/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/**

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements. See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership. The ASF licenses this file

 * to you 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.

 */

package com.sun.org.apache.xml.internal.security.utils;

import java.io.IOException;

import java.io.OutputStream;

/**

 * A simple Unsynced ByteArrayOutputStream

 *

 */

public class UnsyncByteArrayOutputStream extends OutputStream  {

    // Maximum array size. Using same value as ArrayList in OpenJDK.

    // Integer.MAX_VALUE doesn't work on some VMs, as some header values are reserved

    private static final int VM_ARRAY_INDEX_MAX_VALUE = Integer.MAX_VALUE - 8;

    private static final int INITIAL_SIZE = 8192;

    private byte[] buf;

    private int size = INITIAL_SIZE;

    private int pos;

    public UnsyncByteArrayOutputStream() {

        buf = new byte[INITIAL_SIZE];

    }

    public void write(byte[] arg0) {

        if ((VM_ARRAY_INDEX_MAX_VALUE - pos) < arg0.length) {

            throw new OutOfMemoryError();

        }

        int newPos = pos + arg0.length;

        if (newPos > size) {

            expandSize(newPos);

        }

        System.arraycopy(arg0, 0, buf, pos, arg0.length);

        pos = newPos;

    }

    public void write(byte[] arg0, int arg1, int arg2) {

        if ((VM_ARRAY_INDEX_MAX_VALUE - pos) < arg2) {

            throw new OutOfMemoryError();

        }

        int newPos = pos + arg2;

        if (newPos > size) {

            expandSize(newPos);

        }

        System.arraycopy(arg0, arg1, buf, pos, arg2);

        pos = newPos;

    }

    public void write(int arg0) {

        if (VM_ARRAY_INDEX_MAX_VALUE - pos == 0) {

            throw new OutOfMemoryError();

        }

        int newPos = pos + 1;

        if (newPos > size) {

            expandSize(newPos);

        }

        buf[pos++] = (byte)arg0;

    }

    public byte[] toByteArray() {

        byte result[] = new byte[pos];

        System.arraycopy(buf, 0, result, 0, pos);

        return result;

    }

    public void reset() {

        pos = 0;

    }

    /**

     * Takes the contents of this stream and writes it to the output stream

     * {@code out}.

     *

     * @param out

     *            an OutputStream on which to write the contents of this stream.

     * @throws IOException

     *             if an error occurs while writing to {@code out}.

     */

    public void writeTo(OutputStream out) throws IOException {

        out.write(buf, 0, pos);

    }

    private void expandSize(int newPos) {

        int newSize = size;

        while (newPos > newSize) {

            newSize = newSize << 1;

            // Deal with overflow

            if (newSize < 0) {

                newSize = VM_ARRAY_INDEX_MAX_VALUE;

            }

        }

        byte newBuf[] = new byte[newSize];

        System.arraycopy(buf, 0, newBuf, 0, pos);

        buf = newBuf;

        size = newSize;

    }

}