Add git-reup and friends

git_rebase_update.py

+#!/usr/bin/python
+# Copyright (c) 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+import logging

[Ryan Tseng, 2014/02/28 21:22:05]

2 lines before line 5 + sort

+import sys
+import collections
+
+from pprint import pformat
+
+from subprocess2 import CalledProcessError
+
+from git_squash_branch import squash
+

[agable, 2014/02/28 20:14:16]

No newline here, and put git_squash_branch bellow git_common.

+from git_common import run, root, upstream
+from git_common import branches, current_branch, get_or_create_merge_base_tag
+from git_common import clean_refs, hash_one
+
+RebaseRet = collections.namedtuple('TryRebaseRet', 'success message')
+
+
+def bclean():

[Ryan Tseng, 2014/02/28 21:22:05]

What does this stand for?

+  merged = list(branches('--merged', root()))
+
+  logging.debug('merged: %s', merged)
+
+  upstreams = {}
+  downstreams = collections.defaultdict(list)
+  for branch in branches():
+    try:
+      parent = upstream(branch)
+      upstreams[branch] = parent
+      downstreams[parent].append(branch)
+    except CalledProcessError:
+      pass
+
+  logging.debug('upstreams: %s', upstreams)
+  logging.debug('downstreams: %s', downstreams)
+
+  if current_branch() in merged:
+    run('checkout', root())
+  for branch in merged:
+    for down in downstreams[branch]:
+      if down not in merged:
+        run('branch', '--set-upstream-to', upstreams[branch], down)
+        print ('Reparented %s to track %s (was tracking %s)'
+               % (down, upstreams[branch], branch))
+    print run('branch', '-d', branch)
+
+  return 0
+
+
+def rebase(parent, start, branch, abort=False):
+  try:
+    run('rebase', '--onto', parent, start, branch)
+    return RebaseRet(True, '')
+  except CalledProcessError as cpe:
+    if abort:
+      run('rebase', '--abort')
+    return RebaseRet(False, cpe.output)
+
+
+def clean_branch(branch, parent, starting_ref):
+  if (hash_one(parent) != hash_one(starting_ref)

[agable, 2014/02/28 20:14:16]

Main line of code should be at top level. Reverse the test and return inside it.

+      and hash_one(branch) != hash_one(starting_ref)):
+    print 'Rebasing:', branch
+
+    # Try a plain rebase first
+    if rebase(parent, starting_ref, branch, abort=True).success:
+      return
+
+    # Maybe squashing will help?
+    print "Failed! Attempting to squash", branch, "...",
+    squash_branch = branch+"_squash_attempt"
+    run('checkout', '-b', squash_branch)
+    squash()
+
+    squash_ret = rebase(parent, starting_ref, squash_branch, abort=True)
+    run('checkout', branch)
+    run('branch', '-D', squash_branch)
+
+    if squash_ret.success:
+      print 'Success!'
+      squash()
+    final_rebase = rebase(parent, starting_ref, branch)
+    assert final_rebase.success == squash_ret.success

[agable, 2014/02/28 20:14:16]

Add error message here.

+
+    if not squash_ret.success:
+      print squash_ret.message
+      print 'Failure :('
+      print 'Your working copy is in mid-rebase. Please completely resolve and'

[Ryan Tseng, 2014/02/28 21:22:05]

Does this leave HEAD mid rebase?
I think we'll need some instructions about what they do next, (edit files,
remove >>>, ===, <<< lines, add files, git --rebase continue, or git  rebase
--abort to exit).  "Completely resolve" is a bit confusing for git noobies.

[iannucci, 2014/03/20 10:59:37]

It also prints the standard git rebase boilerplate. I don't think adding more
output here is appropriate. I also added some more checks in case they try to
run re-up without resolving things.

+      print 'run `git reup` again.'
+      sys.exit(1)
+
+
+def main():
+  # TODO(iannucci): use argparse

[agable, 2014/02/28 20:14:16]

Probably do this now (less important than the other use of argparse, since
you're only getting one argument right now).

[Ryan Tseng, 2014/02/28 21:22:05]

We at least need a usage string behind --help.  "reup" is not self evident.

+  # TODO(iannucci): have a way to set log level
+  if '--clean' in sys.argv:
+    clean_refs()
+    return 0
+
+  # TODO(iannucci): check for a clean working dir
+  # TODO(iannucci): Tag merge bases more intelligently
+  # TODO(iannucci): Find collapsible branches in a smarter way
+
+  # TODO(iannucci): Allow for root() to be a tag
+  #                 * update all remotes + tags
+  #                 * rebase to tag instead of to branch
+  #                 * when creating a new branch, use the tag as the ref
+  #                 * still need 'upstream' to be origin/master?
+  #                   * configurable?
+
+  orig_branch = current_branch()
+  if orig_branch == 'HEAD':
+    orig_branch = hash_one('HEAD')
+
+  if 'origin' in run('remote').splitlines():

[Ryan Tseng, 2014/02/28 21:22:05]

splitlines() is probably unnecessary.

+    run('fetch', 'origin', stderr=None)

[Ryan Tseng, 2014/02/28 21:22:05]

This might take a while, can we stream the output?

+  else:
+    run('svn', 'fetch', stderr=None)
+  branch_tree = {}
+  for branch in branches():
+    parent = upstream(branch)
+    if not parent:
+      print 'Skipping %s: No upstream specified' % branch
+      continue
+    branch_tree[branch] = parent
+
+  starting_refs = {}
+  for branch, parent in branch_tree.iteritems():
+    starting_refs[branch] = get_or_create_merge_base_tag(branch, parent)
+
+  logging.debug('branch_tree: %s', pformat(branch_tree))
+  logging.debug('starting_refs: %s', pformat(starting_refs))
+
+  # XXX There is a more efficient way to do this, but for now...

[Ryan Tseng, 2014/02/28 21:22:05]

XXX?

+  while branch_tree:
+    this_pass = [i for i in branch_tree.items() if i[1] not in branch_tree]
+    for branch, parent in this_pass:
+      clean_branch(branch, parent, starting_refs[branch])
+      del branch_tree[branch]
+
+  clean_refs()
+
+  bclean()
+
+  if orig_branch in branches():
+    run('checkout', orig_branch)
+  else:
+    run('checkout', root())
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())