tests/sshprotoext.py

treemanifests: remove _loadalllazy in _diff()

The benchmarks below use a similar setup as in ee7ee0c516ca and my other recent
commits.  Yes, in some cases this runs in literally 5% of the time it
previously took.

before = a6f8ab53

    diff --git:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 1.301 s +-  0.004 s    | 1.309 s +-  0.012 s   | 100.6%
    m-u   |   | x | 1.303 s +-  0.009 s    | 1.302 s +-  0.006 s   |  99.9%
    m-u   | x |   | 1.308 s +-  0.006 s    | 1.309 s +-  0.007 s   | 100.1%
    m-u   | x | x | 85.7 ms +-   0.6 ms    | 86.0 ms +-   0.3 ms   | 100.4%
    l-d-r |   |   | 197.5 ms +-   0.7 ms   | 197.8 ms +-   2.2 ms  | 100.2%
    l-d-r |   | x | 199.4 ms +-   0.6 ms   | 199.3 ms +-   0.9 ms  |  99.9%
    l-d-r | x |   | 86.1 ms +-   0.5 ms    | 85.8 ms +-   0.9 ms   |  99.7%
    l-d-r | x | x | 64.4 ms +-   0.4 ms    | 64.4 ms +-   0.3 ms   | 100.0%

    diff -c . --git:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 236.7 ms +-   1.1 ms   | 236.5 ms +-   1.3 ms  |  99.9%
    m-u   |   | x | 158.7 ms +-   1.0 ms   | 128.0 ms +-   1.0 ms  |  80.7% <--
    m-u   | x |   | 239.7 ms +-   1.8 ms   | 238.1 ms +-   1.5 ms  |  99.3%
    m-u   | x | x | 132.4 ms +-   0.9 ms   | 132.3 ms +-   0.6 ms  |  99.9%
    l-d-r |   |   | 81.8 ms +-   0.4 ms    | 81.8 ms +-   0.3 ms   | 100.0%
    l-d-r |   | x | 3.894 s +-  0.017 s    | 193.6 ms +-   0.4 ms  |   5.0% <--
    l-d-r | x |   | 106.9 ms +-   0.4 ms   | 106.6 ms +-   0.3 ms  |  99.7%
    l-d-r | x | x | 182.7 ms +-   0.8 ms   | 183.3 ms +-   0.9 ms  | 100.3%

    rebase -r . --keep -d .^^:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 5.615 s +-  0.109 s    | 5.562 s +-  0.015 s   |  99.1%
    m-u   |   | x | 5.701 s +-  0.027 s    | 5.715 s +-  0.023 s   | 100.2%
    m-u   | x |   | 5.572 s +-  0.128 s    | 5.613 s +-  0.182 s   | 100.7%
    m-u   | x | x | 633.3 ms +-  28.7 ms   | 636.2 ms +-  13.8 ms  | 100.5%
    l-d-r |   |   | 666.4 ms +-  17.0 ms   | 658.5 ms +-   9.3 ms  |  98.8%
    l-d-r |   | x | 6.520 s +-  0.070 s    | 6.505 s +-  0.026 s   |  99.8%
    l-d-r | x |   | 279.0 ms +-  13.0 ms   | 276.5 ms +-   4.7 ms  |  99.1%
    l-d-r | x | x | 1.636 s +-  0.058 s    | 1.657 s +-  0.014 s   | 101.3%

    status --change . --copies:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 218.6 ms +-   1.4 ms   | 217.9 ms +-   1.5 ms  |  99.7%
    m-u   |   | x | 138.5 ms +-   0.4 ms   | 108.4 ms +-   0.2 ms  |  78.3% <--
    m-u   | x |   | 220.1 ms +-   1.3 ms   | 219.7 ms +-   1.5 ms  |  99.8%
    m-u   | x | x | 113.2 ms +-   0.4 ms   | 112.4 ms +-   0.8 ms  |  99.3%
    l-d-r |   |   | 80.2 ms +-   0.3 ms    | 80.6 ms +-   0.6 ms   | 100.5%
    l-d-r |   | x | 3.899 s +-  0.020 s    | 194.8 ms +-   4.0 ms  |   5.0% <--
    l-d-r | x |   | 83.4 ms +-   0.8 ms    | 83.2 ms +-   0.2 ms   |  99.8%
    l-d-r | x | x | 732.2 ms +-   4.3 ms   | 194.9 ms +-   1.0 ms  |  26.6% <--

    status --copies:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 1.917 s +-  0.005 s    | 1.914 s +-  0.004 s   |  99.8%
    m-u   |   | x | 1.909 s +-  0.012 s    | 1.934 s +-  0.004 s   | 101.3%
    m-u   | x |   | 1.915 s +-  0.005 s    | 1.904 s +-  0.004 s   |  99.4%
    m-u   | x | x | 94.8 ms +-   0.3 ms    | 94.7 ms +-   0.2 ms   |  99.9%
    l-d-r |   |   | 593.9 ms +-   1.2 ms   | 594.6 ms +-   9.4 ms  | 100.1%
    l-d-r |   | x | 595.2 ms +-   3.8 ms   | 597.2 ms +-   2.6 ms  | 100.3%
    l-d-r | x |   | 182.5 ms +-   1.6 ms   | 182.1 ms +-   0.6 ms  |  99.8%
    l-d-r | x | x | 149.6 ms +-   0.9 ms   | 149.1 ms +-   0.8 ms  |  99.7%

    update $rev^; ~/src/hg/hg{hg}/hg update $rev:
    repo  | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before
    ------+---+---+------------------------+-----------------------+------------
    m-u   |   |   | 3.121 s +-  0.007 s    | 3.129 s +-  0.012 s   | 100.3%
    m-u   |   | x | 2.972 s +-  0.011 s    | 2.981 s +-  0.012 s   | 100.3%
    m-u   | x |   | 3.144 s +-  0.014 s    | 3.141 s +-  0.011 s   |  99.9%
    m-u   | x | x | 312.2 ms +-   2.4 ms   | 312.3 ms +-   2.1 ms  | 100.0%
    l-d-r |   |   | 444.4 ms +-   4.3 ms   | 446.9 ms +-   5.3 ms  | 100.6%
    l-d-r |   | x | 9.159 s +-  0.069 s    | 9.182 s +-  0.040 s   | 100.3%
    l-d-r | x |   | 254.6 ms +-   1.6 ms   | 255.2 ms +-   1.6 ms  | 100.2%
    l-d-r | x | x | 1.525 s +-  0.007 s    | 1.577 s +-  0.007 s   | 103.4% <--?

Differential Revision: https://phab.mercurial-scm.org/D4845

# sshprotoext.py - Extension to test behavior of SSH protocol
#
# Copyright 2018 Gregory Szorc <[e-mail]>
#
# 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 __future__ import absolute_import

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)