Usage

Injecting the service

import { Injectable } from '@nestjs/common';
import { Cache } from '@o2s/framework/modules';

@Injectable()
export class MyService {
    constructor(private readonly cacheService: Cache.Service) {}
}

Cache-aside pattern

The standard pattern used throughout the framework:

async getData(id: string): Promise<Data> {
    const key = `data-${id}`;
    
    const cached = await this.cacheService.get(key);
    if (cached) {
        return JSON.parse(cached);
    }
    
    const data = await this.fetchFromSource(id);
    await this.cacheService.set(key, JSON.stringify(data));
    
    return data;
}

RxJS pattern (used in CMS)

import { from, of } from 'rxjs';
import { mergeMap, map } from 'rxjs/operators';

private getCachedData<T>(key: string, fetchData: () => Observable<T>): Observable<T> {
    return from(this.cacheService.get(key)).pipe(
        mergeMap((cached) => {
            if (cached) return of(JSON.parse(cached));
            
            return fetchData().pipe(
                map((data) => {
                    this.cacheService.set(key, JSON.stringify(data));
                    return data;
                }),
            );
        }),
    );
}

Cache key patterns

// CMS content
`component-${id}-${locale}`
`page-${id}-${locale}`
`app-config-${locale}`

// Custom data
`user-${userId}-profile`
`product-${productId}-details`

Conventions:

• Use hyphens as separators
• Include identifiers (ID, locale)
• Use descriptive prefixes

Serialization

// Simple objects
await this.cacheService.set(key, JSON.stringify(data));
const parsed = JSON.parse(await this.cacheService.get(key));

// Objects with circular references (use flatted)
import { stringify, parse } from 'flatted';
await this.cacheService.set(key, stringify(data));
const parsed = parse(await this.cacheService.get(key));

Cache invalidation

async updateData(id: string, newData: Data): Promise<void> {
    await this.repository.update(id, newData);
    await this.cacheService.del(`data-${id}`);
}

Debugging

redis-cli KEYS *                    # List all keys
redis-cli GET component-123-en      # Get specific key
redis-cli TTL component-123-en      # Check TTL
redis-cli DBSIZE                    # Count keys