tools: WPR support for testing speculative_prefetch_predictor.

tools/android/customtabs_benchmark/scripts/customtabs_benchmark.py

 #!/usr/bin/python
 #
 # Copyright 2015 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.
 
 """Loops Custom Tabs tests and outputs the results into a CSV file."""
 
 import collections
 import contextlib
@@ skipping 23 matching lines @@
 
 
 # Local build of Chrome (not Chromium).
 _CHROME_PACKAGE = 'com.google.android.apps.chrome'
 _COMMAND_LINE_PATH = '/data/local/tmp/chrome-command-line'
 _TEST_APP_PACKAGE_NAME = 'org.chromium.customtabsclient.test'
 _INVALID_VALUE = -1
 
 
 # Command line arguments for Chrome.
-_CHROME_ARGS = [
+CHROME_ARGS = [
     # Disable backgound network requests that may pollute WPR archive, pollute
     # HTTP cache generation, and introduce noise in loading performance.
     '--disable-background-networking',
     '--disable-default-apps',
     '--no-proxy-server',
     # TODO(droger): Remove once crbug.com/354743 is fixed.
     '--safebrowsing-disable-auto-update',
 
     # Disables actions that chrome performs only on first run or each launches,
     # which can interfere with page load performance, or even block its
@@ skipping 71 matching lines @@
     match = None
     try:
       match = logcat_monitor.WaitFor(result_line_re, timeout=logcat_timeout)
     except device_errors.CommandTimeoutError as _:
       logging.warning('Timeout waiting for the result line')
     logcat_monitor.Stop()
     logcat_monitor.Close()
     return match.group(1) if match is not None else None
 
 
-Result = collections.namedtuple('Result', ['warmup', 'speculation_mode',
-                                           'delay_to_may_launch_url',
-                                           'delay_to_launch_url',
-                                           'commit', 'plt',
-                                           'first_contentful_paint'])
+RESULT_FIELDS = ('warmup', 'speculation_mode', 'delay_to_may_launch_url',
+                 'delay_to_launch_url', 'commit', 'plt',
+                 'first_contentful_paint')
+Result = collections.namedtuple('Result', RESULT_FIELDS)
 
 
 def ParseResult(result_line):
   """Parses a result line, and returns it.
 
   Args:
     result_line: (str) A result line, as returned by RunOnce().
 
   Returns:
     An instance of Result.
@@ skipping 23 matching lines @@
     once: (bool) Run only once.
     should_stop: (threading.Event or None) When the event is set, stop looping.
   """
   with SetupWpr(device, wpr_archive_path, wpr_record, network_condition,
                 wpr_log_path) as wpr_attributes:
     to_stdout = output_filename == '-'
     out = sys.stdout if to_stdout else open(output_filename, 'a')
     try:
       while should_stop is None or not should_stop.is_set():
         config = configs[random.randint(0, len(configs) - 1)]
-        chrome_args = _CHROME_ARGS + wpr_attributes.chrome_args
+        chrome_args = CHROME_ARGS + wpr_attributes.chrome_args
         if config['speculation_mode'] == 'no_state_prefetch':
           # NoStatePrefetch is enabled through an experiment.
           chrome_args.extend([
               '--force-fieldtrials=trial/group',
               '--force-fieldtrial-params=trial.group:mode/no_state_prefetch',
               '--enable-features="NoStatePrefetch<trial"'])
 
         result = RunOnce(device, config['url'], config['warmup'],
                          config['speculation_mode'],
                          config['delay_to_may_launch_url'],
@@ skipping 16 matching lines @@
 def ProcessOutput(filename):
   """Reads an output file, and returns a processed numpy array.
 
   Args:
     filename: (str) file to process.
 
   Returns:
     A numpy structured array.
   """
   import numpy as np
-  data = np.genfromtxt(filename, delimiter=',')
+  data = np.genfromtxt(filename, delimiter=',', skip_header=1)

[pasko, 2016/12/14 19:38:33]

is this function going to be used somewhere?

The csv.DictReader would be more robust if it asserted for expected fields, like
here:
https://codesearch.chromium.org/chromium/src/tools/android/loading/csv_util.p...

Probably not for this change, a TODO would suffice.

[Benoit L, 2016/12/16 14:27:00]

It is used for the analysis.
Acknowledged.

   result = np.array(np.zeros(len(data)),
                     dtype=[('warmup', bool), ('speculation_mode', np.int32),
                            ('delay_to_may_launch_url', np.int32),
                            ('delay_to_launch_url', np.int32),
                            ('commit', np.int32), ('plt', np.int32),
                            ('first_contentful_paint', np.int32)])
   result['warmup'] = data[:, 0]
   result['speculation_mode'] = data[:, 1]
   result['delay_to_may_launch_url'] = data[:, 2]
   result['delay_to_launch_url'] = data[:, 3]
@@ skipping 86 matching lines @@
       'delay_to_launch_url': options.delay_to_launch_url,
       'cold': options.cold,
   }
   LoopOnDevice(device, [config], options.output_file, options.wpr_archive,
                options.record, options.network_condition, options.wpr_log,
                once=options.once)
 
 
 if __name__ == '__main__':
   main()