hgext/narrow/__init__.py

config: document the purpose of the `format` config section

The config section now have a top level documentation to clarify its intend and
usage. In particular, user are now explain when the option are taken in account
and how to convert repository.

There are an handful of experimental options in this section that does not match
its definition. They should be relocated to other section before getting out of
experimental. (see next changeset for one example).

# __init__.py - narrowhg extension
#
# 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.
'''create clones which fetch history data for subset of files (EXPERIMENTAL)'''

from __future__ import absolute_import

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

from mercurial import (
    changegroup,
    extensions,
    hg,
    localrepo,
    registrar,
    verify as verifymod,
)

from . import (
    narrowbundle2,
    narrowchangegroup,
    narrowcommands,
    narrowcopies,
    narrowpatch,
    narrowrepo,
    narrowrevlog,
    narrowtemplates,
    narrowwirepeer,
)

configtable = {}
configitem = registrar.configitem(configtable)
# Narrowhg *has* support for serving ellipsis nodes (which are used at
# least by Google's internal server), but that support is pretty
# fragile and has a lot of problems on real-world repositories that
# have complex graph topologies. This could probably be corrected, but
# absent someone needing the full support for ellipsis nodes in
# repositories with merges, it's unlikely this work will get done. As
# of this writining in late 2017, all repositories large enough for
# ellipsis nodes to be a hard requirement also enforce strictly linear
# history for other scaling reasons.
configitem('experimental', 'narrowservebrokenellipses',
           default=False,
           alias=[('narrow', 'serveellipses')],
)

# Export the commands table for Mercurial to see.
cmdtable = narrowcommands.table

def featuresetup(ui, features):
    features.add(changegroup.NARROW_REQUIREMENT)

def uisetup(ui):
    """Wraps user-facing mercurial commands with narrow-aware versions."""
    localrepo.featuresetupfuncs.add(featuresetup)
    narrowrevlog.setup()
    narrowbundle2.setup()
    narrowcommands.setup()
    narrowchangegroup.setup()
    narrowwirepeer.uisetup()

def reposetup(ui, repo):
    """Wraps local repositories with narrow repo support."""
    if not repo.local():
        return

    if changegroup.NARROW_REQUIREMENT in repo.requirements:
        narrowrepo.wraprepo(repo)
        narrowcopies.setup(repo)
        narrowpatch.setup(repo)
        narrowwirepeer.reposetup(repo)

def _verifierinit(orig, self, repo, matcher=None):
    # The verifier's matcher argument was desgined for narrowhg, so it should
    # be None from core. If another extension passes a matcher (unlikely),
    # we'll have to fail until matchers can be composed more easily.
    assert matcher is None
    orig(self, repo, repo.narrowmatch())

def extsetup(ui):
    extensions.wrapfunction(verifymod.verifier, '__init__', _verifierinit)
    extensions.wrapfunction(hg, 'postshare', narrowrepo.wrappostshare)
    extensions.wrapfunction(hg, 'copystore', narrowrepo.unsharenarrowspec)

templatekeyword = narrowtemplates.templatekeyword
revsetpredicate = narrowtemplates.revsetpredicate