view hgext/share.py @ 18831:17f6644a2fbc

blackbox: defer opening a log file until needed (issue3869) Previously, we opened the log file when creating a repo object. This was inefficient (not all repo creation is going to result in a need to log something), but more importantly it broke subrepo updates when used on NFS. * perform an update in the master repo that triggers a subrepo clone * empty subrepo already exists, and has an open, empty blackbox.log file due to it being opened eagerly/prematurely * hg decides to blow away the skeletal subrepo (see use of shutil.rmtree in subrepo._get) * we crash, due to NFS treating a delete of an open file as really a rename to a hidden ".nfs" file Now that we open the blackbox log file on demand, no file exists at the time the empty subrepo is deleted, so the above problem does not occur.
author Bryan O'Sullivan <bryano@fb.com>
date Tue, 26 Mar 2013 16:27:51 -0700
parents f0564402d059
children 02465cafb0a9
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# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''share a common history between several working directories'''

from mercurial.i18n import _
from mercurial import hg, commands, util

testedwith = 'internal'

def share(ui, source, dest=None, noupdate=False):
    """create a new shared repository

    Initialize a new repository and working directory that shares its
    history with another repository.

    .. note::
       using rollback or extensions that destroy/modify history (mq,
       rebase, etc.) can cause considerable confusion with shared
       clones. In particular, if two shared clones are both updated to
       the same changeset, and one of them destroys that changeset
       with rollback, the other clone will suddenly stop working: all
       operations will fail with "abort: working directory has unknown
       parent". The only known workaround is to use debugsetparents on
       the broken clone to reset it to a changeset that still exists
       (e.g. tip).
    """

    return hg.share(ui, source, dest, not noupdate)

def unshare(ui, repo):
    """convert a shared repository to a normal one

    Copy the store data to the repo and remove the sharedpath data.
    """

    if repo.sharedpath == repo.path:
        raise util.Abort(_("this is not a shared repo"))

    destlock = lock = None
    lock = repo.lock()
    try:
        # we use locks here because if we race with commit, we
        # can end up with extra data in the cloned revlogs that's
        # not pointed to by changesets, thus causing verify to
        # fail

        destlock = hg.copystore(ui, repo, repo.path)

        sharefile = repo.join('sharedpath')
        util.rename(sharefile, sharefile + '.old')

        repo.requirements.discard('sharedpath')
        repo._writerequirements()
    finally:
        destlock and destlock.release()
        lock and lock.release()

    # update store, spath, sopener and sjoin of repo
    repo.__init__(repo.baseui, repo.root)

cmdtable = {
    "share":
    (share,
     [('U', 'noupdate', None, _('do not create a working copy'))],
     _('[-U] SOURCE [DEST]')),
    "unshare":
    (unshare,
    [],
    ''),
}

commands.norepo += " share"