[Findit] Pass changed files info to Fracas, 2 face design.

appengine/findit/crash/scorers/aggregators.py

Index: appengine/findit/crash/scorers/aggregators.py
diff --git a/appengine/findit/crash/scorers/aggregators.py b/appengine/findit/crash/scorers/aggregators.py
new file mode 100644
index 0000000000000000000000000000000000000000..728579130f37b4f8271f3e4d08ab0a739cd86b60
--- /dev/null
+++ b/appengine/findit/crash/scorers/aggregators.py
@@ -0,0 +1,105 @@
+# 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.
+
+"""Aggregator aggregates scorer results list passed in."""
+
+class Aggregator(object):
+
+  def Aggregate(self, data_list):
+    raise NotImplementedError()
+
+  def __call__(self, data_list):
+    data_list = filter(lambda data: not data is None, data_list)
+    if not data_list:
+      return None
+
+    return self.Aggregate(data_list)
+
+
+# TODO(katesonia): Compare this mutiply aggregator with a vector of scores
+# aggregator later.
+class Multiplier(Aggregator):
+
+  def Aggregate(self, data_list):
+    result = 1.0
+    for data in data_list:
+      result *= data
+
+    return result
+
+
+class IdentityAggregator(Aggregator):
+
+  def Aggregate(self, data_list):
+    return data_list
+
+
+class ChangedFilesAggregator(Aggregator):
+  """Aggregates a list of changed files got from many scorers.
+
+  Note: This Aggregator only aggregates the info part of each changed file.
+
+  For example, the data_list is:
+  [
+      [
+          {
+              'file': 'f1',
+              'blame_url': 'https://blame1',
+              'info': 'f1 info scorer1'
+          },
+          {
+              'file': 'f2',
+              'blame_url': 'https://blame2',
+              'info': 'f2 info scorer1'
+          }
+      ],
+      [
+          {
+              'file': 'f1',
+              'blame_url': 'https://blame1',
+              'info': 'f1 info scorer2'
+          },
+          {
+              'file': 'f2',
+              'blame_url': 'https://blame2',
+              'info': 'f2 info scorer2'
+          }
+      ]
+  ]
+
+  Aggregated result should be:
+  [
+      {
+          'file': 'f1',
+          'blame_url': 'https://blame1',
+          'info': 'f1 info scorer1\nf1 info scorer2'
+      },
+      {
+          'file': 'f2',
+          'blame_url': 'https://blame2',
+          'info': 'f2 info scorer1\nf2 info scorer2'
+      }
+  ]
+  """
+
+  def Aggregate(self, data_list):
+
+    def AggregateFileInfos(file_info_list):
+      """Aggregates file infos from different scorers for one file."""
+      infos = []
+      for file_info in file_info_list:
+        if file_info['info']:
+          infos.append(file_info['info'])
+
+      return {
+          'file': file_info_list[0]['file'],
+          'blame_url': file_info_list[0]['blame_url'],
+          'info': '\n'.join(infos)
+      }
+
+    aggregated_changed_files = []
+    for data in zip(*data_list):
+      aggregated_changed_files.append(AggregateFileInfos(data))
+
+    return aggregated_changed_files