Benchmark: WeakMap vs "Symbol with WeakMap fallback"

Script Preparation code:

var c = Symbol === undefined
? (function() {
  var x = function() {
    this._x = new WeakMap();
  }
  x.prototype.get = function(x) { return this._x.get(x); };
  x.prototype.set = function(x,y) { this._x.set(x,y); };
  return x;
})()
: (function() {
  var x = function() {
    this._x = Symbol();
  }
  x.prototype.get = function(x) { return x[this._x]; };
  x.prototype.set = function(x,y) { x[this._x] = y; };
  return x;
})();

var to0 = {};
var to1 = {};
var wm = new WeakMap();
var fwm = new c();
wm.set(to1, 1);
fwm.set(to1, 1);

Tests:

WeakMap get
let r = wm.get(to1);
Symbol with WeakMap fallback get
let r = fwm.get(to1);
WeakMap set
wm.set(to0, 1);
Symbol with WeakMap fallback set
fwm.set(to0, 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
WeakMap get
Symbol with WeakMap fallback get
WeakMap set
Symbol with WeakMap fallback set

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:120.0) Gecko/20100101 Firefox/120.0

Browser/OS: Firefox 120 on Windows

View result in a separate tab

Test name	Executions per second
WeakMap get	35020540.0 Ops/sec
Symbol with WeakMap fallback get	314160600.0 Ops/sec
WeakMap set	19382890.0 Ops/sec
Symbol with WeakMap fallback set	259768800.0 Ops/sec

WeakMap vs "Symbol with WeakMap fallback" (version: 0)

Comparing performance of: WeakMap get vs Symbol with WeakMap fallback get vs WeakMap set vs Symbol with WeakMap fallback set

Created: 4 years ago by: Guest

Jump to the latest result

WeakMap get

Symbol with WeakMap fallback get

WeakMap set

Symbol with WeakMap fallback set

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A