gitsync.py

#! /usr/bin/env python

import sys

from commands import getoutput
from os import listdir, unlink
from subprocess import call
from time import sleep
from traceback import print_exc

BRANCH_MAP = {
  'default': 'master'
  }

def run(*args):
    retcode = call(args)
    if retcode:
        raise RuntimeError(repr(args))

prev = {}
git_branches = set(listdir('.hg/git/refs/heads'))
git_branches.discard('hg')

def main():
    """Update hg, export to git and push up references."""

    run('hg', 'pull', '-u')
    run('hg', 'gexport')

    branches = {}
    hg_heads = getoutput('hg branches --debug')

    for line in hg_heads.split('\n'):
        branch, rev = line.split()[:2]
        rev = rev.split(':')[1]
        branches[branch] = rev

    hg2git = {}
    mapfile = open('.hg/git-mapfile', 'rb')

    for line in mapfile:
        gitsha, hgsha = line.strip().split(' ', 1)
        hg2git[hgsha] = gitsha

    mapfile.close()

    add = {}

    for branch, hgsha in branches.iteritems():
        git_branch = BRANCH_MAP.get(branch, branch)
        add[git_branch] = hg2git[hgsha]

    for branch in list(git_branches):
        if branch not in add:
            if branch in ('master', 'tav-patches'):
                continue
            print "# Removing Branch:", branch
            git_branches.remove(branch)
            run('git', '--git-dir=.hg/git', 'push', '[email protected]:tav/go.git', ':' + branch)
            unlink('.hg/git/refs/heads/' + branch)

    changes_exist = 0

    print "# Updating Branches"
    for branch, id in add.iteritems():
        if branch in prev:
            if prev[branch] == id:
                continue
        changes_exist = 1
        git_branches.add(branch)
        ref = open('.hg/git/refs/heads/' + branch, 'wb')
        ref.write(id + '\n')
        ref.close()
        run('git', '--git-dir=.hg/git', 'push', '[email protected]:tav/go.git', branch, '-v')

    prev.clear()
    prev.update(add)

    if changes_exist:
        run('git', '--git-dir=.hg/git', 'push', '[email protected]:tav/go.git', '--tags', '--force')

while 1:
    print "# Syncing"
    try:
        main()
    except Exception:
        print_exc()
    print "# Sleeping"
    sleep(900)