return(self._check_stmt(site, ip_address))

	def dump(self):
		if self._dump_stmt == None:
			self._dump_stmt = self._db.prepare("select untrip(site), tag, regexp from urls natural join site natural join tag order by site, tag")
		return(self._dump_stmt())

	def load(self, csv_data):
		with self._db.xact():
			if config.options.flush_db:
				self._db.execute('delete from urls;')
				if config.options.flush_site:
					self._db.execute('delete from site;');
			insertreg = self._db.prepare("select set($1, $2, $3)")
			insert = self._db.prepare("select set($1, $2)")
			for row in csv_data:
				if len(row[2]) > 0:
					insertreg(row[0], row[1], row[2])
				else:
					insert(row[0], row[1])
		self._db.execute('vacuum analyze site;')
		self._db.execute('vacuum analyze urls;')

# abstract class with basic checking functionality
class Checker:
	__slots__ = frozenset(['_db', '_log'])

	def __init__(self):
		self._db = tagDB()
		self._log = Logger()
		self._log.info('started\n')

	def process(self, id, site, ip_address, url_path, line = None):
		self._log.info('trying {}\n'.format(site))
		result = self._db.check(site, ip_address)

		reply = '-'
		for row in result:
			if row != None and row[0] != None:
				if row[1] != None:
					self._log.info('trying regexp "{}" versus "{}"\n'.format(row[1], url_path))
					try:
						if re.compile(row[1]).match(url_path):

		parser = optparse.OptionParser()
		parser.add_option('-c', '--config', dest = 'config',
			help = 'config file location', metavar = 'FILE',
			default = '/usr/local/etc/squid-tagger.conf')
		parser.add_option('-d', '--dump', dest = 'dump',
			help = 'dump database', action = 'store_true', metavar = 'bool',
			default = False)
		parser.add_option('-f', '--flush-database', dest = 'flush_db',
			help = 'flush previous database on load', default = False,
			action = 'store_true', metavar = 'bool')
		parser.add_option('-F', '--flush-site', dest = 'flush_site',
			help = 'when flushing previous dtabase flush site index too',
			action = 'store_true', default = False, metavar = 'bool')
		parser.add_option('-l', '--load', dest = 'load',
			help = 'load database', action = 'store_true', metavar = 'bool',
			default = False)

		(self.options, args) = parser.parse_args()

		assert os.access(self.options.config, os.R_OK), "Fatal error: can't read {}".format(self.options.config)

		self._config = configparser.ConfigParser()
		self._config.readfp(open(self.options.config))

	tagdb = tagDB()

	csv_writer = csv.writer(sys.stdout)
	csv_writer.writerow(['site', 'tags', 'regexp'])
	for row in tagdb.dump():
		csv_writer.writerow([row[0], '{' + ','.join(row[1]) + '}', row[2]])

elif config.options.load:
	# loading database
	import csv

	tagdb = tagDB()

	csv_reader = csv.reader(sys.stdin)
	first_row = next(csv_reader)

	assert first_row == ['site', 'tags', 'regexp'], 'File must contain csv data with three columns: "site", "tags" and "regexp".'

	tagdb.load(csv_reader)

else:
	# main loop
	config.section('reactor')
	if config['reactor'] == 'thread':
		checker = CheckerThread()
	elif config['reactor'] == 'plain':
		checker = Checker()
	elif config['reactor'] == 'kqueue':
		checker = CheckerKqueue()

	checker.loop()