# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
# Copyright 2020 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import cloudpickle


class PicklableWrapper(object):
    """
    Wrap an object to make it more picklable, note that it uses
    heavy weight serialization libraries that are slower than pickle.
    It's best to use it only on closures (which are usually not picklable).

    This is a simplified version of
    https://github.com/joblib/joblib/blob/master/joblib/externals/loky/cloudpickle_wrapper.py
    """

    def __init__(self, obj):
        self._obj = obj

    def __reduce__(self):
        s = cloudpickle.dumps(self._obj)
        return cloudpickle.loads, (s,)

    def __call__(self, *args, **kwargs):
        return self._obj(*args, **kwargs)

    def __getattr__(self, attr):
        # Ensure that the wrapped object can be used seamlessly as the previous object.
        if attr not in ["_obj"]:
            return getattr(self._obj, attr)
        return getattr(self, attr)