cache-manager
v6.1.0
cache-manager
Simple and fast NodeJS caching module.
A cache module for NodeJS that allows easy wrapping of functions in cache, tiered caches, and a consistent interface.
- Made with Typescript and compatible with ESModules.
- Easy way to wrap any function in cache, supports a mechanism to refresh expiring cache keys in background.
- Tiered caches -- data gets stored in each cache and fetched from the highest priority cache(s) first.
- Use with any Keyv compatible storage adapter.
- 100% test coverage via vitest.
We moved to using Keyv which are more actively maintained and have a larger community.
A special thanks to Tim Phan who tooke cache-manager v5 and ported it to Keyv which is the foundation of v6. 🎉 Another special thanks to Doug Ayers who wrote promise-coalesce which was used in v5 and now embedded in v6.
If you are looking for older documentation you can find it here:
Table of Contents
- Installation
- Quick start
- Using
CacheableMemoryorlru-cacheas storage adapter - Methods
- Events
- Update on
redisandioredisSupport - Using Legacy Storage Adapters
- Contribute
- License
Installation
npm install cache-manager
By default, everything is stored in memory; you can optionally also install a storage adapter; choose one from any of the storage adapters supported by Keyv:
npm install @keyv/redis
npm install @keyv/memcache
npm install @keyv/mongo
npm install @keyv/sqlite
npm install @keyv/postgres
npm install @keyv/mysql
npm install @keyv/etcd
In addition Keyv supports other storage adapters such as lru-cache and CacheableMemory from Cacheable (more examples below). Please read Keyv document for more information.
Quick start
import { Keyv } from 'keyv';
import { createCache } from 'cache-manager';
// Memory store by default
const cache = createCache()
// Single store which is in memory
const cache = createCache({
stores: [new Keyv()],
})
Here is an example of doing layer 1 and layer 2 caching with the in-memory being CacheableMemory from Cacheable and the second layer being @keyv/redis:
import { Keyv } from 'keyv';
import { KeyvRedis } from '@keyv/redis';
import { CacheableMemory } from 'cacheable';
import { createCache } from 'cache-manager';
// Multiple stores
const cache = createCache({
stores: [
// High performance in-memory cache with LRU and TTL
new Keyv({
store: new CacheableMemory({ ttl: 60000, lruSize: 5000 }),
}),
// Redis Store
new Keyv({
store: new KeyvRedis('redis://user:pass@localhost:6379'),
}),
],
})
Once it is created, you can use the cache object to set, get, delete, and wrap functions in cache.
// With default ttl and refreshThreshold
const cache = createCache({
ttl: 10000,
refreshThreshold: 3000,
})
await cache.set('foo', 'bar')
// => bar
await cache.get('foo')
// => bar
await cache.del('foo')
// => true
await cache.get('foo')
// => null
await cache.wrap('key', () => 'value')
// => value
Using CacheableMemory or lru-cache as storage adapter
Because we are using Keyv, you can use any storage adapter that Keyv supports such as lru-cache or CacheableMemory from Cacheable. Below is an example of using CacheableMemory:
In this example we are using CacheableMemory from Cacheable which is a fast in-memory cache that supports LRU and and TTL expiration.
import { createCache } from 'cache-manager';
import {Keyv} from 'keyv';
import { CacheableMemory } from 'cacheable';
const keyv = new Keyv({ store: new CacheableMemory({ ttl: 60000, lruSize: 5000 }) });
const cache = createCache({ stores: [keyv] });
Here is an example using lru-cache:
import { createCache } from 'cache-manager';
import { Keyv } from 'keyv';
import { LRU } from 'lru-cache';
const keyv = new Keyv({ store: new LRU({ max: 5000, maxAge: 60000 }) });
const cache = createCache({ stores: [keyv] });
Options
stores?: Keyv[]
List of Keyv instance. Please refer to the Keyv document for more information.
ttl?: number - Default time to live in milliseconds.
The time to live in milliseconds. This is the maximum amount of time that an item can be in the cache before it is removed.
refreshThreshold?: number - Default refreshThreshold in milliseconds.
If the remaining TTL is less than refreshThreshold, the system will update the value asynchronously in background.
nonBlocking?: boolean - Default false
If set to true, the system will not block when multiple stores are used. Here is how it affects tye type of functions:
set and mset- will not wait for all stores to finish.get and mget- will return the first (fastest) value found.del and mdel- will not wait for all stores to finish.clear- will not wait for all stores to finish.
