push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
# pullext.py - Simple extension to test pulling
#
# Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from mercurial.i18n import _
from mercurial import (
commands,
error,
extensions,
localrepo,
requirements,
)
def clonecommand(orig, ui, repo, *args, **kwargs):
if kwargs.get('include') or kwargs.get('exclude'):
kwargs['narrow'] = True
if kwargs.get('depth'):
try:
kwargs['depth'] = int(kwargs['depth'])
except ValueError:
raise error.Abort(_('--depth must be an integer'))
return orig(ui, repo, *args, **kwargs)
def featuresetup(ui, features):
features.add(requirements.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)