hgext/narrow/narrowrepo.py

revlog: rename `versionflags` to header

The variable is named as such because it contains "version" information and
"flags" information. However you mostly needs to know the code to understand the
name which is not great. The fact that this is the very first four bytes in all
revlog seems more relevant, so we rename the variable "header".

Differential Revision: https://phab.mercurial-scm.org/D10596

# 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 mercurial import wireprototypes

from . import narrowdirstate


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

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

        def peer(self):
            peer = super(narrowrepository, self).peer()
            peer._caps.add(wireprototypes.NARROWCAP)
            peer._caps.add(wireprototypes.ELLIPSESCAP)
            return peer

    repo.__class__ = narrowrepository