# file_stat means file definitely exists
			file_stat = None
			# requested_ranges holds data about any range requested
			requested_ranges = None
			# records holds data from index locally, should be written back upon successfull completion
			record = None
			info = 'Checking file: ' + self.path

			myPath = re.compile('^(.*?)(\?.*)$').match(self.path)
			if myPath:
				my_path = myPath.group(1)
			else:
				my_path = self.path

			proxy_ignored = ('Accept', 'Accept-Encoding',
				'Cache-Control', 'Connection',
				'Host',
				'User-Agent',
				'Via',
				'X-Forwarded-For',
			)

			print('===============[ Request ]===')
			print('Command:', self.command)

			for header in self.headers:
				if header in proxy_ignored:
					pass
				elif header in ('Range'):
					isRange = re.compile('bytes=(\d+)-(\d+)').match(self.headers[header])
					if isRange:
						requested_ranges = SpaceMap({int(isRange.group(1)): int(isRange.group(2)) + 1})
					else:
						return()
				else:
					print('Unknown header - ', header, ': ', self.headers[header], sep='')
					return()
				print(header, self.headers[header])
			print(my_path)

			# creating empty placeholder in index
			# if there's no space map and there's no file in real directory - we have no file
			# if there's an empty space map - file is full
			# space map generally covers every bit of file we don't posess currently
			if not my_path in index:
				info += '\nThis one is new.'
				reload = True
				record = {'_parts': None}
			else:
				record = index[my_path]
				if '_parts' in index[my_path]:
					print(record['_parts'])
					if index[my_path]['_parts'] == {0: -1}:
						index[my_path]['_parts'] = None

			# creating file name from my_path
			file_name = options.dir + os.sep + re.compile('%20').sub(' ', my_path)
			# partial file or unfinished download
			temp_name = options.dir + os.sep + '.parts' + re.compile('%20').sub(' ', my_path)

			# forcibly checking file if no file present
			if os.access(file_name, os.R_OK):
				file_stat = os.stat(file_name)
			elif '_parts' in record and os.access(temp_name, os.R_OK):
				file_stat = os.stat(temp_name)
			elif not reload:

			if not recheck and not reload and '_time' in record and (datetime.datetime.now() - datetime.timedelta(hours = 4) - record['_time']).days < 0:
				recheck = True

			print(info)
			if reload or recheck:

				try:
					request = options.root + my_path
					if requested_ranges != None:
						if '_parts' in record and record['_parts'] != None:
							needed = record['_parts'] & requested_ranges
						else:
							needed = requested_ranges
						ranges = ()
						print('Requesting ranges:', ranges)

										stream_pos = stream_last + length
										assert not stream_pos > end, 'Received more data then requested: pos:{} start:{} end:{}.'.format(stream_pos, start, end)
										print('Writing', length, 'bytes to temp file at position', stream_last)
										temp_file.seek(stream_last)
										temp_file.write(buffer)
										new_record['_parts'] = new_record['_parts'] - SpaceMap({stream_last: stream_pos})
										print(new_record)
										index[my_path] = old_record
										index.sync()
										old_record = new_record
										stream_last = stream_pos
										if end - stream_last < block_size:
											req_block_size = end - stream_last
										buffer = source.read(req_block_size)
										print(buffer)
										length = len(buffer)
								print(new_record)
								index[my_path] = new_record
								index.sync()
								temp_file.close()

								# moving downloaded data to real file
								if new_record['_parts'] == SpaceMap():

									# just moving
									# drop old dirs XXX
									print('Moving temporary file to new destination.')
									os.renames(temp_name, file_name)

				except urllib.error.HTTPError as error:
					# in case of error we don't need to do anything actually,
					# if file download stalls or fails the file would not be moved to it's location
					print(error)

			print('Sending response.')
			if self.command == 'HEAD':
				print('Sending HEAD response.')
				self.send_response(200)
				if 'Content-Length' in index[my_path]:
					self.send_header('Content-Length', index[my_path]['Content-Length'])
				self.send_header('Accept-Ranges', 'bytes')
				self.send_header('Content-Type', 'application/octet-stream')
				if 'Last-Modified' in index[my_path]:
					self.send_header('Last-Modified', index[my_path]['Last-Modified'])
				self.end_headers()
			else:
				if index[my_path]['_parts'] != SpaceMap():
					file_name = temp_name

				with open(file_name, 'rb') as real_file:
					file_stat = os.stat(file_name)
					self.send_response(200)
					self.send_header('Last-Modified', index[my_path]['Last-Modified'])
					if requested_ranges != None:
						ranges = ()
						requested_ranges.rewind()
						while True:
							pair = requested_ranges.pop()
							if pair[0] == None:
								break
							ranges += '{}-{}'.format(pair[0], str(pair[1] - 1)),
						self.send_header('Content-Range', 'bytes ' + ','.join(ranges) + '/' + index[my_path]['Content-Length'])
					else:
						self.send_header('Content-Length', str(file_stat.st_size))
						requested_ranges = SpaceMap({0: file_stat.st_size})
					self.send_header('Content-Type', 'application/octet-stream')
					self.end_headers()
					if self.command in ('GET'):
						requested_ranges.rewind()