view tests/pullext.py @ 41247:a89b20a49c13

rust-cpython: using MissingAncestors from Python code

As precedently done with LazyAncestors on cpython.rs, we test for the
presence of the 'rustext' module.

incrementalmissingrevs() has two callers within the Mercurial core:
`setdiscovery.partialdiscovery` and the `only()` revset.

This move shows a significant discovery performance improvement
in cases where the baseline is slow: using perfdiscovery on the PyPy
repos, prepared with `contrib/discovery-helper <repo> 50 100`, we
get averaged medians of 403ms with the Rust version vs 742ms without
(about 45% better).

But there are still indications that performance can be worse in cases
the baseline is fast, possibly due to the conversion from Python to
Rust and back becoming the bottleneck. We could measure this on
mozilla-central in cases were the delta is just a few changesets.
This requires confirmation, but if that's the reason, then an
upcoming `partialdiscovery` fully in Rust should solve the problem.

Differential Revision: https://phab.mercurial-scm.org/D5551

# 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)