patch.py

   1 import re
   2 import sys
   3
   4 from git import git
   5
   6 _boundary_line_regex = re.compile(r'^---')
   7 _diff_head_regex = re.compile(r'^diff --git ')
   8 _index_line_regex = re.compile(r'^index ([a-f0-9]{7,})\.\.([a-f0-9]{7,}) ')
   9
  10 class PatchError(Exception):
  11     pass
  12
  13 class Patch(object):
  14
  15     def __init__(self, data):
  16         self.blobs_pre = set()
  17         self.blobs_post = set()
  18         self.data = data
  19         self.notes = None
  20         self._parse(data)
  21
  22     def _parse(self, data):
  23         boundary_seen = False
  24         diff_seen = False
  25         notes = []
  26         for line in data.splitlines(True):
  27             if diff_seen:
  28                 m = _index_line_regex.match(line)
  29                 if m:
  30                     self.blobs_pre.add(m.group(1))
  31                     self.blobs_post.add(m.group(2))
  32                 continue
  33             if _diff_head_regex.match(line):
  34                 diff_seen = True
  35                 continue
  36             if boundary_seen:
  37                 notes.append(line)
  38             if _boundary_line_regex.match(line):
  39                 boundary_seen = True
  40                 continue
  41         if diff_seen:
  42             self.notes = ''.join(notes)
  43
  44     def apply(self):
  45         print 'trying to apply patch-%x' % id(self)
  46         output, ret = git('am', input=self.data)
  47         if ret != 0:
  48             # clean up
  49             git('am', '--abort')
  50             git('reset', '--hard')
  51             raise PatchError()
  52         return output