blob: fc8adc9675e367badf48d3a8c032d0f261edd93c [file] [log] [blame]
# Copyright (C) 2011 Google Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
class AmountChangedPattern:
def __init__(self, compile_regex, index_for_zero_value):
self._regex = compile_regex
self._index_for_zero_value = index_for_zero_value
def match(self, path, diff_file):
examined_strings = set()
for diff_line in diff_file:
if diff_line[self._index_for_zero_value]:
continue
match = self._regex.search(diff_line[2])
if not match:
continue
matching_string = match.group(0)
if matching_string in examined_strings:
continue
if self._instance_difference(diff_file, matching_string) > 0:
return True
# Avoid reprocessing this same string.
examined_strings.add(matching_string)
return False
def _instance_difference(self, diff_file, matching_string):
'''Returns the difference between the number of string occurences in
the added lines and deleted lines (which one is subtracted from the
other depends on _index_for_zero_value).'''
count = 0
for diff_line in diff_file:
# If the line is unchanged, then don't examine it.
if diff_line[self._index_for_zero_value] and diff_line[1 - self._index_for_zero_value]:
continue
location_found = -len(matching_string)
while True:
location_found = diff_line[2].find(matching_string, location_found + len(matching_string))
if location_found == -1:
break
if not diff_line[self._index_for_zero_value]:
count += 1
else:
count -= 1
return count