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

   1 #! /usr/bin/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, popen2, pickle, getopt
  24 import re
  25
  26 # Maps hg version -> git version
  27 hgvers = {}
  28 # List of children for each hg revision
  29 hgchildren = {}
  30 # List of parents for each hg revision
  31 hgparents = {}
  32 # Current branch for each hg revision
  33 hgbranch = {}
  34 # Number of new changesets converted from hg
  35 hgnewcsets = 0
  36
  37 #------------------------------------------------------------------------------
  38
  39 def usage():
  40
  41         print """\
  42 %s: [OPTIONS] <hgprj>
  43
  44 options:
  45     -s, --gitstate=FILE: name of the state to be saved/read
  46                          for incrementals
  47     -n, --nrepack=INT:   number of changesets that will trigger
  48                          a repack (default=0, -1 to deactivate)
  49
  50 required:
  51     hgprj:  name of the HG project to import (directory)
  52 """ % sys.argv[0]
  53
  54 #------------------------------------------------------------------------------
  55
  56 def getgitenv(user, date):
  57     env = ''
  58     elems = re.compile('(.*?)\s+<(.*)>').match(user)
  59     if elems:
  60         env += 'export GIT_AUTHOR_NAME="%s" ;' % elems.group(1)
  61         env += 'export GIT_COMMITER_NAME="%s" ;' % elems.group(1)
  62         env += 'export GIT_AUTHOR_EMAIL="%s" ;' % elems.group(2)
  63         env += 'export GIT_COMMITER_EMAIL="%s" ;' % elems.group(2)
  64     else:
  65         env += 'export GIT_AUTHOR_NAME="%s" ;' % user
  66         env += 'export GIT_COMMITER_NAME="%s" ;' % user
  67         env += 'export GIT_AUTHOR_EMAIL= ;'
  68         env += 'export GIT_COMMITER_EMAIL= ;'
  69
  70     env += 'export GIT_AUTHOR_DATE="%s" ;' % date
  71     env += 'export GIT_COMMITTER_DATE="%s" ;' % date
  72     return env
  73
  74 #------------------------------------------------------------------------------
  75
  76 state = ''
  77 opt_nrepack = 0
  78
  79 try:
  80     opts, args = getopt.getopt(sys.argv[1:], 's:t:n:', ['gitstate=', 'tempdir=', 'nrepack='])
  81     for o, a in opts:
  82         if o in ('-s', '--gitstate'):
  83             state = a
  84             state = os.path.abspath(state)
  85         if o in ('-n', '--nrepack'):
  86             opt_nrepack = int(a)
  87     if len(args) != 1:
  88         raise('params')
  89 except:
  90     usage()
  91     sys.exit(1)
  92
  93 hgprj = args[0]
  94 os.chdir(hgprj)
  95
  96 if state:
  97     if os.path.exists(state):
  98         print 'State does exist, reading'
  99         f = open(state, 'r')
 100         hgvers = pickle.load(f)
 101     else:
 102         print 'State does not exist, first run'
 103
 104 tip = os.popen('hg tip --template "{rev}"').read()
 105 print 'tip is', tip
 106
 107 # Calculate the branches
 108 print 'analysing the branches...'
