sdk/platform-tools/systrace/catapult/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py

   1 # Copyright 2014 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5
   6 class TimelineBasedMetricException(Exception):
   7   """Exception that can be thrown from metrics that implements
   8      TimelineBasedMetric to indicate a problem arose when computing the metric.
   9      """
  10
  11
  12 def _TimeRangesHasOverlap(iterable_time_ranges):
  13   """ Returns True if there is are overlapped ranges in time ranges.
  14   iterable_time_ranges: an iterable of time ranges. Each time range is a
  15   tuple (start time, end time).
  16   """
  17   # Sort the ranges by the start time
  18   sorted_time_ranges = sorted(iterable_time_ranges)
  19   last_range = sorted_time_ranges[0]
  20   for current_range in sorted_time_ranges[1:]:
  21     start_current_range = current_range[0]
  22     end_last_range = last_range[1]
  23     if start_current_range < end_last_range:
  24       return True
  25     last_range = current_range
  26   return False
  27
  28
  29 def IsEventInInteractions(event, interaction_records):
  30   """ Return True if event is in any of the interaction records' time range.
  31
  32   Args:
  33     event: an instance of telemetry.timeline.event.TimelineEvent.
  34     interaction_records: a list of interaction records, whereas each record is
  35       an instance of
  36       telemetry.web_perf.timeline_interaction_record.TimelineInteractionRecord.
  37
  38   Returns:
  39     True if |event|'s start & end time is in any of the |interaction_records|'s
  40     time range.
  41   """
  42   return any(ir.start <= event.start and ir.end >= event.end for ir
  43              in interaction_records)
  44
  45
  46 class TimelineBasedMetric(object):
  47
  48   def __init__(self):
  49     """Computes metrics from a telemetry.timeline Model and a range
  50
  51     """
  52     super(TimelineBasedMetric, self).__init__()
  53
  54   def AddResults(self, model, renderer_thread, interaction_records, results):
  55     """Computes and adds metrics for the interaction_records' time ranges.
  56
  57     The override of this method should compute results on the data **only**
  58     within the interaction_records' start and end time ranges.
  59
  60     Args:
  61       model: An instance of telemetry.timeline.model.TimelineModel.
  62       interaction_records: A list of instances of TimelineInteractionRecord. If
  63         the override of this method doesn't support overlapped ranges, use
  64         VerifyNonOverlappedRecords to check that no records are overlapped.
  65       results: An instance of page.PageTestResults.
  66
  67     """
  68     raise NotImplementedError()
  69
  70   def AddWholeTraceResults(self, model, results):
  71     """Computes and adds metrics corresponding to the entire trace.
  72
  73     Override this method to compute results that correspond to the whole trace.
  74
  75     Args:
  76       model: An instance of telemetry.timeline.model.TimelineModel.
  77       results: An instance of page.PageTestResults.
  78     """
  79     pass
  80
  81   def VerifyNonOverlappedRecords(self, interaction_records):
  82     """This raises exceptions if interaction_records contain overlapped ranges.
  83     """
  84     if _TimeRangesHasOverlap(((r.start, r.end) for r in interaction_records)):
  85       raise TimelineBasedMetricException(
  86           'This metric does not support interaction records with overlapped '
  87           'time range.')