view contrib/revsetbenchmarks.py @ 39629:a86d21e70b2b

exchangev2: start to implement pull with wire protocol v2

Wire protocol version 2 will take a substantially different
approach to exchange than version 1 (at least as far as pulling
is concerned).

This commit establishes a new exchangev2 module for holding
code related to exchange using wire protocol v2. I could have
added things to the existing exchange module. But it is already
quite big. And doing things inline isn't in question because
the existing code is already littered with conditional code
for various states of support for the existing wire protocol
as it evolved over 10+ years. A new module gives us a chance
to make a clean break.

This approach does mean we'll end up writing some duplicate
code. And there's a significant chance we'll miss functionality
as code is ported. The plan is to eventually add #testcase's
to existing tests so the new wire protocol is tested side-by-side
with the existing one. This will hopefully tease out any
features that weren't ported properly. But before we get there,
we need to build up support for the new exchange methods.

Our journey towards implementing a new exchange begins with pulling.
And pulling begins with discovery.

The discovery code added to exchangev2 is heavily drawn from
the following functions:

* exchange._pulldiscoverychangegroup
* discovery.findcommonincoming

For now, we build on top of existing discovery mechanisms. The
new wire protocol should be capable of doing things more efficiently.
But I'd rather defer on this problem.

To foster the transition, we invent a fake capability on the HTTPv2
peer and have the main pull code in exchange.py call into exchangev2
when the new wire protocol is being used.

Differential Revision: https://phab.mercurial-scm.org/D4480

#!/usr/bin/env python

# Measure the performance of a list of revsets against multiple revisions
# defined by parameter. Checkout one by one and run perfrevset with every
# revset in the list to benchmark its performance.
#
# You should run this from the root of your mercurial repository.
#
# call with --help for details

from __future__ import absolute_import, print_function
import math
import optparse  # cannot use argparse, python 2.7 only
import os
import re
import subprocess
import sys

DEFAULTVARIANTS = ['plain', 'min', 'max', 'first', 'last',
                   'reverse', 'reverse+first', 'reverse+last',
                   'sort', 'sort+first', 'sort+last']

def check_output(*args, **kwargs):
    kwargs.setdefault('stderr', subprocess.PIPE)
    kwargs.setdefault('stdout', subprocess.PIPE)
    proc = subprocess.Popen(*args, **kwargs)
    output, error = proc.communicate()
    if proc.returncode != 0:
        raise subprocess.CalledProcessError(proc.returncode, ' '.join(args[0]))
    return output

def update(rev):
    """update the repo to a revision"""
    try:
        subprocess.check_call(['hg', 'update', '--quiet', '--check', str(rev)])
        check_output(['make', 'local'],
                     stderr=None)  # suppress output except for error/warning
    except subprocess.CalledProcessError as exc:
        print('update to revision %s failed, aborting'%rev, file=sys.stderr)
        sys.exit(exc.returncode)


def hg(cmd, repo=None):
    """run a mercurial command

    <cmd> is the list of command + argument,
    <repo> is an optional repository path to run this command in."""
    fullcmd = ['./hg']
    if repo is not None:
        fullcmd += ['-R', repo]
    fullcmd += ['--config',
                'extensions.perf=' + os.path.join(contribdir, 'perf.py')]
    fullcmd += cmd
    return check_output(fullcmd, stderr=subprocess.STDOUT)

def perf(revset, target=None, contexts=False):
    """run benchmark for this very revset"""
    try:
        args = ['perfrevset', revset]
        if contexts:
            args.append('--contexts')
        output = hg(args, repo=target)
        return parseoutput(output)
    except subprocess.CalledProcessError as exc:
        print('abort: cannot run revset benchmark: %s'%exc.cmd, file=sys.stderr)
        if getattr(exc, 'output', None) is None: # no output before 2.7
            print('(no output)', file=sys.stderr)
        else:
            print(exc.output, file=sys.stderr)
        return None

outputre = re.compile(r'! wall (\d+.\d+) comb (\d+.\d+) user (\d+.\d+) '
                      'sys (\d+.\d+) \(best of (\d+)\)')

def parseoutput(output):
    """parse a textual output into a dict

    We cannot just use json because we want to compare with old
    versions of Mercurial that may not support json output.
    """
    match = outputre.search(output)
    if not match:
        print('abort: invalid output:', file=sys.stderr)
        print(output, file=sys.stderr)
        sys.exit(1)
    return {'comb': float(match.group(2)),
            'count': int(match.group(5)),
            'sys': float(match.group(3)),
            'user': float(match.group(4)),
            'wall': float(match.group(1)),
            }

def printrevision(rev):
    """print data about a revision"""
    sys.stdout.write("Revision ")
    sys.stdout.flush()
    subprocess.check_call(['hg', 'log', '--rev', str(rev), '--template',
                           '{if(tags, " ({tags})")} '
                           '{rev}:{node|short}: {desc|firstline}\n'])

def idxwidth(nbidx):
    """return the max width of number used for index

    This is similar to log10(nbidx), but we use custom code here
    because we start with zero and we'd rather not deal with all the
    extra rounding business that log10 would imply.
    """
    nbidx -= 1 # starts at 0
    idxwidth = 0
    while nbidx:
        idxwidth += 1
        nbidx //= 10
    if not idxwidth:
        idxwidth = 1
    return idxwidth

def getfactor(main, other, field, sensitivity=0.05):
    """return the relative factor between values for 'field' in main and other

