import functools

class ArvadosFileBase(object):
    def __init__(self, name, mode):
        self.name = name
        self.mode = mode
        self.closed = False

    @staticmethod
    def _before_close(orig_func):
        @functools.wraps(orig_func)
        def wrapper(self, *args, **kwargs):
            if self.closed:
                raise ValueError("I/O operation on closed stream file")
            return orig_func(self, *args, **kwargs)
        return wrapper

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        try:
            self.close()
        except Exception:
            if exc_type is None:
                raise

    def close(self):
        self.closed = True