rust-discovery: core implementation for take_quick_sample()
This makes in particular `rand` no longer a testing dependency.
We keep a seedable random generator on the `PartialDiscovery` object
itself, to avoid lengthy initialization.
In take_quick_sample() itself, we had to avoid keeping the reference
to `self.undecided` to cope with the mutable reference introduced
by the the call to `limit_sample`, but it's still manageable without
resorting to inner mutability.
Sampling being prone to be improved in the mid-term future, testing
is minimal, amounting to checking which code path got executed.
Differential Revision: https://phab.mercurial-scm.org/D6423
# stack.py - Mercurial functions for stack definition
#
# Copyright Matt Mackall <mpm@selenic.com> and other
#
# 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 . import (
revsetlang,
scmutil,
)
def getstack(repo, rev=None):
"""return a sorted smartrev of the stack containing either rev if it is
not None or the current working directory parent.
The stack will always contain all drafts changesets which are ancestors to
the revision and are not merges.
"""
if rev is None:
rev = '.'
revspec = 'only(%s) and not public() and not ::merge()'
revset = revsetlang.formatspec(revspec, rev)
revisions = scmutil.revrange(repo, [revset])
revisions.sort()
return revisions