Node-Cache

> Simple and Maintained fast Node.js caching


@cacheable/node-cache is compatible with the node-cache package with regular maintenance and additional functionality (async/await and storage adapters) via {NodeCacheStore}. The only thing not implemented is the enableLegacyCallbacks option and functions. If you need them we are happy to take a PR to add them.

* Fully Compatible with node-cache using {NodeCache}
* Faster than the original node-cache package 🚀
* Storage Adapters via Keyv
* Async/Await functionality with {NodeCacheStore}
* Lightweight - uses @cacheable/utils for utilities
* Maintained and Updated Regularly! 🎉

Table of Contents

* Getting Started
* Basic Usage
* Breaking Changes from v1 to v2
* NodeCache Performance
* NodeCache API
* NodeCacheStore
* NodeCacheStore API
* How to Contribute
* License and Copyright

Getting Started

``bash
npm install @cacheable/node-cache --save
`

Basic Usage

`javascript
import NodeCache from '@cacheable/node-cache';

const cache = new NodeCache();
cache.set('foo', 'bar');
cache.get('foo'); // 'bar'

cache.set('foo', 'bar', 10); // 10 seconds

cache.del('foo'); // true

cache.set('bar', 'baz', '35m'); // 35 minutes using shorthand
`

The NodeCache is not the default export, so you need to import it like this:

`javascript
import {NodeCache} from '@cacheable/node-cache';

const cache = new NodeCache();
cache.set('foo', 'bar');
cache.get('foo'); // 'bar'
`

NodeCache also offers the ability to set the type of values that can be cached in Typescript environments.

`typescript
import {NodeCache} from '@cacheable/node-cache';

const cache = new NodeCache();
cache.set('foo', 'bar');
cache.get('foo'); // 'bar'
`

Breaking Changes from v1 to v2

The main NodeCache class API has not changed and remains fully compatible. The primary internal change is that it now uses Keyv as the underlying store.

NodeCacheStore Changes

$3


- V1: nodeCache.cache returned a Cacheable instance
- V2: Use nodeCache.store which returns a Keyv instance

$3

- V1: Supported primary and secondary store options for multi-tier caching
- V2: Uses single store option only

Migration:
`javascript
// V1
const cache = new NodeCacheStore({ primary: keyv1, secondary: keyv2 });

// V2 - use single store
const cache = new NodeCacheStore({ store: keyv });
`

If you need storage tiering functionality, use the cacheable package instead which supports primary and secondary stores.

$3


- V2 uses @cacheable/utils instead of the cacheable package for a lighter footprint

NodeCache Performance

The performance is comparable if not faster to the original node-cache package, but with additional features and improvements.

| name | summary | ops/sec | time/op | margin | samples |
|-----------------------------------|:---------:|----------:|----------:|:--------:|----------:|
| Cacheable NodeCache - set / get | 🥇 | 117K | 9µs | ±1.01% | 111K |
| Node Cache - set / get | -4.6% | 112K | 9µs | ±1.31% | 106K |

NodeCache API

constructor(options?: NodeCacheOptions)

Create a new cache instance. You can pass in options to set the configuration:

`javascript
export type NodeCacheOptions = {
stdTTL?: number;
checkperiod?: number;
useClones?: boolean;
deleteOnExpire?: boolean;
maxKeys?: number;
};
`

Here is a description of the options:

| Option | Default Setting | Description |
|--------|----------------|-------------|
| stdTTL | 0 | The standard time to live (TTL) in seconds for every generated cache element. If set to 0, it means unlimited. If a string is provided, it will be parsed as shorthand and default to milliseconds if it is a number as a string. |
| checkperiod | 600 | The interval in seconds to check for expired keys. If set to 0, it means no periodic check will be performed. |
| useClones | true | If set to true, the cache will clone the returned items via get() functions. This means that every time you set a value into the cache, node-cache makes a deep clone of it. When you get that value back, you receive another deep clone. This mimics the behavior of an external cache like Redis or Memcached, meaning mutations to the returned object do not affect the cached copy (and vice versa). If set to false, the original object will be returned, and mutations will affect the cached copy. |
| deleteOnExpire | true | If set to true, the key will be deleted when it expires. If set to false, the key will remain in the cache, but the value returned by get() will be undefined. You can manage the key with the on('expired') event. |
| maxKeys | -1 | If set to a positive number, it will limit the number of keys in the cache. If the number of keys exceeds this limit, it will throw an error when trying to set more keys than the maximum. If set to -1, it means unlimited keys are allowed. |

