[telemetry] Timeline model cleanups

tools/telemetry/telemetry/core/timeline/counter.py

 # Copyright 2013 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.
 
-class Counter(object):
-  ''' Stores all the samples for a given counter.
-  '''
+import telemetry.core.timeline.event_container as event_container
+
+# Doesnt' inherit from TimelineEvent because its only a temporary wrapper of a

[Tim Song, 2013/07/18 22:56:36]

typo here for Doesn't

+# counter sample into an event. During stable operation, the samples are stored
+# a dense array of values rather than in the long-form done by an Event.
+class CounterSample(object):
+  def __init__(self, counter, sample_index):
+    self._counter = counter
+    self._sample_index = sample_index
+
+  @property
+  def name(self):
+    return None
+
+  @property
+  def start(self):
+    return self._counter.timestamps[self._sample_index]
+
+  @start.setter
+  def start(self, start):
+    self._counter.timestamps[self._sample_index] = start
+
+  @property
+  def duration(self):
+    return 0
+
+  @property
+  def end(self):
+    return self.start
+
+
+class Counter(event_container.TimelineEventContainer):
+  """ Stores all the samples for a given counter.
+  """
   def __init__(self, parent, category, name):
-    self.parent = parent
+    super(Counter, self).__init__(name, parent)
+    self.category = category
     self.full_name  = category + '.' + name
-    self.category = category
-    self.name = name
     self.samples = []
     self.timestamps = []
     self.series_names = []
     self.totals = []
     self.max_total = 0
-    self._bounds = None
 
-  @property
-  def min_timestamp(self):
-    if not self._bounds:
-      self.UpdateBounds()
-    return self._bounds[0]
+  def IterChildContainers(self):
+    return
+    yield # pylint: disable=W0101
 
-  @property
-  def max_timestamp(self):
-    if not self._bounds:
-      self.UpdateBounds()
-    return self._bounds[1]
+  def IterEventsInThisContainer(self):
+    for i in range(len(self.timestamps)):
+      yield CounterSample(self, i)
 
   @property
   def num_series(self):
     return len(self.series_names)
 
   @property
   def num_samples(self):
     return len(self.timestamps)
 
-  def UpdateBounds(self):
+  def FinalizeImport(self):
     if self.num_series * self.num_samples != len(self.samples):
       raise ValueError(
           'Length of samples must be a multiple of length of timestamps.')
 
     self.totals = []
     self.max_total = 0
     if not len(self.samples):
       return
 
-    self._bounds = (self.timestamps[0], self.timestamps[-1])
-
     max_total = None
     for i in xrange(self.num_samples):
       total = 0
       for j in xrange(self.num_series):
         total += self.samples[i * self.num_series + j]
         self.totals.append(total)
       if max_total is None or total > max_total:
         max_total = total
     self.max_total = max_total
-