tests/pullext.py

discovery: compute newly discovered missing in a more efficient way

Calling "descendants" is expensive, instead, we bound the walk inside the know set
of undecided revision.

This help with discovery performance:

# without the revset '%ld' improvement
$ hg perfdiscovery -R pypy-left pypy-right
before: wall 0.675631 comb 0.680000 user 0.670000 sys 0.010000 (median of 15)
after:  wall 0.520145 comb 0.530000 user 0.510000 sys 0.020000 (median of 19)

There is another series in flight that greatly improves performances of "%ld"
substitution in `repo.revs` call. If this changeset is applied above it, we
see a similar performance boost.

# with the revset '%ld' improvement
$ hg perfdiscovery -R pypy-left pypy-right
before: wall 0.477848 comb 0.480000 user 0.480000 sys 0.000000 (median of 22)
after:  wall 0.404163 comb 0.400000 user 0.400000 sys 0.000000 (median of 24)

# 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)