When initializing the cache you can pass in the options to set the configuration like the example below where we set the stdTTL to 10 seconds and checkperiod to 5 seconds.:

`javascript
const cache = new NodeCache({stdTTL: 10, checkperiod: 5});
`

When setting deleteOnExpire to true it will delete the key when it expires. If you set it to false it will keep the key but the value on get() will be undefined. You can manage the key with on('expired') event.

`javascript
const cache = new NodeCache({deleteOnExpire: false});
cache.on('expired', (key, value) => {
console.log(Key ${key} has expired with value ${value});
});
`

set(key: string | number, value: any, ttl?: number): boolean

Set a key value pair with an optional ttl (in seconds). Will return true on success. If the ttl is not set it will default to 0 (no ttl).

`javascript
cache.set('foo', 'bar', 10); // true
`

mset(data: Array): boolean

Set multiple key value pairs at once. This will take an array of objects with the key, value, and optional ttl.

`javascript
cache.mset([{key: 'foo', value: 'bar', ttl: 10}, {key: 'bar', value: 'baz'}]); // true
`

the NodeCacheItem is defined as:

`javascript
export type NodeCacheItem = {
key: string;
value: any;
ttl?: number;
};
`

get(key: string | number): T | undefined

Get a value from the cache by key. If the key does not exist it will return undefined.

`javascript
cache.get('foo'); // 'bar'
`

mget(keys: Array): Record

Get multiple values from the cache by keys. This will return an object with the keys and values.

`javascript
const obj = { my: 'value', my2: 'value2' };
const obj2 = { special: 'value3', life: 'value4' };
cache.set('my', obj);
cache.set('my2', obj2);
cache.mget(['my', 'my2']); // { my: { my: 'value', my2: 'value2' }, my2: { special: 'value3', life: 'value4' } }
`

take(key: string | number): T | undefined

Get a value from the cache by key and delete it. If the key does not exist it will return undefined.

`javascript
cache.set('foo', 'bar');
cache.take('foo'); // 'bar'
cache.get('foo'); // undefined
`

del(key: string | number | Array): number

Delete a key from the cache. Will return the number of deleted entries and never fail. You can also pass in an array of keys to delete multiple keys. All examples assume that you have initialized the cache like const cache = new NodeCache();.

`javascript
cache.del('foo'); // true
`

passing in an array of keys:

`javascript
cache.del(['foo', 'bar']); // true
`

mdel(keys: Array): number

Delete multiple keys from the cache. Will return the number of deleted entries and never fail.

`javascript
cache.mdel(['foo', 'bar']); // true
`

ttl(key: string | number, ttl?: number): boolean

Redefine the ttl of a key. Returns true if the key has been found and changed. Otherwise returns false. If the ttl-argument isn't passed the default-TTL will be used.

`javascript
cache.ttl('foo', 10); // true
`

getTtl(key: string | number): number | undefined

Get the ttl expiration from Date.now() of a key. If the key does not exist it will return undefined.

`javascript
cache.getTtl('foo'); // 1725993344859
`

has(key: string | number): boolean

Check if a key exists in the cache.

`javascript
cache.set('foo', 'bar');
cache.has('foo'); // true
`

keys(): string[]

Get all keys from the cache.

`javascript
await cache.keys(); // ['foo', 'bar']
`

getStats(): NodeCacheStats

Get the stats of the cache.

`javascript
cache.getStats(); // {hits: 1, misses: 1, keys: 1, ksize: 2, vsize: 3}
`

flushAll(): void

Flush the cache. Will remove all keys and reset the stats.

