'Sends some statistics about the library.'

def cmd_stats(self, conn):

    with self.lib.transaction() as tx:
        statement = 'SELECT    COUNT(DISTINCT    artist),    COUNT(DISTINCT    album),    COUNT(id),    SUM(length)    FROM    items'
        (artists, albums, songs, totaltime) = tx.query(statement)[0]
    (yield ((u'artists:    ' + six.text_type(artists)), (u'albums:    ' + six.text_type(albums)), (u'songs:    ' + six.text_type(songs)), (u'uptime:    ' + six.text_type(int((time.time() - self.startup_time)))), (u'playtime:    ' + u'0'), (u'db_playtime:    ' + six.text_type(int(totaltime))), (u'db_update:    ' + six.text_type(int(self.updated_time)))))
