Defer Map
A small Map wrapper with defer and expiry.
Table of Contents
Features
- 💥 Configure expiry to auto remove items.
- 🐙 Uses promises to defer values.
- 🚀 Drop in replacement for native
Map.
- 💪 Written in TypeScript.
Installation
npm install defer-map --save
Usage
import { DeferMap } from 'defer-map';
const expiry = 60 * 60 * 1000; // 1 hours
const map = new DeferMap({ expiry });
map.set('hero', 'Luke Skywalker');
const deferred = map.defer('villain');
console.log(map.size);
// => 2
console.log(await map.get('hero').result);
// => Luke Skywalker
deferred.done('Darth Vadar');
console.log(await map.get('villain').result);
// => Darth Vadar
// ... 1 hour later ....
console.log(map.get('hero'), map.get('villain'));
// => undefined, undefined
The defer-map API follows the native JS Map, with a few key additions.
The constructor (new DeferMap()) takes an optional configuration object with the following properties:
| Property | Type | Description | Default |
|---|
expiry | number | Number of milliseconds before items will expire. | n/a |
If expiry is set, expired items are not instantly removed. If you call get with a key for an expired item, it will
be removed and undefined will be returned. Alternatively, you can call cleanup to remove all expired items.
The get method returns an object, instead of the set value directly. The result property on the object returned
by get is a Promise that is resolved with the set value.
Development
npm install
npm run build
