<reponame>VisualJoyce/caffe2
# Copyright (c) 2016-present, Facebook, Inc.
#
# 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.
##############################################################################

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import abc
import six


class NetModifier(six.with_metaclass(abc.ABCMeta, object)):
    """
    An abstraction class for supporting modifying a generated net.
    Inherited classes should implement the modify_net method where
    related operators are added to the net.

    Example usage:
        modifier = SomeNetModifier(opts)
        modifier(net)
    """

    def __init__(self):
        pass

    @abc.abstractmethod
    def modify_net(self, net, init_net=None, grad_map=None, blob_to_device=None):
        pass

    def __call__(self, net, init_net=None, grad_map=None, blob_to_device=None):
        self.modify_net(
            net,
            init_net=init_net,
            grad_map=grad_map,
            blob_to_device=blob_to_device)
