def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def connection_made(self, transport):
        self.transport = transport
        # Here the buffer is intended to be copied, so that the outgoing buffer
        # won't be wrongly updated by next read
        self.buffer = bytearray(256 * 1024)