#!/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.

#

# - First argument is a revset of mercurial own repo to runs against.

# - Second argument is the file from which the revset array will be taken

#   If second argument is omitted read it from standard input

#

# You should run this from the root of your mercurial repository.

#

# This script also does one run of the current version of mercurial installed

# to compare performance.

import sys

import os

import re

from subprocess import check_call, Popen, CalledProcessError, STDOUT, PIPE

# cannot use argparse, python 2.7 only

from optparse import OptionParser

def check_output(*args, **kwargs):

    kwargs.setdefault('stderr', PIPE)

    kwargs.setdefault('stdout', PIPE)

    proc = Popen(*args, **kwargs)

    output, error = proc.communicate()

    if proc.returncode != 0:

        raise CalledProcessError(proc.returncode, ' '.join(args[0]))

    return output

def update(rev):

    """update the repo to a revision"""

    try:

        check_call(['hg', 'update', '--quiet', '--check', str(rev)])

    except CalledProcessError, exc:

        print >> sys.stderr, 'update to revision %s failed, aborting' % rev

        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=STDOUT)

def perf(revset, target=None):

    """run benchmark for this very revset"""

    try:

        output = hg(['perfrevset', revset], repo=target)

        return parseoutput(output)

    except CalledProcessError, exc:

        print >> sys.stderr, 'abort: cannot run revset benchmark: %s' % exc.cmd

        if exc.output is None:

            print >> sys.stderr, '(no ouput)'

        else:

            print >> sys.stderr, exc.output

        sys.exit(exc.returncode)

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 >> sys.stderr, 'abort: invalid output:'

        print >> sys.stderr, output

        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()

    check_call(['hg', 'log', '--rev', str(rev), '--template',

               '{desc|firstline}\n'])

def idxwidth(nbidx):

    """return the max width of number used for index

    nbidx -= 1 # starts at 0

    idxwidth = 0

    while nbidx:

        idxwidth += 1

        nbidx //= 10

    if not idxwidth:

        idxwidth = 1

    return idxwidth

def printresult(idx, data, maxidx):

    """print a line of result to stdout"""

    mask = '%%0%ii) %%s' % idxwidth(maxidx)

    out = ("wall %f comb %f user %f sys %f (best of %d)"

           % (data['wall'], data['comb'], data['user'],

              data['sys'], data['count']))

    print mask % (idx, out)

def getrevs(spec):

    """get the list of rev matched by a revset"""

    try:

        out = check_output(['hg', 'log', '--template={rev}\n', '--rev', spec])

    except CalledProcessError, exc:

        print >> sys.stderr, "abort, can't get revision from %s" % spec

        sys.exit(exc.returncode)

    return [r for r in out.split() if r]

parser = OptionParser(usage="usage: %prog [options] <revs>")

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")

(options, args) = parser.parse_args()

if len(sys.argv) < 2:

    parser.print_help()

    sys.exit(255)

# the directory where both this script and the perf.py extension live.

contribdir = os.path.dirname(__file__)

target_rev = args[0]

revsetsfile = sys.stdin

if options.file:

    revsetsfile = open(options.file)

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

print "Revsets to benchmark"

print "----------------------------"

for idx, rset in enumerate(revsets):

    print "%i) %s" % (idx, rset)

print "----------------------------"

print

revs = getrevs(target_rev)

results = []

for r in revs:

    print "----------------------------"

    printrevision(r)

    print "----------------------------"

    update(r)

    res = []

    results.append(res)

    for idx, rset in enumerate(revsets):

        data = perf(rset, target=options.repo)

        res.append(data)

        printresult(idx, data, len(revsets))

        sys.stdout.flush()

    print "----------------------------"

print """

Result by revset

================

"""

print 'Revision:', revs

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)

    for idx, data in enumerate(results):

        printresult(idx, data[ridx], len(results))

    print