Add a family of git-commands to assist with the management of multiple CLs/branches.
git-rebase-update - ensure all branches are up to date
git-new-branch - create branches
git-rename-branch - rename a branch while preserving parentage relationships
git-reparent-branch - change the parent of a branch, including rebasing it correctly onto that new parent.
git-squash-branch - collapse a branch into a single commit
git-upstream-diff - show the diff between the current branch and it's upstream branch
git-mark-merge-base - explicitly set what you want the above tools to consider the merge-base for the current branch.
R=agable@chromium.org, hinoka@chromium.org, stip@chromium.org, szager@chromium.org
BUG=261738
Review URL: https://codereview.chromium.org/184253003
git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@259520 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/git_common.py b/git_common.py
index 1296286..284c18c 100644
--- a/git_common.py
+++ b/git_common.py
@@ -1,4 +1,4 @@
-# Copyright 2013 The Chromium Authors. All rights reserved.
+# Copyright 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.
@@ -16,10 +16,12 @@
import binascii
+import collections
import contextlib
import functools
import logging
import os
+import re
import signal
import sys
import tempfile
@@ -29,6 +31,14 @@
GIT_EXE = 'git.bat' if sys.platform.startswith('win') else 'git'
+TEST_MODE = False
+
+FREEZE = 'FREEZE'
+FREEZE_SECTIONS = {
+ 'indexed': 'soft',
+ 'unindexed': 'mixed'
+}
+FREEZE_MATCHER = re.compile(r'%s.(%s)' % (FREEZE, '|'.join(FREEZE_SECTIONS)))
class BadCommitRefException(Exception):
@@ -200,14 +210,48 @@
del self._thread
+def once(function):
+ """@Decorates |function| so that it only performs its action once, no matter
+ how many times the decorated |function| is called."""
+ def _inner_gen():
+ yield function()
+ while True:
+ yield
+ return _inner_gen().next
+
+
+## Git functions
+
+
+def branch_config(branch, option, default=None):
+ return config('branch.%s.%s' % (branch, option), default=default)
+
+
+def branch_config_map(option):
+ """Return {branch: <|option| value>} for all branches."""
+ try:
+ reg = re.compile(r'^branch\.(.*)\.%s$' % option)
+ lines = run('config', '--get-regexp', reg.pattern).splitlines()
+ return {reg.match(k).group(1): v for k, v in (l.split() for l in lines)}
+ except subprocess2.CalledProcessError:
+ return {}
+
+
def branches(*args):
- NO_BRANCH = ('* (no branch)', '* (detached from ')
+ NO_BRANCH = ('* (no branch', '* (detached from ')
for line in run('branch', *args).splitlines():
if line.startswith(NO_BRANCH):
continue
yield line.split()[-1]
+def config(option, default=None):
+ try:
+ return run('config', '--get', option) or default
+ except subprocess2.CalledProcessError:
+ return default
+
+
def config_list(option):
try:
return run('config', '--get-all', option).split()
@@ -216,66 +260,96 @@
def current_branch():
- return run('rev-parse', '--abbrev-ref', 'HEAD')
-
-
-def parse_commitrefs(*commitrefs):
- """Returns binary encoded commit hashes for one or more commitrefs.
-
- A commitref is anything which can resolve to a commit. Popular examples:
- * 'HEAD'
- * 'origin/master'
- * 'cool_branch~2'
- """
try:
- return map(binascii.unhexlify, hash_multi(*commitrefs))
+ return run('rev-parse', '--abbrev-ref', 'HEAD')
except subprocess2.CalledProcessError:
- raise BadCommitRefException(commitrefs)
+ return None
-def run(*cmd, **kwargs):
- """Runs a git command. Returns stdout as a string.
+def del_branch_config(branch, option, scope='local'):
+ del_config('branch.%s.%s' % (branch, option), scope=scope)
- If logging is DEBUG, we'll print the command before we run it.
- kwargs
- autostrip (bool) - Strip the output. Defaults to True.
+def del_config(option, scope='local'):
+ try:
+ run('config', '--' + scope, '--unset', option)
+ except subprocess2.CalledProcessError:
+ pass
+
+
+def freeze():
+ took_action = False
+
+ try:
+ run('commit', '-m', FREEZE + '.indexed')
+ took_action = True
+ except subprocess2.CalledProcessError:
+ pass
+
+ try:
+ run('add', '-A')
+ run('commit', '-m', FREEZE + '.unindexed')
+ took_action = True
+ except subprocess2.CalledProcessError:
+ pass
+
+ if not took_action:
+ return 'Nothing to freeze.'
+
+
+def get_branch_tree():
+ """Get the dictionary of {branch: parent}, compatible with topo_iter.
+
+ Returns a tuple of (skipped, <branch_tree dict>) where skipped is a set of
+ branches without upstream branches defined.
