def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def visitdir(self, dir):
        dir = normalizerootdir(dir, "visitdir")
        if self._prefix and dir in self._fileset:
            return "all"
        if not self._prefix:
            return True
        return (
            dir in self._fileset
            or dir in self._dirs
            or any(parentdir in self._fileset for parentdir in util.finddirs(dir))
        )