Array Getter benchmark

ArrayGet.java

package bench;

import org.openjdk.jmh.annotations.*;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.util.stream.IntStream;

@State(Scope.Benchmark)
public class ArrayGet {
    String[] array;
    int i;
    MethodHandle mh;
    ArrayGetter dynamicGetter;

    @Setup
    public void setup() throws Throwable {
        array = IntStream.range(0, 1000).mapToObj(String::valueOf).toArray(String[]::new);
        mh = MethodHandles.arrayElementGetter(array.getClass());
        dynamicGetter = new DynamicGetter();
    }

    @Benchmark
    public String arrayAccess() {
        return array[nextIndex()];
    }

    @Benchmark
    public String dynamicGetter() {
        return dynamicGetter.get(array, nextIndex());
    }

    @Benchmark
    public String methodHandle() throws Throwable {
        return (String) mh.invokeExact(array, nextIndex());
    }

    private int nextIndex() {
        if (++i >= array.length) i = 0;
        return i;
    }

    interface ArrayGetter {
        String get(String[] array, int index);
    }

    // Pretend that DynamicGetter has been dynamically generated
    static class DynamicGetter implements ArrayGetter {
        @Override
        public String get(String[] array, int index) {
            return array[index];
        }
    }
}

results.txt

Benchmark               Mode  Cnt  Score   Error  Units
ArrayGet.arrayAccess    avgt   10  4,275 ± 0,039  ns/op
ArrayGet.dynamicGetter  avgt   10  5,146 ± 0,095  ns/op
ArrayGet.methodHandle   avgt   10  7,735 ± 0,042  ns/op