telemtry: better error message for not enought frames cases.

tools/perf/metrics/rendering_stats_unittest.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.
 
 import random
 import unittest
 
 from metrics.rendering_stats import UI_COMP_NAME, BEGIN_COMP_NAME, END_COMP_NAME
 from metrics.rendering_stats import GetScrollInputLatencyEvents
 from metrics.rendering_stats import ComputeMouseWheelScrollLatency
 from metrics.rendering_stats import ComputeTouchScrollLatency
 from metrics.rendering_stats import HasRenderingStats
 from metrics.rendering_stats import RenderingStats
+from metrics.rendering_stats import NotEnoughFramesError
 import telemetry.core.timeline.bounds as timeline_bounds
 from telemetry.core.timeline import model
 import telemetry.core.timeline.async_slice as tracing_async_slice
 
 
 class MockTimer(object):
   """A mock timer class which can generate random durations.
 
   An instance of this class is used as a global timer to generate random
   durations for stats and consistent timestamps for all mock trace events.
@@ skipping 193 matching lines @@
     process_without_frames.FinalizeImport()
     self.assertFalse(HasRenderingStats(thread_without_frames))
 
     # A process with rendering stats and frames in them
     process_with_frames = timeline.GetOrCreateProcess(pid = 3)
     thread_with_frames = process_with_frames.GetOrCreateThread(tid = 31)
     AddImplThreadRenderingStats(timer, thread_with_frames, True, None)
     process_with_frames.FinalizeImport()
     self.assertTrue(HasRenderingStats(thread_with_frames))
 
+  def testRangeWithoutFrames(self):
+    timer = MockTimer()
+    timeline = model.TimelineModel()
+
+    # Create a renderer process, with a main thread and impl thread.
+    renderer = timeline.GetOrCreateProcess(pid = 2)
+    renderer_main = renderer.GetOrCreateThread(tid = 21)
+    renderer_compositor = renderer.GetOrCreateThread(tid = 22)
+
+    # Create 10 main and impl rendering stats events for Action A.
+    timer.Advance(2, 4)
+    renderer_main.BeginSlice('webkit.console', 'ActionA', timer.Get(), '')
+    for i in xrange(0, 10):
+      first = (i == 0)
+      AddMainThreadRenderingStats(timer, renderer_main, first, None)
+      AddImplThreadRenderingStats(timer, renderer_compositor, first, None)
+    timer.Advance(2, 4)
+    renderer_main.EndSlice(timer.Get())
+
+    # Create 5 main and impl rendering stats events not within any action.
+    for i in xrange(0, 5):
+      first = (i == 0)
+      AddMainThreadRenderingStats(timer, renderer_main, first, None)
+      AddImplThreadRenderingStats(timer, renderer_compositor, first, None)
+
+    # Create Action B without any frames. This should trigger
+    # NotEnoughFramesError when the RenderingStats object is created.
+    timer.Advance(2, 4)
+    renderer_main.BeginSlice('webkit.console', 'ActionB', timer.Get(), '')
+    timer.Advance(2, 4)
+    renderer_main.EndSlice(timer.Get())
+
+    renderer.FinalizeImport()
+
+    timeline_markers = timeline.FindTimelineMarkers(['ActionA', 'ActionB'])
+    timeline_ranges = [ timeline_bounds.Bounds.CreateFromEvent(marker)
+                        for marker in timeline_markers ]
+    self.assertRaises(NotEnoughFramesError, RenderingStats,
+                      renderer, None, timeline_ranges)
+
   def testFromTimeline(self):
     timeline = model.TimelineModel()
 
     # Create a browser process and a renderer process, and a main thread and
     # impl thread for each.
     browser = timeline.GetOrCreateProcess(pid = 1)
     browser_main = browser.GetOrCreateThread(tid = 11)
     browser_compositor = browser.GetOrCreateThread(tid = 12)
     renderer = timeline.GetOrCreateProcess(pid = 2)
     renderer_main = renderer.GetOrCreateThread(tid = 21)
@@ skipping 163 matching lines @@
     self.assertEquals(touch_scroll_events,
                       ref_latency_stats.touch_scroll_events)
     self.assertEquals(js_touch_scroll_events,
                       ref_latency_stats.js_touch_scroll_events)
     self.assertEquals(ComputeMouseWheelScrollLatency(mouse_wheel_scroll_events),
                       ref_latency_stats.mouse_wheel_scroll_latency)
     self.assertEquals(ComputeTouchScrollLatency(touch_scroll_events),
                       ref_latency_stats.touch_scroll_latency)
     self.assertEquals(ComputeTouchScrollLatency(js_touch_scroll_events),
                       ref_latency_stats.js_touch_scroll_latency)