/*
 * Encog(tm) Core v3.4 - Java Version
 * http://www.heatonresearch.com/encog/
 * https://github.com/encog/encog-java-core
 
 * Copyright 2008-2016 Heaton Research, 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.
 *   
 * For more information on Heaton Research copyrights, licenses 
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */
package org.encog.ml.data.buffer.codec;

/**
 * A CODEC is used to encode and decode data. The DataSetCODEC is designed to
 * move data to/from the Encog binary training file format, used by
 * BufferedNeuralDataSet. CODECs are provided for such items as CSV files,
 * arrays and many other sources.
 * 
 */
public interface DataSetCODEC {

	/**
	 * Read one record of data from an external source.
	 * 
	 * @param input
	 *            The input data array.
	 * @param ideal
	 *            The ideal data array.
	 * @param significance
	 * 			 The significance.  The first element will be modified 
	 * to hold the significance.
	 * @return True, if there is more data to be read.
	 */
	boolean read(double[] input, double[] ideal, double[] significance);

	/**
	 * Write one record of data to an external destination.
	 * 
	 * @param input
	 *            The input data array.
	 * @param ideal
	 *            The ideal data array.
	 * @param significance The significance (full = 1.0)
	 */
	void write(double[] input, double[] ideal, double significance);

	/**
	 * Prepare to write to an external data destination.
	 * 
	 * @param recordCount
	 *            The total record count, that will be written.
	 * @param inputSize
	 *            The input size.
	 * @param idealSize
	 *            The ideal size.
	 */
	void prepareWrite(int recordCount, int inputSize, int idealSize);

	/**
	 * Prepare to read from an external data source.
	 */
	void prepareRead();

	/**
	 * @return The size of the input data.
	 */
	int getInputSize();

	/**
	 * @return The size of the ideal data.
	 */
	int getIdealSize();

	/**
	 * Close any open files.
	 */
	void close();

}