# 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,
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))
repo.dirstate.savebackup(repo.currenttransaction(), self._backupname)
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)
self._active = False
self._closed = True
def _abort(self):
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()