contrib/perf.py
author Gregory Szorc <gregory.szorc@gmail.com>
Wed, 13 Jul 2016 21:35:54 -0700
changeset 29560 303e9300772a
parent 29497 ee2027195847
child 29567 7e2b389418da
permissions -rw-r--r--
sslutil: require TLS 1.1+ when supported Currently, Mercurial will use TLS 1.0 or newer when connecting to remote servers, selecting the highest TLS version supported by both peers. On older Pythons, only TLS 1.0 is available. On newer Pythons, TLS 1.1 and 1.2 should be available. Security professionals recommend avoiding TLS 1.0 if possible. PCI DSS 3.1 "strongly encourages" the use of TLS 1.2. Known attacks like BEAST and POODLE exist against TLS 1.0 (although mitigations are available and properly configured servers aren't vulnerable). I asked Eric Rescorla - Mozilla's resident crypto expert - whether Mercurial should drop support for TLS 1.0. His response was "if you can get away with it." Essentially, a number of servers on the Internet don't support TLS 1.1+. This is why web browsers continue to support TLS 1.0 despite desires from security experts. This patch changes Mercurial's default behavior on modern Python versions to require TLS 1.1+, thus avoiding known security issues with TLS 1.0 and making Mercurial more secure by default. Rather than drop TLS 1.0 support wholesale, we still allow TLS 1.0 to be used if configured. This is a compromise solution - ideally we'd disallow TLS 1.0. However, since we're not sure how many Mercurial servers don't support TLS 1.1+ and we're not sure how much user inconvenience this change will bring, I think it is prudent to ship an escape hatch that still allows usage of TLS 1.0. In the default case our users get better security. In the worst case, they are no worse off than before this patch. This patch has no effect when running on Python versions that don't support TLS 1.1+. As the added test shows, connecting to a server that doesn't support TLS 1.1+ will display a warning message with a link to our wiki, where we can guide people to configure their client to allow less secure connections.

# perf.py - performance test routines
'''helper extension to measure performance'''

# "historical portability" policy of perf.py:
#
# We have to do:
# - make perf.py "loadable" with as wide Mercurial version as possible
#   This doesn't mean that perf commands work correctly with that Mercurial.
#   BTW, perf.py itself has been available since 1.1 (or eb240755386d).
# - make historical perf command work correctly with as wide Mercurial
#   version as possible
#
# We have to do, if possible with reasonable cost:
# - make recent perf command for historical feature work correctly
#   with early Mercurial
#
# We don't have to do:
# - make perf command for recent feature work correctly with early
#   Mercurial

from __future__ import absolute_import
import functools
import os
import random
import sys
import time
from mercurial import (
    branchmap,
    cmdutil,
    commands,
    copies,
    error,
    extensions,
    mdiff,
    merge,
    obsolete,
    repoview,
    revlog,
    scmutil,
    util,
)

# for "historical portability":
# define util.safehasattr forcibly, because util.safehasattr has been
# available since 1.9.3 (or 94b200a11cf7)
_undefined = object()
def safehasattr(thing, attr):
    return getattr(thing, attr, _undefined) is not _undefined
setattr(util, 'safehasattr', safehasattr)

# for "historical portability":
# use locally defined empty option list, if formatteropts isn't
# available, because commands.formatteropts has been available since
# 3.2 (or 7a7eed5176a4), even though formatting itself has been
# available since 2.2 (or ae5f92e154d3)
formatteropts = getattr(commands, "formatteropts", [])

# for "historical portability":
# use locally defined option list, if debugrevlogopts isn't available,
# because commands.debugrevlogopts has been available since 3.7 (or
# 5606f7d0d063), even though cmdutil.openrevlog() has been available
# since 1.9 (or a79fea6b3e77).
revlogopts = getattr(commands, "debugrevlogopts", [
        ('c', 'changelog', False, ('open changelog')),
        ('m', 'manifest', False, ('open manifest')),
        ('', 'dir', False, ('open directory manifest')),
        ])

cmdtable = {}

# for "historical portability":
# define parsealiases locally, because cmdutil.parsealiases has been
# available since 1.5 (or 6252852b4332)
def parsealiases(cmd):
    return cmd.lstrip("^").split("|")

