/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.example.table;


/**
 * Implementation of DataRow that is backed by primitive arrays. Should always
 * be used if more than 50% of the data is sparse. As fast (or even faster than
 * map implementation) but needs considerably less memory. This implementation uses
 * byte arrays instead of double arrays which will reduce the used memory even more.
 * 
 * @author Ingo Mierswa
 */
public class ByteSparseArrayDataRow extends AbstractSparseArrayDataRow {

    private static final long serialVersionUID = -262171191423803150L;
    
	/** Stores the used attribute values. */
    private byte[] values;

    /** Creates an empty sparse array data row with size 0. */
    public ByteSparseArrayDataRow() {
        this(0);
    }

    /** Creates a sparse array data row of the given size. */
    public ByteSparseArrayDataRow(int size) {
        super(size);
        values = new byte[size];
    }

    /**
     * Swaps x[a] with x[b].
     */
    @Override
	protected void swapValues(int a, int b) {
        byte tt = values[a];
        values[a] = values[b];
        values[b] = tt;
    }

    @Override
	public void resizeValues(int length) {
        byte[] d = new byte[length];
        System.arraycopy(values, 0, d, 0, Math.min(values.length, length));
        values = d;
    }

    @Override
	public void removeValue(int index) {
        System.arraycopy(values, index + 1, values, index, (values.length - (index + 1)));
    }

    /** Returns the desired data for the given attribute. */
    @Override
	public double getValue(int index) {
        return values[index];
    }

    /** Sets the given data for the given attribute. */
    @Override
	public void setValue(int index, double v) {
        values[index] = (byte)v;
    }

    @Override
	protected double[] getAllValues() {
        double[] result = new double[this.values.length];
        for (int i = 0; i < result.length; i++)
            result[i] = this.values[i];
        return result;
    }
    
	@Override
	public int getType() {
		return DataRowFactory.TYPE_BYTE_SPARSE_ARRAY;
	}
}