#!/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']

        if contexts:

            args.append('--contexts')

        args.append('--')

        args.append(revset)

        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(br'! wall (\d+.\d+) comb (\d+.\d+) user (\d+.\d+) '

                      br'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 math.log(factor) > 1:

            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 len(var) > 8:

            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()