blob: 3a9ea9224f7cda0d2f81fd3db2f25c304d5f3821 [file] [log] [blame]
# Copyright (C) 2009 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
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""WebKit's Python module for interacting with patches."""
import logging
import re
_log = logging.getLogger(__name__)
# FIXME: This is broken. We should compile our regexps up-front
# instead of using a custom cache.
_regexp_compile_cache = {}
# FIXME: This function should be removed.
def match(pattern, string):
"""Matches the string with the pattern, caching the compiled regexp."""
if not pattern in _regexp_compile_cache:
_regexp_compile_cache[pattern] = re.compile(pattern)
return _regexp_compile_cache[pattern].match(string)
# FIXME: This belongs on DiffParser (e.g. as to_svn_diff()).
def git_diff_to_svn_diff(line):
"""Converts a git formatted diff line to a svn formatted line.
Args:
line: A string representing a line of the diff.
"""
# FIXME: This list should be a class member on DiffParser.
# These regexp patterns should be compiled once instead of every time.
conversion_patterns = (("^diff --git \w/(.+) \w/(?P<FilePath>.+)", lambda matched: "Index: " + matched.group('FilePath') + "\n"),
("^new file.*", lambda matched: "\n"),
("^index (([0-9a-f]{7}\.\.[0-9a-f]{7})|([0-9a-f]{40}\.\.[0-9a-f]{40})) [0-9]{6}", lambda matched: "===================================================================\n"),
("^--- \w/(?P<FilePath>.+)", lambda matched: "--- " + matched.group('FilePath') + "\n"),
("^\+\+\+ \w/(?P<FilePath>.+)", lambda matched: "+++ " + matched.group('FilePath') + "\n"))
for pattern, conversion in conversion_patterns:
matched = match(pattern, line)
if matched:
return conversion(matched)
return line
# This function exists so we can unittest get_diff_converter function
def svn_diff_to_svn_diff(line):
return line
# FIXME: This method belongs on DiffParser
def get_diff_converter(lines):
"""Gets a converter function of diff lines.
Args:
lines: The lines of a diff file.
If this line is git formatted, we'll return a
converter from git to SVN.
"""
for i, line in enumerate(lines[:-1]):
# Stop when we find the first patch
if line[:3] == "+++" and lines[i + 1] == "---":
break
if match(r"^diff --git \w/", line):
return git_diff_to_svn_diff
return svn_diff_to_svn_diff
_INITIAL_STATE = 1
_DECLARED_FILE_PATH = 2
_PROCESSING_CHUNK = 3
class DiffFile(object):
"""Contains the information for one file in a patch.
The field "lines" is a list which contains tuples in this format:
(deleted_line_number, new_line_number, line_string)
If deleted_line_number is zero, it means this line is newly added.
If new_line_number is zero, it means this line is deleted.
"""
# FIXME: Tuples generally grow into classes. We should consider
# adding a DiffLine object.
def added_or_modified_line_numbers(self):
# This logic was moved from patchreader.py, but may not be
# the right API for this object long-term.
return [line[1] for line in self.lines if not line[0]]
def __init__(self, filename):
self.filename = filename
self.lines = []
def add_new_line(self, line_number, line):
self.lines.append((0, line_number, line))
def add_deleted_line(self, line_number, line):
self.lines.append((line_number, 0, line))
def add_unchanged_line(self, deleted_line_number, new_line_number, line):
self.lines.append((deleted_line_number, new_line_number, line))
# If this is going to be called DiffParser, it should be a re-useable parser.
# Otherwise we should rename it to ParsedDiff or just Diff.
class DiffParser(object):
"""A parser for a patch file.
The field "files" is a dict whose key is the filename and value is
a DiffFile object.
"""
def __init__(self, diff_input):
"""Parses a diff.
Args:
diff_input: An iterable object.
"""
self.files = self._parse_into_diff_files(diff_input)
# FIXME: This function is way too long and needs to be broken up.
def _parse_into_diff_files(self, diff_input):
files = {}
state = _INITIAL_STATE
current_file = None
old_diff_line = None
new_diff_line = None
transform_line = get_diff_converter(diff_input)
for line in diff_input:
line = line.rstrip("\n")
line = transform_line(line)
file_declaration = match(r"^Index: (?P<FilePath>.+)", line)
if file_declaration:
filename = file_declaration.group('FilePath')
current_file = DiffFile(filename)
files[filename] = current_file
state = _DECLARED_FILE_PATH
continue
lines_changed = match(r"^@@ -(?P<OldStartLine>\d+)(,\d+)? \+(?P<NewStartLine>\d+)(,\d+)? @@", line)
if lines_changed:
if state != _DECLARED_FILE_PATH and state != _PROCESSING_CHUNK:
_log.error('Unexpected line change without file path '
'declaration: %r' % line)
old_diff_line = int(lines_changed.group('OldStartLine'))
new_diff_line = int(lines_changed.group('NewStartLine'))
state = _PROCESSING_CHUNK
continue
if state == _PROCESSING_CHUNK:
if line.startswith('+'):
current_file.add_new_line(new_diff_line, line[1:])
new_diff_line += 1
elif line.startswith('-'):
current_file.add_deleted_line(old_diff_line, line[1:])
old_diff_line += 1
elif line.startswith(' '):
current_file.add_unchanged_line(old_diff_line, new_diff_line, line[1:])
old_diff_line += 1
new_diff_line += 1
elif line == '\\ No newline at end of file':
# Nothing to do. We may still have some added lines.
pass
else:
_log.error('Unexpected diff format when parsing a '
'chunk: %r' % line)
return files