Prova de conceito (poc) Stream - java/kotlin

readme.txt

# Perguntas:
- o uso de stream/array deixa mais lento, consome mais recursos ?
- em kotlin como seria ?

* tarefa: verificar se existe um elemento null num array de tipo T

# Respostas:
Em java o uso de Stream e reference methods é até um pouco mais rápido.
O consumo de memório entra as duas formas é igual.

Em Kotlin não tem necesside de usar um tipo espeical como Stream pois no
próprio Array já é possivel adicionar operações de verificação e transformações nos elementos.
Notei que o consumo de memória em kt foi menor que java, mas o tempo foi maior.

PocDesempenho.java

package com.alexaleluia12;

import java.time.Duration;
import java.time.LocalTime;
import java.util.Objects;
import java.util.stream.Stream;



public class PocDesempenho {
    // o uso de stream/array deixa mais lento, consome mais recursos ?
    // em kotlin como seria ?
    // tarefa: verificar se existem um elemento num num lista de tipo T
    public static void main(String[] args) {
        long beforeUsedMem=Runtime.getRuntime().totalMemory()-Runtime.getRuntime().freeMemory();
        var now = LocalTime.now();

        verifyForlst();

        var after = LocalTime.now();
        var diff = Duration.between(after, now);
        long afterUsedMem=Runtime.getRuntime().totalMemory()-Runtime.getRuntime().freeMemory();
        long usedMemory = afterUsedMem - beforeUsedMem;
        System.out.println("time operation: " + diff.getNano() / 1000_000.0f + ", nano:" + diff.getNano() + " mem: " + usedMemory);
    }

    public static void verifyForstream() {
        /*
        Com stream foi mais rapido tempo de 972.5919 Milisegundos
        memoria: 638296
         */
        Stream<Integer> l1 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l2 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 9, 3);
        Stream<Integer> l3 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l4 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l5 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l6 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l7 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l8 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> l9 =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);
        Stream<Integer> lA =  Stream.of(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50);

        Stream[] td = new Stream[]{l1, l2, l3, l4, l5, l6, l7, l8, l9, lA};
        for (Stream e: td) {
            Worker.verifyNull(e);
        }
    }

    public static void verifyForlst() {
        /*
        o tempo de uma lista e todas essas eh quase o msm: 998.6295 Milisegundos
        memory: 638296
         */
        Integer[] l1 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l2 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 9, 3,};
        Integer[] l3 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l4 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l5 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l6 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l7 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l8 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] l9 =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};
        Integer[] lA =  {1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50};

        Integer[][] td = {l1, l2, l3, l4, l5, l6, l7, l8, l9, lA};
        for (Integer[] e: td) {
            Worker.verifyNull(e);
        }
    }
}

class Worker {
    public static <T> boolean verifyNull(T[] lst) {
        for (T e: lst) {
            if (e == null)
                return true;
        }
        return false;
    }

    public static <T> boolean verifyNull(Stream<T> lst) {
        return lst.anyMatch(Objects::isNull);
    }
}

PocDesempenho.kt

package com.alexaleluia12

import java.time.Duration
import java.time.LocalTime
import java.util.*

fun main() {
    val beforeUsedMem = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()
    val now = LocalTime.now()

    verifyFor()

    val after = LocalTime.now()
    val diff = Duration.between(after, now)
    val afterUsedMem = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()
    val usedMemory = afterUsedMem - beforeUsedMem
    println("time operation: " + diff.nano / 1000000.0f + ", nano:" + diff.nano + " mem: " + usedMemory)
}

fun verifyFn() {
    // time operation: 995.1205 ms, nano seg:995120542 mem: 545640
    val l1 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,500)
    val l2 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 9, 3)
    val l3 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,43)
    val l4 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,543)
    val l5 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,43)
    val l6 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,45)
    val l7 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,5)
    val l8 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)
    val l9 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)
    val lA =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)

    val td = arrayOf(l1, l2, l3, l4, l5, l6, l7, l8, l9, lA)
    for (k in td) {
        vefiyNullViaFn(k)
    }
}

fun verifyFor() {
    // time operation: 996.43567, nano:996435633 mem: 563744
    val l1 =  arrayOf(1, 2, 3, 4, 5,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,500)
    val l2 =  arrayOf(1, 2, 3, 4, 51,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 9, 3)
    val l3 =  arrayOf(1, 2, 3, 4, 52,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,43)
    val l4 =  arrayOf(1, 2, 3, 4, 53,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,543)
    val l5 =  arrayOf(1, 2, 3, 4, 54,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,43)
    val l6 =  arrayOf(1, 2, 3, 4, 55,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,45)
    val l7 =  arrayOf(1, 2, 3, 4, 56,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,5)
    val l8 =  arrayOf(1, 2, 3, 4, 57,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)
    val l9 =  arrayOf(1, 2, 3, 4, 58,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)
    val lA =  arrayOf(1, 2, 3, 4, 59,6,9, 2, 2, 3,323,523,371,1,1,1,1,12,3,3,34,54,45,3,5,23,2,123,6,null, 3,50)

    val td = arrayOf(l1, l2, l3, l4, l5, l6, l7, l8, l9, lA)
    for (k in td) {
        vefiyNullViaFor(k)
    }
}


fun <T> vefiyNullViaFn(list: Array<T>): Boolean {
    return list.any(Objects::isNull)
}

fun <T> vefiyNullViaFor(list: Array<T>): Boolean {
    for (e in list) {
        if (e == null)
            return true
    }

    return false
}