[Predator] Add TouchCrashedFileMetaFeature.

appengine/findit/libs/gitiles/commit_util.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.
 
 import re
 
 CODE_REVIEW_URL_PATTERN = re.compile(
     '^(?:Review URL|Review-Url): (.*\d+).*$', re.IGNORECASE)
 COMMIT_POSITION_PATTERN = re.compile(
     '^Cr-Commit-Position: refs/heads/master@{#(\d+)}$', re.IGNORECASE)
@@ skipping 53 matching lines @@
   if not lines[0].lower().startswith('revert'):
     return None
 
   for line in reversed(lines):  # pragma: no cover
     # TODO: Handle cases where no reverted_revision in reverting message.
     reverted_revision_match = REVERTED_REVISION_PATTERN.match(line)
     if reverted_revision_match:
       return reverted_revision_match.group(1)
 
 
+# TODO(katesonia): Deprecate this copy (there is a copy in min_distance
+# feature), after scorer-based classfier got depecated.
 def DistanceBetweenLineRanges((start1, end1), (start2, end2)):
   """Given two ranges, compute the (unsigned) distance between them.
 
   Args:
     start1 (int): the first line included in the first range.
     end1 (int): the last line included in the first range. Must be
       greater than or equal to ``start1``.
     start2 (int): the first line included in the second range.
     end2 (int): the last line included in the second range. Must be
       greater than or equal to ``start1``.
 
   Returns:
     If the end of the earlier range comes before the start of the later
     range, then the difference between those points. Otherwise, returns
     zero (because the ranges overlap).
   """
   if end1 < start1:
     raise ValueError('the first range is empty: %d < %d' % (end1, start1))
   if end2 < start2:
     raise ValueError('the second range is empty: %d < %d' % (end2, start2))
   # There are six possible cases, but in all the cases where the two
   # ranges overlap, the latter two differences will be negative.
   return max(0, start2 - end1, start1 - end2)