Quadcap Embeddable Database

com/quadcap/sql/file/ByteUtil.java

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package com.quadcap.sql.file;

/* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

/**
 * This class encapsulates various utilities for manipulating byte arrays
 * which contain primitive values, such as integers, strings, etc.
 *
 * @author Stan Bailes
 */
public class ByteUtil {
    /**
     * Get the two-byte short stored at the specified location in the
     * buffer.
     *
     * @param buf the buffer from which the short is read.
     * @param pos the position in the buffer.
     */
    public static final short getShort(byte[] buf, int pos) {
        return (short)(((buf[pos] & 0xff) << 8) + (buf[pos+1] & 0xff));
    }

    /**
     * Write an short value as two bytes (MSB first) into the buffer
     *
     * @param buf the buffer
     * @param pos the byte offset of the first value
     * @param val the value to write to the buffer
     */
    public static final void putShort(byte[] buf, int pos, short val) {
        buf[pos++] = (byte)((val >>>  8) & 0xff);
        buf[pos]   = (byte)((val       ) & 0xff);
    }

    /**
     * Get the four-byte integer stored at the specified location in the
     * buffer.
     *
     * @param buf the buffer from which the integer is read.
     * @param pos the position in the buffer.
     */
    public static final int getInt(byte[] buf, int pos) {
        return
            ((buf[pos] & 0xff) << 24) +
            ((buf[pos+1] & 0xff) << 16) +
            ((buf[pos+2] & 0xff) << 8) +
            (buf[pos+3] & 0xff);
    }

    /**
     * Write an integer value as four bytes (MSB first) into the buffer
     *
     * @param buf the buffer
     * @param pos the byte offset of the first value
     * @param val the value to write to the buffer
     */
    public static final void putInt(byte[] buf, int pos, int val) {
        buf[pos++] = (byte)((val >>> 24) & 0xff);
        buf[pos++] = (byte)((val >>> 16) & 0xff);
        buf[pos++] = (byte)((val >>>  8) & 0xff);
        buf[pos]   = (byte)((val       ) & 0xff);
    }

    /**
     * Get the eight-byte long stored at the specified location in the
     * buffer.
     *
     * @param buf the buffer from which the long is read.
     * @param pos the position in the buffer.
     */
    public static final long getLong(byte[] buf, int pos) {
        return
            ((long)(buf[pos] & 0xff) << 56) +
            ((long)(buf[pos+1] & 0xff) << 48) +
            ((long)(buf[pos+2] & 0xff) << 40) +
            ((long)(buf[pos+3] & 0xff) << 32) +
            ((long)(buf[pos+4] & 0xff) << 24) +
            ((long)(buf[pos+5] & 0xff) << 16) +
            ((long)(buf[pos+6] & 0xff) << 8) +
            ((long)buf[pos+7] & 0xff);
    }

    /**
     * Write an long value as eight bytes (MSB first) into the buffer
     *
     * @param buf the buffer
     * @param pos the byte offset of the first value
     * @param val the value to write to the buffer
     */
    public static final void putLong(byte[] buf, int pos, long val) {
        buf[pos++] = (byte)((val >>> 56) & 0xff);
        buf[pos++] = (byte)((val >>> 48) & 0xff);
        buf[pos++] = (byte)((val >>> 40) & 0xff);
        buf[pos++] = (byte)((val >>> 32) & 0xff);
        buf[pos++] = (byte)((val >>> 24) & 0xff);
        buf[pos++] = (byte)((val >>> 16) & 0xff);
        buf[pos++] = (byte)((val >>>  8) & 0xff);
        buf[pos]   = (byte)((val       ) & 0xff);
    }


}