source: trunk/src/gcc/libjava/java/io/BufferedInputStream.java@ 1464

/* BufferedInputStream.java -- An input stream that implements buffering
   Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */

 
package java.io;

/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
 * "The Java Language Specification", ISBN 0-201-63451-1
 * plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
 * Status:  Believed complete and correct.
 */
 
/**
 * This subclass of <code>FilterInputStream</code> buffers input from an 
 * underlying implementation to provide a possibly more efficient read
 * mechanism.  It maintains the buffer and buffer state in instance 
 * variables that are available to subclasses.  The default buffer size
 * of 2048 bytes can be overridden by the creator of the stream.
 * <p>
 * This class also implements mark/reset functionality.  It is capable
 * of remembering any number of input bytes, to the limits of
 * system memory or the size of <code>Integer.MAX_VALUE</code>
 * <p>
 * Please note that this class does not properly handle character
 * encodings.  Consider using the <code>BufferedReader</code> class which
 * does.
 *
 * @author Aaron M. Renn ([email protected])
 * @author Warren Levy <[email protected]>
 */
public class BufferedInputStream extends FilterInputStream
{

  /**
   * This is the default buffer size
   */
  private static final int DEFAULT_BUFFER_SIZE = 2048;

  /**
   * The buffer used for storing data from the underlying stream.
   */
  protected byte[] buf;

  /**
   * The number of valid bytes currently in the buffer.  It is also the index
   * of the buffer position one byte past the end of the valid data.
   */
  protected int count = 0;

  /**
   * The index of the next character that will by read from the buffer.
   * When <code>pos == count</code>, the buffer is empty.
   */
  protected int pos = 0;

  /**
   * The value of <code>pos</code> when the <code>mark()</code> method was
   * called.  
   * This is set to -1 if there is no mark set.
   */
  protected int markpos = -1;

  /**