tools/perf/metrics/power.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 logging
   6
   7 from metrics import Metric
   8
   9
  10 class PowerMetric(Metric):
  11   """A metric for measuring power usage."""
  12
  13   _enabed = True
  14
  15   def __init__(self):
  16     super(PowerMetric, self).__init__()
  17     self._results = None
  18
  19   @classmethod
  20   def CustomizeBrowserOptions(cls, options):
  21     PowerMetric._enabed = options.report_root_metrics
  22
  23   def Start(self, _, tab):
  24     if not PowerMetric._enabed:
  25       return
  26
  27     if not tab.browser.platform.CanMonitorPowerAsync():
  28       logging.warning("System doesn't support async power monitoring.")
  29       return
  30
  31     tab.browser.platform.StartMonitoringPowerAsync()
  32
  33   def Stop(self, _, tab):
  34     if not PowerMetric._enabed:
  35       return
  36
  37     if not tab.browser.platform.CanMonitorPowerAsync():
  38       return
  39
  40     self._results = tab.browser.platform.StopMonitoringPowerAsync()
  41
  42   def AddResults(self, _, results):
  43     if not self._results:
  44       return
  45
  46     energy_consumption_mwh = self._results['energy_consumption_mwh']
  47     results.Add('energy_consumption_mwh', 'mWh', energy_consumption_mwh)
  48     self._results = None