src/java.base/share/classes/java/util/zip/Checksum.java

*** 1,7 ****
  /*
!  * Copyright (c) 1996, 1999, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 20,56 ****
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
- 
  package java.util.zip;
  
  /**
   * An interface representing a data checksum.
   *
   * @author      David Connelly
   */
! public
! interface Checksum {
      /**
       * Updates the current checksum with the specified byte.
       *
       * @param b the byte to update the checksum with
       */
      public void update(int b);
  
      /**
       * Updates the current checksum with the specified array of bytes.
       * @param b the byte array to update the checksum with
       * @param off the start offset of the data
       * @param len the number of bytes to use for the update
       */
      public void update(byte[] b, int off, int len);
  
      /**
       * Returns the current checksum value.
       * @return the current checksum value
       */
      public long getValue();
  
      /**
--- 20,132 ----
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  package java.util.zip;
  
+ import java.nio.ByteBuffer;
+ 
  /**
   * An interface representing a data checksum.
   *
   * @author David Connelly
   */
! public interface Checksum {
! 
      /**
       * Updates the current checksum with the specified byte.
       *
       * @param b the byte to update the checksum with
       */
      public void update(int b);
  
      /**
       * Updates the current checksum with the specified array of bytes.
+      *
+      * @implSpec This default implementation is equal to calling
+      * {@code update(b, 0, b.length)}.
+      *
+      * @param b the array of bytes to update the checksum with
+      * 
+      * @throws NullPointerException
+      *         if {@code b} is {@code null}
+      * 
+      * @since 1.9
+      */
+     default public void update(byte[] b) {
+         update(b, 0, b.length);
+     }
+ 
+     /**
+      * Updates the current checksum with the specified array of bytes.
+      *
       * @param b the byte array to update the checksum with
       * @param off the start offset of the data
       * @param len the number of bytes to use for the update
       */
      public void update(byte[] b, int off, int len);
  
      /**
+      * Updates the current checksum with the bytes from the specified buffer.
+      *
+      * The checksum is updated with the remaining bytes in the buffer, starting
+      * at the buffer's position. Upon return, the buffer's position will be
+      * updated to its limit; its limit will not have been changed.
+      *
+      * @apiNote For best performance with DirectByteBuffer and other ByteBuffer
+      * implementations without a backing array implementers of this interface
+      * should override this method.
+      *
+      * @implSpec The default implementation has the following behavior.<br>
+      * For ByteBuffers backed by an accessible byte array.      
+      * <pre>{@code
+      * update(buffer.array(),
+      *        buffer.position() + buffer.arrayOffset(),
+      *        buffer.remaining());
+      * }</pre>
+      * For ByteBuffers not backed by an accessible byte array.
+      * <pre>{@code
+      * byte[] b = new byte[Math.min(buffer.remaining(), 4096)];
+      * while (buffer.hasRemaining()) {
+      *     int length = Math.min(buffer.remaining(), b.length);
+      *     buffer.get(b, 0, length);
+      *     update(b, 0, length);
+      * }
+      * }</pre>
+      *
+      * @param buffer the ByteBuffer to update the checksum with
+      * 
+      * @throws NullPointerException
+      *         if {@code buffer} is {@code null}
+      * 
+      * @since 1.9
+      */
+     default public void update(ByteBuffer buffer) {
+         int pos = buffer.position();
+         int limit = buffer.limit();
+         assert (pos <= limit);
+         int rem = limit - pos;
+         if (rem <= 0) {
+             return;
+         }
+         if (buffer.hasArray()) {
+             update(buffer.array(), pos + buffer.arrayOffset(), rem);
+         } else {
+             byte[] b = new byte[Math.min(buffer.remaining(), 4096)];
+             while (buffer.hasRemaining()) {
+                 int length = Math.min(buffer.remaining(), b.length);
+                 buffer.get(b, 0, length);
+                 update(b, 0, length);                
+             }
+         }
+         buffer.position(limit);
+     }
+ 
+     /**
       * Returns the current checksum value.
+      *
       * @return the current checksum value
       */
      public long getValue();
  
      /**