/*

 * Copyright (c) 2013, 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.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

/*

   @test

   @bug 7088419

   @run main CRCTest

   @summary Use x86 Hardware CRC32 Instruction with java.util.zip.CRC32 and java.util.zip.Adler32

 */

import java.nio.ByteBuffer;

import java.util.zip.CRC32;

import java.util.zip.Checksum;

public class CRCTest {

    public static void main(String[] args) throws Exception {

        byte[] b = initializedBytes(4096 * 4096);

        {

            CRC32 crc1 = new CRC32();

            CRC32 crc2 = new CRC32();

            CRC32 crc3 = new CRC32();

            CRC32 crc4 = new CRC32();

            crc1.update(b, 0, b.length);

            updateSerial(crc2, b, 0, b.length);

            updateDirect(crc3, b, 0, b.length);

            updateSerialSlow(crc4, b, 0, b.length);

            check(crc1, crc2);

            check(crc3, crc4);

            check(crc1, crc3);

            crc1.update(17);

            crc2.update(17);

            crc3.update(17);

            crc4.update(17);

            crc1.update(b, 1, b.length-2);

            updateSerial(crc2, b, 1, b.length-2);

            updateDirect(crc3, b, 1, b.length-2);

            updateSerialSlow(crc4, b, 1, b.length-2);

            check(crc1, crc2);

            check(crc3, crc4);

            check(crc1, crc3);

            report("finished huge crc", crc1, crc2, crc3, crc4);

            for (int i = 0; i < 256; i++) {

                for (int j = 0; j < 256; j += 1) {

                    crc1.update(b, i, j);

                    updateSerial(crc2, b, i, j);

                    updateDirect(crc3, b, i, j);

                    updateSerialSlow(crc4, b, i, j);

                    check(crc1, crc2);

                    check(crc3, crc4);

                    check(crc1, crc3);

                }

            }

            report("finished small survey crc", crc1, crc2, crc3, crc4);

        }

    }

    private static void report(String s, Checksum crc1, Checksum crc2,

            Checksum crc3, Checksum crc4) {

        System.out.println(s + ", crc1 = " + crc1.getValue() +

                ", crc2 = " + crc2.getValue()+

                ", crc3 = " + crc3.getValue()+

                ", crc4 = " + crc4.getValue());

    }

    private static void check(Checksum crc1, Checksum crc2) throws Exception {

        if (crc1.getValue() != crc2.getValue()) {

            String s = "value 1 = " + crc1.getValue() + ", value 2 = " + crc2.getValue();

            System.err.println(s);

            throw new Exception(s);

        }

    }

    private static byte[] initializedBytes(int M) {

        byte[] bytes = new byte[M];

        for (int i = 0; i < bytes.length; i++) {

            bytes[i] = (byte) i;

        }

        return bytes;

    }

    private static void updateSerial(Checksum crc, byte[] b, int start, int length) {

        for (int i = 0; i < length; i++)

            crc.update(b[i+start]);

    }

    private static void updateSerialSlow(Checksum crc, byte[] b, int start, int length) {

        for (int i = 0; i < length; i++)

            crc.update(b[i+start]);

        crc.getValue();

    }

    private static void updateDirect(CRC32 crc3, byte[] b, int start, int length) {

        ByteBuffer buf = ByteBuffer.allocateDirect(length);

        buf.put(b, start, length);

        buf.flip();

        crc3.update(buf);

    }

}