Allow pyauto performance tests in perf.py to run as an autotest.

chrome/test/functional/perf.py

Index: chrome/test/functional/perf.py
diff --git a/chrome/test/functional/perf.py b/chrome/test/functional/perf.py
index dfb70b0124f8a8a5aaefa03378a252f3777ccbce..7aabbe6e1cf06ed1045d6bfc451a19cdede7e61d 100644
--- a/chrome/test/functional/perf.py
+++ b/chrome/test/functional/perf.py
@@ -3,6 +3,17 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+"""Basic pyauto performance tests.
+
+By default, each test in this file runs a single experimental trial (which
+consists of a simple action that is measured for performance, such as opening
+a new tab).  An environment variable 'PYAUTO_PERF_TEST_NUM_TRIALS' can
+optionally be set, which must be an integer >= 0.  If set, this refers to the
+number of additional experimental trials to run for each test after the initial
+trial.  The average and standard deviation of the additional trials will be
+computed.
+"""
+
 import logging
 import math
 import os
@@ -15,7 +26,18 @@ import pyauto
 class PerfTest(pyauto.PyUITest):
   """Basic performance tests."""
 
-  _NUM_ITERATIONS = 50
+  def setUp(self):
+    """Performs necessary setup work before running each test."""

[Nirnimesh, 2011/08/11 18:26:36]

So if it's not defined in the environment, the test will not run anything?
That doesn't sound right. It should do the default 50, when nothing has been
provided, and then the environment var can be used to tweak it.

[dennis_jeffrey, 2011/08/11 19:29:32]

No, if that variable is not defined in the environment, it would have run a
single trial only (the default behavior).
Changed the code based on our offline discussion about how many iterations each
test should run in the default case.

+    self._num_trials = 0
+    if 'PYAUTO_PERF_TEST_NUM_TRIALS' in os.environ:
+      try:
+        self._num_trials = int(os.environ['PYAUTO_PERF_TEST_NUM_TRIALS'])

[Nirnimesh, 2011/08/11 18:26:36]

That's a env var no one will remember. Use NUM_ITERATIONS

[dennis_jeffrey, 2011/08/11 19:29:32]

Done.

+        if self._num_trials < 0:
+          raise ValueError('Environment variable PYAUTO_PERF_TEST_NUM_TRIALS '
+                           'must be an integer >= 0.')
+      except ValueError, e:
+        self.fail('Error processing environment variable: %s' % e)
+    pyauto.PyUITest.setUp(self)
 
   def _MeasureElapsedTime(self, python_command, num_invocations):
     """Measures time (in msec) to execute a python command one or more times.
@@ -58,14 +80,15 @@ class PerfTest(pyauto.PyUITest):
       values: A list of numeric value measurements.
       units: A string specifying the units for the specified measurements.
     """
-    avg, std_dev = self._AvgAndStdDev(values)
-    logging.debug('First trial: %.2f %s', first_val, units)
-    logging.info('Number of iterations: %d', num_iter)
-    for val in values:
-      logging.info('  %.2f %s', val, units)
-    logging.info('  --------------------------')
-    logging.info('  Average: %.2f %s', avg, units)
-    logging.info('  Std dev: %.2f %s', std_dev, units)
+    logging.debug('Single trial: %.2f %s', first_val, units)
+    if self._num_trials:
+      avg, std_dev = self._AvgAndStdDev(values)
+      logging.info('Number of iterations: %d', num_iter)
+      for val in values:
+        logging.info('  %.2f %s', val, units)
+      logging.info('  --------------------------')
+      logging.info('  Average: %.2f %s', avg, units)
+      logging.info('  Std dev: %.2f %s', std_dev, units)
 
   def _RunNewTabTest(self, open_tab_command, num_tabs=1):
     """Runs a perf test that involves opening new tab(s).
@@ -87,7 +110,7 @@ class PerfTest(pyauto.PyUITest):
       self.GetBrowserWindow(0).GetTab(1).Close(True)
 
     timings = []
-    for _ in range(self._NUM_ITERATIONS):
+    for _ in range(self._num_trials):
       elapsed = self._MeasureElapsedTime(open_tab_command, num_tabs)
       self.assertEqual(1 + num_tabs, self.GetTabCount(),
                        msg='Did not open %d new tab(s).' % num_tabs)
@@ -95,7 +118,7 @@ class PerfTest(pyauto.PyUITest):
         self.GetBrowserWindow(0).GetTab(1).Close(True)
       timings.append(elapsed)
 
-    self._PrintSummaryResults(orig_elapsed, self._NUM_ITERATIONS, timings, 'ms')
+    self._PrintSummaryResults(orig_elapsed, self._num_trials, timings, 'ms')
 
   def testNewTab(self):
     """Measures time to open a new tab."""
@@ -144,13 +167,13 @@ class PerfTest(pyauto.PyUITest):
                      msg='Did not clean up after running benchmark suite.')
 
     scores = []
-    for _ in range(self._NUM_ITERATIONS):
+    for _ in range(self._num_trials):
       score = _RunSingleV8BenchmarkSuite()
       self.assertEqual(1, self.GetTabCount(),
                        msg='Did not clean up after running benchmark suite.')
       scores.append(score)
 
-    self._PrintSummaryResults(orig_score, self._NUM_ITERATIONS, scores, 'score')
+    self._PrintSummaryResults(orig_score, self._num_trials, scores, 'score')
 
 
 if __name__ == '__main__':