hg-to-git.py
#!/usr/bin/env python
""" hg-to-git.py - A Mercurial to GIT converter
Copyright (C)2007 Stelian Pop <stelian@popies.net>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
"""
import os, os.path, sys
import tempfile, pickle, getopt
import re
if sys.hexversion < 0x02030000:
# The behavior of the pickle module changed significantly in 2.3
sys.stderr.write("hg-to-git.py: requires Python 2.3 or later.\n")
sys.exit(1)
# Maps hg version -> git version
hgvers = {}
# List of children for each hg revision
hgchildren = {}
# List of parents for each hg revision
hgparents = {}
# Current branch for each hg revision
hgbranch = {}
# Number of new changesets converted from hg
hgnewcsets = 0
#------------------------------------------------------------------------------
def usage():
print """\
%s: [OPTIONS] <hgprj>
options:
-s, --gitstate=FILE: name of the state to be saved/read
for incrementals
-n, --nrepack=INT: number of changesets that will trigger
a repack (default=0, -1 to deactivate)
-v, --verbose: be verbose
required:
hgprj: name of the HG project to import (directory)
""" % sys.argv[0]
#------------------------------------------------------------------------------
def getgitenv(user, date):
env = ''
elems = re.compile('(.*?)\s+<(.*)>').match(user)
if elems:
env += 'export GIT_AUTHOR_NAME="%s" ;' % elems.group(1)
env += 'export GIT_COMMITTER_NAME="%s" ;' % elems.group(1)
env += 'export GIT_AUTHOR_EMAIL="%s" ;' % elems.group(2)
env += 'export GIT_COMMITTER_EMAIL="%s" ;' % elems.group(2)
else:
env += 'export GIT_AUTHOR_NAME="%s" ;' % user
env += 'export GIT_COMMITTER_NAME="%s" ;' % user
env += 'export GIT_AUTHOR_EMAIL= ;'
env += 'export GIT_COMMITTER_EMAIL= ;'
env += 'export GIT_AUTHOR_DATE="%s" ;' % date
env += 'export GIT_COMMITTER_DATE="%s" ;' % date
return env
#------------------------------------------------------------------------------
state = ''
opt_nrepack = 0
verbose = False
try:
opts, args = getopt.getopt(sys.argv[1:], 's:t:n:v', ['gitstate=', 'tempdir=', 'nrepack=', 'verbose'])
for o, a in opts:
if o in ('-s', '--gitstate'):
state = a
state = os.path.abspath(state)
if o in ('-n', '--nrepack'):
opt_nrepack = int(a)
if o in ('-v', '--verbose'):
verbose = True
if len(args) != 1:
raise Exception('params')
except:
usage()
sys.exit(1)
hgprj = args[0]
os.chdir(hgprj)
if state:
if os.path.exists(state):
if verbose:
print 'State does exist, reading'
f = open(state, 'r')
hgvers = pickle.load(f)
else:
print 'State does not exist, first run'
sock = os.popen('hg tip --template "{rev}"')
tip = sock.read()
if sock.close():
sys.exit(1)
if verbose:
print 'tip is', tip
# Calculate the branches
if verbose:
print 'analysing the branches...'
hgchildren["0"] = ()
hgparents["0"] = (None, None)
hgbranch["0"] = "master"
for cset in range(1, int(tip) + 1):
hgchildren[str(cset)] = ()
prnts = os.popen('hg log -r %d --template "{parents}"' % cset).read().strip().split(' ')
prnts = map(lambda x: x[:x.find(':')], prnts)
if prnts[0] != '':
parent = prnts[0].strip()
else:
parent = str(cset - 1)
hgchildren[parent] += ( str(cset), )
if len(prnts) > 1:
mparent = prnts[1].strip()
hgchildren[mparent] += ( str(cset), )
else:
mparent = None
hgparents[str(cset)] = (parent, mparent)
if mparent:
# For merge changesets, take either one, preferably the 'master' branch
if hgbranch[mparent] == 'master':
hgbranch[str(cset)] = 'master'
else:
hgbranch[str(cset)] = hgbranch[parent]
else:
# Normal changesets
# For first children, take the parent branch, for the others create a new branch
if hgchildren[parent][0] == str(cset):
hgbranch[str(cset)] = hgbranch[parent]
else:
hgbranch[str(cset)] = "branch-" + str(cset)
if not hgvers.has_key("0"):
print 'creating repository'
os.system('git init')
# loop through every hg changeset
for cset in range(int(tip) + 1):
# incremental, already seen
if hgvers.has_key(str(cset)):
continue
hgnewcsets += 1
# get info
log_data = os.popen('hg log -r %d --template "{tags}\n{date|date}\n{author}\n"' % cset).readlines()
tag = log_data[0].strip()
date = log_data[1].strip()
user = log_data[2].strip()
parent = hgparents[str(cset)][0]
mparent = hgparents[str(cset)][1]
#get comment
(fdcomment, filecomment) = tempfile.mkstemp()
csetcomment = os.popen('hg log -r %d --template "{desc}"' % cset).read().strip()
os.write(fdcomment, csetcomment)
os.close(fdcomment)
print '-----------------------------------------'
print 'cset:', cset
print 'branch:', hgbranch[str(cset)]
print 'user:', user
print 'date:', date
print 'comment:', csetcomment
if parent:
print 'parent:', parent
if mparent:
print 'mparent:', mparent
if tag:
print 'tag:', tag
print '-----------------------------------------'
# checkout the parent if necessary
if cset != 0:
if hgbranch[str(cset)] == "branch-" + str(cset):
print 'creating new branch', hgbranch[str(cset)]
os.system('git checkout -b %s %s' % (hgbranch[str(cset)], hgvers[parent]))
else:
print 'checking out branch', hgbranch[str(cset)]
os.system('git checkout %s' % hgbranch[str(cset)])
# merge
if mparent:
if hgbranch[parent] == hgbranch[str(cset)]:
otherbranch = hgbranch[mparent]
else:
otherbranch = hgbranch[parent]
print 'merging', otherbranch, 'into', hgbranch[str(cset)]
os.system(getgitenv(user, date) + 'git merge --no-commit -s ours "" %s %s' % (hgbranch[str(cset)], otherbranch))
# remove everything except .git and .hg directories
os.system('find . \( -path "./.hg" -o -path "./.git" \) -prune -o ! -name "." -print | xargs rm -rf')
# repopulate with checkouted files
os.system('hg update -C %d' % cset)
# add new files
os.system('git ls-files -x .hg --others | git update-index --add --stdin')
# delete removed files
os.system('git ls-files -x .hg --deleted | git update-index --remove --stdin')
# commit
os.system(getgitenv(user, date) + 'git commit --allow-empty --allow-empty-message -a -F %s' % filecomment)
os.unlink(filecomment)
# tag
if tag and tag != 'tip':
os.system(getgitenv(user, date) + 'git tag %s' % tag)
# delete branch if not used anymore...
if mparent and len(hgchildren[str(cset)]):
print "Deleting unused branch:", otherbranch
os.system('git branch -d %s' % otherbranch)
# retrieve and record the version
vvv = os.popen('git show --quiet --pretty=format:%H').read()
print 'record', cset, '->', vvv
hgvers[str(cset)] = vvv
if hgnewcsets >= opt_nrepack and opt_nrepack != -1:
os.system('git repack -a -d')
# write the state for incrementals
if state:
if verbose:
print 'Writing state'
f = open(state, 'w')
pickle.dump(hgvers, f)
# vim: et ts=8 sw=4 sts=4