Methods
set
set(key, value, [ttl]): Promise<value>
Sets a key value pair. It is possible to define a ttl (in miliseconds). An error will be throw on any failed
await cache.set('key-1', 'value 1')
// expires after 5 seconds
await cache.set('key 2', 'value 2', 5000)
See unit tests in test/set.test.ts for more information.
mset
mset(keys: [ { key, value, ttl } ]): Promise<true>
Sets multiple key value pairs. It is possible to define a ttl (in miliseconds). An error will be throw on any failed
await cache.mset([
{ key: 'key-1', value: 'value 1' },
{ key: 'key-2', value: 'value 2', ttl: 5000 },
]);
get
get(key): Promise<value>
Gets a saved value from the cache. Returns a null if not found or expired. If the value was found it returns the value.
await cache.set('key', 'value')
await cache.get('key')
// => value
await cache.get('foo')
// => null
See unit tests in test/get.test.ts for more information.
mget
mget(keys: [key]): Promise<value[]>
Gets multiple saved values from the cache. Returns a null if not found or expired. If the value was found it returns the value.
await cache.mset([
{ key: 'key-1', value: 'value 1' },
{ key: 'key-2', value: 'value 2' },
]);
await cache.mget(['key-1', 'key-2', 'key-3'])
// => ['value 1', 'value 2', null]
del
del(key): Promise<true>
Delete a key, an error will be throw on any failed.
await cache.set('key', 'value')
await cache.get('key')
// => value
await cache.del('key')
await cache.get('key')
// => null
See unit tests in test/del.test.ts for more information.
mdel
mdel(keys: [key]): Promise<true>
Delete multiple keys, an error will be throw on any failed.
await cache.mset([
{ key: 'key-1', value: 'value 1' },
{ key: 'key-2', value: 'value 2' },
]);
await cache.mdel(['key-1', 'key-2'])
clear
clear(): Promise<true>
Flush all data, an error will be throw on any failed.
await cache.set('key-1', 'value 1')
await cache.set('key-2', 'value 2')
await cache.get('key-1')
// => value 1
await cache.get('key-2')
// => value 2
await cache.clear()
await cache.get('key-1')
// => null
await cache.get('key-2')
// => null
See unit tests in test/clear.test.ts for more information.
wrap
wrap(key, fn: async () => value, [ttl], [refreshThreshold]): Promise<value>
Wraps a function in cache. The first time the function is run, its results are stored in cache so subsequent calls retrieve from cache instead of calling the function.
If refreshThreshold is set and the remaining TTL is less than refreshThreshold, the system will update the value asynchronously. In the meantime, the system will return the old value until expiration.
await cache.wrap('key', () => 1, 5000, 3000)
// call function then save the result to cache
// => 1
await cache.wrap('key', () => 2, 5000, 3000)
// return data from cache, function will not be called again
// => 1
// wait 3 seconds
await sleep(3000)
await cache.wrap('key', () => 2, 5000, 3000)
// return data from cache, call function in background and save the result to cache
// => 1
await cache.wrap('key', () => 3, 5000, 3000)
// return data from cache, function will not be called
// => 2
await cache.wrap('error', () => {
throw new Error('failed')
})
// => error
NOTES:
- The store that will be checked for refresh is the one where the key will be found first (highest priority).
- If the threshold is low and the worker function is slow, the key may expire and you may encounter a racing condition with updating values.
- If no
ttlis set for the key, the refresh mechanism will not be triggered.
See unit tests in test/wrap.test.ts for more information.
Events
set
Fired when a key has been added or changed.
cache.on('set', ({ key, value, error }) => {
// ... do something ...
})
del
Fired when a key has been removed manually.
cache.on('del', ({ key, error }) => {
// ... do something ...
})
clear
Fired when the cache has been flushed.
cache.on('clear', (error) => {
if (error) {
// ... do something ...
}
})
refresh
Fired when the cache has been refreshed in the background.
cache.on('refresh', ({ key, value, error }) => {
if (error) {
// ... do something ...
}
})
See unit tests in test/events.test.ts for more information.
Update on redis and ioredis Support
We will not be supporting cache-manager-ioredis-yet or cache-manager-redis-yet in the future as we have moved to using Keyv as the storage adapter @keyv/redis.
Using Legacy Storage Adapters
There are many storage adapters built for cache-manager and because of that we wanted to provide a way to use them with KeyvAdapter. Below is an example of using cache-manager-redis-yet:
import { createCache, KeyvAdapter } from 'cache-manager';
import { Keyv } from 'keyv';
import { redisStore } from 'cache-manager-redis-yet';
const adapter = new KeyvAdapter( await redisStore() );
const cache = createCache({
stores: [new Keyv({ store: adapter })],
});
This adapter will allow you to add in any storage adapter. If there are issues it needs to follow CacheManagerStore interface.
Contribute
If you would like to contribute to the project, please read how to contribute here CONTRIBUTING.md.
