tools/telemetry/examples/telemetry_perf_test.py

   1 #!/usr/bin/env python
   2 # Copyright 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 import os
   7 import sys
   8 import time
   9
  10 sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir))
  11
  12 from telemetry.core import browser_finder
  13 from telemetry.core import browser_options
  14
  15
  16 def Main(args):
  17   options = browser_options.BrowserFinderOptions()
  18   parser = options.CreateParser('telemetry_perf_test.py')
  19   options, args = parser.parse_args(args)
  20
  21   browser_to_create = browser_finder.FindBrowser(options)
  22   assert browser_to_create
  23   with browser_to_create.Create(options) as b:
  24     tab = b.tabs[0]
  25
  26     # Measure round-trip-time for evaluate
  27     times = []
  28     for i in range(1000):
  29       start = time.time()
  30       tab.EvaluateJavaScript('%i * 2' % i)
  31       times.append(time.time() - start)
  32     N = float(len(times))
  33     avg = sum(times, 0.0) / N
  34     squared_diffs = [(t - avg) * (t - avg) for t in times]
  35     stdev = sum(squared_diffs, 0.0) / (N - 1)
  36     times.sort()
  37     percentile_75 = times[int(0.75 * N)]
  38
  39     print "%s: avg=%f; stdev=%f; min=%f; 75th percentile = %f" % (
  40       "Round trip time (seconds)",
  41       avg, stdev, min(times), percentile_75)
  42
  43   return 0
  44
  45
  46 if __name__ == '__main__':
  47   sys.exit(Main(sys.argv[1:]))