# dirstateguard.py - class to allow restoring dirstate after failure # # Copyright 2005-2007 Olivia Mackall # # 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()