"""
- autostrip = kwargs.pop('autostrip', True)
+ skipped = set()
+ branch_tree = {}
- retstream, proc = stream_proc(*cmd, **kwargs)
- ret = retstream.read()
- retcode = proc.wait()
- if retcode != 0:
- raise subprocess2.CalledProcessError(retcode, cmd, os.getcwd(), ret, None)
+ for branch in branches():
+ parent = upstream(branch)
+ if not parent:
+ skipped.add(branch)
+ continue
+ branch_tree[branch] = parent
- if autostrip:
- ret = (ret or '').strip()
- return ret
+ return skipped, branch_tree
-def stream_proc(*cmd, **kwargs):
- """Runs a git command. Returns stdout as a file.
+def get_or_create_merge_base(branch, parent=None):
+ """Finds the configured merge base for branch.
- If logging is DEBUG, we'll print the command before we run it.
+ If parent is supplied, it's used instead of calling upstream(branch).
"""
- cmd = (GIT_EXE,) + cmd
- logging.debug('Running %s', ' '.join(repr(tok) for tok in cmd))
- proc = subprocess2.Popen(cmd, stderr=subprocess2.VOID,
- stdout=subprocess2.PIPE, **kwargs)
- return proc.stdout, proc
+ base = branch_config(branch, 'base')
+ if base:
+ try:
+ run('merge-base', '--is-ancestor', base, branch)
+ logging.debug('Found pre-set merge-base for %s: %s', branch, base)
+ except subprocess2.CalledProcessError:
+ logging.debug('Found WRONG pre-set merge-base for %s: %s', branch, base)
+ base = None
+
+ if not base:
+ base = run('merge-base', parent or upstream(branch), branch)
+ manual_merge_base(branch, base)
+
+ return base
-def stream(*cmd, **kwargs):
- return stream_proc(*cmd, **kwargs)[0]
+def hash_multi(*reflike):
+ return run('rev-parse', *reflike).splitlines()
def hash_one(reflike):
return run('rev-parse', reflike)
-def hash_multi(*reflike):
- return run('rev-parse', *reflike).splitlines()
+def in_rebase():
+ git_dir = run('rev-parse', '--git-dir')
+ return (
+ os.path.exists(os.path.join(git_dir, 'rebase-merge')) or
+ os.path.exists(os.path.join(git_dir, 'rebase-apply')))
def intern_f(f, kind='blob'):
@@ -292,10 +366,216 @@
return ret
+def is_dormant(branch):
+ # TODO(iannucci): Do an oldness check?
+ return branch_config(branch, 'dormant', 'false') != 'false'
+
+
+def manual_merge_base(branch, base):
+ set_branch_config(branch, 'base', base)
+
+
+def mktree(treedict):
+ """Makes a git tree object and returns its hash.
+
+ See |tree()| for the values of mode, type, and ref.
+
+ Args:
+ treedict - { name: (mode, type, ref) }
+ """
+ with tempfile.TemporaryFile() as f:
+ for name, (mode, typ, ref) in treedict.iteritems():
+ f.write('%s %s %s\t%s\0' % (mode, typ, ref, name))
+ f.seek(0)
+ return run('mktree', '-z', stdin=f)
+
+
+def parse_commitrefs(*commitrefs):
+ """Returns binary encoded commit hashes for one or more commitrefs.
+
+ A commitref is anything which can resolve to a commit. Popular examples:
+ * 'HEAD'
+ * 'origin/master'
+ * 'cool_branch~2'
+ """
+ try:
+ return map(binascii.unhexlify, hash_multi(*commitrefs))
+ except subprocess2.CalledProcessError:
+ raise BadCommitRefException(commitrefs)
+
+
+RebaseRet = collections.namedtuple('RebaseRet', 'success message')
+
+
+def rebase(parent, start, branch, abort=False):
+ """Rebases |start|..|branch| onto the branch |parent|.
+
+ Args:
+ parent - The new parent ref for the rebased commits.
+ start - The commit to start from
+ branch - The branch to rebase
+ abort - If True, will call git-rebase --abort in the event that the rebase
+ doesn't complete successfully.
+
+ Returns a namedtuple with fields:
+ success - a boolean indicating that the rebase command completed
+ successfully.
+ message - if the rebase failed, this contains the stdout of the failed
+ rebase.
+ """
+ try:
+ args = ['--onto', parent, start, branch]
+ if TEST_MODE:
+ args.insert(0, '--committer-date-is-author-date')
+ run('rebase', *args)
+ return RebaseRet(True, '')
+ except subprocess2.CalledProcessError as cpe:
+ if abort:
+ run('rebase', '--abort')
+ return RebaseRet(False, cpe.output)
+
+
+def remove_merge_base(branch):
+ del_branch_config(branch, 'base')
+
+
+def root():
+ return config('depot-tools.upstream', 'origin/master')
+
+
+def run(*cmd, **kwargs):
+ """The same as run_with_stderr, except it only returns stdout."""
+ return run_with_stderr(*cmd, **kwargs)[0]
+
+
+def run_stream(*cmd, **kwargs):
+ """Runs a git command. Returns stdout as a PIPE (file-like object).
+
+ stderr is dropped to avoid races if the process outputs to both stdout and
+ stderr.
