#!/usr/bin/env python3

#

# hgperf - measure performance of Mercurial commands

#

# Copyright 2014 Olivia Mackall <olivia@selenic.com>

#

# 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()