Using decorator for power monitoring.

tools/perf/measurements/decorators.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.
+
+from metrics import power
+
+
+def Power(original_class):
+  """Decorator for adding power measurement to a measurement.
+
+  Example usage (always returns the same Foo instance):
+    @Power
+    class PageCycler(page_measurement.PageMeasurement):
+
+  Power measurement will then be added to this page measurement. Two separates
+  measurement will be done, one for page loading, and the other one for the
+  interaction with the page.
+  """
+
+  original__init__ = original_class.__init__
+  def new__init__(self, *args, **kws):
+    original__init__(self, *args, **kws)
+    self._load_power_metric = power.PowerMetric()
+    self._page_power_metric = power.PowerMetric()
+  original_class.__init__ = new__init__
+
+  originalCustomizeBrowserOptions = original_class.CustomizeBrowserOptions
+  def newCustomizeBrowserOptions(self, options):
+    originalCustomizeBrowserOptions(self, options)
+    power.PowerMetric.CustomizeBrowserOptions(options)
+  original_class.CustomizeBrowserOptions = newCustomizeBrowserOptions
+
+  originalWillNavigateToPage = original_class.WillNavigateToPage
+  def newWillNavigateToPage(self, page, tab):
+    originalWillNavigateToPage(self, page, tab)
+    self._load_power_metric.Start(page, tab)
+  original_class.WillNavigateToPage = newWillNavigateToPage
+
+  originalDidNavigateToPage = original_class.DidNavigateToPage
+  def newDidNavigateToPage(self, page, tab):
+    self._load_power_metric.Stop(page, tab)
+    originalDidNavigateToPage(self, page, tab)
+    self._page_power_metric.Start(page, tab)
+  original_class.DidNavigateToPage = newDidNavigateToPage
+
+  originalMeasurePage = original_class.MeasurePage
+  def newMeasurePage(self, page, tab, results):
+    self._page_power_metric.Stop(page, tab)
+    originalMeasurePage(self, page, tab, results)
+    self._load_power_metric.AddResults(tab, results, 'load_')
+    self._page_power_metric.AddResults(tab, results)
+  original_class.MeasurePage = newMeasurePage
+
+  return original_class