Smoke test for tracing infrastructure in PyAuto

chrome/test/functional/tracing/tracer.py

+# Copyright (c) 2011 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.
+
+import unittest
+
+import pyauto_tracing
+import pyauto
+import tab_tracker
+
+from timeline_model import TimelineModel

[Nirnimesh, 2012/07/30 21:03:51]

This need not be in a separate section. Move to line 10

+
+import os
+
+class Tracer:
+  """The tracer class allows you to start and stop chrome and system tracing,
+  and get an instance of a TimelineModel which represents the results from a
+  trace.
+  """
+
+  def __init__(self, browser, tab_tracker):
+    """
+    Args:
+      browser: an instance of a PyUITest
+      tab_tracker: an instance of a TabTracker
+    """
+    self._browser = browser
+    self._tab_tracker = tab_tracker
+    self._tab_uuid = tab_tracker.CreateTab('chrome://tracing')
+
+    # I'm not happy with importing timeline_model_shim.js

[Nirnimesh, 2012/07/30 21:03:51]

Add a TODO?

+    # here. I'd rather pull it in from within TimelineModelProxy.
+    # tracing_test.js depends on timeline_model_shim.js however.
+    files = ["timeline_model_shim.js", "tracer.js"]
+    for fileName in files:
+      fileJs, fd = (None, None)
+      try:
+        fd = open(os.path.join(os.path.dirname(__file__), fileName), "r")
+        fileJs = fd.read()
+      finally:
+        if fd:
+          fd.close()
+      self._ExecuteJavascript(fileJs);
+
+  def __del__(self):
+    self._tab_tracker.ReleaseTab(self._tab_uuid)
+
+  def _ExecuteJavascript(self, js):
+    return self._browser.ExecuteJavascript(
+      js = js,
+      windex = self._tab_tracker.GetWindowIndex(),
+      tab_index = self._tab_tracker.GetTabIndex(self._tab_uuid)
+    )
+
+  def BeginTracing(self, system_tracing=True):
+    """Start tracing
+
+    Args:
+      system_tracing: whether or not to gather system traces along with chrome
+      traces.
+    """
+    self._ExecuteJavascript(
+      """
+        window.domAutomationController.send(
+          window.pyautoRecordTrace(%s)
+        );
+      """ % (
+        "true" if system_tracing else "false"
+      )
+    )
+
+  def EndTracing(self):
+    """End tracing and return a TimelineModel
+
+    Returns:
+      an instance of a TimelineModel which contains the results of the trace
+    """
+    return TimelineModel(
+      js_executor = self._ExecuteJavascript.__get__(self, Tracer),
+      shim_id = self._ExecuteJavascript(
+        """tracingController.endTracing();"""
+      )
+    )
+
+class TracerFactory:
+  """A TracerFactory is used to produce a Tracer
+
+  It's recommended to use the same TracerFactory to produce all Tracers so that
+  the same TabTracker can be used throughout
+
+  Args:
+    browser: an instance of a PyUITest"""

[Nirnimesh, 2012/07/30 21:03:51]

move """ to next line

+  def __init__(self, browser):
+    self._tab_tracker = tab_tracker.TabTracker(browser)
+    self._browser = browser
+
+  def Produce(self):
+    """Produce an instance of a Tracer"""
+    return Tracer(self._browser, self._tab_tracker)