 109 hgchildren["0"] = ()
 110 hgparents["0"] = (None, None)
 111 hgbranch["0"] = "master"
 112 for cset in range(1, int(tip) + 1):
 113     hgchildren[str(cset)] = ()
 114     prnts = os.popen('hg log -r %d --template "{parents}"' % cset).read().strip().split(' ')
 115     prnts = map(lambda x: x[:x.find(':')], prnts)
 116     if prnts[0] != '':
 117         parent = prnts[0].strip()
 118     else:
 119         parent = str(cset - 1)
 120     hgchildren[parent] += ( str(cset), )
 121     if len(prnts) > 1:
 122         mparent = prnts[1].strip()
 123         hgchildren[mparent] += ( str(cset), )
 124     else:
 125         mparent = None
 126
 127     hgparents[str(cset)] = (parent, mparent)
 128
 129     if mparent:
 130         # For merge changesets, take either one, preferably the 'master' branch
 131         if hgbranch[mparent] == 'master':
 132             hgbranch[str(cset)] = 'master'
 133         else:
 134             hgbranch[str(cset)] = hgbranch[parent]
 135     else:
 136         # Normal changesets
 137         # For first children, take the parent branch, for the others create a new branch
 138         if hgchildren[parent][0] == str(cset):
 139             hgbranch[str(cset)] = hgbranch[parent]
 140         else:
 141             hgbranch[str(cset)] = "branch-" + str(cset)
 142
 143 if not hgvers.has_key("0"):
 144     print 'creating repository'
 145     os.system('git-init-db')
 146
 147 # loop through every hg changeset
 148 for cset in range(int(tip) + 1):
 149
 150     # incremental, already seen
 151     if hgvers.has_key(str(cset)):
 152         continue
 153     hgnewcsets += 1
 154
 155     # get info
 156     log_data = os.popen('hg log -r %d --template "{tags}\n{date|date}\n{author}\n"' % cset).readlines()
 157     tag = log_data[0].strip()
 158     date = log_data[1].strip()
 159     user = log_data[2].strip()
 160     parent = hgparents[str(cset)][0]
 161     mparent = hgparents[str(cset)][1]
 162
 163     #get comment
 164     (fdcomment, filecomment) = tempfile.mkstemp()
 165     csetcomment = os.popen('hg log -r %d --template "{desc}"' % cset).read().strip()
 166     os.write(fdcomment, csetcomment)
 167     os.close(fdcomment)
 168
 169     print '-----------------------------------------'
 170     print 'cset:', cset
 171     print 'branch:', hgbranch[str(cset)]
 172     print 'user:', user
 173     print 'date:', date
 174     print 'comment:', csetcomment
 175     if parent:
 176         print 'parent:', parent
 177     if mparent:
 178         print 'mparent:', mparent
 179     if tag:
 180         print 'tag:', tag
 181     print '-----------------------------------------'
 182
 183     # checkout the parent if necessary
 184     if cset != 0:
 185         if hgbranch[str(cset)] == "branch-" + str(cset):
 186             print 'creating new branch', hgbranch[str(cset)]
 187             os.system('git-checkout -b %s %s' % (hgbranch[str(cset)], hgvers[parent]))
 188         else:
 189             print 'checking out branch', hgbranch[str(cset)]
 190             os.system('git-checkout %s' % hgbranch[str(cset)])
 191
 192     # merge
 193     if mparent:
 194         if hgbranch[parent] == hgbranch[str(cset)]:
 195             otherbranch = hgbranch[mparent]
 196         else:
 197             otherbranch = hgbranch[parent]
 198         print 'merging', otherbranch, 'into', hgbranch[str(cset)]
 199         os.system(getgitenv(user, date) + 'git-merge --no-commit -s ours "" %s %s' % (hgbranch[str(cset)], otherbranch))
 200
 201     # remove everything except .git and .hg directories
 202     os.system('find . \( -path "./.hg" -o -path "./.git" \) -prune -o ! -name "." -print | xargs rm -rf')
 203
 204     # repopulate with checkouted files
 205     os.system('hg update -C %d' % cset)
 206
 207     # add new files
 208     os.system('git-ls-files -x .hg --others | git-update-index --add --stdin')
 209     # delete removed files
 210     os.system('git-ls-files -x .hg --deleted | git-update-index --remove --stdin')
 211
 212     # commit
 213     os.system(getgitenv(user, date) + 'git commit --allow-empty -a -F %s' % filecomment)
 214     os.unlink(filecomment)
 215
 216     # tag
 217     if tag and tag != 'tip':
 218         os.system(getgitenv(user, date) + 'git-tag %s' % tag)
 219
 220     # delete branch if not used anymore...
 221     if mparent and len(hgchildren[str(cset)]):
 222         print "Deleting unused branch:", otherbranch
 223         os.system('git-branch -d %s' % otherbranch)
 224
 225     # retrieve and record the version
 226     vvv = os.popen('git-show --quiet --pretty=format:%H').read()
 227     print 'record', cset, '->', vvv
 228     hgvers[str(cset)] = vvv
 229
 230 if hgnewcsets >= opt_nrepack and opt_nrepack != -1:
 231     os.system('git-repack -a -d')
 232
 233 # write the state for incrementals
 234 if state:
 235     print 'Writing state'
 236     f = open(state, 'w')
 237     pickle.dump(hgvers, f)
 238
 239 # vim: et ts=8 sw=4 sts=4