allmirrors()
{
	"$@" git  ''   git://git.xonotic.org/xonotic/      ''
	"$@" http ''   http://git.xonotic.org/xonotic/     ''
	"$@" ssh  ''   ssh://xonotic@git.xonotic.org/      ''

	"$@" ssh  push ssh://xonotic@push.git.xonotic.org/ ''

	"$@" git  de   git://de.git.xonotic.org/xonotic/   ''
	"$@" http de   http://de.git.xonotic.org/xonotic/  ''

	"$@" git  nl   git://nl.git.xonotic.org/xonotic/   '*3/2'
	"$@" http nl   http://nl.git.xonotic.org/xonotic/  '*3/2'

	"$@" git  us   git://us.git.xonotic.org/xonotic/   ''
	"$@" http us   http://us.git.xonotic.org/xonotic/  ''
}

allrepos()
{
	"$@" .                             xonotic.git                  master         ""
	"$@" data/xonotic-data.pk3dir      xonotic-data.pk3dir.git      master         ""
	"$@" data/xonotic-music.pk3dir     xonotic-music.pk3dir.git     master         ""
	"$@" data/xonotic-nexcompat.pk3dir xonotic-nexcompat.pk3dir.git master         "no"
	"$@" darkplaces                    darkplaces.git               div0-stable    "svn"
	"$@" netradiant                    netradiant.git               master         ""
	"$@" div0-gittools                 div0-gittools.git            master         "no"
	"$@" d0_blind_id                   d0_blind_id.git              master         ""
	"$@" data/xonotic-maps.pk3dir      xonotic-maps.pk3dir.git      master         ""
	"$@" mediasource                   mediasource.git              master         "no"
	"$@" fteqcc                        fteqcc.git                   xonotic-stable "noautocrlf"
}

mirrorspeed()
{
	if ! { time -p true; } >/dev/null 2>&1; then
		echo 0
		return
	fi
	# first result is to be ignored, but we use it to check status
	git ls-remote "$1" refs/heads/master >/dev/null 2>&1 || return 1
	# now actually time it
	(
		set +x
		{ time -p git ls-remote "$1" refs/heads/master; } 2>&1 >/dev/null | head -n 1 | cut -d ' ' -f 2 | tr -d . | sed 's,^0*,,' | grep . || echo 0
			# unit: clock ticks (depends on what "time" returns
	)
}
bestmirror()
{
	oldurl="$1"
	newprotocol="$2"
	newlocation="$3"
	oldprotocol=
	oldlocation=
	testrepo=
	bestmirror_firstrepo()
	{
		if [ -z "$testrepo" ]; then
			testrepo=$2
		fi
	}
	allrepos bestmirror_firstrepo
	bestmirror_findold()
	{
		if [ x"$oldurl" = x"$3" ]; then
			oldprotocol=$1
			oldlocation=$2
		fi
	}
	allmirrors bestmirror_findold
	besturl=
	bestlocation=
	besttime=
	bestcount=
	bestmirror_benchmark()
	{
		if [ -z "$2" ]; then
			# empty location is not allowed
			return
		fi
		if [ x"$1" != x"$newprotocol" ]; then
			return
		fi
		# only working mirrors
		if ! thistime=`mirrorspeed "$3$testrepo"`; then
			return
		fi
		thistime=$(($thistime $4))
		# anything is better than nothing
		if [ -z "$besttime" ]; then
			besturl=$3
			bestlocation=$2
			besttime=$thistime
			bestcount=1
			return
		fi
		# prefer location match
		if [ x"$2" = x"$newlocation" ]; then
			if [ x"$bestlocation" != x"$newlocation" ]; then
				besturl=$3
				bestlocation=$2
				besttime=$thistime
				bestcount=1
				return
			fi
		else
			if [ x"$bestlocation" = x"$newlocation" ]; then
				return
			fi
		fi
		# if we get here, we must compare mirror speed as we have more than one match
		if [ $thistime -gt $besttime ]; then
			return
		elif [ $thistime -lt $besttime ]; then
			besturl=$3
			besttime=$thistime
			bestcount=1
			return
		fi
		# both location and time match. Random decision.
		bestcount=$(($bestcount + 1))
		if [ $((($RANDOM + 0) % $bestcount)) -eq 0 ]; then
			besturl=$3
		fi
	}
	allmirrors bestmirror_benchmark
	echo "$besturl"
}