1# Copyright 2013 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
5from metrics import startup_metric
6from telemetry.page import page_measurement
7
8class Startup(page_measurement.PageMeasurement):
9  """Performs a measurement of Chromium's startup performance.
10
11  This test must be invoked with either --warm or --cold on the command line. A
12  cold start means none of the Chromium files are in the disk cache. A warm
13  start assumes the OS has already cached much of Chromium's content. For warm
14  tests, you should repeat the page set to ensure it's cached.
15  """
16
17  def __init__(self):
18    super(Startup, self).__init__(needs_browser_restart_after_each_run=True)
19
20  def AddCommandLineOptions(self, parser):
21    parser.add_option('--cold', action='store_true',
22                      help='Clear the OS disk cache before performing the test')
23    parser.add_option('--warm', action='store_true',
24                      help='Start up with everything already cached')
25
26  def CustomizeBrowserOptions(self, options):
27    # TODO: Once the bots start running benchmarks, enforce that either --warm
28    # or --cold is explicitly specified.
29    # assert options.warm != options.cold, \
30    #     "You must specify either --warm or --cold"
31    if options.cold:
32      browser_options = options.browser_options
33      browser_options.clear_sytem_cache_for_browser_and_profile_on_start = True
34    else:
35      self.discard_first_result = True
36
37    options.AppendExtraBrowserArgs([
38        '--enable-stats-collection-bindings'
39    ])
40
41  def RunNavigateSteps(self, page, tab):
42    # Overriden so that no page navigation occurs - startup to the NTP.
43    pass
44
45  def MeasurePage(self, page, tab, results):
46    startup_metric.StartupMetric().AddResults(tab, results)
47