jerolba

public class Test {
    static int objectCount = 0;

    public static int getObjectCount() {
        return objectCount;
    }

    public Test() {
        objectCount++;

jerolba

public class ObjectArrayParameterByValue {

    public static void main(String[] args) {
        String[] data = { "Foo", "Bar" };
        System.out.println(data[0]);
    }

    public void changeArray(String[] data) {
        data[0] = "Changed";

jerolba

Otras iniciativas:
Neuralink: https://neuralink.com/
Boring company: https://www.boringcompany.com/
Hyperloop: https://es.wikipedia.org/wiki/Hyperloop
OpenAI: https://es.wikipedia.org/wiki/OpenAI

Elon Musk fumado
https://gizmodo.com/elon-musk-smoking-joe-rogans-weed-somehow-ended-up-cost-1839116211

Financial rounds Tesla: 20.4B

jerolba

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

public class MapViews {

    public static void main(String[] args) {
        mapChangeModifiesValuesSet();
        mapChangeModifiesKeysSet();

jerolba

//BikeySet<Avenger, Film> avengerFilms = new TableBikeySet<>();
BikeySet<String, String> avengerFilms = new TableBikeySet<>();
avengerFilms.add("Hulk", "The Avengers");
avengerFilms.add("Iron Man", "The Avengers");
avengerFilms.add("Thor", "Avengers: Age of Ultron");
avengerFilms.add("Thor", "Thor: Ragnarok");
avengerFilms.add("Captain America", "Avengers: Infinity War");
....

if (avengerFilms.contains("Iron Man", "Black Panther")) {

jerolba

//Given the stock of some products and stores
//BikeyMap<Product, Store, Stock> stock = new TableBikeyMap<>();
BikeyMap<String, String, Integer> stock = new TableBikeyMap<>();
stock.put("shirt-ref-123", "store-76", 10);
stock.put("pants-ref-456", "store-12", 24);
...
stock.put("tie-ref-789", "store-23", 2);

//Get the stock of a product/store
Integer inStock = stock.get("shirt-ref-1234", "store-45");

jerolba

MemoryMXBean mbean = ManagementFactory.getMemoryMXBean();
MemoryUsage beforeHeapMemoryUsage = mbean.getHeapMemoryUsage();

Object instance = codeThatCreatesComplexDataStructure();

MemoryUsage afterHeapMemoryUsage = mbean.getHeapMemoryUsage();
long consumed = afterHeapMemoryUsage.getUsed() - 
                beforeHeapMemoryUsage.getUsed();
System.out.println("Total consumed Memory:" + consumed);

jerolba

methodThatDoesThings();
MemoryHistogram diff = Histogramer.getDiff(() -> {
    return methodThatDoesThings();
});
System.out.println(diff);

jerolba

MemoryHistogram filterd = diff.filter("Object[]", "java.util.HashMap*", 
                                      ArrayList.class, Pattern.compile(".*Hibernate.*"));

jerolba

MemoryHistogram diff = Histogramer.getDiff(() -> {
    HashMap<Integer, String> map = new HashMap<>();
    for (int i = 0; i < 10000; i++) {
        map.put(i, "" + i);
    }
    return new ArrayList<>(map.values());
});
System.out.println(diff);