config: add sanity assert that files are opened as binary
This helps with some debugging in Python 3, and shouldn't hurt
anything in Python 2. The unusual construction using getattr is done
so that StringIO/BytesIO instances can be used as well as real files.
# 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,
)
class dirstateguard(object):
'''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._suffix = '.backup.%s.%d' % (name, id(self))
repo.dirstate.savebackup(repo.currenttransaction(), self._suffix)
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: dirstate%s")
% self._suffix)
raise error.Abort(msg)
self._repo.dirstate.clearbackup(self._repo.currenttransaction(),
self._suffix)
self._active = False
self._closed = True
def _abort(self):
self._repo.dirstate.restorebackup(self._repo.currenttransaction(),
self._suffix)
self._active = False
def release(self):
if not self._closed:
if not self._active: # already inactivated
msg = (_("can't release already inactivated backup:"
" dirstate%s")
% self._suffix)
raise error.Abort(msg)
self._abort()