contrib/hg-to-git/hg-to-git.py

   1 #!/usr/bin/env python
   2
   3 """ hg-to-git.py - A Mercurial to GIT converter
   4
   5     Copyright (C)2007 Stelian Pop <stelian@popies.net>
   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 as published by
   9     the Free Software Foundation; either version 2, or (at your option)
  10     any later version.
  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., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 """
  21
  22 import os, os.path, sys
  23 import tempfile, pickle, getopt
  24 import re
  25
  26 if sys.hexversion < 0x02030000:
  27    # The behavior of the pickle module changed significantly in 2.3
  28    sys.stderr.write("hg-to-git.py: requires Python 2.3 or later.\n")
  29    sys.exit(1)
  30
  31 # Maps hg version -> git version
  32 hgvers = {}
  33 # List of children for each hg revision
  34 hgchildren = {}
  35 # List of parents for each hg revision
  36 hgparents = {}
  37 # Current branch for each hg revision
  38 hgbranch = {}
  39 # Number of new changesets converted from hg
  40 hgnewcsets = 0
  41
  42 #------------------------------------------------------------------------------
  43
  44 def usage():
  45
  46         print """\
  47 %s: [OPTIONS] <hgprj>
  48
  49 options:
  50     -s, --gitstate=FILE: name of the state to be saved/read
  51                          for incrementals
  52     -n, --nrepack=INT:   number of changesets that will trigger
  53                          a repack (default=0, -1 to deactivate)
  54     -v, --verbose:       be verbose
  55
  56 required:
  57     hgprj:  name of the HG project to import (directory)
  58 """ % sys.argv[0]
  59
  60 #------------------------------------------------------------------------------
  61
  62 def getgitenv(user, date):
  63     env = ''
  64     elems = re.compile('(.*?)\s+<(.*)>').match(user)
  65     if elems:
  66         env += 'export GIT_AUTHOR_NAME="%s" ;' % elems.group(1)
  67         env += 'export GIT_COMMITTER_NAME="%s" ;' % elems.group(1)
  68         env += 'export GIT_AUTHOR_EMAIL="%s" ;' % elems.group(2)
  69         env += 'export GIT_COMMITTER_EMAIL="%s" ;' % elems.group(2)
  70     else:
  71         env += 'export GIT_AUTHOR_NAME="%s" ;' % user
  72         env += 'export GIT_COMMITTER_NAME="%s" ;' % user
  73         env += 'export GIT_AUTHOR_EMAIL= ;'
  74         env += 'export GIT_COMMITTER_EMAIL= ;'
  75
  76     env += 'export GIT_AUTHOR_DATE="%s" ;' % date
  77     env += 'export GIT_COMMITTER_DATE="%s" ;' % date
  78     return env
  79
  80 #------------------------------------------------------------------------------
  81
  82 state = ''
  83 opt_nrepack = 0
  84 verbose = False
  85
  86 try:
  87     opts, args = getopt.getopt(sys.argv[1:], 's:t:n:v', ['gitstate=', 'tempdir=', 'nrepack=', 'verbose'])
  88     for o, a in opts:
  89         if o in ('-s', '--gitstate'):
  90             state = a
  91             state = os.path.abspath(state)
  92         if o in ('-n', '--nrepack'):
  93             opt_nrepack = int(a)
  94         if o in ('-v', '--verbose'):
  95             verbose = True
  96     if len(args) != 1:
  97         raise Exception('params')
  98 except:
  99     usage()
 100     sys.exit(1)
 101
 102 hgprj = args[0]
 103 os.chdir(hgprj)
 104
 105 if state:
 106     if os.path.exists(state):
 107         if verbose:
 108             print 'State does exist, reading'
 109         f = open(state, 'r')
 110         hgvers = pickle.load(f)
 111     else:
 112         print 'State does not exist, first run'
 113
 114 sock = os.popen('hg tip --template "{rev}"')
 115 tip = sock.read()
 116 if sock.close():
 117     sys.exit(1)
 118 if verbose:
 119     print 'tip is', tip
 120
 121 # Calculate the branches
 122 if verbose:
 123     print 'analysing the branches...'
