mdw@git.distorted.org.uk Git - stgit/blob - stgit/gitmergeonefile.py

   1 """Performs a 3-way merge for GIT files
   2 """
   3
   4 __copyright__ = """
   5 Copyright (C) 2006, Catalin Marinas <catalin.marinas@gmail.com>
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License version 2 as
   9 published by the Free Software Foundation.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 """
  20
  21 import sys, os
  22 from stgit.config import config
  23 from stgit.utils import append_string
  24
  25
  26 class GitMergeException(Exception):
  27     pass
  28
  29
  30 #
  31 # Options
  32 #
  33 try:
  34     merger = config.get('gitmergeonefile', 'merger')
  35 except Exception, err:
  36     raise GitMergeException, 'Configuration error: %s' % err
  37
  38 if config.has_option('gitmergeonefile', 'keeporig'):
  39     keeporig = config.get('gitmergeonefile', 'keeporig')
  40 else:
  41     keeporig = 'yes'
  42
  43
  44 #
  45 # Utility functions
  46 #
  47 def __str2none(x):
  48     if x == '':
  49         return None
  50     else:
  51         return x
  52
  53 def __output(cmd):
  54     f = os.popen(cmd, 'r')
  55     string = f.readline().rstrip()
  56     if f.close():
  57         raise GitMergeException, 'Error: failed to execute "%s"' % cmd
  58     return string
  59
  60 def __checkout_files(orig_hash, file1_hash, file2_hash,
  61                      path,
  62                      orig_mode, file1_mode, file2_mode):
  63     """Check out the files passed as arguments
  64     """
  65     global orig, src1, src2
  66
  67     if orig_hash:
  68         orig = '%s.older' % path
  69         tmp = __output('git-unpack-file %s' % orig_hash)
  70         os.chmod(tmp, int(orig_mode, 8))
  71         os.renames(tmp, orig)
  72     if file1_hash:
  73         src1 = '%s.local' % path
  74         tmp = __output('git-unpack-file %s' % file1_hash)
  75         os.chmod(tmp, int(file1_mode, 8))
  76         os.renames(tmp, src1)
  77     if file2_hash:
  78         src2 = '%s.remote' % path
  79         tmp = __output('git-unpack-file %s' % file2_hash)
  80         os.chmod(tmp, int(file2_mode, 8))
  81         os.renames(tmp, src2)
  82
  83 def __remove_files(orig_hash, file1_hash, file2_hash):
  84     """Remove any temporary files
  85     """
  86     if orig_hash:
  87         os.remove(orig)
  88     if file1_hash:
  89         os.remove(src1)
  90     if file2_hash:
  91         os.remove(src2)
  92     pass
  93
  94 # GIT_DIR value cached
  95 __base_dir = None
  96
  97 def __conflict(path):
  98     """Write the conflict file for the 'path' variable and exit
  99     """
 100     global __base_dir
 101
 102     if not __base_dir:
 103         if 'GIT_DIR' in os.environ:
 104             __base_dir = os.environ['GIT_DIR']
 105         else:
 106             __base_dir = __output('git-rev-parse --git-dir')
 107
 108     append_string(os.path.join(__base_dir, 'conflicts'), path)
 109
 110
 111 #
 112 # Main algorithm
 113 #
 114 def merge(orig_hash, file1_hash, file2_hash,
 115           path,
 116           orig_mode, file1_mode, file2_mode):
 117     """Three-way merge for one file algorithm
 118     """
 119     __checkout_files(orig_hash, file1_hash, file2_hash,
 120                      path,
 121                      orig_mode, file1_mode, file2_mode)
 122
 123     # file exists in origin
 124     if orig_hash:
 125         # modified in both
 126         if file1_hash and file2_hash:
 127             # if modes are the same (git-read-tree probably dealt with it)
 128             if file1_hash == file2_hash:
 129                 if os.system('git-update-index --cacheinfo %s %s %s'
 130                              % (file1_mode, file1_hash, path)) != 0:
 131                     print >> sys.stderr, 'Error: git-update-index failed'
 132                     __conflict(path)
 133                     return 1
 134                 if os.system('git-checkout-index -u -f -- %s' % path):
 135                     print >> sys.stderr, 'Error: git-checkout-index failed'
 136                     __conflict(path)
 137                     return 1
 138                 if file1_mode != file2_mode:
 139                     print >> sys.stderr, \
 140                           'Error: File added in both, permissions conflict'
 141                     __conflict(path)
 142                     return 1
 143             # 3-way merge
 144             else:
 145                 merge_ok = os.system(merger % {'branch1': src1,
 146                                                'ancestor': orig,
 147                                                'branch2': src2,
 148                                                'output': path }) == 0
 149
 150                 if merge_ok:
 151                     os.system('git-update-index -- %s' % path)
