retimer

What is retimer?

The 'retimer' npm package is a utility for creating and managing timers that can be reset. It is useful for scenarios where you need to repeatedly reset a timer based on certain events or conditions.

What are retimer's main functionalities?

Creating a Timer

This feature allows you to create a timer that will execute a callback function after a specified delay. In this example, the timer will log 'Timer expired' after 1000 milliseconds.

const retimer = require('retimer');

const timer = retimer(() => {
  console.log('Timer expired');
}, 1000);

Resetting a Timer

This feature allows you to reset the timer to a new delay. In this example, the timer is initially set to expire in 1000 milliseconds, but it is reset to expire in another 1000 milliseconds after 500 milliseconds have passed.

const retimer = require('retimer');

const timer = retimer(() => {
  console.log('Timer expired');
}, 1000);

// Reset the timer to expire in another 1000 milliseconds
setTimeout(() => {
  timer.reschedule(1000);
}, 500);

Clearing a Timer

This feature allows you to clear the timer before it expires. In this example, the timer is cleared after 500 milliseconds, so the 'Timer expired' message will not be logged.

const retimer = require('retimer');

const timer = retimer(() => {
  console.log('Timer expired');
}, 1000);

// Clear the timer before it expires
setTimeout(() => {
  timer.clear();
  console.log('Timer cleared');
}, 500);

Other packages similar to retimer

node-schedule

The 'node-schedule' package is a flexible cron-like and not-cron-like job scheduler for Node.js. It allows you to schedule jobs using cron syntax or by specifying a specific date. Unlike 'retimer', which focuses on resetting timers, 'node-schedule' is more suited for scheduling recurring tasks.

cron

The 'cron' package provides a way to schedule jobs using cron syntax. It is useful for running tasks at specific intervals or times. While 'retimer' is designed for timers that can be reset, 'cron' is more focused on scheduling tasks based on time patterns.

later

The 'later' package is a library for describing recurring schedules and calculating future occurrences. It provides a more advanced scheduling mechanism compared to 'retimer', which is primarily focused on simple timer management.

README

retimer  

reschedulable setTimeout for your node needs. This library is built for building a keep alive functionality across a large numbers of clients/sockets.

Rescheduling a 10000 functions 20 times with an interval of 50ms (see bench.js), with 100 repetitions:

• benchSetTimeout*100: 40.295s
• benchRetimer*100: 36.122s

Install

npm install retimer --save

Example

var retimer = require('retimer')
var timer = retimer(function () {
  throw new Error('this should never get called!')
}, 20)

setTimeout(function () {
  timer.reschedule(50)
  setTimeout(function () {
    timer.clear()
  }, 10)
}, 10)

API

retimer(callback, timeout, [...args])

Exactly like your beloved setTimeout. Returns a Retimer object

timer.reschedule(timeout)

Reschedule the timer. Retimer will not gove any performance benefit if the specified timeout comes before the original timeout.

timer.clear()

Clear the timer, like your beloved clearTimeout.

How it works

Timers are stored in a Linked List in node.js, if you create a lot of timers this Linked List becomes massive which makes removing a timer an expensive operation. Retimer let the old timer run at its time, and schedule a new one accordingly, when the new one is after the original timeout. There is no performance gain when the new timeout is before the original one as retimer will just remove the previous timer.

License

MIT