ClientCache

ClientCache extends JavaScript’s native Map class, so it inherits all the methods of Map. It is a simple cache implementation that stores key-value pairs in memory.

Types

ClientCache is a generic type, which means you can specify the type of the key and value.

const cache = new ClientCache<valueType>(options);

Options

ClientCache accepts an options object as a parameter. The options object can have the following properties:

maxSize

The maximum size of the cache. If the cache exceeds this size, the least recently used item will be removed.

const cache = new ClientCache({ maxSize: 100 });

Methods

get(key: string)

It overrides the native get method, it checks the cache is exist or not, if it’s not exist, it will return undefined.

const cache = new ClientCache();
cache.get("key");

set(key: string, value: valueType)

It overrides the native set method, it checks the maximum size of the cache, if the cache exceeds the maximum size, it won’t add the new item to the cache.

const cache = new ClientCache();
cache.set("key", "value");

sweep(fn: SweepFilterOptions<V>)

It removes the items from the cache that match the filter function.

SweepFilterOptions:

type SweepFilterOptions<V> = (value: { value: V; timestamp: number; size: number }, key: string) => boolean;

Usage:

const cache = new ClientCache();
cache.sweep(value => value.size > 100);