| #!/usr/bin/env python3 | |
| ## | |
| ## Copyright (c) 2016, Alliance for Open Media. All rights reserved. | |
| ## | |
| ## This source code is subject to the terms of the BSD 2 Clause License and | |
| ## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License | |
| ## was not distributed with this source code in the LICENSE file, you can | |
| ## obtain it at www.aomedia.org/license/software. If the Alliance for Open | |
| ## Media Patent License 1.0 was not distributed with this source code in the | |
| ## PATENTS file, you can obtain it at www.aomedia.org/license/patent. | |
| ## | |
| """Classes for representing diff pieces.""" | |
| __author__ = "jkoleszar@google.com" | |
| import re | |
| class DiffLines(object): | |
| """A container for one half of a diff.""" | |
| def __init__(self, filename, offset, length): | |
| self.filename = filename | |
| self.offset = offset | |
| self.length = length | |
| self.lines = [] | |
| self.delta_line_nums = [] | |
| def Append(self, line): | |
| l = len(self.lines) | |
| if line[0] != " ": | |
| self.delta_line_nums.append(self.offset + l) | |
| self.lines.append(line[1:]) | |
| assert l+1 <= self.length | |
| def Complete(self): | |
| return len(self.lines) == self.length | |
| def __contains__(self, item): | |
| return item >= self.offset and item <= self.offset + self.length - 1 | |
| class DiffHunk(object): | |
| """A container for one diff hunk, consisting of two DiffLines.""" | |
| def __init__(self, header, file_a, file_b, start_a, len_a, start_b, len_b): | |
| self.header = header | |
| self.left = DiffLines(file_a, start_a, len_a) | |
| self.right = DiffLines(file_b, start_b, len_b) | |
| self.lines = [] | |
| def Append(self, line): | |
| """Adds a line to the DiffHunk and its DiffLines children.""" | |
| if line[0] == "-": | |
| self.left.Append(line) | |
| elif line[0] == "+": | |
| self.right.Append(line) | |
| elif line[0] == " ": | |
| self.left.Append(line) | |
| self.right.Append(line) | |
| elif line[0] == "\\": | |
| # Ignore newline messages from git diff. | |
| pass | |
| else: | |
| assert False, ("Unrecognized character at start of diff line " | |
| "%r" % line[0]) | |
| self.lines.append(line) | |
| def Complete(self): | |
| return self.left.Complete() and self.right.Complete() | |
| def __repr__(self): | |
| return "DiffHunk(%s, %s, len %d)" % ( | |
| self.left.filename, self.right.filename, | |
| max(self.left.length, self.right.length)) | |
| def ParseDiffHunks(stream): | |
| """Walk a file-like object, yielding DiffHunks as they're parsed.""" | |
| file_regex = re.compile(r"(\+\+\+|---) (\S+)") | |
| range_regex = re.compile(r"@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))?") | |
| hunk = None | |
| while True: | |
| line = stream.readline() | |
| if not line: | |
| break | |
| if hunk is None: | |
| # Parse file names | |
| diff_file = file_regex.match(line) | |
| if diff_file: | |
| if line.startswith("---"): | |
| a_line = line | |
| a = diff_file.group(2) | |
| continue | |
| if line.startswith("+++"): | |
| b_line = line | |
| b = diff_file.group(2) | |
| continue | |
| # Parse offset/lengths | |
| diffrange = range_regex.match(line) | |
| if diffrange: | |
| if diffrange.group(2): | |
| start_a = int(diffrange.group(1)) | |
| len_a = int(diffrange.group(3)) | |
| else: | |
| start_a = 1 | |
| len_a = int(diffrange.group(1)) | |
| if diffrange.group(5): | |
| start_b = int(diffrange.group(4)) | |
| len_b = int(diffrange.group(6)) | |
| else: | |
| start_b = 1 | |
| len_b = int(diffrange.group(4)) | |
| header = [a_line, b_line, line] | |
| hunk = DiffHunk(header, a, b, start_a, len_a, start_b, len_b) | |
| else: | |
| # Add the current line to the hunk | |
| hunk.Append(line) | |
| # See if the whole hunk has been parsed. If so, yield it and prepare | |
| # for the next hunk. | |
| if hunk.Complete(): | |
| yield hunk | |
| hunk = None | |
| # Partial hunks are a parse error | |
| assert hunk is None |