+ """
+ kwargs.setdefault('stderr', subprocess2.VOID)
+ kwargs.setdefault('stdout', subprocess2.PIPE)
+ cmd = (GIT_EXE,) + cmd
+ proc = subprocess2.Popen(cmd, **kwargs)
+ return proc.stdout
+
+
+def run_with_stderr(*cmd, **kwargs):
+ """Runs a git command.
+
+ Returns (stdout, stderr) as a pair of strings.
+
+ kwargs
+ autostrip (bool) - Strip the output. Defaults to True.
+ indata (str) - Specifies stdin data for the process.
+ """
+ kwargs.setdefault('stdin', subprocess2.PIPE)
+ kwargs.setdefault('stdout', subprocess2.PIPE)
+ kwargs.setdefault('stderr', subprocess2.PIPE)
+ autostrip = kwargs.pop('autostrip', True)
+ indata = kwargs.pop('indata', None)
+
+ cmd = (GIT_EXE,) + cmd
+ proc = subprocess2.Popen(cmd, **kwargs)
+ ret, err = proc.communicate(indata)
+ retcode = proc.wait()
+ if retcode != 0:
+ raise subprocess2.CalledProcessError(retcode, cmd, os.getcwd(), ret, err)
+
+ if autostrip:
+ ret = (ret or '').strip()
+ err = (err or '').strip()
+
+ return ret, err
+
+
+def set_branch_config(branch, option, value, scope='local'):
+ set_config('branch.%s.%s' % (branch, option), value, scope=scope)
+
+
+def set_config(option, value, scope='local'):
+ run('config', '--' + scope, option, value)
+
+def squash_current_branch(header=None, merge_base=None):
+ header = header or 'git squash commit.'
+ merge_base = merge_base or get_or_create_merge_base(current_branch())
+ log_msg = header + '\n'
+ if log_msg:
+ log_msg += '\n'
+ log_msg += run('log', '--reverse', '--format=%H%n%B', '%s..HEAD' % merge_base)
+ run('reset', '--soft', merge_base)
+ run('commit', '-a', '-F', '-', indata=log_msg)
+
+
def tags(*args):
return run('tag', *args).splitlines()
+def thaw():
+ took_action = False
+ for sha in (s.strip() for s in run_stream('rev-list', 'HEAD').xreadlines()):
+ msg = run('show', '--format=%f%b', '-s', 'HEAD')
+ match = FREEZE_MATCHER.match(msg)
+ if not match:
+ if not took_action:
+ return 'Nothing to thaw.'
+ break
+
+ run('reset', '--' + FREEZE_SECTIONS[match.group(1)], sha)
+ took_action = True
+
+
+def topo_iter(branch_tree, top_down=True):
+ """Generates (branch, parent) in topographical order for a branch tree.
+
+ Given a tree:
+
+ A1
+ B1 B2
+ C1 C2 C3
+ D1
+
+ branch_tree would look like: {
+ 'D1': 'C3',
+ 'C3': 'B2',
+ 'B2': 'A1',
+ 'C1': 'B1',
+ 'C2': 'B1',
+ 'B1': 'A1',
+ }
+
+ It is OK to have multiple 'root' nodes in your graph.
+
+ if top_down is True, items are yielded from A->D. Otherwise they're yielded
+ from D->A. Within a layer the branches will be yielded in sorted order.
+ """
+ branch_tree = branch_tree.copy()
+
+ # TODO(iannucci): There is probably a more efficient way to do these.
+ if top_down:
+ while branch_tree:
+ this_pass = [(b, p) for b, p in branch_tree.iteritems()
+ if p not in branch_tree]
+ assert this_pass, "Branch tree has cycles: %r" % branch_tree
+ for branch, parent in sorted(this_pass):
+ yield branch, parent
+ del branch_tree[branch]
+ else:
+ parent_to_branches = collections.defaultdict(set)
+ for branch, parent in branch_tree.iteritems():
+ parent_to_branches[parent].add(branch)
+
+ while branch_tree:
+ this_pass = [(b, p) for b, p in branch_tree.iteritems()
+ if not parent_to_branches[b]]
+ assert this_pass, "Branch tree has cycles: %r" % branch_tree
+ for branch, parent in sorted(this_pass):
+ yield branch, parent
+ parent_to_branches[parent].discard(branch)
+ del branch_tree[branch]
+
+
def tree(treeref, recurse=False):
"""Returns a dict representation of a git tree object.
@@ -339,18 +619,3 @@
branch+'@{upstream}')
except subprocess2.CalledProcessError:
return None
-
-
-def mktree(treedict):
- """Makes a git tree object and returns its hash.
-
- See |tree()| for the values of mode, type, and ref.
-
- Args:
- treedict - { name: (mode, type, ref) }
- """
- with tempfile.TemporaryFile() as f:
- for name, (mode, typ, ref) in treedict.iteritems():
- f.write('%s %s %s\t%s\0' % (mode, typ, ref, name))
- f.seek(0)
- return run('mktree', '-z', stdin=f)