comparison mercurial/cmdutil.py @ 30488:751639bf6fc4

dirstateguard: move to new module so I can break some layering violations

Recently in a review I noticed that localrepo almost has no reason to
import cmdutil anymore. Also, cmdutil is a little on the enormous
side, so breaking this class out strikes me as a win.

30487:88a448a12ae8

from . import (
    bookmarks,
    changelog,
    copies,
    crecord as crecordmod,
    encoding,
    error,
    formatter,
    graphmod,
    lock as lockmod,

    hint = None
    if after[1]:
        hint = after[0]
    raise error.Abort(_('no %s in progress') % task, hint=hint)

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()

30488:751639bf6fc4

from . import (
    bookmarks,
    changelog,
    copies,
    crecord as crecordmod,
    dirstateguard as dirstateguardmod,
    encoding,
    error,
    formatter,
    graphmod,
    lock as lockmod,

    hint = None
    if after[1]:
        hint = after[0]
    raise error.Abort(_('no %s in progress') % task, hint=hint)

dirstateguard = dirstateguardmod.dirstateguard