使用getter和setter定义两个对象，使用相同的代码
在benchmark.js
node v7.3.0进行测试
const builtInObject1 = (function (object) {
let lastA = 1;
return Object.defineProperties(object, {
a:{
get(){
return lastA
},
set(newValue){
lastA = newValue;
}
}
})
})({});
const builtInObject2 = (function (object) {
let lastA = 1;
return Object.defineProperties(object, {
a:{
get(){
return lastA
},
set(newValue){
lastA = newValue;
}
}
})
})({});
〜添加es2015的{{1}}案例
getter/setter〜
const builtInObject3 = (function () {
let lastA = 1;
return {
get a(){
return lastA
},
set a(value){
lastA = value;
}
}
})();
〜
const builtInObject4 = (function (object) {
let last = 1;
return Object.defineProperties(object, {
b:{
get(){
return last
},
set(newValue){
last = newValue;
}
}
})
})({});
const builtInObject5 = (function (object) {
let last = 1;
return Object.defineProperties(object, {
c:{
get(){
return last
},
set(newValue){
last = newValue;
}
}
})
})({});
(new Benchmark.Suite("object-assign-properties"))
.add("#built-in object1.a getter and setter", function () {
builtInObject1.a = builtInObject1.a + 1;
})
.add("#built-in object2.a getter and setter", function () {
builtInObject2.a = builtInObject2.a + 1;
})
.add("#built-in object3.a es6 getter and setter", function () {
builtInObject3.a = builtInObject3.a + 1;
})
.add("#built-in object4.b getter and setter", function () {
builtInObject4.b = builtInObject4.b + 1;
})
.add("#built-in object5.c getter and setter", function () {
builtInObject5.c = builtInObject5.c + 1;
})
.on('cycle', function(event) {
console.log(String(event.target));
})
.on('complete', function() {
console.log('Fastest is ' + this.filter('fastest').map('name'));
})
.run({ 'async': false });
这些测试#built-in object1.a getter and setter x 80,459,419 ops/sec ±0.65% (88 runs sampled)
#built-in object2.a getter and setter x 3,967,313 ops/sec ±0.36% (91 runs sampled)
#built-in object3.a es6 getter and setter x 3,982,725 ops/sec ±0.51% (93 runs sampled)
#built-in object4.b getter and setter x 79,608,022 ops/sec ±4.06% (87 runs sampled)
#built-in object5.c getter and setter x 78,849,808 ops/sec ±0.82% (92 runs sampled)
Fastest is #built-in object1.a getter and setter
之间的差异让我感到困惑
是什么造成这些差异？
累积到bluebird | Optimization-killers，ops/sec不会被优化，但为什么object3变得那么慢？
object2 opt / sec