hgext/narrow/narrowrepo.py

revlog: skip over empty revision when looking for delta base

There is no point in keeping an empty revision in the middle of a chain since
they won't contribute any data. So we filter them out when looking for a valid
base delta.

# 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