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.
# sshprotoext.py - Extension to test behavior of SSH protocol
#
# 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.
# This extension replaces the SSH server started via `hg serve --stdio`.
# The server behaves differently depending on environment variables.
from mercurial import (
error,
extensions,
registrar,
sshpeer,
wireprotoserver,
wireprotov1server,
)
configtable = {}
configitem = registrar.configitem(configtable)
configitem(b'sshpeer', b'mode', default=None)
configitem(b'sshpeer', b'handshake-mode', default=None)
class bannerserver(wireprotoserver.sshserver):
"""Server that sends a banner to stdout."""
def serve_forever(self):
for i in range(10):
self._fout.write(b'banner: line %d\n' % i)
super(bannerserver, self).serve_forever()
class prehelloserver(wireprotoserver.sshserver):
"""Tests behavior when connecting to <0.9.1 servers.
The ``hello`` wire protocol command was introduced in Mercurial
0.9.1. Modern clients send the ``hello`` command when connecting
to SSH servers. This mock server tests behavior of the handshake
when ``hello`` is not supported.
"""
def serve_forever(self):
l = self._fin.readline()
assert l == b'hello\n'
# Respond to unknown commands with an empty reply.
wireprotoserver._sshv1respondbytes(self._fout, b'')
l = self._fin.readline()
assert l == b'between\n'
proto = wireprotoserver.sshv1protocolhandler(
self._ui, self._fin, self._fout
)
rsp = wireprotov1server.dispatch(self._repo, proto, b'between')
wireprotoserver._sshv1respondbytes(self._fout, rsp.data)
super(prehelloserver, self).serve_forever()
def performhandshake(orig, ui, stdin, stdout, stderr):
"""Wrapped version of sshpeer._performhandshake to send extra commands."""
mode = ui.config(b'sshpeer', b'handshake-mode')
if mode == b'pre-no-args':
ui.debug(b'sending no-args command\n')
stdin.write(b'no-args\n')
stdin.flush()
return orig(ui, stdin, stdout, stderr)
elif mode == b'pre-multiple-no-args':
ui.debug(b'sending unknown1 command\n')
stdin.write(b'unknown1\n')
ui.debug(b'sending unknown2 command\n')
stdin.write(b'unknown2\n')
ui.debug(b'sending unknown3 command\n')
stdin.write(b'unknown3\n')
stdin.flush()
return orig(ui, stdin, stdout, stderr)
else:
raise error.ProgrammingError(b'unknown HANDSHAKECOMMANDMODE: %s' % mode)
def extsetup(ui):
# It's easier for tests to define the server behavior via environment
# variables than config options. This is because `hg serve --stdio`
# has to be invoked with a certain form for security reasons and
# `dummyssh` can't just add `--config` flags to the command line.
servermode = ui.environ.get(b'SSHSERVERMODE')
if servermode == b'banner':
wireprotoserver.sshserver = bannerserver
elif servermode == b'no-hello':
wireprotoserver.sshserver = prehelloserver
elif servermode:
raise error.ProgrammingError(b'unknown server mode: %s' % servermode)
peermode = ui.config(b'sshpeer', b'mode')
if peermode == b'extra-handshake-commands':
extensions.wrapfunction(sshpeer, '_performhandshake', performhandshake)
elif peermode:
raise error.ProgrammingError(b'unknown peer mode: %s' % peermode)