contrib/hgperf

revlog: fix revset in reachableroots docstring

`reachableroots` will only return a subset of `roots` when `includepath` is
False. For example, given the following linear DAG:

  2
  |
  1
  |
  0

Using roots=0+2, heads=1, the definition in the docstring does not match what
`reachableroots` actually does:

  ipdb> repo.changelog.reachableroots(0, roots=[0,2],heads=[1])
  [0]
  ipdb> repo.revs('heads(::(0+2) & (0+2)::1)')
  <baseset+ [1]>

The fix is to do `heads & ::roots` (or `heads & heads::roots`) first, then
select their ancestors:

  ipdb> repo.revs('heads(::((0+2) & (0+2)::1))')
  <baseset+ [0]>

The docstring was introduced by fd92bfbbe02d9 (2015-06-19 "revset: rename
revsbetween to reachableroots and add an argument"), which introduced the
`includepath=False` behavior for graphlog grandparents use-case. I believe
the docstring instead of the code should be changed because changing the
code to match the docstring can result in suboptimal graphlog like:

  o
  :\
  : o
  : :
  :/
  o

As opposite to the current "linearized" graphlog:

  o
  |
  o
  :
  o

Differential Revision: https://phab.mercurial-scm.org/D7518

#!/usr/bin/env python
#
# hgperf - measure performance of Mercurial commands
#
# Copyright 2014 Matt 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()