view mercurial/rcutil.py @ 37295:45b39c69fae0

wireproto: separate commands tables for version 1 and 2 commands

We can't easily reuse existing command handlers for version 2
commands because the response types will be different. e.g. many
commands return nodes encoded as hex. Our new wire protocol is
binary safe, so we'll wish to encode nodes as binary.

We /could/ teach each command handler to look at the protocol
handler and change behavior based on the version in use. However,
this would make logic a bit unwieldy over time and would make
it harder to design a unified protocol handler interface. I think
it's better to create a clean break between version 1 and version 2
of commands on the server.

What I imagine happening is we will have separate @wireprotocommand
functions for each protocol generation. Those functions will parse the
request, dispatch to a common function to process it, then generate
the response in its own, transport-specific manner.

This commit establishes a separate table for tracking version 1
commands from version 2 commands. The HTTP server pieces have been
updated to use this new table.

Most commands are marked as both version 1 and version 2, so there is
little practical impact to this change.

A side-effect of this change is we now rely on transport registration
in wireprototypes.TRANSPORTS and certain properties of the protocol
interface. So a test had to be updated to conform.

Differential Revision: https://phab.mercurial-scm.org/D2982

# rcutil.py - utilities about config paths, special config sections etc.
#
#  Copyright Mercurial Contributors
#
# 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

import os

from . import (
    encoding,
    pycompat,
    util,
)

if pycompat.iswindows:
    from . import scmwindows as scmplatform
else:
    from . import scmposix as scmplatform

fallbackpager = scmplatform.fallbackpager
systemrcpath = scmplatform.systemrcpath
userrcpath = scmplatform.userrcpath

def _expandrcpath(path):
    '''path could be a file or a directory. return a list of file paths'''
    p = util.expandpath(path)
    if os.path.isdir(p):
        join = os.path.join
        return [join(p, f) for f, k in util.listdir(p) if f.endswith('.rc')]
    return [p]

def envrcitems(env=None):
    '''Return [(section, name, value, source)] config items.

    The config items are extracted from environment variables specified by env,
    used to override systemrc, but not userrc.

    If env is not provided, encoding.environ will be used.
    '''
    if env is None:
        env = encoding.environ
    checklist = [
        ('EDITOR', 'ui', 'editor'),
        ('VISUAL', 'ui', 'editor'),
        ('PAGER', 'pager', 'pager'),
    ]
    result = []
    for envname, section, configname in checklist:
        if envname not in env:
            continue
        result.append((section, configname, env[envname], '$%s' % envname))
    return result

def defaultrcpath():
    '''return rc paths in default.d'''
    path = []
    defaultpath = os.path.join(util.datapath, 'default.d')
    if os.path.isdir(defaultpath):
        path = _expandrcpath(defaultpath)
    return path

def rccomponents():
    '''return an ordered [(type, obj)] about where to load configs.

    respect $HGRCPATH. if $HGRCPATH is empty, only .hg/hgrc of current repo is
    used. if $HGRCPATH is not set, the platform default will be used.

    if a directory is provided, *.rc files under it will be used.

    type could be either 'path' or 'items', if type is 'path', obj is a string,
    and is the config file path. if type is 'items', obj is a list of (section,
    name, value, source) that should fill the config directly.
    '''
    envrc = ('items', envrcitems())

    if 'HGRCPATH' in encoding.environ:
        # assume HGRCPATH is all about user configs so environments can be
        # overridden.
        _rccomponents = [envrc]
        for p in encoding.environ['HGRCPATH'].split(pycompat.ospathsep):
            if not p:
                continue
            _rccomponents.extend(('path', p) for p in _expandrcpath(p))
    else:
        normpaths = lambda paths: [('path', os.path.normpath(p)) for p in paths]
        _rccomponents = normpaths(defaultrcpath() + systemrcpath())
        _rccomponents.append(envrc)
        _rccomponents.extend(normpaths(userrcpath()))
    return _rccomponents

def defaultpagerenv():
    '''return a dict of default environment variables and their values,
    intended to be set before starting a pager.
    '''
    return {'LESS': 'FRX', 'LV': '-c'}