 124 hgchildren["0"] = ()
 125 hgparents["0"] = (None, None)
 126 hgbranch["0"] = "master"
 127 for cset in range(1, int(tip) + 1):
 128     hgchildren[str(cset)] = ()
 129     prnts = os.popen('hg log -r %d --template "{parents}"' % cset).read().strip().split(' ')
 130     prnts = map(lambda x: x[:x.find(':')], prnts)
 131     if prnts[0] != '':
 132         parent = prnts[0].strip()
 133     else:
 134         parent = str(cset - 1)
 135     hgchildren[parent] += ( str(cset), )
 136     if len(prnts) > 1:
 137         mparent = prnts[1].strip()
 138         hgchildren[mparent] += ( str(cset), )
 139     else:
 140         mparent = None
 141
 142     hgparents[str(cset)] = (parent, mparent)
 143
 144     if mparent:
 145         # For merge changesets, take either one, preferably the 'master' branch
 146         if hgbranch[mparent] == 'master':
 147             hgbranch[str(cset)] = 'master'
 148         else:
 149             hgbranch[str(cset)] = hgbranch[parent]
 150     else:
 151         # Normal changesets
 152         # For first children, take the parent branch, for the others create a new branch
 153         if hgchildren[parent][0] == str(cset):
 154             hgbranch[str(cset)] = hgbranch[parent]
 155         else:
 156             hgbranch[str(cset)] = "branch-" + str(cset)
 157
 158 if not hgvers.has_key("0"):
 159     print 'creating repository'
 160     os.system('git init')
 161
 162 # loop through every hg changeset
 163 for cset in range(int(tip) + 1):
 164
 165     # incremental, already seen
 166     if hgvers.has_key(str(cset)):
 167         continue
 168     hgnewcsets += 1
 169
 170     # get info
 171     log_data = os.popen('hg log -r %d --template "{tags}\n{date|date}\n{author}\n"' % cset).readlines()
 172     tag = log_data[0].strip()
 173     date = log_data[1].strip()
 174     user = log_data[2].strip()
 175     parent = hgparents[str(cset)][0]
 176     mparent = hgparents[str(cset)][1]
 177
 178     #get comment
 179     (fdcomment, filecomment) = tempfile.mkstemp()
 180     csetcomment = os.popen('hg log -r %d --template "{desc}"' % cset).read().strip()
 181     os.write(fdcomment, csetcomment)
 182     os.close(fdcomment)
 183
 184     print '-----------------------------------------'
 185     print 'cset:', cset
 186     print 'branch:', hgbranch[str(cset)]
 187     print 'user:', user
 188     print 'date:', date
 189     print 'comment:', csetcomment
 190     if parent:
 191         print 'parent:', parent
 192     if mparent:
 193         print 'mparent:', mparent
 194     if tag:
 195         print 'tag:', tag
 196     print '-----------------------------------------'
 197
 198     # checkout the parent if necessary
 199     if cset != 0:
 200         if hgbranch[str(cset)] == "branch-" + str(cset):
 201             print 'creating new branch', hgbranch[str(cset)]
 202             os.system('git checkout -b %s %s' % (hgbranch[str(cset)], hgvers[parent]))
 203         else:
 204             print 'checking out branch', hgbranch[str(cset)]
 205             os.system('git checkout %s' % hgbranch[str(cset)])
 206
 207     # merge
 208     if mparent:
 209         if hgbranch[parent] == hgbranch[str(cset)]:
 210             otherbranch = hgbranch[mparent]
 211         else:
 212             otherbranch = hgbranch[parent]
 213         print 'merging', otherbranch, 'into', hgbranch[str(cset)]
 214         os.system(getgitenv(user, date) + 'git merge --no-commit -s ours "" %s %s' % (hgbranch[str(cset)], otherbranch))
 215
 216     # remove everything except .git and .hg directories
 217     os.system('find . \( -path "./.hg" -o -path "./.git" \) -prune -o ! -name "." -print | xargs rm -rf')
 218
 219     # repopulate with checkouted files
 220     os.system('hg update -C %d' % cset)
 221
 222     # add new files
 223     os.system('git ls-files -x .hg --others | git update-index --add --stdin')
 224     # delete removed files
 225     os.system('git ls-files -x .hg --deleted | git update-index --remove --stdin')
 226
 227     # commit
 228     os.system(getgitenv(user, date) + 'git commit --allow-empty --allow-empty-message -a -F %s' % filecomment)
 229     os.unlink(filecomment)
 230
 231     # tag
 232     if tag and tag != 'tip':
 233         os.system(getgitenv(user, date) + 'git tag %s' % tag)
 234
 235     # delete branch if not used anymore...
 236     if mparent and len(hgchildren[str(cset)]):
 237         print "Deleting unused branch:", otherbranch
 238         os.system('git branch -d %s' % otherbranch)
 239
 240     # retrieve and record the version
 241     vvv = os.popen('git show --quiet --pretty=format:%H').read()
 242     print 'record', cset, '->', vvv
 243     hgvers[str(cset)] = vvv
 244
 245 if hgnewcsets >= opt_nrepack and opt_nrepack != -1:
 246     os.system('git repack -a -d')
 247
 248 # write the state for incrementals
 249 if state:
 250     if verbose:
 251         print 'Writing state'
 252     f = open(state, 'w')
 253     pickle.dump(hgvers, f)
 254
 255 # vim: et ts=8 sw=4 sts=4