Nestjs Service level caching - nestjs

Question

Looking at Netsjs documentation I can see that the general approach is controller level caching utilizing CacheInterceptor,
What I am looking to achieve is Service/DB level caching - use case is mainly for Static DB data that is required by other services, Is there a way to extend the supplied Cache Module to be used from within services ?

Answer 1

I was also looking for a way to do this.
For now I made it work based on some research by injecting the cacheManager instance in the service, and using it directly.
import { CACHE_MANAGER, Inject, Injectable } from '#nestjs/common';
#Injectable()
export class MyService {
constructor(
#Inject(CACHE_MANAGER) protected readonly cacheManager
) {}
public async myMethod() {
const cachedData = await this.cacheManager.get(cacheKey);
if (cachedData) return cachedData;
const data = ''; // Do normal stuff here
this.cacheManager.set(cacheKey, data);
return data;
}
}
But I'm still looking for a way to create a caching decorator that would contain the cache logic, and would use the function arguments as cache key

Answer 2

This is how I do it (some hook):
import {CACHE_MANAGER, CacheModule, Inject, Module} from '#nestjs/common';
import {Cache} from 'cache-manager';
let cache: Cache;
#Module({
imports: [CacheModule.register({ttl: 60 * 60})]
})
export class CacheableModule {
constructor(#Inject(CACHE_MANAGER) private cacheManager: Cache) {
cache = cacheManager;
}
}
export const Cacheable = (target: any, propertyKey: string, descriptor: PropertyDescriptor) => {
const originalMethod = descriptor.value;
descriptor.value = async function (...args: any[]) {
const cacheKey = originalMethod.name + "_" + args.join('_')
const cachedData = await cache.get(cacheKey);
if (cachedData) {
originalMethod.apply(this, args).then((data: any) => {
cache.set(cacheKey, data);
})
return cachedData;
}
const result = await originalMethod.apply(this, args);
cache.set(cacheKey, result);
return result;
};
};
and use it
#Cacheable
async getProducts(projectName: string): Promise<{ [id: string]: Product }> {}

Answer 3

You can use one of the cache stores listed here: https://github.com/BryanDonovan/node-cache-manager#store-engines
Then you simply register that store in the cache module (https://docs.nestjs.com/techniques/caching#different-stores):
import * as redisStore from 'cache-manager-redis-store';
import { CacheModule, Module } from '#nestjs/common';
import { AppController } from './app.controller';
#Module({
imports: [
CacheModule.register({
store: redisStore,
host: 'localhost',
port: 6379,
}),
],
controllers: [AppController],
})
export class ApplicationModule {}