mdw@git.distorted.org.uk Git - stgit/blob - 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
  39
  40 #
  41 # Options
  42 #
  43 try:
  44     merger = config.get('gitmergeonefile', 'merger')
  45 except Exception, err:
  46     print >> sys.stderr, 'Configuration error: %s' % err
  47     sys.exit(1)
  48
  49 if config.has_option('gitmergeonefile', 'keeporig'):
  50     keeporig = config.get('gitmergeonefile', 'keeporig')
  51 else:
  52     keeporig = 'yes'
  53
  54
  55 #
  56 # Global variables
  57 #
  58 if 'GIT_DIR' in os.environ:
  59     base_dir = os.environ['GIT_DIR']
  60 else:
  61     base_dir = '.git'
  62
  63
  64 #
  65 # Utility functions
  66 #
  67 def __str2none(x):
  68     if x == '':
  69         return None
  70     else:
  71         return x
  72
  73 def __output(cmd):
  74     f = os.popen(cmd, 'r')
  75     string = f.readline().strip()
  76     if f.close():
  77         print >> sys.stderr, 'Error: failed to execute "%s"' % cmd
  78         sys.exit(1)
  79     return string
  80
  81 def __checkout_files():
  82     """Check out the files passed as arguments
  83     """
  84     global orig, src1, src2
  85
  86     if orig_hash:
  87         orig = '%s.older' % path
  88         tmp = __output('git-unpack-file %s' % orig_hash)
  89         os.chmod(tmp, int(orig_mode, 8))
  90         os.renames(tmp, orig)
  91     if file1_hash:
  92         src1 = '%s.local' % path
  93         tmp = __output('git-unpack-file %s' % file1_hash)
  94         os.chmod(tmp, int(file1_mode, 8))
  95         os.renames(tmp, src1)
  96     if file2_hash:
  97         src2 = '%s.remote' % path
  98         tmp = __output('git-unpack-file %s' % file2_hash)
  99         os.chmod(tmp, int(file2_mode, 8))
 100         os.renames(tmp, src2)
 101
 102 def __remove_files():
 103     """Remove any temporary files
 104     """
 105     if orig_hash:
 106         os.remove(orig)
 107     if file1_hash:
 108         os.remove(src1)
 109     if file2_hash:
 110         os.remove(src2)
 111     pass
 112
 113 def __conflict():
 114     """Write the conflict file for the 'path' variable and exit
 115     """
 116     append_string(os.path.join(base_dir, 'conflicts'), path)
 117     sys.exit(1)
 118
 119
 120 #   $1 - original file SHA1 (or empty)
 121 #   $2 - file in branch1 SHA1 (or empty)
 122 #   $3 - file in branch2 SHA1 (or empty)
 123 #   $4 - pathname in repository
 124 #   $5 - orignal file mode (or empty)
 125 #   $6 - file in branch1 mode (or empty)
 126 #   $7 - file in branch2 mode (or empty)
 127 #
 128 #print 'gitmergeonefile.py "%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
 129 #      % tuple(sys.argv[1:8])
 130 orig_hash, file1_hash, file2_hash, path, orig_mode, file1_mode, file2_mode = \
 131            [__str2none(x) for x in sys.argv[1:8]]
 132
 133
 134 #
 135 # Main algorithm
 136 #
 137 __checkout_files()
 138
 139 # file exists in origin
 140 if orig_hash:
 141     # modified in both
 142     if file1_hash and file2_hash:
 143         # if modes are the same (git-read-tree probably dealed with it)
 144         if file1_hash == file2_hash:
 145             if os.system('git-update-cache --cacheinfo %s %s %s'
 146                          % (file1_mode, file1_hash, path)) != 0:
 147                 print >> sys.stderr, 'Error: git-update-cache failed'
 148                 __conflict()
 149             if os.system('git-checkout-cache -u -f -- %s' % path):
 150                 print >> sys.stderr, 'Error: git-checkout-cache failed'
 151                 __conflict()
 152             if file1_mode != file2_mode:
 153                 print >> sys.stderr, \
 154                       'Error: File added in both, permissions conflict'
 155                 __conflict()
 156         # 3-way merge
 157         else:
 158             merge_ok = os.system(merger % {'branch1': src1,
 159                                            'ancestor': orig,
 160                                            'branch2': src2,
 161                                            'output': path }) == 0
 162
 163             if merge_ok:
 164                 os.system('git-update-cache -- %s' % path)
 165                 __remove_files()
 166                 sys.exit(0)
 167             else:
 168                 print >> sys.stderr, \
 169                       'Error: three-way merge tool failed for file "%s"' % path
 170                 # reset the cache to the first branch
 171                 os.system('git-update-cache --cacheinfo %s %s %s'
 172                           % (file1_mode, file1_hash, path))
 173                 if keeporig != 'yes':
 174                     __remove_files()
 175                 __conflict()
 176     # file deleted in both or deleted in one and unchanged in the other
 177     elif not (file1_hash or file2_hash) \
 178            or file1_hash == orig_hash or file2_hash == orig_hash:
 179         if os.path.exists(path):
 180             os.remove(path)
 181         __remove_files()
 182         sys.exit(os.system('git-update-cache --remove -- %s' % path))
 183 # file does not exist in origin
 184 else:
 185     # file added in both
 186     if file1_hash and file2_hash:
 187         # files are the same
 188         if file1_hash == file2_hash:
 189             if os.system('git-update-cache --add --cacheinfo %s %s %s'
 190                          % (file1_mode, file1_hash, path)) != 0:
 191                 print >> sys.stderr, 'Error: git-update-cache failed'
 192                 __conflict()
 193             if os.system('git-checkout-cache -u -f -- %s' % path):
 194                 print >> sys.stderr, 'Error: git-checkout-cache failed'
 195                 __conflict()
 196             if file1_mode != file2_mode:
 197                 print >> sys.stderr, \
 198                       'Error: File "s" added in both, permissions conflict' \
 199                       % path
 200                 __conflict()
 201         # files are different
 202         else:
 203             print >> sys.stderr, \
 204                   'Error: File "%s" added in branches but different' % path
 205             __conflict()
 206     # file added in one
 207     elif file1_hash or file2_hash:
 208         if file1_hash:
 209             mode = file1_mode
 210             obj = file1_hash
 211         else:
 212             mode = file2_mode
 213             obj = file2_hash
 214         if os.system('git-update-cache --add --cacheinfo %s %s %s'
 215                      % (mode, obj, path)) != 0:
 216             print >> sys.stderr, 'Error: git-update-cache failed'
 217             __conflict()
 218         __remove_files()
 219         sys.exit(os.system('git-checkout-cache -u -f -- %s' % path))
 220
 221 # Un-handled case
 222 print >> sys.stderr, 'Error: Un-handled merge conflict'
 223 print >> sys.stderr, 'gitmergeonefile.py "%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
 224       % tuple(sys.argv[1:8])
 225 __conflict()