gitmergeonefile.py

   1 #!/usr/bin/env python
   2 """Performs a 3-way merge for GIT files
   3 """
   4
   5 __copyright__ = """
   6 Copyright (C) 2005, Catalin Marinas <catalin.marinas@gmail.com>
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License version 2 as
  10 published by the Free Software Foundation.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20 """
  21
  22 import sys, os
  23
  24 # Try to detect where it is run from and set prefix and the search path.
  25 # It is assumed that the user installed StGIT using the --prefix= option
  26 prefix, bin = os.path.split(sys.path[0])
  27
  28 if bin == 'bin' and prefix != sys.prefix:
  29     major, minor = sys.version_info[0:2]
  30     local_path = [os.path.join(prefix, 'lib', 'python'),
  31                   os.path.join(prefix, 'lib', 'python%s.%s' % (major, minor)),
  32                   os.path.join(prefix, 'lib', 'python%s.%s' % (major, minor),
  33                                'site-packages')]
  34     sys.path = local_path + sys.path
  35
  36 from stgit.config import config
  37 from stgit.utils import append_string
  38 from stgit.git import get_base_dir
  39
  40
  41 #
  42 # Options
  43 #
  44 try:
  45     merger = config.get('gitmergeonefile', 'merger')
  46 except Exception, err:
  47     print >> sys.stderr, 'Configuration error: %s' % err
  48     sys.exit(1)
  49
  50 if config.has_option('gitmergeonefile', 'keeporig'):
  51     keeporig = config.get('gitmergeonefile', 'keeporig')
  52 else:
  53     keeporig = 'yes'
  54
  55
  56 #
  57 # Utility functions
  58 #
  59 def __str2none(x):
  60     if x == '':
  61         return None
  62     else:
  63         return x
  64
  65 def __output(cmd):
  66     f = os.popen(cmd, 'r')
  67     string = f.readline().strip()
  68     if f.close():
  69         print >> sys.stderr, 'Error: failed to execute "%s"' % cmd
  70         sys.exit(1)
  71     return string
  72
  73 def __checkout_files():
  74     """Check out the files passed as arguments
  75     """
  76     global orig, src1, src2
  77
  78     if orig_hash:
  79         orig = '%s.older' % path
  80         tmp = __output('git-unpack-file %s' % orig_hash)
  81         os.chmod(tmp, int(orig_mode, 8))
  82         os.renames(tmp, orig)
  83     if file1_hash:
  84         src1 = '%s.local' % path
  85         tmp = __output('git-unpack-file %s' % file1_hash)
  86         os.chmod(tmp, int(file1_mode, 8))
  87         os.renames(tmp, src1)
  88     if file2_hash:
  89         src2 = '%s.remote' % path
  90         tmp = __output('git-unpack-file %s' % file2_hash)
  91         os.chmod(tmp, int(file2_mode, 8))
  92         os.renames(tmp, src2)
  93
  94 def __remove_files():
  95     """Remove any temporary files
  96     """
  97     if orig_hash:
  98         os.remove(orig)
  99     if file1_hash:
 100         os.remove(src1)
 101     if file2_hash:
 102         os.remove(src2)
 103     pass
 104
 105 def __conflict():
 106     """Write the conflict file for the 'path' variable and exit
 107     """
 108     append_string(os.path.join(get_base_dir(), 'conflicts'), path)
 109     sys.exit(1)
 110
 111
 112 #   $1 - original file SHA1 (or empty)
 113 #   $2 - file in branch1 SHA1 (or empty)
 114 #   $3 - file in branch2 SHA1 (or empty)
 115 #   $4 - pathname in repository
 116 #   $5 - original file mode (or empty)
 117 #   $6 - file in branch1 mode (or empty)
 118 #   $7 - file in branch2 mode (or empty)
 119 #
 120 #print 'gitmergeonefile.py "%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
 121 #      % tuple(sys.argv[1:8])
 122 orig_hash, file1_hash, file2_hash, path, orig_mode, file1_mode, file2_mode = \
 123            [__str2none(x) for x in sys.argv[1:8]]
 124
 125
 126 #
 127 # Main algorithm
 128 #
 129 __checkout_files()
 130
 131 # file exists in origin
 132 if orig_hash:
 133     # modified in both
 134     if file1_hash and file2_hash:
 135         # if modes are the same (git-read-tree probably dealt with it)
 136         if file1_hash == file2_hash:
 137             if os.system('git-update-index --cacheinfo %s %s %s'
 138                          % (file1_mode, file1_hash, path)) != 0:
 139                 print >> sys.stderr, 'Error: git-update-index failed'
 140                 __conflict()
