view mercurial/dirstateguard.py @ 32679:3d488079750b

test-clonebundles: conditionalize output for Windows

This was the fallout from 9d6031df42c8 (on stable).  Now that individual lines
can be conditionalized, it seems better to be explicit, rather than mash all of
this into one regex.  "getaddrinfo failed" was added in 4e566f513fd8 to support
Windows.

# dirstateguard.py - class to allow restoring dirstate after failure
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# 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()