Performance Between Set Map and Object

2018年01月29日

测试Set, Map和Object键值对的读写速度。
写入速度：可以看到Set和Map基本在一个级别，Object慢得多
随机读：Map非常快，Object次之，Set较慢

1M长度数组提重：

	Set	Map	Obj
1	276	263	757
2	251	287	738
3	270	290	754

Code

let mockArr = []
let len = 1000000
for(let i=0; i<len; i++) {
  mockArr.push(Math.random().toFixed(8))
}

//Set
let t1 = new Date().getTime()
let found1 = new Set()
let uniq1 = new Set()
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  if(uniq1.has(cur)){
    found1.add(cur)
  }
  else{
    uniq1.add(cur)
  }
}
console.log(new Date().getTime() - t1)

//Map
let t2 = new Date().getTime()
let found2 = new Set()
let uniq2 = new Map()
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  if(uniq2.has(cur)){
    found2.add(cur)
  }
  else{
    uniq2.set(cur, 1)
  }
}
console.log(new Date().getTime() - t2)

//Obj
let t3 = new Date().getTime()
let found3 = new Set()
let uniq3 = {}
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  if(uniq3[cur]){
    found3.add(cur)
  }
  else{
    uniq3[cur] = true
  }
}
console.log(new Date().getTime() - t3)

随机读：

	Set	Map	Obj
1	111	11	46
2	105	9	63
3	117	11	47

code

let mockArr = []
let len = 1000000
for(let i=0; i<len; i++) {
  mockArr.push(Math.random().toFixed(8))
}

//Set
let uniq1 = new Set(mockArr)
let t1 = new Date().getTime()
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  uniq1.has(cur)
}
console.log(new Date().getTime() - t1)

//Map
let uniq2 = new Map()
for(let x=0; x<len; x++){
  uniq2.set(mockArr[x], 1)
}
let t2 = new Date().getTime()
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  uniq2.has(cur)
  uniq2.get(cur) // the same
}
console.log(new Date().getTime() - t2)

//Obj
let uniq3 = {}
for(let x=0; x<len; x++){
  uniq3[mockArr[x]] = 1
}
let t3 = new Date().getTime()
for(let x=0; x<len; x++){
  let cur = mockArr[x]
  uniq3[cur]
}
console.log(new Date().getTime() - t3)

带重复插入：

	Set	Map	Obj
1	244	258	797
2	242	237	643
3	233	248	833

code

let mockArr = []
let len = 1000000
for(let i=0; i<len; i++) {
  mockArr.push(Math.random().toFixed(8))
}

//Set
let uniq1 = new Set()
let t1 = new Date().getTime()
for(let x=0; x<len; x++){
  uniq1.add(mockArr[x])
}
console.log(new Date().getTime() - t1)

//Map
let uniq2 = new Map()
let t2 = new Date().getTime()
for(let x=len-1; x>=0; x--){
  uniq2.set(mockArr[x], 1)
}
console.log(new Date().getTime() - t2)

//Obj
let uniq3 = {}
let t3 = new Date().getTime()
for(let x=0; x<len; x++){
  uniq3[mockArr[x]] = 1
}
console.log(new Date().getTime() - t3)