hgext/narrow/narrowrepo.py

localrepo: do not cache auditor/nofsauditor which would make reference cycle

Before, self.auditor and self.nofsauditor held self through self._checknested,
and the following code couldn't free a repo by ref-counting.

  def main():
      repo = localrepo.localrepository(uimod.ui(), '../testrepos/hello')
  main()

With this change, the cache of the nofsauditor is limited to a single match
session. I think that's okay as the nofsauditor doesn't do any filesystem
access. Alternatively, maybe we can remove the callback from nofsauditor
since it isn't used unless realfs=True, but I have no idea whether it is
a bug or not.

# narrowrepo.py - repository which supports narrow revlogs, lazy loading
#
# Copyright 2017 Google, Inc.
#
# 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 . import (
    narrowdirstate,
    narrowrevlog,
)

def wraprepo(repo):
    """Enables narrow clone functionality on a single local repository."""

    class narrowrepository(repo.__class__):

        def file(self, f):
            fl = super(narrowrepository, self).file(f)
            narrowrevlog.makenarrowfilelog(fl, self.narrowmatch())
            return fl

        def _makedirstate(self):
            dirstate = super(narrowrepository, self)._makedirstate()
            return narrowdirstate.wrapdirstate(self, dirstate)

    repo.__class__ = narrowrepository