Memory Usage from https://twitter.com/he_zhenghao

memory-usage.js

function memoryUsed() {
  gc();
  const mbUsed = process.memoryUsage().heapTotal / 1024 / 1024;
  return mbUsed;
}

function getRandomString() {
  // stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
  return (
    Math.random().toString(36).substring(2, 15) +
    Math.random().toString(36).substring(2, 15)
  );
}

function getRandomSmallIntegerString(max) {
  return Math.floor(Math.random() * max).toString();
}

function getRandomSmallInteger(max) {
  return Math.floor(Math.random() * max);
}

function getRandomNumericString() {
  return Math.random().toString();
}

function getRandomNumeric() {
  return Math.random();
}

const randomKeyByType = {
  "string-key": getRandomString,
  "string-numeric-key": getRandomNumericString,
  "numeric-key": getRandomNumeric,
  "string-integer-key": (max) => getRandomSmallIntegerString(max),
  "integer-key": (max) => getRandomSmallInteger(max),
};

const sizes = [ 10000, 50000, 100000, 500000, 1000000];

const memoryUsage = {'object': {}, map: {}};
const createByType = { object: createObject, map: createMap};

function fn() {
  ["object", "map"].forEach((type) => {
    sizes.forEach((size) => {
      Object.keys(randomKeyByType).forEach((randomKeyType) => {
        gc();
        const getRandomKey = randomKeyByType[randomKeyType]
        const before = memoryUsed();
        const obj = createByType[type](getRandomKey, size);
        const after = memoryUsed();
        const diff = after - before;
        if (!memoryUsage[type][randomKeyType]) {memoryUsage[type][randomKeyType] = {}}
        memoryUsage[type][randomKeyType][size] = diff;
        gc();
      });
    });
  });
}
fn();
console.log(memoryUsage);

function createObject(getRandomKey, width) {
  const obj = {};
  for (let i = 0; i < width; i++) {
    obj[getRandomKey(width)] = {};
  }

  return obj;
}

function createMap(getRandomKey, width) {
  const map = new Map();
  for (let i = 0; i < width; i++) {
    map.set(getRandomKey(width), i);
  }
  return map;
}