What is lru-cache?
The lru-cache package is a JavaScript library that provides a cache object that deletes the least-recently-used items. It is useful for storing a limited amount of data in a way that allows for fast retrieval of entries based on keys.
What are lru-cache's main functionalities?
Creating a cache instance
This code sample demonstrates how to create a new LRU cache instance with a maximum of 500 items and a maximum age of one hour for each item.
{"const LRU = require('lru-cache');
const options = { max: 500, maxAge: 1000 * 60 * 60 };
const cache = new LRU(options);"}
Setting and getting cache items
This code sample shows how to set a value in the cache with a key and then retrieve that value using the same key.
{"const LRU = require('lru-cache');
const cache = new LRU();
cache.set('key', 'value');
const value = cache.get('key');"}
Checking if a key is in the cache
This code sample illustrates how to check if a key is present in the cache without updating the recent-ness or deleting it.
{"const LRU = require('lru-cache');
const cache = new LRU();
cache.set('key', 'value');
const hasKey = cache.has('key');"}
Deleting a key from the cache
This code sample shows how to delete a specific key from the cache.
{"const LRU = require('lru-cache');
const cache = new LRU();
cache.set('key', 'value');
cache.del('key');"}
Resetting the cache
This code sample demonstrates how to completely clear the cache.
{"const LRU = require('lru-cache');
const cache = new LRU();
cache.set('key', 'value');
cache.reset();"}
Other packages similar to lru-cache
node-cache
node-cache is an in-memory cache module for Node.js. It is similar to lru-cache but does not specifically implement the LRU (Least Recently Used) cache algorithm. Instead, it provides a simple caching mechanism with TTL (time to live) support.
cache-manager
cache-manager is a cache module that allows easy switching between different cache stores. It supports a variety of stores (e.g., memory, Redis, MongoDB) and includes LRU cache functionality. It is more flexible than lru-cache in terms of storage options but may be more complex to use.
quick-lru
quick-lru is an LRU cache implementation that is optimized for performance. It claims to be faster than lru-cache for certain use cases, especially when dealing with a large number of items or frequent evictions.
lru cache
A cache object that deletes the least-recently-used items.
Usage:
var LRU = require("lru-cache")
, cache = LRU(10, // max length. default = Infinity
// calculate how "big" each item is
//
// defaults to function(){return 1}, ie, just limit
// the item count, without any knowledge as to their
// relative size.
function (item) { return item.length },
// maxAge in ms
// defaults to infinite
// items are not pre-emptively pruned, but they
// are deleted when fetched if they're too old.
1000 * 60)
cache.set("key", "value")
cache.get("key") // "value"
cache.reset() // empty the cache
If you put more stuff in it, then items will fall out.
If you try to put an oversized thing in it, then it'll fall out right
away.
RTFS for more info.