Index: squid-tagger.py
==================================================================
--- squid-tagger.py
+++ squid-tagger.py
@@ -46,10 +46,11 @@
 	__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 = '{}://{}/{}'.format(req[4], req[1], req[3])
@@ -161,11 +162,11 @@
 		import select
 		self._select = select
 
 		# kreating kqueue
 		self._kq = self._select.kqueue()
-		assert (self._kq.fileno() != -1)
+		assert self._kq.fileno() != -1, "Fatal error: can't initialise kqueue."
 
 		# watching sys.stdin for data
 		self._kq.control([self._select.kevent(sys.stdin, self._select.KQ_FILTER_READ, self._select.KQ_EV_ADD)], 0)
 
 		# creating data queue
@@ -177,14 +178,21 @@
 		eof = False
 		buffer = ''
 		while True:
 			# checking if there is any data or witing for data to arrive
 			kevs = self._kq.control(None, 1, timeout)
-			if len(kevs) > 0 and kevs[0].filter == self._select.KQ_FILTER_READ and kevs[0].data > 0:
+
+			assert len(kevs) > 0, 'Fatal error: we should receive at least one event.'
+
+			# detect end of stream and exit if possible
+			if kevs[0].flags >> 15 == 1:
+				eof = True
+
+			if kevs[0].filter == self._select.KQ_FILTER_READ and kevs[0].data > 0:
 				# reading data in
 				new_buffer = sys.stdin.read(kevs[0].data)
-				# if no data was sent - we have reached and of file
+				# if no data was sent - we have reached end of file
 				if len(new_buffer) == 0:
 					eof = True
 				else:
 					# adding current buffer to old buffer remains
 					buffer += new_buffer
@@ -197,22 +205,22 @@
 						for line in lines[:-1]:
 							# add data to the queue
 							if self.check(line + '\n'):
 								# don't wait for more data, start processing
 								timeout = 0
-				# if kq reports en of stream refuse to read more of it
-				if kevs[0].flags >> 15 == 1:
-					eof = True
 			else:
 				if len(self._queue) > 0:
+					# get one request and process it
 					req = self._queue.pop(0)
 					Checker.process(self, req[0], req[1], req[2], req[3])
 					if len(self._queue) == 0:
 						# wait for data - we have nothing to process
 						timeout = None
-				elif eof:
-					break
+
+			# if queue is empty and we reached end of stream - we can exit
+			if len(self._queue) == 0 and eof:
+				break
 
 	def process(self, id, site, ip_address, url_path, line):
 		# simply adding data to the queue
 		self._queue.append((id, site, ip_address, url_path))
 		self._log.info('request {} queued ({})\n'.format(id, line))
@@ -239,13 +247,11 @@
 			help = 'config file location', metavar = 'FILE',
 			default = '/usr/local/etc/squid-tagger.conf')
 
 		(options, args) = parser.parse_args()
 
-		if not os.access(options.config, os.R_OK):
-			print("Can't read {}: exitting".format(options.config))
-			sys.exit(2)
+		assert os.access(options.config, os.R_OK), "Fatal error: can't read {}".format(options.config)
 
 		self._config = configparser.ConfigParser()
 		self._config.readfp(open(options.config))
 
 	# function to select config file section or create one