outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
# bruterebase.py - brute force rebase testing
#
# Copyright 2017 Facebook, Inc.
#
# 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 import (
error,
registrar,
revsetlang,
)
from hgext import rebase
cmdtable = {}
command = registrar.command(cmdtable)
@command(b'debugbruterebase')
def debugbruterebase(ui, repo, source, dest):
"""for every non-empty subset of source, run rebase -r subset -d dest
Print one line summary for each subset. Assume obsstore is enabled.
"""
srevs = list(repo.revs(source))
with repo.wlock(), repo.lock():
repolen = len(repo)
cl = repo.changelog
def getdesc(rev):
result = cl.changelogrevision(rev).description
if rev >= repolen:
result += b"'"
return result
for i in range(1, 2 ** len(srevs)):
subset = [rev for j, rev in enumerate(srevs) if i & (1 << j) != 0]
spec = revsetlang.formatspec(b'%ld', subset)
tr = repo.transaction(b'rebase')
tr._report = lambda x: 0 # hide "transaction abort"
with ui.silent():
try:
rebase.rebase(ui, repo, dest=dest, rev=[spec])
except error.Abort as ex:
summary = b'ABORT: %s' % ex.message
except Exception as ex:
summary = b'CRASH: %s' % ex
else:
# short summary about new nodes
cl = repo.changelog
descs = []
for rev in range(repolen, len(repo)):
desc = b'%s:' % getdesc(rev)
for prev in cl.parentrevs(rev):
if prev > -1:
desc += getdesc(prev)
descs.append(desc)
descs.sort()
summary = b' '.join(descs)
repo.vfs.tryunlink(b'rebasestate')
subsetdesc = b''.join(getdesc(rev) for rev in subset)
ui.write(b'%s: %s\n' % (subsetdesc.rjust(len(srevs)), summary))
tr.abort()