if safehasattr(cmdutil, 'command'):
    import inspect
    command = cmdutil.command(cmdtable)
    if 'norepo' not in inspect.getargspec(command)[0]:
        # for "historical portability":
        # wrap original cmdutil.command, because "norepo" option has
        # been available since 3.1 (or 75a96326cecb)
        _command = command
        def command(name, options=(), synopsis=None, norepo=False):
            if norepo:
                commands.norepo += ' %s' % ' '.join(parsealiases(name))
            return _command(name, list(options), synopsis)
else:
    # for "historical portability":
    # define "@command" annotation locally, because cmdutil.command
    # has been available since 1.9 (or 2daa5179e73f)
    def command(name, options=(), synopsis=None, norepo=False):
        def decorator(func):
            if synopsis:
                cmdtable[name] = func, list(options), synopsis
            else:
                cmdtable[name] = func, list(options)
            if norepo:
                commands.norepo += ' %s' % ' '.join(parsealiases(name))
            return func
        return decorator

def getlen(ui):
    if ui.configbool("perf", "stub"):
        return lambda x: 1
    return len

def gettimer(ui, opts=None):
    """return a timer function and formatter: (timer, formatter)

    This function exists to gather the creation of formatter in a single
    place instead of duplicating it in all performance commands."""

    # enforce an idle period before execution to counteract power management
    # experimental config: perf.presleep
    time.sleep(ui.configint("perf", "presleep", 1))

    if opts is None:
        opts = {}
    # redirect all to stderr
    ui = ui.copy()
    ui.fout = ui.ferr
    # get a formatter
    fm = ui.formatter('perf', opts)
    # stub function, runs code only once instead of in a loop
    # experimental config: perf.stub
    if ui.configbool("perf", "stub"):
        return functools.partial(stub_timer, fm), fm
    return functools.partial(_timer, fm), fm

def stub_timer(fm, func, title=None):
    func()

def _timer(fm, func, title=None):
    results = []
    begin = time.time()
    count = 0
    while True:
        ostart = os.times()
        cstart = time.time()
        r = func()
        cstop = time.time()
        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

    fm.startitem()

    if title:
        fm.write('title', '! %s\n', title)
    if r:
        fm.write('result', '! result: %s\n', r)
    m = min(results)
    fm.plain('!')
    fm.write('wall', ' wall %f', m[0])
    fm.write('comb', ' comb %f', m[1] + m[2])
    fm.write('user', ' user %f', m[1])
    fm.write('sys',  ' sys %f', m[2])
    fm.write('count',  ' (best of %d)', count)
    fm.plain('\n')

@command('perfwalk', formatteropts)
def perfwalk(ui, repo, *pats, **opts):
    timer, fm = gettimer(ui, opts)
    try:
        m = scmutil.match(repo[None], pats, {})
        timer(lambda: len(list(repo.dirstate.walk(m, [], True, False))))
    except Exception:
        try:
            m = scmutil.match(repo[None], pats, {})
            timer(lambda: len([b for a, b, c in repo.dirstate.statwalk([], m)]))
        except Exception:
            timer(lambda: len(list(cmdutil.walk(repo, pats, {}))))
    fm.end()

@command('perfannotate', formatteropts)
def perfannotate(ui, repo, f, **opts):
    timer, fm = gettimer(ui, opts)
    fc = repo['.'][f]
    timer(lambda: len(fc.annotate(True)))
    fm.end()

@command('perfstatus',
         [('u', 'unknown', False,
           'ask status to look for unknown files')] + formatteropts)
def perfstatus(ui, repo, **opts):
    #m = match.always(repo.root, repo.getcwd())
    #timer(lambda: sum(map(len, repo.dirstate.status(m, [], False, False,
    #                                                False))))
    timer, fm = gettimer(ui, opts)
    timer(lambda: sum(map(len, repo.status(unknown=opts['unknown']))))
    fm.end()

