def updateInfo(self, item, newlinks, oldlinks):
		'''爬虫爬完之后对数据库内容进行更新'''
		cur = self.conn.cursor()
		cur.execute("SELECT wid,did FROM Websites WHERE url=?", (item['url'],))
		wid, did = cur.fetchone()
		# website记录更新
		cur.execute("UPDATE Websites SET title=?,visited=1 WHERE wid=?", (item['title'], wid,))
		# 对应的domain记录中出度也需要更新
		cur.execute("UPDATE Domains SET outdegree=outdegree+? WHERE did=?", (len(item['links']), did,))

		# 对该网页中所有链接涉及的记录进行更新
		# 外部判断未出现过的链接
		for link,domain in newlinks:
			self.insertWebsite(link, domain)

		# 外部判断出现过的链接
		for link,domain in oldlinks:
			# 对对应的domain记录入度增加
			cur.execute("UPDATE Domains SET outdegree=outdegree+1 WHERE domain=?", (domain,))
		# 写入到文件
		self.conn.commit()
def _GetOutputStream(output_format, output_dir):
  assert output_format in _OUTPUT_FORMAT_CHOICES, 'Must specify a valid format.'
  assert output_format not in ('gtest', 'none'), (
      'Cannot set stream for \'gtest\' or \'none\' output formats.')

  if output_format == 'buildbot':
    return sys.stdout

  assert output_format in _OUTPUT_FILENAME_LOOKUP, (
      'No known filename for the \'%s\' output format' % output_format)
  output_file = os.path.join(output_dir, _OUTPUT_FILENAME_LOOKUP[output_format])
  open(output_file, 'a').close()  # Create file if it doesn't exist.
  return open(output_file, 'r+')