closure-arrow-bench.js

'use strict';

function MyObject() {
  this.counter = 0;
}

MyObject.prototype.doSomeWork = function doSomeWork() {
  this.counter++;
};

MyObject.prototype.allocateClosure =
function allocateClosure() {
  var self = this;

  return function doWork() {
    self.doSomeWork();
  }
};

MyObject.prototype.allocateArrow =
function allocateArrow() {
  return () => { this.doSomeWork() };
};

var ALLOC_COUNTER = 50 * 1000 * 1000;
var CALL_COUNTER = 400 * 1000 * 1000;

function testAllocateClosure() {
  console.log('test allocate closure');

  var obj = new MyObject();
  var resultArr = new Array(10);
  var start = Date.now();

  for (var i = 0; i < ALLOC_COUNTER; i++) {
    resultArr[i % 10] = obj.allocateClosure();
  }

  var end = Date.now();
  console.log('time taken', end - start);
}

function testAllocateArrow() {
  console.log('test allocate arrow');

  var obj = new MyObject();
  var resultArr = new Array(10);
  var start = Date.now();

  for (var i = 0; i < ALLOC_COUNTER; i++) {
    resultArr[i % 10] = obj.allocateArrow();
  }

  var end = Date.now();
  console.log('time taken', end - start);
}

function testCallArrow() {
  console.log('test call arrow');

  var obj = new MyObject();
  var arrow = obj.allocateArrow();
  var start = Date.now();

  for (var i = 0; i < CALL_COUNTER; i++) {
    arrow();
  }

  var end = Date.now();
  console.log('time taken', end - start);
}

function testCallClosure() {
  console.log('test call closure');

  var obj = new MyObject();
  var closure = obj.allocateClosure();
  var start = Date.now();

  for (var i = 0; i < CALL_COUNTER; i++) {
    closure();
  }

  var end = Date.now();
  console.log('time taken', end - start);
}

function main(mode) {
  if (mode === 'alloc-closure') {
    testAllocateClosure();
  } else if (mode === 'alloc-arrow') {
    testAllocateArrow();
  } else if (mode === 'call-closure') {
    testCallClosure();
  } else if (mode === 'call-arrow') {
    testCallArrow();
  } else {
    console.log('unsupported mode', mode);
  }
}

main(process.argv[2]);

raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ node -v
v6.4.0
raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ node -p 'process.versions.v8'
5.0.71.60

raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ time node foo.js alloc-arrow
test allocate arrow
time taken 1365

real    0m1.415s
user    0m1.400s
sys 0m0.008s
raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ time node foo.js alloc-closure
test allocate closure
time taken 1346

real    0m1.400s
user    0m1.396s
sys 0m0.000s

raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ time node foo.js call-arrow
test call arrow
time taken 686

real    0m0.742s
user    0m0.740s
sys 0m0.000s
raynos at raynos-ThinkPad-T440p  ~/tmp/toy-func
$ time node foo.js call-closure
test call closure
time taken 677

real    0m0.739s
user    0m0.736s
sys 0m0.000s