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 wait_time_gen():
        count = 0
        while True:
            rand = random.randrange(round(interval.total_seconds()))
            tmp = round(start + interval.total_seconds() * count + rand - loop.time())
            yield tmp
            count += 1