package test;

import java.util.concurrent.TimeUnit;
import java.util.*;

import org.openjdk.jmh.infra.Blackhole;
import org.openjdk.jmh.annotations.*;
 
@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Fork(3)
@State(Scope.Benchmark)
public class OptionalTest {
    @Param({"10", "1000", "1000000"})
    int n;

    int[] input;

    @Setup
    public void setup() {
        input = new Random(1).ints(n).toArray();
    }

    OptionalInt toOptional(int i) {
        return i % 2 == 0 ? OptionalInt.of(i) : OptionalInt.empty();
    }

    @Benchmark    
    public int testOptionalStream() {
        return Arrays.stream(input)
                     .mapToObj(this::toOptional).flatMapToInt(OptionalInt::stream).sum();
    }

    @Benchmark    
    public int testOptionalFilterGet() {
        return Arrays.stream(input).mapToObj(this::toOptional)
                     .filter(OptionalInt::isPresent).mapToInt(OptionalInt::getAsInt).sum();
    }
}