( )⚙ D10221 perf-helper: add a small extension with revsets to select repository subset

This is an archive of the discontinued Mercurial Phabricator instance.

Differential D10221

perf-helper: add a small extension with revsets to select repository subset
ClosedPublic

Authored by marmoute on Mar 15 2021, 7:00 PM.

Details

Reviewers
None
Group Reviewers
hg-reviewers
Commits
rHGcb70dabe5718: perf-helper: add a small extension with revsets to select repository subset
Summary

Playing with discovery requires building interesting case. To do this we
need revsets to try to generate them. We start with a quite simple one. See
documentation for details.

Diff Detail

Repository
rHG Mercurial
Branch
default
Lint
No Linters Available
Unit
No Unit Test Coverage

Event Timeline

marmoute created this revision.Mar 15 2021, 7:00 PM
marmoute added a commit: rHGcb70dabe5718: perf-helper: add a small extension with revsets to select repository subset.Mar 16 2021, 5:59 PM
This revision was not accepted when it landed; it landed in state Needs Review.
Closed by commit rHGcb70dabe5718: perf-helper: add a small extension with revsets to select repository subset (authored by marmoute). · Explain Why
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
AMcontrib/perf-utils/subsetmaker.py (94 lines)

Diff 26386

contrib/perf-utils/subsetmaker.py

  • This file was added.
"""revset to select sample of repository
Hopefully this is useful to create interesting discovery cases.
"""
import collections
import random
from mercurial.i18n import _
from mercurial import (
registrar,
revset,
revsetlang,
smartset,
)
revsetpredicate = registrar.revsetpredicate()
@revsetpredicate(b'scratch(REVS, <count>, [seed])')
def scratch(repo, subset, x):
"""randomly remove <count> revision from the repository top
This subset is created by recursively picking changeset starting from the
heads. It can be summarized using the following algorithm::
selected = set()
for i in range(<count>):
unselected = repo.revs("not <selected>")
candidates = repo.revs("heads(<unselected>)")
pick = random.choice(candidates)
selected.add(pick)
"""
m = _(b"scratch expects revisions, count argument and an optional seed")
args = revsetlang.getargs(x, 2, 3, m)
if len(args) == 2:
x, n = args
rand = random
elif len(args) == 3:
x, n, seed = args
seed = revsetlang.getinteger(seed, _(b"seed should be a number"))
rand = random.Random(seed)
else:
assert False
n = revsetlang.getinteger(n, _(b"scratch expects a number"))
selected = set()
heads = set()
children_count = collections.defaultdict(lambda: 0)
parents = repo.changelog._uncheckedparentrevs
baseset = revset.getset(repo, smartset.fullreposet(repo), x)
baseset.sort()
for r in baseset:
heads.add(r)
p1, p2 = parents(r)
if p1 >= 0:
heads.discard(p1)
children_count[p1] += 1
if p2 >= 0:
heads.discard(p2)
children_count[p2] += 1
for h in heads:
assert children_count[h] == 0
selected = set()
for x in range(n):
if not heads:
break
pick = rand.choice(list(heads))
heads.remove(pick)
assert pick not in selected
selected.add(pick)
p1, p2 = parents(pick)
if p1 in children_count:
assert p1 in children_count
children_count[p1] -= 1
assert children_count[p1] >= 0
if children_count[p1] == 0:
assert p1 not in selected, (r, p1)
heads.add(p1)
if p2 in children_count:
assert p2 in children_count
children_count[p2] -= 1
assert children_count[p2] >= 0
if children_count[p2] == 0:
assert p2 not in selected, (r, p2)
heads.add(p2)
return smartset.baseset(selected) & subset