atomicupdate: add an experimental option to use atomictemp when updating
In some cases Mercurial truncating files when updating causes problems. It can
happens when processes are currently reading the file or with big file or on
NFS mounts.
We add an experimental option to use the atomictemp option of vfs.__call__ in
order to avoid the problem.
The localrepository.wwrite seems to assume the files are created without the
`x` flag; with atomictempfile, the new file might inherit the `x` flag from
the destination. We force remove it afterward. This code could be refactored
and the flag processing could be moved inside vfs.
This patch should be tested with
`--extra-config-opt experimental.update.atomic-file=True`
as we disabled the option by default.
Differential Revision: https://phab.mercurial-scm.org/D1882
# split.py - split a changeset into smaller ones
#
# Copyright 2015 Laurent Charignon <lcharignon@fb.com>
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""command to split a changeset into smaller ones (EXPERIMENTAL)"""
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial.node import (
nullid,
short,
)
from mercurial import (
bookmarks,
cmdutil,
commands,
error,
hg,
obsolete,
phases,
registrar,
revsetlang,
scmutil,
)
# allow people to use split without explicitly enabling rebase extension
from . import (
rebase,
)
cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
@command('^split',
[('r', 'rev', '', _("revision to split"), _('REV')),
('', 'rebase', True, _('rebase descendants after split')),
] + cmdutil.commitopts2,
_('hg split [--no-rebase] [[-r] REV]'))
def split(ui, repo, *revs, **opts):
"""split a changeset into smaller ones
Repeatedly prompt changes and commit message for new changesets until there
is nothing left in the original changeset.
If --rev was not given, split the working directory parent.
By default, rebase connected non-obsoleted descendants onto the new
changeset. Use --no-rebase to avoid the rebase.
"""
revlist = []
if opts.get('rev'):
revlist.append(opts.get('rev'))
revlist.extend(revs)
with repo.wlock(), repo.lock(), repo.transaction('split') as tr:
revs = scmutil.revrange(repo, revlist or ['.'])
if len(revs) > 1:
raise error.Abort(_('cannot split multiple revisions'))
rev = revs.first()
ctx = repo[rev]
if rev is None or ctx.node() == nullid:
ui.status(_('nothing to split\n'))
return 1
if ctx.node() is None:
raise error.Abort(_('cannot split working directory'))
# rewriteutil.precheck is not very useful here because:
# 1. null check is done above and it's more friendly to return 1
# instead of abort
# 2. mergestate check is done below by cmdutil.bailifchanged
# 3. unstable check is more complex here because of --rebase
#
# So only "public" check is useful and it's checked directly here.
if ctx.phase() == phases.public:
raise error.Abort(_('cannot split public changeset'),
hint=_("see 'hg help phases' for details"))
descendants = list(repo.revs('(%d::) - (%d)', rev, rev))
alloworphaned = obsolete.isenabled(repo, obsolete.allowunstableopt)
if opts.get('rebase'):
# Skip obsoleted descendants and their descendants so the rebase
# won't cause conflicts for sure.
torebase = list(repo.revs('%ld - (%ld & obsolete())::',
descendants, descendants))
if not alloworphaned and len(torebase) != len(descendants):
raise error.Abort(_('split would leave orphaned changesets '
'behind'))
else:
if not alloworphaned and descendants:
raise error.Abort(
_('cannot split changeset with children without rebase'))
torebase = ()
if len(ctx.parents()) > 1:
raise error.Abort(_('cannot split a merge changeset'))
cmdutil.bailifchanged(repo)
# Deactivate bookmark temporarily so it won't get moved unintentionally
bname = repo._activebookmark
if bname and repo._bookmarks[bname] != ctx.node():
bookmarks.deactivate(repo)
wnode = repo['.'].node()
top = None
try:
top = dosplit(ui, repo, tr, ctx, opts)
finally:
# top is None: split failed, need update --clean recovery.
# wnode == ctx.node(): wnode split, no need to update.
if top is None or wnode != ctx.node():
hg.clean(repo, wnode, show_stats=False)
if bname:
bookmarks.activate(repo, bname)
if torebase and top:
dorebase(ui, repo, torebase, top)
def dosplit(ui, repo, tr, ctx, opts):
committed = [] # [ctx]
# Set working parent to ctx.p1(), and keep working copy as ctx's content
# NOTE: if we can have "update without touching working copy" API, the
# revert step could be cheaper.
hg.clean(repo, ctx.p1().node(), show_stats=False)
parents = repo.changelog.parents(ctx.node())
ui.pushbuffer()
cmdutil.revert(ui, repo, ctx, parents)
ui.popbuffer() # discard "reverting ..." messages
# Any modified, added, removed, deleted result means split is incomplete
incomplete = lambda repo: any(repo.status()[:4])
# Main split loop
while incomplete(repo):
if committed:
header = (_('HG: Splitting %s. So far it has been split into:\n')
% short(ctx.node()))
for c in committed:
firstline = c.description().split('\n', 1)[0]
header += _('HG: - %s: %s\n') % (short(c.node()), firstline)
header += _('HG: Write commit message for the next split '
'changeset.\n')
else:
header = _('HG: Splitting %s. Write commit message for the '
'first split changeset.\n') % short(ctx.node())
opts.update({
'edit': True,
'interactive': True,
'message': header + ctx.description(),
})
commands.commit(ui, repo, **opts)
newctx = repo['.']
committed.append(newctx)
if not committed:
raise error.Abort(_('cannot split an empty revision'))
scmutil.cleanupnodes(repo, {ctx.node(): [c.node() for c in committed]},
operation='split')
return committed[-1]
def dorebase(ui, repo, src, dest):
rebase.rebase(ui, repo, rev=[revsetlang.formatspec('%ld', src)],
dest=revsetlang.formatspec('%d', dest))