
  28         'description': 'Maximum time spent decoding one frame.',
  29     },
  30     # TODO(phoglund): Add much more interesting metrics.
  31 }
  32
  33
  34 def GetReportKind(report):
  35   if 'audioInputLevel' in report or 'audioOutputLevel' in report:
  36     return 'audio'
  37   if 'googFrameRateSent' in report or 'googFrameRateReceived' in report:
  38     return 'video'
  39
  40   logging.debug('Did not recognize report batch: %s.', report.keys())
  41   # There are other kinds of reports, such as bwestats, which we don't care
  42   # about here. For these cases just return 'unknown' which will ignore the
  43   # report
  44   return 'unknown'
  45
  46
  47 def DistinguishAudioAndVideo(report, stat_name):
  48   return GetReportKind(report) + '_' + stat_name
  49
  50
  51 def StripAudioVideoDistinction(stat_name):
  52   return re.sub('^(audio|video)_', '', stat_name)
  53
  54
  55 def SortStatsIntoTimeSeries(report_batches):
  56   time_series = {}
  57   for report_batch in report_batches:
  58     for report in report_batch:
  59       for stat_name, value in report.iteritems():
  60         if stat_name not in INTERESTING_METRICS:
  61           continue
  62         if GetReportKind(report) == 'unknown':
  63           continue
  64         full_stat_name = DistinguishAudioAndVideo(report, stat_name)
  65         time_series.setdefault(full_stat_name, []).append(float(value))
  66
  67   return time_series
  68
  69
  70 class WebRtcStatisticsMetric(Metric):
  71   """Makes it possible to measure stats from peer connections."""
  72
  73   def __init__(self):
  74     super(WebRtcStatisticsMetric, self).__init__()
  75     self._all_reports = None
  76
  77   def Start(self, page, tab):
  78     pass
  79
  80   def Stop(self, page, tab):
  81     """Digs out stats from data populated by the javascript in webrtc_cases."""
  82     self._all_reports = tab.EvaluateJavaScript(
  83         'JSON.stringify(window.peerConnectionReports)')
  84
  85   def AddResults(self, tab, results):
  86     if not self._all_reports:
  87       return
  88
  89     reports = json.loads(self._all_reports)
  90     for i, report in enumerate(reports):
  91       time_series = SortStatsIntoTimeSeries(report)
  92
  93       for stat_name, values in time_series.iteritems():
  94         stat_name_underscored = camel_case.ToUnderscore(stat_name)
  95         trace_name = 'peer_connection_%d_%s' % (i, stat_name_underscored)
  96         general_name = StripAudioVideoDistinction(stat_name)
  97         results.AddValue(list_of_scalar_values.ListOfScalarValues(
  98             results.current_page, trace_name,
  99             INTERESTING_METRICS[general_name]['units'], values,
 100             description=INTERESTING_METRICS[general_name]['description'],
 101             important=False))