# quick-lru [![Build Status](https://travis-ci.org/sindresorhus/quick-lru.svg?branch=master)](https://travis-ci.org/sindresorhus/quick-lru) [![Coverage Status](https://coveralls.io/repos/github/sindresorhus/quick-lru/badge.svg?branch=master)](https://coveralls.io/github/sindresorhus/quick-lru?branch=master) > Simple [“Least Recently Used” (LRU) cache](https://en.m.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_.28LRU.29) Useful when you need to cache something and limit memory usage. Inspired by the [`hashlru` algorithm](https://github.com/dominictarr/hashlru#algorithm), but instead uses [`Map`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Map) to support keys of any type, not just strings, and values can be `undefined`. ## Install ``` $ npm install quick-lru ``` ## Usage ```js const QuickLRU = require('quick-lru'); const lru = new QuickLRU({maxSize: 1000}); lru.set('🦄', '🌈'); lru.has('🦄'); //=> true lru.get('🦄'); //=> '🌈' ``` ## API ### new QuickLRU(options?) Returns a new instance. ### options Type: `object` #### maxSize *Required*\ Type: `number` The maximum number of items before evicting the least recently used items. #### maxAge Type: `number`\ Default: `Infinity` The maximum number of milliseconds an item should remain in cache. By default maxAge will be Infinity, which means that items will never expire. Lazy expiration happens upon the next `write` or `read` call. Individual expiration of an item can be specified by the `set(key, value, options)` method. #### onEviction *Optional*\ Type: `(key, value) => void` Called right before an item is evicted from the cache. Useful for side effects or for items like object URLs that need explicit cleanup (`revokeObjectURL`). ### Instance The instance is [`iterable`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols) so you can use it directly in a [`for…of`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for...of) loop. Both `key` and `value` can be of any type. #### .set(key, value, options?) Set an item. Returns the instance. Individual expiration of an item can be specified with the `maxAge` option. If not specified, the global `maxAge` value will be used in case it is specified on the constructor, otherwise the item will never expire. #### .get(key) Get an item. #### .has(key) Check if an item exists. #### .peek(key) Get an item without marking it as recently used. #### .delete(key) Delete an item. Returns `true` if the item is removed or `false` if the item doesn't exist. #### .clear() Delete all items. #### .resize(maxSize) Update the `maxSize`, discarding items as necessary. Insertion order is mostly preserved, though this is not a strong guarantee. Useful for on-the-fly tuning of cache sizes in live systems. #### .keys() Iterable for all the keys. #### .values() Iterable for all the values. #### .entriesAscending() Iterable for all entries, starting with the oldest (ascending in recency). #### .entriesDescending() Iterable for all entries, starting with the newest (descending in recency). #### .size The stored item count. ---

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c	File Name	Size	T	Date
-	index.d.ts	3236	ts	2025-10-15 10:07:38
-	index.js	5347	js	2025-10-15 10:07:38
-	license	1109	%	2025-10-15 10:07:38
-	package.json	747	json	2025-10-15 10:07:38
-	readme.md	3660	md	2025-10-15 10:07:38

🌲 / linkwarden node_modules @alloc quick-lru

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