Queueue

Queue with concurency and context for tasks

Instalation

npm i queueue

Usage

const Q = require("queueue");
//creating queueue instance with concurrency 4
const q = new Q(4);

//when queue is empty and all tasks done print "Done"
q.on("drain", () => console.log("Done"));

const log = function(task, name, cb) {
  console.log(task, name);
  cb(); // or you can return a Promise
}

//pushing task and run it
q.push({
  ctx: this,
  method: "log",
  args: ["some", "task"];
});

Constructor

new Q(concurrency); // 'auto' or undefined is equals to cpus number

Tasks

• ctx — context to run task in
• method — method or method name to run
• args — arguments for task's method, last argument is always callback

All tasks must return a Promise or run a callback when finished

Methods

push(task)

adds task or array of tasks to end of the queue

unshift(task)

adds task or array of tasks to beginnig of the queue

bind(ctx, [method])

bind default ctx and/or method for all tasks with no ctx and/or method defined

abort()

cleans up the task queue, and will stop after all current tasks will be finished

length()

returns queue length

running()

returns number of current workers

Events

Queueue is event emmitter

drain

emited when all tasks are done

empty

emited when queue is empty

saturate

emited when number of workers is exceeded

task

emited before task will run

done

emited when task is done

error

emited when task returns error as first argument to callback function

License: MIT