@davidegheri/lru

Tiny Javascript Least Recently Used cache, for both Browsers and NodeJs. No dependencies needed.

Installation

npm install --save @davidegheri/lru
# Or
yarn add @davidegheri/lru

Usage

Require the module

const lru = require('@davidegheri/lru');

Or with imports

import lru from '@davidegheri/lru';

Create a new cache instance

const maxEntries = 5; // Defaults 10
const cache = lru(maxEntries);

Methods

get(key): any

Retrieve a cached element by its key. Moves the element as head of the cache.

cache.get('key');

set(key, value): Lru

Add a new element to the cache if not already present. Moves the element as head of the cache

cache.set('key', 'fooBar');

has(key): boolean

Check if the given key exists, this not move the element as head of the cache

cache.has('key1');

delete(key): Lru

Remove a cached element by its key. Moves every other elements consequently

cache.delete('key');

reset(limit?: number): Lru

Reset the cache, deletes all cached elements, optionally change the cache limit

cache.reset();

Properties

size: number

Get the number of cached elements

cache.set('key1', 'foo');
cache.set('key2', 'bar');

console.log(cache.size) // 2

head: any

Get the head element (last used or inserted)

cache.set('key1', 'foo');
cache.set('key2', 'bar');

console.log(cache.head); // bar (key2)
console.log(cache.get('key1')); // foo
console.log(cache.head); // foo (key1)

tail: any

Get the tail element (oldest used or inserted)

cache.set('key1', 'foo');
cache.set('key2', 'bar');

console.log(cache.tail); // foo (key1)
console.log(cache.get('key1')); // foo
console.log(cache.tail); // bar (key2)