Smoke test for tracing infrastructure in PyAuto

chrome/test/functional/tracing/timeline_model.py

Index: chrome/test/functional/tracing/timeline_model.py
diff --git a/chrome/test/functional/tracing/timeline_model.py b/chrome/test/functional/tracing/timeline_model.py
new file mode 100644
index 0000000000000000000000000000000000000000..e655024633caee715ac6d0b046e6d369dd567614
--- /dev/null
+++ b/chrome/test/functional/tracing/timeline_model.py
@@ -0,0 +1,62 @@
+# Copyright (c) 2011 The Chromium Authors. All rights reserved.

[Nirnimesh, 2012/07/31 20:05:57]

2012

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import json
+import os
+
+def escape_for_quoted_javascript_execution(js):

[Nirnimesh, 2012/07/31 20:05:57]

CapitalizeAndRemoveSpaces

Prefix _ for private functions

+    # Poor man's string escape.
+    return js.replace("'", "\\'");
+
+
+class TimelineModelProxy:
+  """A proxy for the TimelineModel class located in V8 in a chrome://tracing

[Nirnimesh, 2012/07/31 20:05:57]

Make it fit within 1 line please.

+  tab.
+  """
+  def __init__(self, js_executor, shim_id):
+    self._js_executor = js_executor
+    self._shim_id = shim_id
+
+  # Warning: The JSON serialization process removes cyclic references.
+  # TODO(eatnumber): regenerate these cyclic references on deserialization.
+  def _CallModelMethod(self, method_name, *args):
+    result = self._js_executor(
+      """

[Nirnimesh, 2012/07/31 20:05:57]

Can be moved to previous line

+        window.timelineModelShims['%s'].invokeMethod('%s', '%s')
+      """ % (

[Nirnimesh, 2012/07/31 20:05:57]

indent 2 more chars to the right

+        self._shim_id,
+        escape_for_quoted_javascript_execution(method_name),
+        escape_for_quoted_javascript_execution(json.dumps(args))
+      )
+    )
+    if result["success"]:

[Nirnimesh, 2012/07/31 20:05:57]

use ' for quoting

+      return result["data"]
+    # TODO(eatnumber): Make these exceptions more reader friendly.
+    raise Exception(result)

[Nirnimesh, 2012/07/31 20:05:57]

RuntimeError

+
+  def __del__(self):
+    self._js_executor(
+      """

[Nirnimesh, 2012/07/31 20:05:57]

Needs to be indented 4 chars wrt previous line

[Russ Harmon, 2012/07/31 20:54:18]

It doesn't make sense to further indent this as there is no additional enclosing
scope.

From PEP8: "Continuation lines should align wrapped elements either vertically
using Python's implicit line joining inside parentheses, brackets and braces, or
using a hanging indent. When using a hanging indent the following considerations
should be applied; there should be no arguments on the first line and further
indentation should be used to clearly distinguish itself as a continuation
line."

This code uses a single hanging indent as PEP8 recommends. Since the next
non-continuation line has a lesser indentation level, it is clearly
distinguished.

[Nirnimesh, 2012/07/31 21:15:06]

Chromium python style is based loosely on google python style guide.
For hanging indent, it specifically calls for indentation by 4 spaces
http://google-styleguide.googlecode.com/svn/trunk/pyguide.html?showone=Indent...

+        window.timelineModelShims['%s'] = undefined;
+        window.domAutomationController.send('');
+      """ % self._shim_id
+    )
+
+  def GetAllThreads(self):
+    return self._CallModelMethod("getAllThreads")
+
+  def GetAllCpus(self):
+    return self._CallModelMethod("getAllCpus")
+
+  def GetAllProcesses(self):
+    return self._CallModelMethod("getAllProcesses")
+
+  def GetAllCounters(self):
+    return self._CallModelMethod("getAllCounters")
+
+  def FindAllThreadsNamed(self, name):
+    return self._CallModelMethod("findAllThreadsNamed", name);
+
+# Alias TimelineModel to TimelineModelProxy for convenience.
+TimelineModel = TimelineModelProxy