view contrib/hgperf @ 47315:825d5a5907b4

exewrapper: avoid directly linking against python3X.dll

Subsequent code calls `LoadLibrary()` to attempt to load the DLL, but because of
this symbol reference, there is an attempt to load the DLL used during the build
prior to `_main()` running.  This causes the whole process to fail if the DLL
isn't in the standard search path.  That also means it will never load the DLL
for HackableMercurial.  (Maybe we should get rid of that for py3, since you can
install python for a user without admin rights?)

This could also be resolved by calling `GetProcAddress()` on the symbol and
dereferencing it, but using the environment variable is consistent with the
*.bat file since fc8a5c9ecee0.  (The environment variable persists after the
interpreter is initialized.)

Far more concerning is somehow I've gotten my system into a state where setting
the flag causes any output to the pager to be lost (as if it wasn't set at all)
in MSYS, cmd.exe, WSL, and PowerShell using py3.9.0, but the environment
variable works properly.  I'm sure this flag worked on some versions of py3, so
I'm not sure what's going on here.  This is might be related to init config
related changes in 3.8[1], since it works with 3.7.8, but fails with 3.8.1.
Somebody who understands encoding issues better than I do should give some
thought to if we need to make some changes to our encoding strategy on Windows
with py3.

With or without the flag/envvar, there is proper output if the command is
directly paged by piping to `more.com` (in any environment) or `less` (in MSYS
and WSL), or if paging is disabled with `--pager=no`.  Legacy mode is required
though when Mercurial decides to spin up a pager.

[1] https://bugs.python.org/issue41941

Differential Revision: https://phab.mercurial-scm.org/D10756

#!/usr/bin/env python3
#
# hgperf - measure performance of Mercurial commands
#
# Copyright 2014 Olivia Mackall <[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.

'''measure performance of Mercurial commands

Using ``hgperf`` instead of ``hg`` measures performance of the target
Mercurial command. For example, the execution below measures
performance of :hg:`heads --topo`::

    $ hgperf heads --topo

All command output via ``ui`` is suppressed, and just measurement
result is displayed: see also "perf" extension in "contrib".

Costs of processing before dispatching to the command function like
below are not measured::

    - parsing command line (e.g. option validity check)
    - reading configuration files in

But ``pre-`` and ``post-`` hook invocation for the target command is
measured, even though these are invoked before or after dispatching to
the command function, because these may be required to repeat
execution of the target command correctly.
'''

import os
import sys

libdir = '@LIBDIR@'

if libdir != '@' 'LIBDIR' '@':
    if not os.path.isabs(libdir):
        libdir = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), libdir
        )
        libdir = os.path.abspath(libdir)
    sys.path.insert(0, libdir)

# enable importing on demand to reduce startup time
try:
    from mercurial import demandimport

    demandimport.enable()
except ImportError:
    import sys

    sys.stderr.write(
        "abort: couldn't find mercurial libraries in [%s]\n"
        % ' '.join(sys.path)
    )
    sys.stderr.write("(check your install and PYTHONPATH)\n")
    sys.exit(-1)

from mercurial import (
    dispatch,
    util,
)


def timer(func, title=None):
    results = []
    begin = util.timer()
    count = 0
    while True:
        ostart = os.times()
        cstart = util.timer()
        r = func()
        cstop = util.timer()
        ostop = os.times()
        count += 1
        a, b = ostart, ostop
        results.append((cstop - cstart, b[0] - a[0], b[1] - a[1]))
        if cstop - begin > 3 and count >= 100:
            break
        if cstop - begin > 10 and count >= 3:
            break
    if title:
        sys.stderr.write("! %s\n" % title)
    if r:
        sys.stderr.write("! result: %s\n" % r)
    m = min(results)
    sys.stderr.write(
        "! wall %f comb %f user %f sys %f (best of %d)\n"
        % (m[0], m[1] + m[2], m[1], m[2], count)
    )


orgruncommand = dispatch.runcommand


def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions):
    ui.pushbuffer()
    lui.pushbuffer()
    timer(
        lambda: orgruncommand(
            lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions
        )
    )
    ui.popbuffer()
    lui.popbuffer()


dispatch.runcommand = runcommand

dispatch.run()