<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>promise test</title>
</head>
<body>
<script>
Promise.serial = function(promiseGens,allowFail){
let seq = Promise.resolve();
promiseGens.forEach(function(item){
seq = allowFail ? seq.then(item).catch(err => err) : seq.then(item);
});
return seq;
}
//单个promise reject后，继续执行
Promise.parallel = function(promiseGens){
let allPromise = new Promise(function(resolve,reject){
let results = [];
promiseGens.forEach(function(item){
item()
.then(data => results.push(data))
.catch(err => results.push(err))
.finally(function(){
if(results.length == promiseGens.length){
resolve(results);
}
})
});
});
return allPromise;
}
Promise.concurrency = function(promiseGens,concurrency,allowFail){
let promiseGenCopys = [].concat(promiseGens);
let concurrencyPromises = [];
let res = [];
while(concurrency--){
concurrencyPromises.push(recur(promiseGenCopys));
}
return Promise.all(concurrencyPromises).then(_ => res);
// return Promise.parallel(concurrencyPromises);
function recur(promiseGens){
if(!promiseGens.length) return Promise.resolve();
let first = promiseGens.shift();
return first().then(function(data){
res.push(data);
return recur(promiseGens);
}).catch(function(err){
res.push(err);
return allowFail ? recur(promiseGens) : err;
})
}
}
</script>
<script>
// 异步函数a
var a = function () {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('resolve a');
resolve('a');
}, 500)
})
}
// 异步函数b
var b = function (data) {
return new Promise(function (resolve, reject) {
setTimeout(() => {
console.log('reject b',data);
reject(data||'reject'+ 'b');
},500)
})
}
// 异步函数c
var c = function (data) {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('resolve c',data);
resolve(data||'reject' + 'c');
}, 500)
})
}
// 异步函数c
var d = function (data) {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('resolve d',data);
resolve(data||'reject' + 'd');
}, 500)
})
}
// 异步函数c
var e = function (data) {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('reject e',data);
reject(data||'reject' + 'e');
}, 500)
})
}
// 异步函数c
var f = function (data) {
return new Promise(function (resolve, reject) {
setTimeout(function () {
console.log('reject f',data);
reject(data||'reject' + 'f');
}, 500)
})
}
//串行测试
// Promise.serial([a,b,c,d,e,f],true).then(function(data){
// console.log(data);
// }).catch(function(err){
// console.log('catch',err);
// });
//并行测试
// Promise.parallel([a,b,c,d,e,f]).then(function(data){
// console.log(data);
// }).catch(function(err){
// console.log(err);
// });
//并发测试
Promise.concurrency([a,b,c,d,e,f],2,true).then(function(data){
console.log(data);
}).catch(function(err){
console.log(err);
})
</script>
</body>
</html>
