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 * 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.bcel.internal.util;

import java.io.ByteArrayInputStream;

import java.io.DataInputStream;

/**

 * Utility class that implements a sequence of bytes which can be read

 * via the `readByte()' method. This is used to implement a wrapper for the

 * Java byte code stream to gain some more readability.

 *

 * @version $Id: ByteSequence.java 1747278 2016-06-07 17:28:43Z britter $

 */

public final class ByteSequence extends DataInputStream {

    private final ByteArrayStream byteStream;

    public ByteSequence(final byte[] bytes) {

        super(new ByteArrayStream(bytes));

        byteStream = (ByteArrayStream) in;

    }

    public final int getIndex() {

        return byteStream.getPosition();

    }

    final void unreadByte() {

        byteStream.unreadByte();

    }

    private static final class ByteArrayStream extends ByteArrayInputStream {

        ByteArrayStream(final byte[] bytes) {

            super(bytes);

        }

        final int getPosition() {

            // pos is protected in ByteArrayInputStream

            return pos;

        }

        final void unreadByte() {

            if (pos > 0) {

                pos--;

            }

        }

    }

}