[Findit] Reorganizing findit_for_*.py

appengine/findit/crash/test/occurrence_test.py

 # 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.
 
 from common import constants
 from common.pipeline_wrapper import pipeline_handlers
-from crash.classifier import Occurrence
-from crash.classifier import Classifier
-from crash.classifier import DefaultRankFunction
+from crash.occurrence import Occurrence
+from crash.occurrence import DefaultOccurrenceRanking
+from crash.occurrence import RankByOccurrence
 from crash.stacktrace import StackFrame
 from crash.stacktrace import CallStack
 from crash.results import Result
 from crash.test.crash_testcase import CrashTestCase
 
 
-class DummyClassifier(Classifier):
+class DummyClassifier(object):
 
   def GetClassFromStackFrame(self, frame):
     if frame.dep_path == 'src/':
       return 'class_1'
 
     return 'class_2'
 
-  def GetClassFromResult(self, result):  # pragma: no cover.
+  def GetClassFromResult(self, _result):  # pragma: no cover.
     return 'class_3'
 
   def Classify(self, results, crash_stack):
-    class_list = self._Classify(results, crash_stack, 4, 1)
+    top_n_frames = 4
+    if results:
+      classes = map(self.GetClassFromResult, results[:top_n_frames])
+    else:
+      classes = map(self.GetClassFromStackFrame, crash_stack[:top_n_frames])
+
+    class_list = RankByOccurrence(classes, 1)
     if class_list:
       return class_list[0]
 
     return ''
 
 
 class ClassifierTest(CrashTestCase):
 
-  def testDefaultRankFunction(self):
-    self.assertEqual(DefaultRankFunction(Occurrence('c1', [0])),
+  def testDefaultOccurrenceRanking(self):
+    self.assertEqual(DefaultOccurrenceRanking(Occurrence('c1', [0])),
         (-1, 0))
-    self.assertEqual(DefaultRankFunction(Occurrence('c1', [0, 1])),
+    self.assertEqual(DefaultOccurrenceRanking(Occurrence('c1', [0, 1])),
         (-float('inf'), 0))
 
   def testClassifyCrashStack(self):
     dummy_classifier = DummyClassifier()
 
     crash_stack = CallStack(0)
     self.assertEqual(dummy_classifier.Classify([], crash_stack), '')
 
     crash_stack.extend(
         [StackFrame(0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]),
@@ skipping 15 matching lines @@
 
     result = Result(self.GetDummyChangeLog(), 'src/')
     result.file_to_stack_infos = {
         'f0.cc': [(StackFrame(
             0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]), 0)]
     }
 
     self.assertEqual(dummy_classifier.Classify([result], CallStack(0)),
                      'class_3')
 
-