def insertWebsite(self, url, domain):
		'''增加一个网页,标记为未访问,并对相应的domain增加其入度'''
		cur = self.conn.cursor()
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		result = cur.fetchone()
		if not result:
			# 未有对应domain记录, 先创建domain, 把入度设为1
			if VERBOSE:
				print 'Spot Domain:',domain
			self.insertDomain(domain, indegree=1)
			cur.execute("SELECT did FROM Domains WHERE domain=?", (domain,))
			did = cur.fetchone()[0]
		else:
			did = result[0]
			# 对应的domain记录已经存在, 对其入度+1
			cur.execute("UPDATE Domains SET outdegree=outdegree+1 WHERE domain=?", (domain,))

		cur.execute("INSERT INTO Websites VALUES (NULL,?,?,NULL,0)", (did, url,))
		# 写入到文件
		self.conn.commit()
def get_spec(field, limit=10, query='', query_dsl=''):
    """Returns aggregation specs for a term of filtered events.

    The aggregation spec will summarize values of an attribute
    whose events fall under a filter.

    Args:
        field (str): this denotes the event attribute that is used
            for aggregation.
        limit (int): How many buckets to return, defaults to 10.
        query (str): the query field to run on all documents prior to
            aggregating the results.
        query_dsl (str): the query DSL field to run on all documents prior
            to aggregating the results (optional). Either a query string
            or a query DSL has to be present.

    Raises:
        ValueError: if neither query_string or query_dsl is provided.

    Returns:
        a dict value that can be used as an aggregation spec.
    """
    if query:
        query_filter = {
            'bool': {
                'must': [
                    {
                        'query_string': {
                            'query': query
                        }
                    }
                ]
            }
        }
    elif query_dsl:
        query_filter = query_dsl
    else:
        raise ValueError('Neither query nor query DSL provided.')


    return {
        'query': query_filter,
        'aggs': {
            'aggregation': {
                'terms': {
                    'field': field,
                    'size': limit
                }
            }
        }
    }