Mercurial > hg
view mercurial/dirstateguard.py @ 47072:4c041c71ec01
revlog: introduce an explicit tracking of what the revlog is about
Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.
In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.
So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.
The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.
Differential Revision: https://phab.mercurial-scm.org/D10352
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 06 Apr 2021 05:20:24 +0200 |
parents | 222a42ac5b2d |
children | 6000f5b25c9b |
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# dirstateguard.py - class to allow restoring dirstate after failure # # Copyright 2005-2007 Olivia Mackall <olivia@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 import os from .i18n import _ from . import ( error, narrowspec, requirements, 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 def getname(prefix): fd, fname = repo.vfs.mkstemp(prefix=prefix) os.close(fd) return fname self._backupname = getname(b'dirstate.backup.%s.' % name) repo.dirstate.savebackup(repo.currenttransaction(), self._backupname) # Don't make this the empty string, things may join it with stuff and # blindly try to unlink it, which could be bad. self._narrowspecbackupname = None if requirements.NARROW_REQUIREMENT in repo.requirements: self._narrowspecbackupname = getname( b'narrowspec.backup.%s.' % name ) narrowspec.savewcbackup(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 = ( _(b"can't close already inactivated backup: %s") % self._backupname ) raise error.Abort(msg) self._repo.dirstate.clearbackup( self._repo.currenttransaction(), self._backupname ) if self._narrowspecbackupname: narrowspec.clearwcbackup(self._repo, self._narrowspecbackupname) self._active = False self._closed = True def _abort(self): if self._narrowspecbackupname: narrowspec.restorewcbackup(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 = ( _(b"can't release already inactivated backup: %s") % self._backupname ) raise error.Abort(msg) self._abort()