hg

wireproto: support disabling bundle1 only if repo is generaldelta

I recently implemented the server.bundle1* options to control whether
bundle1 exchange is allowed.

After thinking about Mozilla's strategy for handling generaldelta
rollout a bit more, I think server operators need an additional
lever: disable bundle1 if and only if the repo is generaldelta.

bundle1 exchange for non-generaldelta repos will not have the potential
for CPU explosion that generaldelta repos do. Therefore, it makes sense
for server operators to continue to allow bundle1 exchange for
non-generaldelta repos without having to set a per-repo hgrc option
to change the policy depending on whether the repo is generaldelta.

This patch introduces a new set of options to control bundle1 behavior
for generaldelta repos. These options enable server operators to limit
bundle1 restrictions to the class of repos that can be performance
issues. It also allows server operators to tie bundle1 access to store
format. In many server environments (including Mozilla's), legacy repos
will not be generaldelta and new repos will or might be. New repos often
aren't bound by legacy access requirements, so setting a global policy
that disallows access to new/generaldelta repos via bundle1 could be a
reasonable policy in many server environments. This patch makes this
policy very easy to implement (modify global hgrc, add options to
existing generaldelta repos to grandfather them in).

#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# 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.

import os
import sys

if os.environ.get('HGUNICODEPEDANTRY', False):
    reload(sys)
    sys.setdefaultencoding("undefined")


libdir = '@LIBDIR@'

if libdir != '@' 'LIBDIR' '@':
    if not os.path.isabs(libdir):
        libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
                              libdir)
        libdir = os.path.abspath(libdir)
    sys.path.insert(0, libdir)

# enable importing on demand to reduce startup time
try:
    from mercurial import demandimport; demandimport.enable()
except ImportError:
    import sys
    sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
                     ' '.join(sys.path))
    sys.stderr.write("(check your install and PYTHONPATH)\n")
    sys.exit(-1)

import mercurial.util
import mercurial.dispatch

for fp in (sys.stdin, sys.stdout, sys.stderr):
    mercurial.util.setbinary(fp)

mercurial.dispatch.run()