Testing time and space consumption of allocating JSON and DOM nodes - with 0 properties each

testspeed2.txt

"use strict";

const testDOMSpeed = function (its) {
    const array = [];
    for (let i = 0; i < its; ++i) {
        const element = document.createElement("div");
        array.push(element);
    }
    return array;
};

const testJSONSpeed = function (its) {
    const array = [];
    for (let i = 0; i < its; ++i) {
        const element = {};
        array.push(element);
    }
    return array;
};

const clone = function (toclone) {
    const togo = {};
    for (let key in toclone) {
        togo[key] = toclone[key];
    }
    return togo;
};

const timeIt = function (its, fn, name) {
    const now = Date.now();
    const oldShot = clone(performance.memory);
    const value = fn(its);
    const delay = Date.now() - now;
    const newShot = performance.memory;
    const bytes = newShot.usedJSHeapSize - oldShot.usedJSHeapSize;
    console.log("Testing allocation of " + name);
    console.log(its + " iterations in " + delay + " ms: " + 1000 * (delay / its) + " us/it");
    console.log("Used heap size " + bytes + ": " + (bytes / its) + " bytes per object");
    console.log("Oldshot" , oldShot);
    console.log("Newshot", newShot);
    return value;
};

function testSpeed() {
    timeIt(1000000, testDOMSpeed, "DOM nodes");
    timeIt(10000000, testJSONSpeed, "JSON objects");
}

document.getElementById("run-tests").addEventListener("click", testSpeed);

Testing allocation of DOM nodes
testspeed.js:41 1000000 iterations in 698 ms: 0.6980000000000001 us/it
testspeed.js:42 Used heap size 34964264: 34.964264 bytes per object
testspeed.js:40 Testing allocation of JSON objects
testspeed.js:41 10000000 iterations in 2471 ms: 0.2471 us/it
testspeed.js:42 Used heap size 342355028: 34.2355028 bytes per object

testspeed.js:40 Testing allocation of DOM nodes
testspeed.js:41 1000000 iterations in 672 ms: 0.6719999999999999 us/it
testspeed.js:42 Used heap size 40833645: 40.833645 bytes per object
testspeed.js:40 Testing allocation of JSON objects
testspeed.js:41 10000000 iterations in 2512 ms: 0.2512 us/it
testspeed.js:42 Used heap size 338121356: 33.8121356 bytes per object

testspeed.js:40 Testing allocation of DOM nodes
testspeed.js:41 1000000 iterations in 638 ms: 0.638 us/it
testspeed.js:42 Used heap size 40987036: 40.987036 bytes per object
testspeed.js:40 Testing allocation of JSON objects
testspeed.js:41 10000000 iterations in 2010 ms: 0.201 us/it
testspeed.js:42 Used heap size 382067844: 38.2067844 bytes per object

testspeed.js:40 Testing allocation of DOM nodes
testspeed.js:41 1000000 iterations in 702 ms: 0.7020000000000001 us/it
testspeed.js:42 Used heap size 36669940: 36.66994 bytes per object
testspeed.js:40 Testing allocation of JSON objects
testspeed.js:41 10000000 iterations in 2440 ms: 0.244 us/it
testspeed.js:42 Used heap size 342350124: 34.2350124 bytes per object