tools/perf/measurements/startup.py

# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

from metrics import startup_metric
from telemetry.page import page_measurement


class Startup(page_measurement.PageMeasurement):
  """Performs a measurement of Chromium's startup performance.

  This test must be invoked with either --warm or --cold on the command line. A
  cold start means none of the Chromium files are in the disk cache. A warm
  start assumes the OS has already cached much of Chromium's content. For warm
  tests, you should repeat the page set to ensure it's cached.
  """

  def __init__(self, action_name_to_run = ''):
    super(Startup, self).__init__(needs_browser_restart_after_each_page=True,
                                  action_name_to_run=action_name_to_run)

  @classmethod
  def AddCommandLineArgs(cls, parser):
    parser.add_option('--cold', action='store_true',
                      help='Clear the OS disk cache before performing the test')
    parser.add_option('--warm', action='store_true',
                      help='Start up with everything already cached')

  @classmethod
  def ProcessCommandLineArgs(cls, parser, args):
    cls._cold = args.cold
    # TODO: Once the bots start running benchmarks, enforce that either --warm
    # or --cold is explicitly specified.
    # if args.warm == args.cold:
    #   parser.error('You must specify either --warm or --cold')

  def CustomizeBrowserOptions(self, options):
    if self._cold:
      options.clear_sytem_cache_for_browser_and_profile_on_start = True
    else:
      self.discard_first_result = True

    options.AppendExtraBrowserArgs([
        '--enable-stats-collection-bindings'
    ])

  def RunNavigateSteps(self, page, tab):
    # Overriden so that no page navigation occurs - startup to the NTP.
    pass

  def MeasurePage(self, page, tab, results):
    startup_metric.StartupMetric().AddResults(tab, results)


class StartWithUrl(Startup):
  """Performs a measurement of Chromium's performance starting with a URL.

  This test must be invoked with either --warm or --cold on the command line. A
  cold start means none of the Chromium files are in the disk cache. A warm
  start assumes the OS has already cached much of Chromium's content. For warm
  tests, you should repeat the page set to ensure it's cached.

  The startup URL is taken from the page set's startup_url. This
  allows the testing of multiple different URLs in a single benchmark.
  """

  def __init__(self):
    super(StartWithUrl, self).__init__(action_name_to_run='RunNavigateSteps')