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

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*** 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(); /** --- 20,124 ---- * * 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.limit() - buffer.position()); + * }</pre> For ByteBuffers not backed by an accessible byte array. + * <pre>{@code + * byte[] b = new byte[buffer.limit() - buffer.position()]; + * buffer.get(b); + * update(b, 0, b.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[rem]; + buffer.get(b); + update(b, 0, b.length); + } + buffer.position(limit); + } + + /** * Returns the current checksum value. + * * @return the current checksum value */ public long getValue(); /**