#!/bin/sh

GROONGA_HTTPD=groonga-httpd
PIDFILE=/var/run/groonga/${GROONGA_HTTPD}.pid
OLD_PIDFILE=$PIDFILE.oldbin
TIMEOUT=3

# Source function library.
if [ -f /lib/lsb/init-functions ]; then
    . /lib/lsb/init-functions
elif [ -f /etc/init.d/functions ]; then
    . /etc/init.d/functions
fi

wait_until_file_is_created () {
	timeout $TIMEOUT tail -F $1 --quiet 2> /dev/null | read 2> /dev/null
}

wait_until_process_is_finished () {
	timeout $TIMEOUT tail -F /dev/null --pid=$1
}

if [ "$1" = "try-restart" ]; then
	if [ ! -f "$PIDFILE" ]; then
		exit 0
	fi
fi

killproc -p $PIDFILE ${GROONGA_HTTPD} -USR2

wait_until_file_is_created $OLD_PIDFILE
if [ ! -f "$OLD_PIDFILE" ]; then
	echo "Failed to start new groonga-httpd master."
	exit 1
fi

OLD_PID=`cat $OLD_PIDFILE`

# Switch worker process.
kill -WINCH `cat $OLD_PIDFILE`

wait_until_file_is_created $PIDFILE
if [ ! -f "$PIDFILE" ]; then
	echo "Failed to switch worker process."
	exit 2
fi
PID=`cat $PIDFILE`

OLD_WORKER_PROCESS=`pgrep -P $OLD_PID | grep -v $PID`
for pid in $OLD_WORKER_PROCESS; do
	wait_until_process_is_finished $pid
done
OLD_WORKER_PROCESS=`pgrep -P $OLD_PID | grep -v $PID`
if [ -n "$OLD_WORKER_PROCESS" ]; then
	echo "Failed to stop old groonga-httpd worker process."
	killproc -p $PIDFILE ${GROONGA_HTTPD} -QUIT
	echo "Rollback to old groonga-httpd master."
	exit 2
fi

# Stop old master process.
killproc -p $OLD_PIDFILE ${GROONGA_HTTPD} -QUIT
exit $?