alvarocastro/volatile-map

# VolatileMap

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Minimalist and performant `Map` object that is fully compatible with the [ES6 `Map` object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) (it extends from it) whose values are deleted after a TTL of being set, like a cache.

- [Install](#install)
- [Usage](#usage)
- [Contributing](#contributing)
- [Support](#support)

## Install

```bash
npm install volatile-map
```

## Usage

```js
import VolatileMap from 'volatile-map';

const cache = new VolatileMap(3000); // Values expire after 3 seconds

cache.set('foo', 'bar');
cache.set('baz', 'qux', 5000);
console.log(cache.get('foo'));
// => 'bar'
console.log(cache.get('baz'));
// => 'qux'

setTimeout(function () {
    console.log(cache.get('foo'));
    // => undefined
    console.log(cache.get('baz'));
    // => 'qux'
}, 4000);
```

### VolatileMap([ttl = 600000])

Constructor.

#### ttl

Type: `Number`

Time to live of the values and keys of the map, after that time, keys and values are deleted.

#### VolatileMap.set(key, value[, ttl])

This method behaves the same as the [ES6 `Map.set()` method](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/set), but adds an extra optional argument `ttl` that allows to set a specific time to live to each key. By default uses the `ttl` supplied when constructing the object.

#### Other methods

See the [ES6 `Map` object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) documentation to see all the methods.

## Contributing

Contributions are always welcome! Please run `npm test` beforehand to ensure everything is ok.

## Support

If you use this package please consider starring it :)