@command('perfaddremove', formatteropts)
def perfaddremove(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    try:
        oldquiet = repo.ui.quiet
        repo.ui.quiet = True
        matcher = scmutil.match(repo[None])
        timer(lambda: scmutil.addremove(repo, matcher, "", dry_run=True))
    finally:
        repo.ui.quiet = oldquiet
        fm.end()

def clearcaches(cl):
    # behave somewhat consistently across internal API changes
    if util.safehasattr(cl, 'clearcaches'):
        cl.clearcaches()
    elif util.safehasattr(cl, '_nodecache'):
        from mercurial.node import nullid, nullrev
        cl._nodecache = {nullid: nullrev}
        cl._nodepos = None

@command('perfheads', formatteropts)
def perfheads(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    cl = repo.changelog
    def d():
        len(cl.headrevs())
        clearcaches(cl)
    timer(d)
    fm.end()

@command('perftags', formatteropts)
def perftags(ui, repo, **opts):
    import mercurial.changelog
    import mercurial.manifest
    timer, fm = gettimer(ui, opts)
    def t():
        repo.changelog = mercurial.changelog.changelog(repo.svfs)
        repo.manifest = mercurial.manifest.manifest(repo.svfs)
        repo._tags = None
        return len(repo.tags())
    timer(t)
    fm.end()

@command('perfancestors', formatteropts)
def perfancestors(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    heads = repo.changelog.headrevs()
    def d():
        for a in repo.changelog.ancestors(heads):
            pass
    timer(d)
    fm.end()

@command('perfancestorset', formatteropts)
def perfancestorset(ui, repo, revset, **opts):
    timer, fm = gettimer(ui, opts)
    revs = repo.revs(revset)
    heads = repo.changelog.headrevs()
    def d():
        s = repo.changelog.ancestors(heads)
        for rev in revs:
            rev in s
    timer(d)
    fm.end()

@command('perfdirs', formatteropts)
def perfdirs(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    dirstate = repo.dirstate
    'a' in dirstate
    def d():
        dirstate.dirs()
        del dirstate._dirs
    timer(d)
    fm.end()

@command('perfdirstate', formatteropts)
def perfdirstate(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    "a" in repo.dirstate
    def d():
        repo.dirstate.invalidate()
        "a" in repo.dirstate
    timer(d)
    fm.end()

@command('perfdirstatedirs', formatteropts)
def perfdirstatedirs(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    "a" in repo.dirstate
    def d():
        "a" in repo.dirstate._dirs
        del repo.dirstate._dirs
    timer(d)
    fm.end()

@command('perfdirstatefoldmap', formatteropts)
def perfdirstatefoldmap(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    dirstate = repo.dirstate
    'a' in dirstate
    def d():
        dirstate._filefoldmap.get('a')
        del dirstate._filefoldmap
    timer(d)
    fm.end()

@command('perfdirfoldmap', formatteropts)
def perfdirfoldmap(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    dirstate = repo.dirstate
    'a' in dirstate
    def d():
        dirstate._dirfoldmap.get('a')
        del dirstate._dirfoldmap
        del dirstate._dirs
    timer(d)
    fm.end()

@command('perfdirstatewrite', formatteropts)
def perfdirstatewrite(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    ds = repo.dirstate
    "a" in ds
    def d():
        ds._dirty = True
        ds.write(repo.currenttransaction())
    timer(d)
    fm.end()

@command('perfmergecalculate',
         [('r', 'rev', '.', 'rev to merge against')] + formatteropts)
def perfmergecalculate(ui, repo, rev, **opts):
    timer, fm = gettimer(ui, opts)
    wctx = repo[None]
    rctx = scmutil.revsingle(repo, rev, rev)
    ancestor = wctx.ancestor(rctx)
    # we don't want working dir files to be stat'd in the benchmark, so prime
    # that cache
    wctx.dirty()
    def d():
        # acceptremote is True because we don't want prompts in the middle of
        # our benchmark
        merge.calculateupdates(repo, wctx, rctx, [ancestor], False, False,
                               acceptremote=True, followcopies=True)
    timer(d)
    fm.end()

