[IndexedDB] Adding traces, perf tests

tools/telemetry/telemetry/web_perf/metrics/trace_event_aggregator.py

Index: tools/telemetry/telemetry/web_perf/metrics/trace_event_aggregator.py
diff --git a/tools/telemetry/telemetry/web_perf/metrics/trace_event_aggregator.py b/tools/telemetry/telemetry/web_perf/metrics/trace_event_aggregator.py
new file mode 100644
index 0000000000000000000000000000000000000000..6627e822db1be76633cb56ded760842bdf6316ca
--- /dev/null
+++ b/tools/telemetry/telemetry/web_perf/metrics/trace_event_aggregator.py
@@ -0,0 +1,100 @@
+# Copyright 2015 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 telemetry.value import list_of_scalar_values
+from telemetry.value import scalar
+from telemetry.web_perf.metrics import timeline_based_metric
+
+class TraceEventAggregatorInput(object):

[cmumford, 2015/08/03 17:31:34]

This class doesn't seem to do anything. Why not simply use a dictionary?

[dmurph, 2015/08/05 15:30:33]

I'm going to defer to you and Ned for this. It seems nice to have the
documentation, but maybe this is easier as a dictionary? I don't know python. 
How do I define a dictionary with the documentation?

+  """Input for the TraceEventAggregator.
+
+    event_name: The name of the event to track.
+    list_metric_name: The name of the list metric name, which accumulates
+                      all of the times of the events.
+    list_metric_description: Description of the list metric.
+    units: Units for the list metric.
+    count_metric_name: The name of the metric that is the count of the events.
+    count_metric_description: The description of the count metric.
+    process_name: The name of the process to inspect for the trace events.
+  """
+  def __init__(self, event_name, list_metric_name,
+               list_metric_description, units, count_metric_name,
+               count_metric_description, process_name=None):
+    self.event_name = event_name
+    self.list_metric_name = list_metric_name
+    self.list_metric_description = list_metric_description
+    self.units = units
+    self.count_metric_name = count_metric_name
+    self.count_metric_description = count_metric_description
+    self.process_name = process_name
+
+
+class TraceEventAggregator(timeline_based_metric.TimelineBasedMetric):
+  """Reports durations and counts of given trace events.

[nednguyen, 2015/08/03 16:12:21]

This seems similar to single_event in web_perf/metrics. Though I like your
version better.

[dmurph, 2015/08/05 15:30:33]

yay!  I tried to make it as performant as possible by filtering as much as it
possibly can.

+  """
+
+  def __init__(self, trace_event_aggregator_inputs=[]):
+    super(TraceEventAggregator, self).__init__()
+    self._inputs_by_process_name = dict()
+    self._IndexNewInputs(trace_event_aggregator_inputs)
+
+  def AddInput(self, trace_event_aggregator_input):
+    self._IndexNewInputs([trace_event_aggregator_input])
+
+  def _IndexNewInputs(self, input_list):
+    for input_obj in input_list:
+      if input_obj.process_name not in self._inputs_by_process_name:
+        self._inputs_by_process_name[input_obj.process_name] = list()
+      self._inputs_by_process_name[input_obj.process_name].append(input_obj)
+
+  @staticmethod
+  def ThreadDurationIfPresent(event):
+    if event.thread_duration:

[cmumford, 2015/08/03 17:31:34]

Could you ever have a thread_duration of zero?

[dmurph, 2015/08/05 15:30:33]

I imagine so.

+      return event.thread_duration
+    else:
+      return event.end - event.start
+
+  def AddResults(self, model, renderer_thread, interactions, results):
+    assert interactions
+    # NOTE: This means duplicate names can cause problems.
+    for p in model.GetAllProcesses():
+      if (p.name is renderer_thread.name and
+          None in self._inputs_by_process_name):
+        self._AddResultsInternal(renderer_thread.parent.IterAllSlices(),
+                                 interactions, results,
+                                 self._inputs_by_process_name[None])
+      elif p.name in self._inputs_by_process_name:
+        self._AddResultsInternal(p.parent.IterAllSlices(),
+                                 interactions, results,
+                                 self._inputs_by_process_name[p.name])
+
+  def _AddResultsInternal(self, events, interactions, results, inputs):
+    times_by_event_name = dict([[input_obj.event_name, []]
+                                for input_obj in inputs])
+    inputs_by_event_name = dict([[input_obj.event_name, input_obj]
+                                 for input_obj in inputs])
+    for event in events:
+      if event.name not in inputs_by_event_name or not any(
+          interaction.start <= event.start <= interaction.end
+          for interaction in interactions):
+        continue
+      times_by_event_name[event.name].append(
+          self.ThreadDurationIfPresent(event))
+
+    for (event_name, times) in times_by_event_name.iteritems():
+      input_for_event = inputs_by_event_name[event_name]
+      results.AddValue(scalar.ScalarValue(
+        page=results.current_page,
+        name=input_for_event.count_metric_name,
+        units='count',
+        value=len(times),
+        description=input_for_event.count_metric_description))
+      if len(times) == 0:

[cmumford, 2015/08/03 17:31:34]

Not pythonic. Just do:

if not times:
  continue

[dmurph, 2015/08/05 15:30:33]

Done.

+        continue
+      results.AddValue(list_of_scalar_values.ListOfScalarValues(
+        page=results.current_page,
+        name=input_for_event.list_metric_name,
+        units=input_for_event.units,
+        values=times,
+        description=input_for_event.list_metric_description))