git-gradual-push

#!/usr/bin/env python
# -*- mode:python -*-

# Copyright (c) 2014 Primiano Tucci -- www.primianotucci.com
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
# * The name of Primiano Tucci may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import os
import subprocess
import sys


_TMP_REF = 'refs/hidden/tmpupload'


def main():
  if len(sys.argv) < 4:
    print ('%s <remote> <local-branch> <remote-branch> ' +
        '[max-commits-per-push=20000]') % sys.argv[0]
    print 'E.g., %s origin master refs/heads/master 20000' % sys.argv[0]
    return 1

  remote, local_branch, remote_branch = sys.argv[1:4]
  chunk_size = int(sys.argv[4]) if len(sys.argv) > 4 else 20000

  print ('Remember to: git config credential.helper \'cache --timeout=3600\' ' +
      'to avoid surprises')

  print 'Reading rev-list for branch ', local_branch
  revs = subprocess.check_output(['git', 'rev-list', local_branch]).splitlines()

  chunks = range(0, len(revs), chunk_size)
  print 'Got %d revisions. Uploading in %d chunks' % (len(revs), len(chunks))
  chunk_count = 0
  skip = int(os.getenv('SKIP', 0))
  for i in chunks:
    chunk_count += 1
    if skip:
      skip -= 1
      continue
    rev_idx = max(len(revs) - i - chunk_size, 0)
    rev = revs[rev_idx]
    print '\nPush [%d/%d] (%d-th rev) %s -> %s' % (
        chunk_count, len(chunks), rev_idx, rev[:12], _TMP_REF)
    subprocess.check_call(['git', 'push', remote, '+%s:%s' % (rev, _TMP_REF)])

  print '\nFinal push to the actual branch (%s) + cleanup.' % remote_branch
  subprocess.check_call(['git', 'push', remote,
                         '+%s:%s' % (local_branch, remote_branch),
                         ':%s' % _TMP_REF])


if __name__ == "__main__":
  main()
  sys.exit(0)