[Telemetry] Introduce SummarizableValue.

tools/telemetry/telemetry/value/histogram.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 json
 
 from telemetry.util import perf_tests_helper
 from telemetry import value as value_module
 from telemetry.value import histogram_util
+from telemetry.value import summarizable
 
 
 class HistogramValueBucket(object):
   def __init__(self, low, high, count=0):
     self.low = low
     self.high = high
     self.count = count
 
   def AsDict(self):
     return {
       'low': self.low,
       'high': self.high,
       'count': self.count
     }
 
   def ToJSONString(self):
     return '{%s}' % ', '.join([
       '"low": %i' % self.low,
       '"high": %i' % self.high,
       '"count": %i' % self.count])
 
-class HistogramValue(value_module.Value):
+class HistogramValue(summarizable.SummarizableValue):
   def __init__(self, page, name, units,
                raw_value=None, raw_value_json=None, important=True,
-               description=None, tir_label=None):
+               description=None, tir_label=None, improvement_direction=None):
     super(HistogramValue, self).__init__(page, name, units, important,
-                                         description, tir_label)
+                                         description, tir_label,
+                                         improvement_direction)
     if raw_value_json:
       assert raw_value == None, \
              'Don\'t specify both raw_value and raw_value_json'
       raw_value = json.loads(raw_value_json)
     if raw_value:
       self.buckets = []
       for bucket in histogram_util.GetHistogramBucketsFromRawValue(raw_value):
         self.buckets.append(HistogramValueBucket(
           low=bucket['low'],
           high=bucket['high'],
           count=bucket['count']))
     else:
       self.buckets = []
 
   def __repr__(self):
     if self.page:
       page_name = self.page.display_name
     else:
       page_name = 'None'
     return ('HistogramValue(%s, %s, %s, raw_json_string="%s", '
-            'important=%s, description=%s, tir_label=%s') % (
+            'important=%s, description=%s, tir_label=%s, '
+            'improvement_direction=%s') % (
                 page_name,
                 self.name, self.units,
                 self.ToJSONString(),
                 self.important,
                 self.description,
-                self.tir_label)
+                self.tir_label,
+                self.improvement_direction)
 
   def GetBuildbotDataType(self, output_context):
     if self._IsImportantGivenOutputIntent(output_context):
       return 'histogram'
     return 'unimportant-histogram'
 
   def GetBuildbotValue(self):
     # More buildbot insanity: perf_tests_results_helper requires the histogram
     # to be an array of size one.
     return [self.ToJSONString()]
@@ skipping 24 matching lines @@
 
   def AsDict(self):
     d = super(HistogramValue, self).AsDict()
     d['buckets'] = [b.AsDict() for b in self.buckets]
     return d
 
   @staticmethod
   def FromDict(value_dict, page_dict):
     kwargs = value_module.Value.GetConstructorKwArgs(value_dict, page_dict)
     kwargs['raw_value'] = value_dict
+    kwargs['improvement_direction'] = value_dict['improvement_direction']
 
     if 'tir_label' in value_dict:
       kwargs['tir_label'] = value_dict['tir_label']
 
     return HistogramValue(**kwargs)
 
   @classmethod
   def MergeLikeValuesFromSamePage(cls, values):
     assert len(values) > 0
     v0 = values[0]
     return HistogramValue(
         v0.page, v0.name, v0.units,
         raw_value_json=histogram_util.AddHistograms(
             [v.ToJSONString() for v in values]),
-        important=v0.important, tir_label=v0.tir_label)
+        important=v0.important, tir_label=v0.tir_label,
+        improvement_direction=v0.improvement_direction)
 
   @classmethod
   def MergeLikeValuesFromDifferentPages(cls, values):
     # Histograms cannot be merged across pages, at least for now. It should be
     # theoretically possible, just requires more work. Instead, return None.
     # This signals to the merging code that the data is unmergable and it will
     # cope accordingly.
     return None