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Differential D10221

perf-helper: add a small extension with revsets to select repository subset
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Authored by marmoute on Mar 15 2021, 7:00 PM.

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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.

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rHG Mercurial
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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 26447

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