Pyauto performance tests now output data to be graphed using 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 e3938351b865950a33659b0420fe567fb011ec53..1a425464a52094fdee424d403656d4fe65349a82 100644
--- a/chrome/test/functional/perf.py
+++ b/chrome/test/functional/perf.py
@@ -16,7 +16,7 @@ to run.
 import logging
 import math
 import os
-import time
+import timeit
 
 import pyauto_functional  # Must be imported before pyauto.
 import pyauto
@@ -26,6 +26,8 @@ class PerfTest(pyauto.PyUITest):
   """Basic performance tests."""
 
   _DEFAULT_NUM_ITERATIONS = 50
+  _PERF_OUTPUT_MARKER_PRE = '_PERF_PRE_'
+  _PERF_OUTPUT_MARKER_POST = '_PERF_POST_'
 
   def setUp(self):
     """Performs necessary setup work before running each test."""
@@ -40,6 +42,9 @@ class PerfTest(pyauto.PyUITest):
         self.fail('Error processing environment variable: %s' % e)
     pyauto.PyUITest.setUp(self)
 
+  # TODO(dennisjeffrey): Reorganize the code to create a base PerfTest class
+  # to separate out common functionality, then create specialized subclasses
+  # such as TabPerfTest that implement the test-specific functionality.
   def _MeasureElapsedTime(self, python_command, num_invocations):
     """Measures time (in msec) to execute a python command one or more times.
 
@@ -52,11 +57,11 @@ class PerfTest(pyauto.PyUITest):
       times, in milliseconds as a float.
     """
     assert callable(python_command)
-    start_time = time.time()
-    for _ in range(num_invocations):
-      python_command()
-    stop_time = time.time()
-    return (stop_time - start_time) * 1000  # Convert to milliseconds.
+    def RunCommand():
+      for _ in range(num_invocations):
+        python_command()
+    timer = timeit.Timer(stmt=lambda: RunCommand())
+    return timer.timeit(number=1) * 1000  # Convert seconds to milliseconds.
 
   def _AvgAndStdDev(self, values):
     """Computes the average and standard deviation of a set of values.
@@ -67,19 +72,38 @@ class PerfTest(pyauto.PyUITest):
     Returns:
       A 2-tuple of floats (average, standard_deviation).
     """
-    avg = float(sum(values)) / len(values)
-    temp_vals = [math.pow(x - avg, 2) for x in values]
-    std_dev = math.sqrt(sum(temp_vals) / len(temp_vals))
+    avg = 0.0
+    std_dev = 0.0
+    if values:
+      avg = float(sum(values)) / len(values)
+      if len(values) > 1:
+        temp_vals = [math.pow(x - avg, 2) for x in values]
+        std_dev = math.sqrt(sum(temp_vals) / (len(temp_vals) - 1))
     return avg, std_dev
 
-  def _PrintSummaryResults(self, first_val, units, values=[]):
+  def _OutputPerfGraphValue(self, description, value):
+    """Outputs a performance value to have it graphed on the performance bots.
+
+    Only used for ChromeOS.
+
+    Args:
+      description: A string description of the performance value.
+      value: A numeric value representing a single performance measurement.
+    """
+    if self.IsChromeOS():
+      print '\n%s(\'%s\', %.2f)%s' % (self._PERF_OUTPUT_MARKER_PRE, description,
+                                      value, self._PERF_OUTPUT_MARKER_POST)
+
+  def _PrintSummaryResults(self, description, first_val, units, values=[]):
     """Logs summary measurement information.
 
     Args:
+      description: A string description for the specified results.
       first_val: A numeric measurement value for a single initial trial.
       units: A string specifying the units for the specified measurements.
       values: A list of numeric value measurements.
     """
+    logging.info('Results for: ' + description)
     logging.debug('Single trial: %.2f %s', first_val, units)
     if values:
       avg, std_dev = self._AvgAndStdDev(values)
@@ -89,8 +113,11 @@ class PerfTest(pyauto.PyUITest):
       logging.info('  --------------------------')
       logging.info('  Average: %.2f %s', avg, units)
       logging.info('  Std dev: %.2f %s', std_dev, units)
+      self._OutputPerfGraphValue('%s_%s' % (units, description), avg)
+    else:
+      self._OutputPerfGraphValue('%s_%s' % (units, description), first_val)
 
-  def _RunNewTabTest(self, open_tab_command, num_tabs=1):
+  def _RunNewTabTest(self, description, open_tab_command, num_tabs=1):
     """Runs a perf test that involves opening new tab(s).
 
     This helper function can be called from different tests to do perf testing
@@ -98,11 +125,14 @@ class PerfTest(pyauto.PyUITest):
     will open up a single tab.
 
     Args:
+      description: A string description of the associated tab test.
       open_tab_command: A callable that will open a single tab.
       num_tabs: The number of tabs to open, i.e., the number of times to invoke
                 the |open_tab_command|.
     """
     assert callable(open_tab_command)
+
+    # TODO(dennisjeffrey): Consider not taking an initial sample here.
     orig_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)
@@ -118,25 +148,30 @@ class PerfTest(pyauto.PyUITest):
         self.GetBrowserWindow(0).GetTab(1).Close(True)
       timings.append(elapsed)
 
-    self._PrintSummaryResults(orig_elapsed, 'ms', values=timings)
+    self._PrintSummaryResults(description, orig_elapsed, 'milliseconds',
+                              values=timings)
 
   def testNewTab(self):
     """Measures time to open a new tab."""
-    self._RunNewTabTest(lambda: self.AppendTab(pyauto.GURL('chrome://newtab')))
+    self._RunNewTabTest('NewTabPage',
+                        lambda: self.AppendTab(pyauto.GURL('chrome://newtab')))
 
   def testNewTabPdf(self):
     """Measures time to open a new tab navigated to a PDF file."""
     url = self.GetFileURLForDataPath('pyauto_private', 'pdf', 'TechCrunch.pdf')
-    self._RunNewTabTest(lambda: self.AppendTab(pyauto.GURL(url)))
+    self._RunNewTabTest('NewTabPdfPage',
+                        lambda: self.AppendTab(pyauto.GURL(url)))
 
   def testNewTabFlash(self):
     """Measures time to open a new tab navigated to a flash page."""
     url = self.GetFileURLForDataPath('plugin', 'flash.swf')
-    self._RunNewTabTest(lambda: self.AppendTab(pyauto.GURL(url)))
+    self._RunNewTabTest('NewTabFlashPage',
+                        lambda: self.AppendTab(pyauto.GURL(url)))
 
   def test20Tabs(self):
     """Measures time to open 20 tabs."""
     self._RunNewTabTest(
+        '20TabsNewTabPage',
         lambda: self.AppendTab(pyauto.GURL('chrome://newtab')), num_tabs=20)
 
   def testV8BenchmarkSuite(self):
@@ -154,7 +189,7 @@ class PerfTest(pyauto.PyUITest):
         msg='Timed out when waiting for v8 benchmark score.')
     val = self.ExecuteJavascript(js, 0, 1)
     score = int(val[val.find(':') + 2:])
-    self._PrintSummaryResults(score, 'score')
+    self._PrintSummaryResults('V8Benchmark', score, 'score')
 
 
 if __name__ == '__main__':