async-process-limit

This library can be used in the NodeJs, Browser and Espruino , but platform need support Promise or async/await only.

Installation

npm install async-process-limit

How to use

require the library

const Queue = require("async-process-limit");

create example

const array=[1,2,3,4,5,6,7....]
const q=new Queue({
    list: array,
    limit: 3,
    async process(val, taskId) {
      //....
    }
});

Parameters

new Queue(options)

options

This library support follow options:

• process: A function that will be called when a process ( Callback(cursorValue, taskId) )
• error: A function that will be called when on error ( Callback(Error, cursorValue, tryCount, taskId) )
• list: A array set process value list ( Default: [] )
• start: A boolean set execute now ( Default: false )
• limit: A number set task max length ( Default: 1 )
• retry: A number set task retry count ( Default: 0 )

Methods

q.start()

start forEach and process

q.stop()

Stops the queue. can be resumed with q.start().

q.end()

Stop and empty the queue immediately.

q.push(item1,item2,item3...)

q.concat([item1,item2,item3...])

example

simple start :

const queue = new Queue({
  list: rows,
  start: true,
  limit: 3,
  async process(val, taskId) {
    // processing
  },
});

// or

q.start();

normal demo :

I tested it in my espruino board( ESP32 / ESP8266 ). It's OK

const queue = new Queue({
  list: array,
  start: true,
  limit: 3,
  process: (val, taskId) => {
    return new Promise((r) => {
      // processing
    });
  },
});

async function :

const queue = new Queue({
  list: array,
  start: true,
  limit: 3,
  async process(val, taskId) {
    // processing
  },
});

retry :

const queue = new Queue({
  limit: 3,
  retry: 3, //<===
  async process(val, taskId) {
    // processing
  },
  error(err, val, tryCount, taskId) {
    // error
  },
});

PromiseArray

const queue = new Queue({
  list: PromiseArray,
  limit: 3,
  start: true,
  retry: 3,
});

Push / Concat

const queue = new Queue({
  start: true,
  limit: 3,
  async process(val, taskId) {
    // processing
  },
});

queue.push(...array);
queue.concat(array);