Promise Pool Tool

check test.js to see full examples.

Promise Pool

Run async functions in Limit Concurrency Number.

OPTIONS

• concurrency Max thread when runing async functions Default: 10
• maxRetry Max retry time when a task throw errors Default: 5
• retryWait Timeout(millseconds) when retry the task Default: 1000
• onProgress: (index: number, result: T, error: Error) => void Event on a Task Finished
• onFinish: (results: T[], errors: Error[]) => void Event on all Tasks Finished

USAGE

const { PromisePool } = require("./promise-pool-tool");
const options = { concurrency: 2 };
const tasks = [
  //
  async function () {},
  async function () {},
  async function () {},
  async function () {},
];
const promisePool = new PromisePool(tasks, options);
const results = await promisePool.start();
console.info("All Finish");

Promise Queue

Run async functions in a Queue. (Extend From PromisePool with concurrency=1)

USAGE

// simulation of second buy
let promiseQueue = new PromiseQueue();
let quantity = 5;
Array.from({ length: 10 }).map(async (unknow, index) => {
  setTimeout(() => {
    // push async task in the queue
    promiseQueue.push(async function () {
      await wait(1);
      if (quantity > 0) {
        quantity--;
        console.info(`[PromiseQueue Test 1] ${index} Buy Success`);
      } else {
        console.info(`[PromiseQueue Test 1] ${index} Sold Out`);
      }
    });
  }, Math.floor(Math.random() * 100));
});

Global Async Function

Create an async function that returning the same Promise before resolved.

USAGE

// they all will return the same number
let globalAsyncFunction = new GlobalAsyncFunction("sampleKey", async function () {
  await wait(2000);
  return Math.random();
});

globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
globalAsyncFunction().then(console.info);
GlobalAsyncFunction.get("sampleKey")().then(console.info);
GlobalAsyncFunction.get("sampleKey")().then(console.info);
GlobalAsyncFunction.get("sampleKey")().then(console.info);
GlobalAsyncFunction.get("sampleKey")().then(console.info);
GlobalAsyncFunction.get("sampleKey")().then(console.info);