/* BinaryRefAddr.java -- RefAddr that uses a byte array as content.
   Copyright (C) 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 javax.naming;

import java.util.Arrays;

/**
 * RefAddr that uses a byte array as content.
 * This can be used to reference objects that can only be represented as
 * byte arrays.
 *
 * @see Reference
 * @since 1.3
 * @author Mark Wielaard (mark@klomp.org)
 */
public class BinaryRefAddr extends RefAddr
{

  /**
   * The possibly null content of this RefAddr.
   * Set by the constructor and returned by getContent.
   */
  private final byte[] buf;

  /**
   * Contructs a new BinaryRefAddr with the given type and content.
   * The complete content of the byte array is copied to a new array.
   */
  public BinaryRefAddr (String addrType, byte[] buf)
  {
    this(addrType, buf, 0, buf.length);
  }

  /**
   * Contructs a new BinaryRefAddr with the given type and the content
   * taken from the given byte array.
   * The content of the byte array is copied to a new array.
   */
  public BinaryRefAddr (String addrType, byte[] buf, int off, int length)
  {
    super(addrType);
    this.buf = new byte[length];
    System.arraycopy(buf, off, this.buf, 0, length);
  }

  /**
   * Returns the byte array contents as given to the constructor.
   * The returned byte array is shared with this object and other callers.
   * Changing the content of the buffer is discouraged and should only be
   * done when the byte array is locked.
   */
  public Object getContent ()
  {
    return buf;
  }

  /**
   * Checks if the object is a BinaryRefAddr with the same type and with the
   * same bytes in the content.
   *
   * @return true if the given object is an instance of BinaryRefAddr,
   *         the addrType is the same as this addrType and the bytes of the
   *         content are the same.
   */
  public boolean equals (Object o)
  {
    if (o instanceof BinaryRefAddr)
      {
        BinaryRefAddr refAddr = (BinaryRefAddr) o;
        if (this.getType().equals(refAddr.getType()))
	  {
	    byte[] c1 = (byte[]) this.getContent();
	    byte[] c2 = (byte[]) refAddr.getContent();
	    return Arrays.equals(c1, c2);
	  }
      }
    return false;
  }

  /**
   * Returns the hashCode which is the hasCode of the String returned by
   * <code>getType()</code> plus the hashCode of the byte array returned by
   * <code>getContent</code>. The hashCode of the byte array is calculated
   * by taking the xor of all the bytes in the array, or zero when there are
   * no bytes in the array.
   */
  public int hashCode()
  {
    int result = 0;
    byte[] b = (byte[]) getContent();
    for (int i=0; i < b.length; i++)
      result = result^b[i];

    return getType().hashCode() + result;
  }

  private static char[] hex = {'0', '1', '2', '3', '4', '5', '6', '7',
			       '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
  /**
   * Returns a String representation of the RefAddr. Only the first 32 bytes
   * of the content are added as hex encoded characters.
   * Should only be used for debugging purposes.
   */
  public String toString()
  {
    StringBuffer sb = new StringBuffer("[RefAddr type: ");
    sb.append(getType());
    sb.append(" content: 0x");
    byte[] b = (byte[]) getContent();
    for (int i=0; i < b.length && i < 32; i++)
      {
	sb.append(hex[(b[i]&0xf0)>>4]);
	sb.append(hex[b[i]&0x0f]);
      }
    if (b.length > 32)
      sb.append("...");
    sb.append("]");
    return sb.toString();
  }
}