`javascript
cache.flushAll();
await cache.keys(); // []
cache.getStats(); // {hits: 0, misses: 0, keys: 0, ksize: 0, vsize: 0}
`

flushStats(): void

Flush the stats. Will reset the stats but keep the keys.

`javascript
await cache.set('foo', 'bar');
cache.flushStats();
cache.getStats(); // {hits: 0, misses: 0, keys: 0, ksize: 0, vsize: 0}
await cache.keys(); // ['foo']
`

on(event: string, callback: Function): void

Listen to events. Here are the events that you can listen to:
* set - when a key is set and it will pass in the key and value.
* expired - when a key is expired and it will pass in the key and value.
* flush - when the cache is flushed
* flush_stats - when the stats are flushed
* del - when a key is deleted and it will pass in the key and value.

`javascript
cache.on('set', (key, value) => {
console.log(Key ${key} has been set with value ${value});
});
`

NodeCacheStore

NodeCacheStore has a similar API to NodeCache but it is using async / await as it uses Keyv under the hood. This means that you can use any storage adapter that is available in Keyv and it will work seamlessly with the NodeCacheStore. To learn more about the Keyv storage adapters you can check out the Keyv documentation.

`javascript
import {NodeCacheStore} from '@cacheable/node-cache';

const cache = new NodeCacheStore();
await cache.set('foo', 'bar');
await cache.get('foo'); // 'bar'
`

Here is an example of how to use the NodeCacheStore with a Redis storage adapter:

`javascript
import {NodeCacheStore} from '@cacheable/node-cache';
import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const keyv = new Keyv({store: new KeyvRedis('redis://user:pass@localhost:6379')});
const cache = new NodeCacheStore({store: keyv});

// with storage you have the same functionality as the NodeCache but will be using async/await
await cache.set('foo', 'bar');
await cache.get('foo'); // 'bar'
`

When initializing the cache you can pass in the options below:

`javascript
export type NodeCacheStoreOptions = {
ttl?: number | string; // The standard ttl as number in milliseconds for every generated cache element. 0 = unlimited. Supports shorthand like '1h' for 1 hour.
store?: Keyv; // The storage adapter (defaults to in-memory Keyv)
maxKeys?: number; // Default is 0 (unlimited). If this is set it will return false when trying to set more keys than the max.
stats?: boolean; // Default is true, if this is set to false it will not track stats internally
};
`

Note: the ttl is now in milliseconds and not seconds like stdTTL in NodeCache. You can also use shorthand notation for TTL values. Here is an example:

`javascript
const cache = new NodeCacheStore({ttl: 60000 }); // 1 minute as it defaults to milliseconds
await cache.set('foo', 'bar', '1h'); // 1 hour
await cache.set('longfoo', 'bar', '1d'); // 1 day
`

NodeCacheStore API

* set(key: string | number, value: any, ttl?: number | string): Promise - Set a key value pair with an optional ttl (in milliseconds or shorthand string). Will return true on success, false if maxKeys limit is reached. If the ttl is not set it will default to the instance ttl or no expiration.
* mset(data: Array): Promise - Set multiple key value pairs at once
* get(key: string | number): Promise - Get a value from the cache by key
* mget(keys: Array): Promise> - Get multiple values from the cache by keys
* take(key: string | number): Promise - Get a value from the cache by key and delete it
* del(key: string | number): Promise - Delete a key
* mdel(keys: Array): Promise - Delete multiple keys
* clear(): Promise - Clear the cache
* setTtl(key: string | number, ttl?: number): Promise - Set the ttl of an existing key
* disconnect(): Promise - Disconnect the storage adapter
* ttl: number | string | undefined - The standard ttl for every generated cache element. undefined = unlimited
* store: Keyv - The storage adapter (read-only)
* maxKeys: number - If this is set it will return false when trying to set more keys than the max

How to Contribute

You can contribute by forking the repo and submitting a pull request. Please make sure to add tests and update the documentation. To learn more about how to contribute go to our main README https://github.com/jaredwray/cacheable. This will talk about how to Open a Pull Request, Ask a Question, or Post an Issue`.

License and Copyright

MIT © Jared Wray