/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
package com.sun.org.apache.bcel.internal.util;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    if any, must include the following acknowledgment:
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 *        Apache Software Foundation (http://www.apache.org/)."
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 *    if and wherever such third-party acknowledgments normally appear.
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 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
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 */
import java.io.*;

/**
 * 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.
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public final class ByteSequence extends DataInputStream {
  private ByteArrayStream byte_stream;

  public ByteSequence(byte[] bytes) {
    super(new ByteArrayStream(bytes));
    byte_stream = (ByteArrayStream)in;
  }

  public final int getIndex()   { return byte_stream.getPosition(); }
  final  void      unreadByte() { byte_stream.unreadByte(); }

  private static final class ByteArrayStream extends ByteArrayInputStream {
    ByteArrayStream(byte[] bytes) { super(bytes); }
    final int  getPosition() { return pos; } // is protected in ByteArrayInputStream
    final void unreadByte()  { if(pos > 0) pos--; }
  }
}