Tiny LRU

Least Recently Used cache for Client or Server.

Using the factory

import {lru} from "tiny-lru";
const cache = lru(max, ttl = 0, resetTtl = false);

Using the Class

import {LRU} from "tiny-lru";
const cache = new LRU(max, ttl = 0, resetTtl = false);

import {LRU} from "tiny-lru";
class MyCache extends LRU {}

Interoperability

Lodash provides a memoize function with a cache that can be swapped out as long as it implements the right interface. See the lodash docs for more on memoize.

Example

_.memoize.Cache = lru().constructor;
const memoized = _.memoize(myFunc);
memoized.cache.max = 10;

Testing

Tiny-LRU has 100% code coverage with its tests.

--------------|---------|----------|---------|---------|-------------------
File          | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------|---------|----------|---------|---------|-------------------
All files     |     100 |    91.54 |     100 |     100 |
 tiny-lru.cjs |     100 |    91.54 |     100 |     100 | 11-31,150,184
--------------|---------|----------|---------|---------|-------------------

API

Properties

first

Item in "first" or "bottom" position; default is null

Example

const cache = lru();

cache.first; // null - it's a new cache!

last

Item in "last" or "top" position; default is null

Example

const cache = lru();

cache.last; // null - it's a new cache!

max

Max items to hold in cache; default is 1000

Example

const cache = lru(500);

cache.max; // 500

resetTtl

Resets item.expiry with each set() if true; default is false

Example

const cache = lru(500, 5*6e4, true);

cache.resetTtl; // true

size

Number of items in cache

Example

const cache = lru();

cache.size; // 0 - it's a new cache!

ttl

Milliseconds an item will remain in cache; lazy expiration upon next get() of an item

Example

const cache = lru(100, 3e4);

cache.ttl; // 30000;

Methods

clear

Clears the contents of the cache

return {Object} LRU instance

Example

cache.clear();

delete

Removes item from cache

param  {String} key Item key
return {Object}     LRU instance

Example

cache.delete("myKey");

entries(["key1", "key2"])

Returns an Array cache items

param  {Array} keys (Optional) Cache item keys to get, defaults to `this.keys()` if not provided
return {Object} LRU instance

Example

cache.entries(['myKey1', 'myKey2']);

evict

Evicts the least recently used item from cache

return {Object} LRU instance

Example

cache.evict();

expiresAt

Gets expiration time for cached item

param  {String} key Item key
return {Mixed}      Undefined or number (epoch time)

Example

const item = cache.expiresAt("myKey");

get

Gets cached item and moves it to the front

param  {String} key Item key
return {Mixed}      Undefined or Item value

Example

const item = cache.get("myKey");

has

Returns a Boolean indicating if key is in cache

return {Object} LRU instance

Example

cache.has('myKey');

keys

Returns an Array of cache item keys (first to last)

return {Array} Array of keys

Example

console.log(cache.keys());

set

Sets item in cache as first

param  {String} key   Item key
param  {Mixed}  value Item value
return {Object}       LRU instance

Example

cache.set("myKey", {prop: true});

values(["key1", "key2"])

Returns an Array cache items

param  {Array} keys (Optional) Cache item keys to get
return {Array} Cache items

Example

cache.values(['abc', 'def']);

License

Current Tags

11.2.11 ... latest (2 years ago)

Tiny LRU

Using the factory

Using the Class

Interoperability

Example

Testing

API

Properties

first

last

max

resetTtl

size

ttl

Methods

clear

delete

entries(["key1", "key2"])

evict

expiresAt

get

has

keys

set

values(["key1", "key2"])

License

Current Tags

102 Versions