    Return None if the factor is insignificant (less than <sensitivity>
    variation)."""
    factor = 1
    if main is not None:
        factor = other[field] / main[field]
    low, high = 1 - sensitivity, 1 + sensitivity
    if (low < factor < high):
        return None
    return factor

def formatfactor(factor):
    """format a factor into a 4 char string

     22%
    156%
    x2.4
     x23
    x789
    x1e4
    x5x7

    """
    if factor is None:
        return '    '
    elif factor < 2:
        return '%3i%%' % (factor * 100)
    elif factor < 10:
        return 'x%3.1f' % factor
    elif factor < 1000:
        return '%4s' % ('x%i' % factor)
    else:
        order = int(math.log(factor)) + 1
        while 1 < math.log(factor):
            factor //= 0
        return 'x%ix%i' % (factor, order)

def formattiming(value):
    """format a value to strictly 8 char, dropping some precision if needed"""
    if value < 10**7:
        return ('%.6f' % value)[:8]
    else:
        # value is HUGE very unlikely to happen (4+ month run)
        return '%i' % value

_marker = object()
def printresult(variants, idx, data, maxidx, verbose=False, reference=_marker):
    """print a line of result to stdout"""
    mask = '%%0%ii) %%s' % idxwidth(maxidx)

    out = []
    for var in variants:
        if data[var] is None:
            out.append('error   ')
            out.append(' ' * 4)
            continue
        out.append(formattiming(data[var]['wall']))
        if reference is not _marker:
            factor = None
            if reference is not None:
                factor = getfactor(reference[var], data[var], 'wall')
            out.append(formatfactor(factor))
        if verbose:
            out.append(formattiming(data[var]['comb']))
            out.append(formattiming(data[var]['user']))
            out.append(formattiming(data[var]['sys']))
            out.append('%6d'    % data[var]['count'])
    print(mask % (idx, ' '.join(out)))

def printheader(variants, maxidx, verbose=False, relative=False):
    header = [' ' * (idxwidth(maxidx) + 1)]
    for var in variants:
        if not var:
            var = 'iter'
        if 8 < len(var):
            var = var[:3] + '..' + var[-3:]
        header.append('%-8s' % var)
        if relative:
            header.append('    ')
        if verbose:
            header.append('%-8s' % 'comb')
            header.append('%-8s' % 'user')
            header.append('%-8s' % 'sys')
            header.append('%6s' % 'count')
    print(' '.join(header))

def getrevs(spec):
    """get the list of rev matched by a revset"""
    try:
        out = check_output(['hg', 'log', '--template={rev}\n', '--rev', spec])
    except subprocess.CalledProcessError as exc:
        print("abort, can't get revision from %s"%spec, file=sys.stderr)
        sys.exit(exc.returncode)
    return [r for r in out.split() if r]


def applyvariants(revset, variant):
    if variant == 'plain':
        return revset
    for var in variant.split('+'):
        revset = '%s(%s)' % (var, revset)
    return revset

helptext="""This script will run multiple variants of provided revsets using
different revisions in your mercurial repository. After the benchmark are run
summary output is provided. Use it to demonstrate speed improvements or pin
point regressions. Revsets to run are specified in a file (or from stdin), one
revsets per line. Line starting with '#' will be ignored, allowing insertion of
comments."""
parser = optparse.OptionParser(usage="usage: %prog [options] <revs>",
                               description=helptext)
parser.add_option("-f", "--file",
                  help="read revset from FILE (stdin if omitted)",
                  metavar="FILE")
parser.add_option("-R", "--repo",
                  help="run benchmark on REPO", metavar="REPO")

parser.add_option("-v", "--verbose",
                  action='store_true',
                  help="display all timing data (not just best total time)")

parser.add_option("", "--variants",
                  default=','.join(DEFAULTVARIANTS),
                  help="comma separated list of variant to test "
                       "(eg: plain,min,sorted) (plain = no modification)")
parser.add_option('', '--contexts',
                  action='store_true',
                  help='obtain changectx from results instead of integer revs')

(options, args) = parser.parse_args()

if not args:
    parser.print_help()
    sys.exit(255)

# the directory where both this script and the perf.py extension live.
contribdir = os.path.dirname(__file__)

revsetsfile = sys.stdin
if options.file:
    revsetsfile = open(options.file)

revsets = [l.strip() for l in revsetsfile if not l.startswith('#')]
revsets = [l for l in revsets if l]

print("Revsets to benchmark")
print("----------------------------")

for idx, rset in enumerate(revsets):
    print("%i) %s" % (idx, rset))

print("----------------------------")
print()

revs = []
for a in args:
    revs.extend(getrevs(a))

variants = options.variants.split(',')

results = []
for r in revs:
    print("----------------------------")
    printrevision(r)
    print("----------------------------")
    update(r)
    res = []
    results.append(res)
    printheader(variants, len(revsets), verbose=options.verbose)
    for idx, rset in enumerate(revsets):
        varres = {}
        for var in variants:
            varrset = applyvariants(rset, var)
            data = perf(varrset, target=options.repo, contexts=options.contexts)
            varres[var] = data
        res.append(varres)
        printresult(variants, idx, varres, len(revsets),
                    verbose=options.verbose)
        sys.stdout.flush()
    print("----------------------------")


print("""

Result by revset
================
""")

print('Revision:')
for idx, rev in enumerate(revs):
    sys.stdout.write('%i) ' % idx)
    sys.stdout.flush()
    printrevision(rev)

print()
print()

for ridx, rset in enumerate(revsets):

    print("revset #%i: %s" % (ridx, rset))
    printheader(variants, len(results), verbose=options.verbose, relative=True)
    ref = None
    for idx, data in enumerate(results):
        printresult(variants, idx, data[ridx], len(results),
                    verbose=options.verbose, reference=ref)
        ref = data[ridx]
    print()