def robotsrulesetOfDomain(self, domain):
		'''检查domain是否在数据库中,
			否 --> (False, None)
			是 --> (True, 数据库中存储的robots.txt内容)
		'''
		exist = False
		cur = self.conn.cursor()
		# 是否存在
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		if cur.fetchone() :
			exist = True
		# 存在的话,结果是什么
		cur.execute("SELECT rules FROM Domains,Rulesets "
			"WHERE domain=? AND Domains.did=Rulesets.did"
			,(domain,) )
		ruleset = cur.fetchone()
		return (exist, ruleset)
def update_message_data_string(self):
        fuz_start = self.current_label_start
        fuz_end = self.current_label_end
        num_proto_bits = 10
        num_fuz_bits = 16

        proto_start = fuz_start - num_proto_bits
        preambel = "... "
        if proto_start <= 0:
            proto_start = 0
            preambel = ""

        proto_end = fuz_end + num_proto_bits
        postambel = " ..."
        if proto_end >= len(self.message_data) - 1:
            proto_end = len(self.message_data) - 1
            postambel = ""

        fuzamble = ""
        if fuz_end - fuz_start > num_fuz_bits:
            fuz_end = fuz_start + num_fuz_bits
            fuzamble = "..."

        self.ui.lPreBits.setText(preambel + self.message_data[proto_start:self.current_label_start])
        self.ui.lFuzzedBits.setText(self.message_data[fuz_start:fuz_end] + fuzamble)
        self.ui.lPostBits.setText(self.message_data[self.current_label_end:proto_end] + postambel)
        self.set_add_spinboxes_maximum_on_label_change()