@command('perfpathcopies', [], "REV REV")
def perfpathcopies(ui, repo, rev1, rev2, **opts):
    timer, fm = gettimer(ui, opts)
    ctx1 = scmutil.revsingle(repo, rev1, rev1)
    ctx2 = scmutil.revsingle(repo, rev2, rev2)
    def d():
        copies.pathcopies(ctx1, ctx2)
    timer(d)
    fm.end()

@command('perfmanifest', [], 'REV')
def perfmanifest(ui, repo, rev, **opts):
    timer, fm = gettimer(ui, opts)
    ctx = scmutil.revsingle(repo, rev, rev)
    t = ctx.manifestnode()
    def d():
        repo.manifest.clearcaches()
        repo.manifest.read(t)
    timer(d)
    fm.end()

@command('perfchangeset', formatteropts)
def perfchangeset(ui, repo, rev, **opts):
    timer, fm = gettimer(ui, opts)
    n = repo[rev].node()
    def d():
        repo.changelog.read(n)
        #repo.changelog._cache = None
    timer(d)
    fm.end()

@command('perfindex', formatteropts)
def perfindex(ui, repo, **opts):
    import mercurial.revlog
    timer, fm = gettimer(ui, opts)
    mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg
    n = repo["tip"].node()
    def d():
        cl = mercurial.revlog.revlog(repo.svfs, "00changelog.i")
        cl.rev(n)
    timer(d)
    fm.end()

@command('perfstartup', formatteropts)
def perfstartup(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    cmd = sys.argv[0]
    def d():
        if os.name != 'nt':
            os.system("HGRCPATH= %s version -q > /dev/null" % cmd)
        else:
            os.environ['HGRCPATH'] = ''
            os.system("%s version -q > NUL" % cmd)
    timer(d)
    fm.end()

@command('perfparents', formatteropts)
def perfparents(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    # control the number of commits perfparents iterates over
    # experimental config: perf.parentscount
    count = ui.configint("perf", "parentscount", 1000)
    if len(repo.changelog) < count:
        raise error.Abort("repo needs %d commits for this test" % count)
    repo = repo.unfiltered()
    nl = [repo.changelog.node(i) for i in xrange(count)]
    def d():
        for n in nl:
            repo.changelog.parents(n)
    timer(d)
    fm.end()

@command('perfctxfiles', formatteropts)
def perfctxfiles(ui, repo, x, **opts):
    x = int(x)
    timer, fm = gettimer(ui, opts)
    def d():
        len(repo[x].files())
    timer(d)
    fm.end()

@command('perfrawfiles', formatteropts)
def perfrawfiles(ui, repo, x, **opts):
    x = int(x)
    timer, fm = gettimer(ui, opts)
    cl = repo.changelog
    def d():
        len(cl.read(x)[3])
    timer(d)
    fm.end()

@command('perflookup', formatteropts)
def perflookup(ui, repo, rev, **opts):
    timer, fm = gettimer(ui, opts)
    timer(lambda: len(repo.lookup(rev)))
    fm.end()

@command('perfrevrange', formatteropts)
def perfrevrange(ui, repo, *specs, **opts):
    timer, fm = gettimer(ui, opts)
    revrange = scmutil.revrange
    timer(lambda: len(revrange(repo, specs)))
    fm.end()

@command('perfnodelookup', formatteropts)
def perfnodelookup(ui, repo, rev, **opts):
    timer, fm = gettimer(ui, opts)
    import mercurial.revlog
    mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg
    n = repo[rev].node()
    cl = mercurial.revlog.revlog(repo.svfs, "00changelog.i")
    def d():
        cl.rev(n)
        clearcaches(cl)
    timer(d)
    fm.end()

@command('perflog',
         [('', 'rename', False, 'ask log to follow renames')] + formatteropts)
def perflog(ui, repo, rev=None, **opts):
    if rev is None:
        rev=[]
    timer, fm = gettimer(ui, opts)
    ui.pushbuffer()
    timer(lambda: commands.log(ui, repo, rev=rev, date='', user='',
                               copies=opts.get('rename')))
    ui.popbuffer()
    fm.end()

@command('perfmoonwalk', formatteropts)
def perfmoonwalk(ui, repo, **opts):
    """benchmark walking the changelog backwards

