tools/chrome_proxy/common/chrome_proxy_measurements.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 base64
   6 import logging
   7
   8 from common import chrome_proxy_metrics as metrics
   9 from telemetry.core import exceptions
  10 from telemetry.page import page_test
  11
  12
  13 def WaitForViaHeader(tab, url="http://check.googlezip.net/test.html"):
  14   """Wait until responses start coming back with the Chrome Proxy via header.
  15
  16   Poll |url| in |tab| until the Chrome Proxy via header is present in a
  17   response.
  18
  19   This function is useful when testing with the Data Saver API, since Chrome
  20   won't actually start sending requests to the Data Reduction Proxy until the
  21   Data Saver API fetch completes. This function can be used to wait for the Data
  22   Saver API fetch to complete.
  23   """
  24
  25   tab.Navigate('data:text/html;base64,%s' % base64.b64encode(
  26     '<html><body><script>'
  27     'function ProbeViaHeader(url, wanted_via) {'
  28       'var xmlhttp = new XMLHttpRequest();'
  29       'xmlhttp.open("HEAD",url,false);'
  30       'xmlhttp.send();'
  31       'var via=xmlhttp.getResponseHeader("via");'
  32       'return (via && via.indexOf(wanted_via) != -1);'
  33     '}'
  34     '</script>'
  35     'Waiting for Chrome to start using the DRP...'
  36     '</body></html>'))
  37
  38   # Ensure the page has started loading before attempting the DRP check.
  39   tab.WaitForJavaScriptExpression('performance.timing.loadEventStart', 300)
  40   tab.WaitForJavaScriptExpression(
  41     'ProbeViaHeader("%s", "%s")' % (url, metrics.CHROME_PROXY_VIA_HEADER), 300)
  42
  43
  44 class ChromeProxyValidation(page_test.PageTest):
  45   """Base class for all chrome proxy correctness measurements."""
  46
  47   # Value of the extra via header. |None| if no extra via header is expected.
  48   extra_via_header = None
  49
  50   def __init__(self, restart_after_each_page=False, metrics=None):
  51     super(ChromeProxyValidation, self).__init__(
  52         needs_browser_restart_after_each_page=restart_after_each_page)
  53     self._metrics = metrics
  54     self._page = None
  55
  56   def CustomizeBrowserOptions(self, options):
  57     # Enable the chrome proxy (data reduction proxy).
  58     options.AppendExtraBrowserArgs('--enable-spdy-proxy-auth')
  59
  60   def WillNavigateToPage(self, page, tab):
  61     WaitForViaHeader(tab)
  62
  63     tab.ClearCache(force=True)
  64     assert self._metrics
  65     self._metrics.Start(page, tab)
  66
  67   def ValidateAndMeasurePage(self, page, tab, results):
  68     self._page = page
  69     # Wait for the load event.
  70     tab.WaitForJavaScriptExpression('performance.timing.loadEventStart', 300)
  71     assert self._metrics
  72     self._metrics.Stop(page, tab)
  73     if ChromeProxyValidation.extra_via_header:
  74       self._metrics.AddResultsForExtraViaHeader(
  75           tab, results, ChromeProxyValidation.extra_via_header)
  76     self.AddResults(tab, results)
  77
  78   def AddResults(self, tab, results):
  79     raise NotImplementedError
  80
  81   def StopBrowserAfterPage(self, browser, page):  # pylint: disable=W0613
  82     if hasattr(page, 'restart_after') and page.restart_after:
  83       return True
  84     return False