package org.sample;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Level;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;

import java.util.ArrayList;
import java.util.Random;

@State(Scope.Benchmark)
public class ArrayListBenchmark {

    @State(Scope.Benchmark)
    public static class Data {

        @Param({"10", "100", "1000", "10000"})
        public int size;

        ArrayList<Integer> arrayRandom = new ArrayList<Integer>(size);

        @Setup(Level.Invocation)
        public void initArrayList() {
            Random rand = new Random();
            rand.setSeed(System.currentTimeMillis());
            // Populate the ArrayList with size-5 elements 
            for (int i=0; i<size-5; i++)
            {
                Integer r = rand.nextInt() % 256;
                arrayRandom.add(r);
            }
        }
    }

    @Benchmark
    public ArrayList construct_new_array_list(Data d) {
        ArrayList al = new ArrayList(d.arrayRandom);
        // once a new ArrayList is created add a new element
        al.add(new Integer(900));
        return al;
    }
}