def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def patkind(pattern, default=None):
    """If pattern is 'kind:pat' with a known kind, return kind."""
    return _patsplit(pattern, default)[0]