    This also loads the changelog data for each revision in the changelog.
    """
    timer, fm = gettimer(ui, opts)
    def moonwalk():
        for i in xrange(len(repo), -1, -1):
            ctx = repo[i]
            ctx.branch() # read changelog data (in addition to the index)
    timer(moonwalk)
    fm.end()

@command('perftemplating', formatteropts)
def perftemplating(ui, repo, rev=None, **opts):
    if rev is None:
        rev=[]
    timer, fm = gettimer(ui, opts)
    ui.pushbuffer()
    timer(lambda: commands.log(ui, repo, rev=rev, date='', user='',
                               template='{date|shortdate} [{rev}:{node|short}]'
                               ' {author|person}: {desc|firstline}\n'))
    ui.popbuffer()
    fm.end()

@command('perfcca', formatteropts)
def perfcca(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    timer(lambda: scmutil.casecollisionauditor(ui, False, repo.dirstate))
    fm.end()

@command('perffncacheload', formatteropts)
def perffncacheload(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    s = repo.store
    def d():
        s.fncache._load()
    timer(d)
    fm.end()

@command('perffncachewrite', formatteropts)
def perffncachewrite(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    s = repo.store
    s.fncache._load()
    lock = repo.lock()
    tr = repo.transaction('perffncachewrite')
    def d():
        s.fncache._dirty = True
        s.fncache.write(tr)
    timer(d)
    lock.release()
    tr.close()
    fm.end()

@command('perffncacheencode', formatteropts)
def perffncacheencode(ui, repo, **opts):
    timer, fm = gettimer(ui, opts)
    s = repo.store
    s.fncache._load()
    def d():
        for p in s.fncache.entries:
            s.encode(p)
    timer(d)
    fm.end()

@command('perfdiffwd', formatteropts)
def perfdiffwd(ui, repo, **opts):
    """Profile diff of working directory changes"""
    timer, fm = gettimer(ui, opts)
    options = {
        'w': 'ignore_all_space',
        'b': 'ignore_space_change',
        'B': 'ignore_blank_lines',
        }

    for diffopt in ('', 'w', 'b', 'B', 'wB'):
        opts = dict((options[c], '1') for c in diffopt)
        def d():
            ui.pushbuffer()
            commands.diff(ui, repo, **opts)
            ui.popbuffer()
        title = 'diffopts: %s' % (diffopt and ('-' + diffopt) or 'none')
        timer(d, title)
    fm.end()

@command('perfrevlog', revlogopts + formatteropts +
         [('d', 'dist', 100, 'distance between the revisions'),
          ('s', 'startrev', 0, 'revision to start reading at')],
         '-c|-m|FILE')
def perfrevlog(ui, repo, file_=None, startrev=0, **opts):
    """Benchmark reading a series of revisions from a revlog.

    By default, we read every ``-d/--dist`` revision from 0 to tip of
    the specified revlog.

    The start revision can be defined via ``-s/--startrev``.
    """
    timer, fm = gettimer(ui, opts)
    dist = opts['dist']
    _len = getlen(ui)
    def d():
        r = cmdutil.openrevlog(repo, 'perfrevlog', file_, opts)
        for x in xrange(startrev, _len(r), dist):
            r.revision(r.node(x))

    timer(d)
    fm.end()

@command('perfrevlogrevision', revlogopts + formatteropts +
         [('', 'cache', False, 'use caches instead of clearing')],
         '-c|-m|FILE REV')
def perfrevlogrevision(ui, repo, file_, rev=None, cache=None, **opts):
    """Benchmark obtaining a revlog revision.