 141             if os.system('git-checkout-index -u -f -- %s' % path):
 142                 print >> sys.stderr, 'Error: git-checkout-index failed'
 143                 __conflict()
 144             if file1_mode != file2_mode:
 145                 print >> sys.stderr, \
 146                       'Error: File added in both, permissions conflict'
 147                 __conflict()
 148         # 3-way merge
 149         else:
 150             merge_ok = os.system(merger % {'branch1': src1,
 151                                            'ancestor': orig,
 152                                            'branch2': src2,
 153                                            'output': path }) == 0
 154
 155             if merge_ok:
 156                 os.system('git-update-index -- %s' % path)
 157                 __remove_files()
 158                 sys.exit(0)
 159             else:
 160                 print >> sys.stderr, \
 161                       'Error: three-way merge tool failed for file "%s"' % path
 162                 # reset the cache to the first branch
 163                 os.system('git-update-index --cacheinfo %s %s %s'
 164                           % (file1_mode, file1_hash, path))
 165                 if keeporig != 'yes':
 166                     __remove_files()
 167                 __conflict()
 168     # file deleted in both or deleted in one and unchanged in the other
 169     elif not (file1_hash or file2_hash) \
 170            or file1_hash == orig_hash or file2_hash == orig_hash:
 171         if os.path.exists(path):
 172             os.remove(path)
 173         __remove_files()
 174         sys.exit(os.system('git-update-index --remove -- %s' % path))
 175     # file deleted in one and changed in the other
 176     else:
 177         # Do something here - we must at least merge the entry in the cache,
 178         # instead of leaving it in U(nmerged) state. In fact, stg resolved
 179         # does not handle that.
 180
 181         # Do the same thing cogito does - remove the file in any case.
 182         os.system('git-update-index --remove -- %s' % path)
 183
 184         #if file1_hash:
 185             ## file deleted upstream and changed in the patch. The patch is
 186             ## probably going to move the changes elsewhere.
 187
 188             #os.system('git-update-index --remove -- %s' % path)
 189         #else:
 190             ## file deleted in the patch and changed upstream. We could re-delete
 191             ## it, but for now leave it there - and let the user check if he
 192             ## still wants to remove the file.
 193
 194             ## reset the cache to the first branch
 195             #os.system('git-update-index --cacheinfo %s %s %s'
 196                       #% (file1_mode, file1_hash, path))
 197         __conflict()
 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()
 209             if os.system('git-checkout-index -u -f -- %s' % path):
 210                 print >> sys.stderr, 'Error: git-checkout-index failed'
 211                 __conflict()
 212             if file1_mode != file2_mode:
 213                 print >> sys.stderr, \
 214                       'Error: File "s" added in both, permissions conflict' \
 215                       % path
 216                 __conflict()
 217         # files are different
 218         else:
 219             print >> sys.stderr, \
 220                   'Error: File "%s" added in branches but different' % path
 221             __conflict()
 222     # file added in one
 223     elif file1_hash or file2_hash:
 224         if file1_hash:
 225             mode = file1_mode
 226             obj = file1_hash
 227         else:
 228             mode = file2_mode
 229             obj = file2_hash
 230         if os.system('git-update-index --add --cacheinfo %s %s %s'
 231                      % (mode, obj, path)) != 0:
 232             print >> sys.stderr, 'Error: git-update-index failed'
 233             __conflict()
 234         __remove_files()
 235         sys.exit(os.system('git-checkout-index -u -f -- %s' % path))
 236
 237 # Unhandled case
 238 print >> sys.stderr, 'Error: Unhandled merge conflict'
 239 print >> sys.stderr, 'gitmergeonefile.py "%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
 240       % tuple(sys.argv[1:8])
 241 __conflict()