Run results for: Proxy overhead test vs classes

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.6 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 months ago

Test name	Executions per second
Baseline Map object	20045.4 Ops/sec
Object	20599.1 Ops/sec
Subclass	20590.7 Ops/sec
Proxy	8747.0 Ops/sec

Script Preparation code:

var text = "Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?"


var simple_map = new Map();
var simple_obj = {};

class DefaultMap extends Map {
    constructor(defaultValue) {
        super();
        this.defaultValue = defaultValue;
    }
    get(key) {
        if (!this.has(key)) {
            this.set(key, this.defaultValue);
        }
        return super.get(key);
    }
}

var dm = new DefaultMap(0)


let base_obj = {};
var proxy_obj = new Proxy(base_obj, {
    get: function(target, prop, receiver) {
        return Reflect.get(target, prop, receiver) ?? 0;
    },
});

Tests:

Baseline Map object
for (const c of text) { simple_map.set(c, (simple_map.get(c) ?? 0) + 1) }
Object
for (const c of text) { simple_obj[c] = (simple_obj[c] ?? 0) + 1 }
Subclass
for (const c of text) { dm.set(c, dm.get(c)+1) }
Proxy
for (const c of text) { proxy_obj[c] += 1; }

Run results for: Proxy overhead test vs classes

Baseline Map object

Object

Subclass

Proxy