/*
 * Copyright 2014-2019 Real Logic Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.agrona;

import org.openjdk.jmh.annotations.*;

import java.nio.ByteBuffer;
import java.util.concurrent.TimeUnit;
import java.util.zip.CRC32;

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Benchmark)
public class Crc32Benchmark
{
    @Param({ "8", "32", "128", "256", "1376", "2048", "4096" })
    private int length;

    private int offset = 32;
    private long address;
    private ByteBuffer directByteBuffer;

    @Setup(Level.Trial)
    public void setup()
    {
        directByteBuffer = BufferUtil.allocateDirectAligned(length + offset, 64);
        address = BufferUtil.address(directByteBuffer);
        directByteBuffer.position(offset);

        for (int i = 0; i < length; i++)
        {
            directByteBuffer.put((byte)i);
        }

        directByteBuffer.flip().position(offset);
    }

    @Benchmark
    public int publicApi()
    {
        final ByteBuffer buffer = this.directByteBuffer;
        final int limit = buffer.limit();
        final int position = buffer.position();

        final CRC32 crc32 = new CRC32();
        crc32.update(buffer);
        final int checksum = (int)crc32.getValue();
        buffer.limit(limit).position(position);

        return checksum;
    }

    @Benchmark
    public int crc32Native()
    {
        return Checksums.crc32(0, address, offset, length);
    }

}

@@ -897,40 +897,67 @@
 %22, %22
-32%22, %22128%22, %22256%22, %221376%22, %222048
+16%22, %2232%22, %2264%22, %22128%22, %22256%22, %22512%22, %221024%22, %221296%22, %221376
 %22, %22

Add more length to test the problematic cases