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_revision_sha(cls, dest, rev):
        """
        Return (sha_or_none, is_branch), where sha_or_none is a commit hash
        if the revision names a remote branch or tag, otherwise None.

        Args:
          dest: the repository directory.
          rev: the revision name.
        """
        # Pass rev to pre-filter the list.
        output = cls.run_command(
            ['show-ref', rev],
            cwd=dest,
            show_stdout=False,
            stdout_only=True,
            on_returncode='ignore',
        )
        refs = {}
        for line in output.strip().splitlines():
            try:
                sha, ref = line.split()
            except ValueError:
                # Include the offending line to simplify troubleshooting if
                # this error ever occurs.
                raise ValueError('unexpected show-ref line: {!r}'.format(line))

            refs[ref] = sha

        branch_ref = 'refs/remotes/origin/{}'.format(rev)
        tag_ref = 'refs/tags/{}'.format(rev)

        sha = refs.get(branch_ref)
        if sha is not None:
            return (sha, True)

        sha = refs.get(tag_ref)

        return (sha, False)