@avanio/expire-cache

@avanio/expire-cache

Typescript/Javascript cache interfaces and expiration cache class.

This package contains:

• ICache a common cache interface
• IAsyncCache a common async cache interface
• ICacheOrAsync a type for both cache interfaces
• ExpireCache a class which implements the ICache interface with value expiration

examples

Synchronous example:

import {ICache, ExpireCache, ExpireTimeoutCache} from '@avanio/expire-cache';

const cache = new ExpireCache<string>(); // expiration on read operations
const cache = new ExpireTimeoutCache<string>(); // expiration with setTimeout

cache.onClear((cleared) => {
	for (const [key, value] of cleared.entries()) {
		console.log(`key ${String(key)} expired, deleted or clear with value ${value}`);
	}
});

cache.add('key', 'value', new Date(Date.now() + 1000)); // expires in 1000ms
cache.add('key2', 'value2'); // never expires (if no default expiration is set)

cache.get('key'); // 'value'

cache.has('key'); // true

cache.delete('key');

cache.clear();

cache.size(); // 1

function useCache(cache: ICache<string>) {
	const value = cache.get('key'); // 'value'
}

Synchronous/Asynchronous example (works with both ICache and IAsyncCache interfaces):

import {ICacheOrAsync} from '@avanio/expire-cache';

function useCache(cache: ICacheOrAsync<string>) {
	const value = await cache.get('key'); // 'value'
}

Advanced logging example, see default log mapping

const cache = new ExpireCache<string>(console, {
	get: LogLevel.Info,
	set: LogLevel.Info,
});

(Optional) default expiration in milliseconds if not specified in add() method. (If both are undefined, cache entry never expires):

const cache = new ExpireCache<string>(console, undefined, 60 * 1000); // sets default 60 seconds expiration for add() method