Chrome proxy telemetry test: better via header checking

tools/perf/metrics/chrome_proxy.py

 # Copyright 2014 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.
 
 import datetime
+import logging
 import os
 
 from telemetry.page import page_measurement
 from metrics import network
 
 
 class ChromeProxyMetricException(page_measurement.MeasurementFailure):
   pass
 
 
@@ skipping 28 matching lines @@
 class ChromeProxyResponse(network.HTTPResponse):
   """ Represents an HTTP response from a timeleine event."""
   def __init__(self, event):
     super(ChromeProxyResponse, self).__init__(event)
 
   def ShouldHaveChromeProxyViaHeader(self):
     resp = self.response
     # Ignore https and data url
     if resp.url.startswith('https') or resp.url.startswith('data:'):
       return False
-    # Ignore 304 Not Modified.
-    if resp.status == 304:
+    # Ignore 304 Not Modified and cache hit.
+    if resp.status == 304 or resp.served_from_cache:
+      return False
+    # Ignore invalid responses that don't have any header. Log a warning.
+    if not resp.headers:
+      logging.warning('response for %s does not any have header '
+                      '(refer=%s, status=%s)',
+                      resp.url, resp.GetHeader('Referer'), resp.status)
       return False
     return True
 
   def HasChromeProxyViaHeader(self):
     via_header = self.response.GetHeader('Via')
     if not via_header:
       return False
     vias = [v.strip(' ') for v in via_header.split(',')]
     # The Via header is valid if it is the old format or the new format
     # with 4-character version prefix, for example,
@@ skipping 49 matching lines @@
         resources_via_proxy += 1
       else:
         resources_direct += 1
 
     results.Add('resources_via_proxy', 'count', resources_via_proxy)
     results.Add('resources_from_cache', 'count', resources_from_cache)
     results.Add('resources_direct', 'count', resources_direct)
 
   def AddResultsForHeaderValidation(self, tab, results):
     via_count = 0
+    bypass_count = 0
     for resp in self.IterResponses(tab):
       if resp.IsValidByViaHeader():
         via_count += 1
+      elif tab and self.IsProxyBypassed(tab):
+        logging.warning('Proxy bypassed for %s', resp.response.url)
+        bypass_count += 1
       else:
         r = resp.response
         raise ChromeProxyMetricException, (
             '%s: Via header (%s) is not valid (refer=%s, status=%d)' % (
                 r.url, r.GetHeader('Via'), r.GetHeader('Referer'), r.status))
     results.Add('checked_via_header', 'count', via_count)
+    results.Add('request_bypassed', 'count', bypass_count)
+
+  def IsProxyBypassed(self, tab):
+    """ Returns True if all configured proxies are bypassed."""
+    info = GetProxyInfoFromNetworkInternals(tab)
+    if not info['enabled']:
+      raise ChromeProxyMetricException, (
+          'Chrome proxy should be enabled. proxy info: %s' % info)
+
+    bad_proxies = [str(p['proxy']) for p in info['badProxies']].sort()
+    proxies = [self.effective_proxies['proxy'],
+               self.effective_proxies['fallback']].sort()
+    return bad_proxies == proxies
 
   @staticmethod
   def VerifyBadProxies(
       badProxies, expected_proxies,
       retry_seconds_low = DEFAULT_BYPASS_MIN_SECONDS,
       retry_seconds_high = DEFAULT_BYPASS_MAX_SECONDS):
     """Verify the bad proxy list and their retry times are expected. """
     if not badProxies or (len(badProxies) != len(expected_proxies)):
       return False
 
@@ skipping 84 matching lines @@
 
     bad_proxies = []
     if 'badProxies' in info and info['badProxies']:
       bad_proxies = [p['proxy'] for p in info['badProxies']
                      if 'proxy' in p and p['proxy']]
     if bad_proxies != expected_bad_proxies:
       raise ChromeProxyMetricException, (
           'Wrong bad proxies (%s). Expect: "%s"' % (
           str(bad_proxies), str(expected_bad_proxies)))
     results.Add('http_fallback', 'boolean', True)