tests/pullext.py

util: extract compression code in `mercurial.utils.compression`

The code seems large enough to be worth extracting. This is similar to what was
done for various module in `mercurial/utils/`.

Since None of the compression logic takes a `ui` objet, issuing deprecation
warning is tricky. Luckly the logic does not seems to have many external users.

# pullext.py - Simple extension to test pulling
#
# Copyright 2018 Gregory Szorc <[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.

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    commands,
    error,
    extensions,
    localrepo,
    repository,
)

def clonecommand(orig, ui, repo, *args, **kwargs):
    if kwargs.get(r'include') or kwargs.get(r'exclude'):
        kwargs[r'narrow'] = True

    if kwargs.get(r'depth'):
        try:
            kwargs[r'depth'] = int(kwargs[r'depth'])
        except ValueError:
            raise error.Abort(_('--depth must be an integer'))

    return orig(ui, repo, *args, **kwargs)

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

def extsetup(ui):
    entry = extensions.wrapcommand(commands.table, b'clone', clonecommand)

    hasinclude = any(x[1] == b'include' for x in entry[1])
    hasdepth = any(x[1] == b'depth' for x in entry[1])

    if not hasinclude:
        entry[1].append((b'', b'include', [],
                         _(b'pattern of file/directory to clone')))
        entry[1].append((b'', b'exclude', [],
                         _(b'pattern of file/directory to not clone')))

    if not hasdepth:
        entry[1].append((b'', b'depth', b'',
                         _(b'ancestry depth of changesets to fetch')))

    localrepo.featuresetupfuncs.add(featuresetup)