intersect-diffs.py (2488B)
1 #!/usr/bin/env python3 2 ## 3 ## Copyright (c) 2016, Alliance for Open Media. All rights reserved. 4 ## 5 ## This source code is subject to the terms of the BSD 2 Clause License and 6 ## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License 7 ## was not distributed with this source code in the LICENSE file, you can 8 ## obtain it at www.aomedia.org/license/software. If the Alliance for Open 9 ## Media Patent License 1.0 was not distributed with this source code in the 10 ## PATENTS file, you can obtain it at www.aomedia.org/license/patent. 11 ## 12 """Calculates the "intersection" of two unified diffs. 13 14 Given two diffs, A and B, it finds all hunks in B that had non-context lines 15 in A and prints them to stdout. This is useful to determine the hunks in B that 16 are relevant to A. The resulting file can be applied with patch(1) on top of A. 17 """ 18 19 __author__ = "jkoleszar@google.com" 20 21 import sys 22 23 import diff 24 25 26 def FormatDiffHunks(hunks): 27 """Re-serialize a list of DiffHunks.""" 28 r = [] 29 last_header = None 30 for hunk in hunks: 31 this_header = hunk.header[0:2] 32 if last_header != this_header: 33 r.extend(hunk.header) 34 last_header = this_header 35 else: 36 r.extend(hunk.header[2]) 37 r.extend(hunk.lines) 38 r.append("\n") 39 return "".join(r) 40 41 42 def ZipHunks(rhs_hunks, lhs_hunks): 43 """Join two hunk lists on filename.""" 44 for rhs_hunk in rhs_hunks: 45 rhs_file = rhs_hunk.right.filename.split("/")[1:] 46 47 for lhs_hunk in lhs_hunks: 48 lhs_file = lhs_hunk.left.filename.split("/")[1:] 49 if lhs_file != rhs_file: 50 continue 51 yield (rhs_hunk, lhs_hunk) 52 53 54 def main(): 55 old_hunks = [x for x in diff.ParseDiffHunks(open(sys.argv[1], "r"))] 56 new_hunks = [x for x in diff.ParseDiffHunks(open(sys.argv[2], "r"))] 57 out_hunks = [] 58 59 # Join the right hand side of the older diff with the left hand side of the 60 # newer diff. 61 for old_hunk, new_hunk in ZipHunks(old_hunks, new_hunks): 62 if new_hunk in out_hunks: 63 continue 64 old_lines = old_hunk.right 65 new_lines = new_hunk.left 66 67 # Determine if this hunk overlaps any non-context line from the other 68 for i in old_lines.delta_line_nums: 69 if i in new_lines: 70 out_hunks.append(new_hunk) 71 break 72 73 if out_hunks: 74 print(FormatDiffHunks(out_hunks)) 75 sys.exit(1) 76 77 if __name__ == "__main__": 78 main()