undeexcepturi
Version:
TypeScript ORM for Node.js based on Data Mapper, Unit of Work and Identity Map patterns. Supports MongoDB, MySQL, PostgreSQL and SQLite databases as well as usage with vanilla JavaScript.
85 lines (66 loc) • 2.27 kB
Markdown
---
title: Result cache
---
MikroORM has simple result caching mechanism. It works with those methods of `EntityManager`: `find()`, `findOne()`, `findAndCount()`, `findOneOrFail()`, `count()`, as well as with `QueryBuilder` result methods (including `execute`).
By default, in memory cache is used, that is shared for the whole `MikroORM` instance. Default expiration is 1 second.
```ts
const res = await em.find(Book, { author: { name: 'Jon Snow' } }, {
populate: ['author', 'tags'],
cache: 50, // set expiration to 50ms
// cache: ['cache-key', 50], // set custom cache key and expiration
// cache: true, // use default cache key and expiration
});
```
Or with query builder:
```ts
const res = await em.createQueryBuilder(Book)
.where({ author: { name: 'Jon Snow' } })
.cache()
.getResultList();
```
We can change the default expiration as well as provide custom cache adapter in the ORM configuration:
```ts
const orm = await MikroORM.init({
resultCache: {
// following options are the defaults
adapter: MemoryCacheAdapter,
expiration: 1000, // 1s
options: {},
// cache can be also enabled globally
// global: 50, // 50ms
},
// ...
});
```
To clear the cached result, we need to load it with explicit cache key, and later on we can use `em.clearCache(cacheKey)` method.
```ts
// set the cache key to 'book-cache-key', with expiration of 60s
const res = await em.find(Book, { ... }, { cache: ['book-cache-key', 60_000] });
// clear the cache key by name
await em.clearCache('book-cache-key');
```
Custom cache adapters need to implement `CacheAdapter` interface.
```ts
export interface CacheAdapter {
/**
* Gets the items under `name` key from the cache.
*/
get(name: string): Promise<any>;
/**
* Sets the item to the cache. `origin` is used for cache invalidation and should reflect the change in data.
*/
set(name: string, data: any, origin: string, expiration?: number): Promise<void>;
/**
* Removes the item from cache.
*/
remove(name: string): Promise<void>;
/**
* Clears all items stored in the cache.
*/
clear(): Promise<void>;
/**
* Called inside `MikroORM.close()` Allows graceful shutdowns (e.g. for redis).
*/
close?(): Promise<void>;
}
```