#!/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
from subprocess import check_call, check_output, CalledProcessError


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 perf(revset):
    """run benchmark for this very revset"""
    try:
        check_call(['./hg', '--config', 'extensions.perf=contrib/perf.py',
                    'perfrevset', revset])
    except CalledProcessError, exc:
        print >> sys.stderr, 'abort: cannot run revset benchmark'
        sys.exit(exc.returncode)

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'])


target_rev = sys.argv[1]

revsetsfile = sys.stdin
if len(sys.argv) > 2:
    revsetsfile = open(sys.argv[2])

revsets = [l.strip() for l in revsetsfile]

print "Revsets to benchmark"
print "----------------------------"

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

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

revs = check_output("hg log --template='{rev}\n' --rev " + target_rev,
                    shell=True)

revs = [r for r in revs.split() if r]

# Benchmark revisions
for r in revs:
    print "----------------------------"
    printrevision(r)
    print "----------------------------"
    update(r)
    for idx, rset in enumerate(revsets):
        sys.stdout.write("%i) " % idx)
        sys.stdout.flush()
        perf(rset)
    print "----------------------------"