##// END OF EJS Templates
copies: introduce the hg-cpython wrapper for `combine_changeset_copies`...
copies: introduce the hg-cpython wrapper for `combine_changeset_copies` This patch focus on the `hg-cpython` part of this work. Bridging the python code with the new rust code in `hg-core`. The next patch will actually plug this in the python code. The rust code use multiple Python callback, python related error within this callback are not expected unless they are a programming error or a data corruption. In addition, these callback will slowly be replaced by native Rust code. For these reasons, we use will deal with unexpected error within this callback using rust Panic and let the `rust-cpython` layer deal with raising a Python exception. The code dealing with the ChangedFile instance is repeating itself a lot. I did not factor these duplication out because that whole code will get replaced by entirely different one in a handful of changesets. Differential Revision: https://phab.mercurial-scm.org/D9298

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dirstateguard.py
84 lines | 2.6 KiB | text/x-python | PythonLexer
# 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 = b'dirstate.backup.%s.%d' % (name, id(self))
self._narrowspecbackupname = b'narrowspec.backup.%s.%d' % (
name,
id(self),
)
repo.dirstate.savebackup(repo.currenttransaction(), self._backupname)
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
)
narrowspec.clearwcbackup(self._repo, self._narrowspecbackupname)
self._active = False
self._closed = True
def _abort(self):
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()