 152                     __remove_files(orig_hash, file1_hash, file2_hash)
 153                     return 0
 154                 else:
 155                     print >> sys.stderr, \
 156                           'Error: three-way merge tool failed for file "%s"' \
 157                           % path
 158                     # reset the cache to the first branch
 159                     os.system('git-update-index --cacheinfo %s %s %s'
 160                               % (file1_mode, file1_hash, path))
 161                     if keeporig != 'yes':
 162                         __remove_files(orig_hash, file1_hash, file2_hash)
 163                     __conflict(path)
 164                     return 1
 165         # file deleted in both or deleted in one and unchanged in the other
 166         elif not (file1_hash or file2_hash) \
 167                or file1_hash == orig_hash or file2_hash == orig_hash:
 168             if os.path.exists(path):
 169                 os.remove(path)
 170             __remove_files(orig_hash, file1_hash, file2_hash)
 171             return os.system('git-update-index --remove -- %s' % path)
 172         # file deleted in one and changed in the other
 173         else:
 174             # Do something here - we must at least merge the entry in
 175             # the cache, instead of leaving it in U(nmerged) state. In
 176             # fact, stg resolved does not handle that.
 177
 178             # Do the same thing cogito does - remove the file in any case.
 179             os.system('git-update-index --remove -- %s' % path)
 180
 181             #if file1_hash:
 182                 ## file deleted upstream and changed in the patch. The
 183                 ## patch is probably going to move the changes
 184                 ## elsewhere.
 185
 186                 #os.system('git-update-index --remove -- %s' % path)
 187             #else:
 188                 ## file deleted in the patch and changed upstream. We
 189                 ## could re-delete it, but for now leave it there -
 190                 ## and let the user check if he still wants to remove
 191                 ## the file.
 192
 193                 ## reset the cache to the first branch
 194                 #os.system('git-update-index --cacheinfo %s %s %s'
 195                 #          % (file1_mode, file1_hash, path))
 196             __conflict(path)
 197             return 1
 198
 199     # file does not exist in origin
 200     else:
 201         # file added in both
 202         if file1_hash and file2_hash:
 203             # files are the same
 204             if file1_hash == file2_hash:
 205                 if os.system('git-update-index --add --cacheinfo %s %s %s'
 206                              % (file1_mode, file1_hash, path)) != 0:
 207                     print >> sys.stderr, 'Error: git-update-index failed'
 208                     __conflict(path)
 209                     return 1
 210                 if os.system('git-checkout-index -u -f -- %s' % path):
 211                     print >> sys.stderr, 'Error: git-checkout-index failed'
 212                     __conflict(path)
 213                     return 1
 214                 if file1_mode != file2_mode:
 215                     print >> sys.stderr, \
 216                           'Error: File "s" added in both, ' \
 217                           'permissions conflict' % path
 218                     __conflict(path)
 219                     return 1
 220             # files are different
 221             else:
 222                 print >> sys.stderr, \
 223                       'Error: File "%s" added in branches but different' % path
 224                 __conflict(path)
 225                 return 1
 226         # file added in one
 227         elif file1_hash or file2_hash:
 228             if file1_hash:
 229                 mode = file1_mode
 230                 obj = file1_hash
 231             else:
 232                 mode = file2_mode
 233                 obj = file2_hash
 234             if os.system('git-update-index --add --cacheinfo %s %s %s'
 235                          % (mode, obj, path)) != 0:
 236                 print >> sys.stderr, 'Error: git-update-index failed'
 237                 __conflict(path)
 238                 return 1
 239             __remove_files(orig_hash, file1_hash, file2_hash)
 240             return os.system('git-checkout-index -u -f -- %s' % path)
 241
 242     # Unhandled case
 243     print >> sys.stderr, 'Error: Unhandled merge conflict: ' \
 244           '"%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
 245           % (orig_hash, file1_hash, file2_hash,
 246              path,
 247              orig_mode, file1_mode, file2_mode)
 248     __conflict(path)
 249     return 1