1 /*
   2  * Copyright (c) 1996, 1999, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.zip;
  27 
  28 /**
  29  * An interface representing a data checksum.
  30  *
  31  * @author      David Connelly
  32  */
  33 public
  34 interface Checksum {
  35     /**
  36      * Updates the current checksum with the specified byte.
  37      *
  38      * @param b the byte to update the checksum with
  39      */
  40     public void update(int b);
  41 
  42     /**
  43      * Updates the current checksum with the specified array of bytes.
  44      * @param b the byte array to update the checksum with
  45      * @param off the start offset of the data
  46      * @param len the number of bytes to use for the update
  47      */
  48     public void update(byte[] b, int off, int len);
  49 
  50     /**
  51      * Returns the current checksum value.
  52      * @return the current checksum value
  53      */
  54     public long getValue();
  55 
  56     /**
  57      * Resets the checksum to its initial value.
  58      */
  59     public void reset();
  60 }