lib/portage/proxy/objectproxy.py

# Copyright 2008-2020 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2


__all__ = ["ObjectProxy"]


class ObjectProxy:

    """
    Object that acts as a proxy to another object, forwarding
    attribute accesses and method calls. This can be useful
    for implementing lazy initialization.
    """

    __slots__ = ()

    def _get_target(self):
        raise NotImplementedError(self)

    def __getattribute__(self, attr):
        result = object.__getattribute__(self, "_get_target")()
        return getattr(result, attr)

    def __setattr__(self, attr, value):
        result = object.__getattribute__(self, "_get_target")()
        setattr(result, attr, value)

    def __call__(self, *args, **kwargs):
        result = object.__getattribute__(self, "_get_target")()
        return result(*args, **kwargs)

    def __enter__(self):
        return object.__getattribute__(self, "_get_target")().__enter__()

    def __exit__(self, exc_type, exc_value, traceback):
        return object.__getattribute__(self, "_get_target")().__exit__(
            exc_type, exc_value, traceback
        )

    def __setitem__(self, key, value):
        object.__getattribute__(self, "_get_target")()[key] = value

    def __getitem__(self, key):
        return object.__getattribute__(self, "_get_target")()[key]

    def __delitem__(self, key):
        del object.__getattribute__(self, "_get_target")()[key]

    def __contains__(self, key):
        return key in object.__getattribute__(self, "_get_target")()

    def __iter__(self):
        return iter(object.__getattribute__(self, "_get_target")())

    def __len__(self):
        return len(object.__getattribute__(self, "_get_target")())

    def __repr__(self):
        return repr(object.__getattribute__(self, "_get_target")())

    def __str__(self):
        return str(object.__getattribute__(self, "_get_target")())

    def __add__(self, other):
        return self.__str__() + other

    def __hash__(self):
        return hash(object.__getattribute__(self, "_get_target")())

    def __ge__(self, other):
        return object.__getattribute__(self, "_get_target")() >= other

    def __gt__(self, other):
        return object.__getattribute__(self, "_get_target")() > other

    def __le__(self, other):
        return object.__getattribute__(self, "_get_target")() <= other

    def __lt__(self, other):
        return object.__getattribute__(self, "_get_target")() < other

    def __eq__(self, other):
        return object.__getattribute__(self, "_get_target")() == other

    def __ne__(self, other):
        return object.__getattribute__(self, "_get_target")() != other

    def __bool__(self):
        return bool(object.__getattribute__(self, "_get_target")())

    def __int__(self):
        return int(object.__getattribute__(self, "_get_target")())