Mercurial > hg
view mercurial/dirstateguard.py @ 39505:c6b8eab5db19
snapshot: also consider the snapshot chain of one unrelated revision
To maximize the chance of good delta chain reuse, we inject an unrelated delta
chain into our search. To do so, we search for the highest revision unrelated
to the parents of the current revision and use its snapshot chain too.
Adding this extra snapshot into the mix can have a performance impact. We'll
deal with performance impact in a later series.
author | Boris Feld <boris.feld@octobus.net> |
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date | Fri, 07 Sep 2018 11:18:45 -0400 |
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()