/*

 * Copyright (c) 2001, 2002, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.corba.se.impl.ior ;

public class ByteBuffer {

    /**

     * The array buffer into which the components of the ByteBuffer are

     * stored. The capacity of the ByteBuffer is the length of this array buffer,

     * and is at least large enough to contain all the ByteBuffer's elements.<p>

     *

     * Any array elements following the last element in the ByteBuffer are 0.

     */

    protected byte elementData[];

    /**

     *

     * @serial

     */

    protected int elementCount;

    /**

     * The amount by which the capacity of the ByteBuffer is automatically

     * incremented when its size becomes greater than its capacity.  If

     * the capacity increment is less than or equal to zero, the capacity

     * of the ByteBuffer is doubled each time it needs to grow.

     *

     * @serial

     */

    protected int capacityIncrement;

    /**

     * Constructs an empty ByteBuffer with the specified initial capacity and

     * capacity increment.

     *

     * @param   initialCapacity     the initial capacity of the ByteBuffer.

     * @param   capacityIncrement   the amount by which the capacity is

     *                              increased when the ByteBuffer overflows.

     * @exception IllegalArgumentException if the specified initial capacity

     *               is negative

     */

    public ByteBuffer(int initialCapacity, int capacityIncrement) {

        super();

        if (initialCapacity < 0)

            throw new IllegalArgumentException("Illegal Capacity: "+

                                               initialCapacity);

        this.elementData = new byte[initialCapacity];

        this.capacityIncrement = capacityIncrement;

    }

    /**

     * Constructs an empty ByteBuffer with the specified initial capacity and

     * with its capacity increment equal to zero.

     *

     * @param   initialCapacity   the initial capacity of the ByteBuffer.

     * @exception IllegalArgumentException if the specified initial capacity

     *               is negative

     */

    public ByteBuffer(int initialCapacity) {

        this(initialCapacity, 0);

    }

    /**

     * Constructs an empty ByteBuffer so that its internal data array

     * zero.

     */

    public ByteBuffer() {

        this(200);

    }

    /**

     * Trims the capacity of this ByteBuffer to be the ByteBuffer's current

     * size. If the capacity of this cector is larger than its current

     * size, then the capacity is changed to equal the size by replacing

     * with a smaller one. An application can use this operation to

     * minimize the storage of a ByteBuffer.

     */

    public void trimToSize() {

        int oldCapacity = elementData.length;

        if (elementCount < oldCapacity) {

            byte oldData[] = elementData;

            elementData = new byte[elementCount];

            System.arraycopy(oldData, 0, elementData, 0, elementCount);

        }

    }

    /**

     * This implements the unsynchronized semantics of ensureCapacity.

     * Synchronized methods in this class can internally call this

     * method for ensuring capacity without incurring the cost of an

     * extra synchronization.

     *

     * @see java.util.ByteBuffer#ensureCapacity(int)

     */

    private void ensureCapacityHelper(int minCapacity) {

        int oldCapacity = elementData.length;

        if (minCapacity > oldCapacity) {

            byte oldData[] = elementData;

            int newCapacity = (capacityIncrement > 0) ?

                (oldCapacity + capacityIncrement) : (oldCapacity * 2);

            if (newCapacity < minCapacity) {

                newCapacity = minCapacity;

            }

            elementData = new byte[newCapacity];

            System.arraycopy(oldData, 0, elementData, 0, elementCount);

        }

    }

    /**

     * Returns the current capacity of this ByteBuffer.

     *

     * @return  the current capacity (the length of its internal

     *          of this ByteBuffer.

     */

    public int capacity() {

        return elementData.length;

    }

    /**

     * Returns the number of components in this ByteBuffer.

     *

     * @return  the number of components in this ByteBuffer.

     */

    public int size() {

        return elementCount;

    }

    /**

     * Tests if this ByteBuffer has no components.

     *

     *          no components, that is, its size is zero;

     */

    public boolean isEmpty() {

        return elementCount == 0;

    }

    public void append(byte value)

    {

        ensureCapacityHelper(elementCount + 1);

        elementData[elementCount++] = value;

    }

    public void append( int value )

    {

        ensureCapacityHelper(elementCount + 4);

        doAppend( value ) ;

    }

    private void doAppend( int value )

    {

        int current = value ;

        for (int ctr=0; ctr<4; ctr++) {

            elementData[elementCount+ctr] = (byte)(current & 255) ;

            current = current >> 8 ;

        }

        elementCount += 4 ;

    }

    public void append( String value )

    {

        byte[] data = value.getBytes() ;

        ensureCapacityHelper( elementCount + data.length + 4 ) ;

        doAppend( data.length ) ;

        System.arraycopy( data, 0, elementData, elementCount, data.length ) ;

        elementCount += data.length ;

    }

    /**

     * Returns an array containing all of the elements in this ByteBuffer

     * in the correct order.

     *

     * @since 1.2

     */

    public byte[] toArray() {

        return elementData ;

    }

}