clovis: Identify prefetchable resources from dependencies and tracing.

tools/android/loading/tracing.py

 # Copyright 2016 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.
 
 """Monitor tracing events on chrome via chrome remote debugging."""
 
 import bisect
 import itertools
 import logging
 import operator
@@ skipping 73 matching lines @@
       sample and counter) events are never included. Event end times are
       exclusive, so that an event ending at the usec parameter will not be
       returned.
     """
     self._IndexEvents()
     return self._interval_tree.EventsAt(msec)
 
   def ToJsonDict(self):
     return {'events': [e.ToJsonDict() for e in self._events]}
 
-  def TracingTrackForThread(self, pid_tid):
-    """Returns a new TracingTrack with only the events from a given thread.
+  def Filter(self, pid=None, tid=None, categories=None):
+    """Returns a new TracingTrack with a subset of the events.
 
     Args:
-      pid_tid: ((int, int) PID and TID.
-
-    Returns:
-      A new instance of TracingTrack.
+      pid: (int or None) Selects events from this PID.
+      tid: (int or None) Selects events from this TID.
+      categories: (set([str]) or None) Selects events belonging to one of the
+                  categories.
     """
-    (pid, tid) = pid_tid
-    events = [e for e in self._events
-              if (e.tracing_event['pid'] == pid
-                  and e.tracing_event['tid'] == tid)]
+    events = self._events
+    if pid is not None:
+      events = filter(lambda e : e.tracing_event['pid'] == pid, events)
+    if tid is not None:
+      events = filter(lambda e : e.tracing_event['tid'] == tid, events)
+    if categories is not None:
+      events = filter(
+          lambda e : set(e.category.split(',')).intersection(categories),
+          events)
     tracing_track = TracingTrack(None)
     tracing_track._events = events
     return tracing_track
 
   @classmethod
   def FromJsonDict(cls, json_dict):
     assert 'events' in json_dict
     events = [Event(e) for e in json_dict['events']]
     tracing_track = TracingTrack(None)
     tracing_track._events = events
@@ skipping 372 matching lines @@
     self._left = _IntervalTree(self.start, left_end, left_events)
     self._right = _IntervalTree(right_start, self.end, right_events)
 
   def _IsLeaf(self):
     return self._left is None
 
   @classmethod
   def _Overlaps(cls, event, start, end):
     return (min(end, event.end_msec) - max(start, event.start_msec) > 0
             or start <= event.start_msec < end)  # For instant events.