/*
 *  ******************************************************************************
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 *  * This program and the accompanying materials are made available under the
 *  * terms of the Apache License, Version 2.0 which is available at
 *  * https://www.apache.org/licenses/LICENSE-2.0.
 *  *
 *  *  See the NOTICE file distributed with this work for additional
 *  *  information regarding copyright ownership.
 *  * 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
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package org.deeplearning4j.nn.api;

import org.deeplearning4j.nn.gradient.Gradient;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.deeplearning4j.nn.workspace.LayerWorkspaceMgr;

import java.io.Serializable;

/**
 * Update the model
 *
 * @author Adam Gibson
 */
public interface Updater extends Serializable {

    /**
     * Set the internal (historical) state view array for this updater
     *
     * @param layer      Layer that this updater belongs to
     * @param viewArray  View array
     * @param initialize Whether to initialize the array or not
     */
    void setStateViewArray(Trainable layer, INDArray viewArray, boolean initialize);

    /**
     * @return the view array for this updater
     */
    INDArray getStateViewArray();

    /**
     * Updater: updates the model
     *
     * @param layer
     * @param gradient
     * @param iteration
     */
    void update(Trainable layer, Gradient gradient, int iteration, int epoch, int miniBatchSize, LayerWorkspaceMgr workspaceMgr);
}