    Obtaining a revlog revision consists of roughly the following steps:

    1. Compute the delta chain
    2. Obtain the raw chunks for that delta chain
    3. Decompress each raw chunk
    4. Apply binary patches to obtain fulltext
    5. Verify hash of fulltext

    This command measures the time spent in each of these phases.
    """
    if opts.get('changelog') or opts.get('manifest'):
        file_, rev = None, file_
    elif rev is None:
        raise error.CommandError('perfrevlogrevision', 'invalid arguments')

    r = cmdutil.openrevlog(repo, 'perfrevlogrevision', file_, opts)
    node = r.lookup(rev)
    rev = r.rev(node)

    def dodeltachain(rev):
        if not cache:
            r.clearcaches()
        r._deltachain(rev)

    def doread(chain):
        if not cache:
            r.clearcaches()
        r._chunkraw(chain[0], chain[-1])

    def dodecompress(data, chain):
        if not cache:
            r.clearcaches()

        start = r.start
        length = r.length
        inline = r._inline
        iosize = r._io.size
        buffer = util.buffer
        offset = start(chain[0])

        for rev in chain:
            chunkstart = start(rev)
            if inline:
                chunkstart += (rev + 1) * iosize
            chunklength = length(rev)
            b = buffer(data, chunkstart - offset, chunklength)
            revlog.decompress(b)

    def dopatch(text, bins):
        if not cache:
            r.clearcaches()
        mdiff.patches(text, bins)

    def dohash(text):
        if not cache:
            r.clearcaches()
        r._checkhash(text, node, rev)

    def dorevision():
        if not cache:
            r.clearcaches()
        r.revision(node)

    chain = r._deltachain(rev)[0]
    data = r._chunkraw(chain[0], chain[-1])[1]
    bins = r._chunks(chain)
    text = str(bins[0])
    bins = bins[1:]
    text = mdiff.patches(text, bins)

    benches = [
        (lambda: dorevision(), 'full'),
        (lambda: dodeltachain(rev), 'deltachain'),
        (lambda: doread(chain), 'read'),
        (lambda: dodecompress(data, chain), 'decompress'),
        (lambda: dopatch(text, bins), 'patch'),
        (lambda: dohash(text), 'hash'),
    ]

    for fn, title in benches:
        timer, fm = gettimer(ui, opts)
        timer(fn, title=title)
        fm.end()

@command('perfrevset',
         [('C', 'clear', False, 'clear volatile cache between each call.'),
          ('', 'contexts', False, 'obtain changectx for each revision')]
         + formatteropts, "REVSET")
def perfrevset(ui, repo, expr, clear=False, contexts=False, **opts):
    """benchmark the execution time of a revset

    Use the --clean option if need to evaluate the impact of build volatile
    revisions set cache on the revset execution. Volatile cache hold filtered
    and obsolete related cache."""
    timer, fm = gettimer(ui, opts)
    def d():
        if clear:
            repo.invalidatevolatilesets()
        if contexts:
            for ctx in repo.set(expr): pass
        else:
            for r in repo.revs(expr): pass
    timer(d)
    fm.end()

@command('perfvolatilesets', formatteropts)
def perfvolatilesets(ui, repo, *names, **opts):
    """benchmark the computation of various volatile set

    Volatile set computes element related to filtering and obsolescence."""
    timer, fm = gettimer(ui, opts)
    repo = repo.unfiltered()

    def getobs(name):
        def d():
            repo.invalidatevolatilesets()
            obsolete.getrevs(repo, name)
        return d

    allobs = sorted(obsolete.cachefuncs)
    if names:
        allobs = [n for n in allobs if n in names]

    for name in allobs:
        timer(getobs(name), title=name)

    def getfiltered(name):
        def d():
            repo.invalidatevolatilesets()
            repoview.filterrevs(repo, name)
        return d

    allfilter = sorted(repoview.filtertable)
    if names:
        allfilter = [n for n in allfilter if n in names]

    for name in allfilter:
        timer(getfiltered(name), title=name)
    fm.end()

@command('perfbranchmap',
         [('f', 'full', False,
           'Includes build time of subset'),
         ] + formatteropts)
def perfbranchmap(ui, repo, full=False, **opts):
    """benchmark the update of a branchmap

