A simple FIFO queue

npm install SimpleQueue

There are plenty queues for node, but even those branded as FIFO (first in first out) usually destroy the order. Eg. when mapping over an RSS feeds & doing something with all of the pages, you need to know what element had what position - so I created this little helper.

A simple FIFO queue, delivering items in order.

+ new SimpleQueue(worker: (element: T, callback: (error: Error | null, result: R) => void) => void, callback: (error: Error | null, result: R, element: T) => void, done?: undefined | () => void, concurrent?: number): SimpleQueue

Defined in index.ts:16

Creates a new FIFO queue.

Returns: SimpleQueue

• paused: boolean = false

Defined in index.ts:16

▸ abort(): void

Defined in index.ts:48

Clears the queue (can't stop running processes).

Returns: void

▸ pause(): void

Defined in index.ts:57

Pause the queue execution. Will not stop already in-flight items.

Returns: void

▸ push(props: T): void

Defined in index.ts:41

Adds an element to the queue.

Returns: void

▸ resume(): void

Defined in index.ts:64

Resume the queue execution, and catch up with remaining items.

Returns: void

import SimpleQueue from "SimpleQueue";

const queue = new SimpleQueue(
    (element, callback) => {
        // Set
        setTimeout(() => callback(null, element / 1000), element);
    },
    (err, result, element) => {
        console.log(result);
    },
    () => {
        console.log("done");
    },
    4,
);

queue.push(1000);
queue.push(5000);
queue.push(3000);
queue.push(4000);
queue.push(8000);
queue.push(2000);
queue.push(0);

Output:

1, 5, 3, 4, 8, 2, 0, "done"

This takes 9 seconds to run.