promise-formation

Document

https://github.com/zobor/promise-formation

promise-fomation 提供类似 Promise.all 的功能，拓展了并发控制的能力。

Promise.all 的异步执行是不能控制数量和顺序的，promise-fomation 针对这些做了优化。

场景是响应操作前、过程中、后的各种用户操作。支持控制并发允许的 Promise 数量，支持异步添加任务，支持异步停止任务。

PromiseFormation VS Promise.all

| | Promise.all | PromiseFormation | | ---------------- | ----------- | ---------------- | | 并行执行异步函数 | ✔ | ✔ | | 控制任务顺序 | ✘ | ✔ | | 限制并发数量 | ✘ | ✔ | | 动态添加任务 | ✘ | ✔ | | 动态停止任务 | ✘ | ✔ | | 停止指定的任务 | ✘ | ✔ |

安装

$ npm install promise-formation -S

代码运行对比

Promise.all

const p1 = new Promise(resolve => {
  setTimeout(() => {
    console.log(1);
    resolve("A");
  }, 3);
});
const p2 = new Promise(resolve => {
  setTimeout(() => {
    console.log(2);
    resolve("B");
  }, 2);
});
const p3 = new Promise(resolve => {
  setTimeout(() => {
    console.log(3);
    resolve("C");
  }, 1);
});

Promise.all([p1, p2, p3]).then(rs => {
  console.log(rs);
});
// 3
// 2
// 1
// A B C

Promilse.formation

import promiseFormation from "promise-formation";

const p1 = () =>
  new Promise(resolve => {
    setTimeout(() => {
      console.log(1);
      resolve("A");
    }, 3);
  });
const p2 = () =>
  new Promise(resolve => {
    setTimeout(() => {
      console.log(2);
      resolve("B");
    }, 2);
  });
const p3 = () =>
  new Promise(resolve => {
    setTimeout(() => {
      console.log(3);
      resolve("C");
    }, 1);
  });

promiseFormation([p1, p2, p3]).then(rs => {
  console.log(rs);
  // 1
  // 2
  // 3
  // ["A", "B", "C"]
});

用法

import promiseFormation from "promise-formation";

const getPromises = (len: number): any =>
  Array(len)
    .fill(null)
    .map((_, index) => () =>
      new Promise(async resolve => {
        await new Promise(rs => {
          setTimeout(() => {
            rs();
          }, 1000);
        });
        resolve(index + 1);
      })
    );

promiseFormation(getPromises(3)).then((res: number[]) => {
  console.log(res);
});

// 输出
[1, 2, 3];

设置并发数量

const getPromises = (len: number): any =>
  Array(len)
    .fill(null)
    .map((_, index) => () =>
      new Promise(async resolve => {
        await new Promise(rs => {
          setTimeout(() => {
            rs();
          }, 1000);
        });
        resolve(index + 1);
      })
    );
promiseFormation(getPromises(9), 3).then((res: number[]) => {
  console.log(res);
});

// 输出
1;
2;
3;

4;
5;
6;

7;
8;
(9)[(1, 2, 3, 4, 5, 6, 7, 8, 9)];

异步添加任务

const promiseOptions: any = {};
promiseFormation(getPromises(2), 1, promiseOptions).then((res: number[]) => {
  console.log(res);
});
promiseOptions.addOne(getPromises(1)[0]);

// 输出
[1, 2, 1];

异步停止任务

const isError = v => Object.prototype.toString.call(v) === "[object Error]";
const promiseOptions: any = {};
const p = getPromises(3).map((fn: any, index: number) => {
  fn.id = `test-${index + 1}`;
  return fn;
});
promiseFormation(p, 1, promiseOptions).then((res: any[]) => {
  console.log(res.length);
  console.log(isError(res[1]));
});
promiseOptions.stopOne("test-2");

// 输出
3;
true;

参数

type promiseListItem = (value: void) => Promise<any>;

promiseFormation(promiseList, max, options);

• promiseList: promiseListItem[] 任务列表
• max: number 最大并行任务数，默认 1
• options
  • options.addOne: (promiseListItem) => vid 添加一个任务
  • options.stop: boolean 执行过程中，修改options.stop为 true 之后 后面的任务全部立即返回失败(闭包内部的实参是形参的引用)
  • options.stopOne: (taskId: string) => void 指定要停止的任务