    This benchmarks the full repo.branchmap() call with read and write disabled
    """
    timer, fm = gettimer(ui, opts)
    def getbranchmap(filtername):
        """generate a benchmark function for the filtername"""
        if filtername is None:
            view = repo
        else:
            view = repo.filtered(filtername)
        def d():
            if full:
                view._branchcaches.clear()
            else:
                view._branchcaches.pop(filtername, None)
            view.branchmap()
        return d
    # add filter in smaller subset to bigger subset
    possiblefilters = set(repoview.filtertable)
    allfilters = []
    while possiblefilters:
        for name in possiblefilters:
            subset = branchmap.subsettable.get(name)
            if subset not in possiblefilters:
                break
        else:
            assert False, 'subset cycle %s!' % possiblefilters
        allfilters.append(name)
        possiblefilters.remove(name)

    # warm the cache
    if not full:
        for name in allfilters:
            repo.filtered(name).branchmap()
    # add unfiltered
    allfilters.append(None)
    oldread = branchmap.read
    oldwrite = branchmap.branchcache.write
    try:
        branchmap.read = lambda repo: None
        branchmap.write = lambda repo: None
        for name in allfilters:
            timer(getbranchmap(name), title=str(name))
    finally:
        branchmap.read = oldread
        branchmap.branchcache.write = oldwrite
    fm.end()

@command('perfloadmarkers')
def perfloadmarkers(ui, repo):
    """benchmark the time to parse the on-disk markers for a repo

    Result is the number of markers in the repo."""
    timer, fm = gettimer(ui)
    timer(lambda: len(obsolete.obsstore(repo.svfs)))
    fm.end()

@command('perflrucachedict', formatteropts +
    [('', 'size', 4, 'size of cache'),
     ('', 'gets', 10000, 'number of key lookups'),
     ('', 'sets', 10000, 'number of key sets'),
     ('', 'mixed', 10000, 'number of mixed mode operations'),
     ('', 'mixedgetfreq', 50, 'frequency of get vs set ops in mixed mode')],
    norepo=True)
def perflrucache(ui, size=4, gets=10000, sets=10000, mixed=10000,
                 mixedgetfreq=50, **opts):
    def doinit():
        for i in xrange(10000):
            util.lrucachedict(size)

    values = []
    for i in xrange(size):
        values.append(random.randint(0, sys.maxint))

    # Get mode fills the cache and tests raw lookup performance with no
    # eviction.
    getseq = []
    for i in xrange(gets):
        getseq.append(random.choice(values))

    def dogets():
        d = util.lrucachedict(size)
        for v in values:
            d[v] = v
        for key in getseq:
            value = d[key]
            value # silence pyflakes warning

    # Set mode tests insertion speed with cache eviction.
    setseq = []
    for i in xrange(sets):
        setseq.append(random.randint(0, sys.maxint))

    def dosets():
        d = util.lrucachedict(size)
        for v in setseq:
            d[v] = v

    # Mixed mode randomly performs gets and sets with eviction.
    mixedops = []
    for i in xrange(mixed):
        r = random.randint(0, 100)
        if r < mixedgetfreq:
            op = 0
        else:
            op = 1

        mixedops.append((op, random.randint(0, size * 2)))

    def domixed():
        d = util.lrucachedict(size)

        for op, v in mixedops:
            if op == 0:
                try:
                    d[v]
                except KeyError:
                    pass
            else:
                d[v] = v

    benches = [
        (doinit, 'init'),
        (dogets, 'gets'),
        (dosets, 'sets'),
        (domixed, 'mixed')
    ]

    for fn, title in benches:
        timer, fm = gettimer(ui, opts)
        timer(fn, title=title)
        fm.end()

def uisetup(ui):
    if (util.safehasattr(cmdutil, 'openrevlog') and
        not util.safehasattr(commands, 'debugrevlogopts')):
        # for "historical portability":
        # In this case, Mercurial should be 1.9 (or a79fea6b3e77) -
        # 3.7 (or 5606f7d0d063). Therefore, '--dir' option for
        # openrevlog() should cause failure, because it has been
        # available since 3.5 (or 49c583ca48c4).
        def openrevlog(orig, repo, cmd, file_, opts):
            if opts.get('dir') and not util.safehasattr(repo, 'dirlog'):
                raise error.Abort("This version doesn't support --dir option",
                                  hint="use 3.5 or later")
            return orig(repo, cmd, file_, opts)
        extensions.wrapfunction(cmdutil, 'openrevlog', openrevlog)