repository: formalize peer interface with abstract base class
There are various interfaces for interacting with repositories
and peers. They form a contract for how one should interact with
a repo or peer object.
The contracts today aren't very well-defined or enforced. There
have been several bugs over the years where peers or repo types
have forgotten to implement certain methods. In addition, the
inheritance of some classes is wonky. For example, localrepository
doesn't inherit from an interface and the god-object nature of
that class means the repository interface isn't well-defined. Other
repository types inherit from localrepository then stub out
methods that don't make sense (e.g. statichttprepository
re-defining locking methods to fail fast).
Not having well-defined interfaces makes implementing alternate
storage backends, wire protocol transports, and repository types
difficult because it isn't clear what exactly needs to be
implemented.
This patch starts the process of attempting to establish more
order to the type system around repositories and peers.
Our first patch starts with a problem space that already has a
partial solution: peers. The peer.peerrepository class already
somewhat defines a peer interface. But it is missing a few things
and the total interface isn't well-defined because it is combined
with wireproto.wirepeer.
Our newly-established basepeer class uses the abc module to
declare an abstract base class with the properties and methods that
a generic peer must implement.
We create a new class that inherits from it. This class will hold
our other future abstract base classes / interfaces so we can expose
a unified base class/interface.
We don't yet use the new interface because subsequent additions
will break existing code without some refactoring first.
A new module (repository.py) was created to hold the interfaces.
I could have put things in peer.py. However, I have plans to
eventually add interfaces to define repository and storage types.
These almost certainly require a new module. And I figured having
all the interfaces live in one module makes sense. So I created
repository.py to be that future home.
Differential Revision: https://phab.mercurial-scm.org/D332
# pager.py - display output using a pager
#
# Copyright 2008 David Soria Parra <dsp@php.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# To load the extension, add it to your configuration file:
#
# [extension]
# pager =
#
# Run 'hg help pager' to get info on configuration.
'''browse command output with an external pager (DEPRECATED)
Forcibly enable paging for individual commands that don't typically
request pagination with the attend-<command> option. This setting
takes precedence over ignore options and defaults::
[pager]
attend-cat = false
'''
from __future__ import absolute_import
from mercurial import (
cmdutil,
commands,
dispatch,
extensions,
)
# 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'
def uisetup(ui):
def pagecmd(orig, ui, options, cmd, cmdfunc):
auto = options['pager'] == 'auto'
if auto and not ui.pageractive:
usepager = False
attend = ui.configlist('pager', 'attend', attended)
ignore = ui.configlist('pager', 'ignore')
cmds, _ = cmdutil.findcmd(cmd, commands.table)
for cmd in cmds:
var = 'attend-%s' % cmd
if ui.config('pager', var):
usepager = ui.configbool('pager', var)
break
if (cmd in attend or
(cmd not in ignore and not attend)):
usepager = True
break
if usepager:
# Slight hack: the attend list is supposed to override
# the ignore list for the pager extension, but the
# core code doesn't know about attend, so we have to
# lobotomize the ignore list so that the extension's
# behavior is preserved.
ui.setconfig('pager', 'ignore', '', 'pager')
ui.pager('extension-via-attend-' + cmd)
else:
ui.disablepager()
return orig(ui, options, cmd, cmdfunc)
extensions.wrapfunction(dispatch, '_runcommand', pagecmd)
attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']