Mercurial > hg
view mercurial/dirstateguard.py @ 40042:208303a8172c
obsolete: explicitly track folds inside the markers
We now record information to be able to recognize "fold" event from
obsolescence markers. To do so, we track the following pieces of information:
a) a fold ID. Unique to that fold (per successor),
b) the number of predecessors,
c) the index of the predecessor in that fold.
We will now be able to create an algorithm able to find "predecessorssets".
We now store this data in the generic "metadata" field of the markers.
Updating the format to have a more compact storage for this would be useful.
This way of tracking a fold through multiple markers could be applied to split
too. This would have two advantages:
1) We get a simpler format, since number of successors is limited to [0-1].
2) We can better deal with situations where only some of the split successors
are pushed to a remote repository.
We should look into the relevance of such a change before updating the on-disk
format.
note: unlike splits, folds do not have to deal with cases where only some of
the markers have been synchronized. As they all share the same successor
changesets, they are all relevant to the same nodes.
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Wed, 26 Sep 2018 23:50:14 +0200 |
parents | ad24b581e4d9 |
children | b74481038438 |
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# dirstateguard.py - class to allow restoring dirstate after failure # # Copyright 2005-2007 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. from __future__ import absolute_import from .i18n import _ from . import ( error, narrowspec, util, ) class dirstateguard(util.transactional): '''Restore dirstate at unexpected failure. At the construction, this class does: - write current ``repo.dirstate`` out, and - save ``.hg/dirstate`` into the backup file This restores ``.hg/dirstate`` from backup file, if ``release()`` is invoked before ``close()``. This just removes the backup file at ``close()`` before ``release()``. ''' def __init__(self, repo, name): self._repo = repo self._active = False self._closed = False self._backupname = 'dirstate.backup.%s.%d' % (name, id(self)) self._narrowspecbackupname = ('narrowspec.backup.%s.%d' % (name, id(self))) repo.dirstate.savebackup(repo.currenttransaction(), self._backupname) narrowspec.savebackup(repo, self._narrowspecbackupname) self._active = True def __del__(self): if self._active: # still active # this may occur, even if this class is used correctly: # for example, releasing other resources like transaction # may raise exception before ``dirstateguard.release`` in # ``release(tr, ....)``. self._abort() def close(self): if not self._active: # already inactivated msg = (_("can't close already inactivated backup: %s") % self._backupname) raise error.Abort(msg) self._repo.dirstate.clearbackup(self._repo.currenttransaction(), self._backupname) narrowspec.clearbackup(self._repo, self._narrowspecbackupname) self._active = False self._closed = True def _abort(self): narrowspec.restorebackup(self._repo, self._narrowspecbackupname) self._repo.dirstate.restorebackup(self._repo.currenttransaction(), self._backupname) self._active = False def release(self): if not self._closed: if not self._active: # already inactivated msg = (_("can't release already inactivated backup: %s") % self._backupname) raise error.Abort(msg) self._abort()