CResRefData.java

// <editor-fold defaultstate="collapsed" desc="license">
/*
 * Copyright (c) 2014, Karl H. Beckers
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of the <ORGANIZATION> nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 **/
// </editor-fold>
package net.jarre_de_the.griffin.types.data;

import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Arrays;
import java.util.Locale;
import net.jarre_de_the.griffin.Util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Implementation of CRESREF. The GFF CRESREF physically consists of a single
 * byte length and as many bytes of content. The maximum content length is 16
 * bytes.<br>
 * The CRESREF is used to refer to file names (which apparently were considered
 * to not need more than 16 characters). The characters are single-byte encoded
 * and there is no string termination. A CRESREF is used in contexts not
 * case-sensitive and stores all characters as lower-case.
 * <p>
 * @author charly4711
 */
public class CResRefData extends AbstractData
        implements Cloneable {

    /**
     * A CRESREF's maximum length in bytes.
     */
    public static final int MAX_SIZE = 16;
    private static final Logger LOGGER = LoggerFactory.getLogger(CResRefData.class);
    private byte[] value;

    /*
     *
     * constructors
     *
     */
    protected CResRefData() {
    }

    /**
     * Creates a new instance of {@code CResRefData} and sets the defined value.
     * <p>
     * @param buf String contents as a byte array.
     * @see #setValue(byte[])
     */
    public CResRefData(byte[] buf) {
        setValue(buf);
    }

    /*
     *
     * read from file
     *
     */
    /**
     * Creates a new instance of {@code CResRefData} based on the data read from
     * the file passed. Note that the contents are read from whatever position
     * the file pointer is at.
     * <p>
     * @param in An open {@code RandomAccessFile}.
     * @return
     * @throws java.io.IOException If there are any I/O related problems with
     * file access to in.
     */
    public static CResRefData read(RandomAccessFile in)
            throws IOException {
        LOGGER.debug("Reading CResRefData from file.");
        byte len = in.readByte();
        LOGGER.trace("Need to read " + len + " bytes.");
        byte[] buf = new byte[len];
        in.readFully(buf);
        LOGGER.trace("Read " + new String(buf, Util.CHARSET_US_ASCII));
        return new CResRefData(buf);
    }

    /*
     *
     * setter
     *
     */
    /**
     * Sets the value of this instance. The byte array is copied internally.
     * <p>
     * @param buf The byte array containing the string. If the length of the
     * byte array exceeds 16 it will be truncated. Any upper-case characters
     * will also be converted to lower-case.
     */
    private void setValue(byte[] buf) {
        if (buf != null) {
            String s = new String(buf, Util.CHARSET_US_ASCII);
            s = s.substring(0, Math.min(MAX_SIZE, s.length()));
            s = s.toLowerCase(Locale.US);
            this.value = s.getBytes(Util.CHARSET_US_ASCII);

            LOGGER.debug("Set CResRefData value to: "
                    + new String(this.value, Util.CHARSET_US_ASCII));
        }
    }

    /*
     *
     * getter
     *
     */
    /**
     * Returns this instance's bit-field value as a byte array in the same order
     * it would be stored in a GFF file. Note, this does not prepend the length.
     * <p>
     * @return This instance's value as a bit field of variable length.
     */
    public byte[] getValueAsByteArray() {
        byte[] buf;

        if (null != value) {
            buf = new byte[value.length];
            System.arraycopy(value, 0, buf, 0, value.length);
            LOGGER.debug("Retrieving byte array " + new String(buf, Util.CHARSET_US_ASCII));
        } else {
            buf = null;
        }
        return buf;
    }

    /*
     *
     * utility
     *
     */
    /**
     * Overrides the {@code java.lang.Object} method to ensure we always get
     * back an instance of {@code CExoStringData} rather than just
     * {@code Object}.
     * <p>
     * @return A deep copy of this object.
     * @throws java.lang.CloneNotSupportedException
     */
    @Override
    public CResRefData clone() throws CloneNotSupportedException {
        LOGGER.debug("Cloning object");
        CResRefData clone = (CResRefData) super.clone();
        clone.setValue(value); // setValue does an arraycopy

        return clone;
    }

    /**
     * Overrides the {@code java.lang.Object} method to make test for equality
     * possible for this class.
     * <p>
     * @param o The Object to compare this object with.
     * @return True if the objects have the same value, false if not.
     */
    @Override
    public boolean equals(Object o) {
        if (o == this) {
            return true;
        }

        if (!(o instanceof CResRefData)) {
            return false;
        }

        CResRefData d = (CResRefData) o;
        if (Arrays.equals(d.getValueAsByteArray(), this.getValueAsByteArray())) {
            return true;
        }

        return false;
    }

    /**
     * Overrides the {@code java.lang.Object} method to ensure we have a hash
     * code consistent with the test for equality.
     * <p>
     * @return The hash returned is based on the value.
     */
    @Override
    public int hashCode() {
        return Arrays.hashCode(value);
    }

    @Override
    public String toString() {
        String result = EMPTY_VALUE;

        if (value != null && value.length > 0) {
            result = new String(this.value, Util.CHARSET_US_ASCII);
        }

        return result;
    }
}