org.glassfish.grizzly.compression.lzma.impl.CRC Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eve-bundle-full-embed Show documentation
There is a newer version: 3.1.1
Show newest version
/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2011 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.glassfish.grizzly.compression.lzma.impl;

/**
 * CRC
 *
 * @author Igor Pavlov
 */
public class CRC {

    static final int[] TABLE = new int[256];

    static {
        for (int i = 0; i < 256; i++) {
            int r = i;
            for (int j = 0; j < 8; j++) {
                if ((r & 1) != 0) {
                    r = (r >>> 1) ^ 0xEDB88320;
                } else {
                    r >>>= 1;
                }
            }
            TABLE[i] = r;
        }
    }
    int _value = -1;

    public void init() {
        _value = -1;
    }

    public void update(byte[] data, int offset, int size) {
        for (int i = 0; i < size; i++) {
            _value = TABLE[(_value ^ data[offset + i]) & 0xFF] ^ (_value >>> 8);
        }
    }

    public void update(byte[] data) {
        int size = data.length;
        for (int i = 0; i < size; i++) {
            _value = TABLE[(_value ^ data[i]) & 0xFF] ^ (_value >>> 8);
        }
    }

    public void updateByte(int b) {
        _value = TABLE[(_value ^ b) & 0xFF] ^ (_value >>> 8);
    }

    public int getDigest() {
        return _value ^ (-1);
    }
}