cache.ts•1.93 kB
import NodeCache from 'node-cache';
import { createHash } from 'crypto';
import { logger } from '../utils/logger.js';
export class ResponseCache {
private cache: NodeCache;
constructor(ttlSeconds: number = 300) {
this.cache = new NodeCache({
stdTTL: ttlSeconds,
checkperiod: ttlSeconds * 0.2,
useClones: false,
});
this.cache.on('expired', (key) => {
logger.debug(`Cache expired for key: ${key}`);
});
}
generateKey(provider: string, prompt: string, options?: Record<string, unknown>): string {
const data = JSON.stringify({ provider, prompt, options });
return createHash('sha256').update(data).digest('hex');
}
get<T>(key: string): T | undefined {
return this.cache.get<T>(key);
}
set<T>(key: string, value: T, ttl?: number): boolean {
if (ttl !== undefined) {
return this.cache.set(key, value, ttl);
} else {
return this.cache.set(key, value);
}
}
has(key: string): boolean {
return this.cache.has(key);
}
delete(key: string): number {
return this.cache.del(key);
}
flush(): void {
this.cache.flushAll();
logger.debug('Cache flushed');
}
getStats() {
const stats = this.cache.getStats();
return {
keys: this.cache.keys().length,
hits: stats.hits,
misses: stats.misses,
hitRate: stats.hits / (stats.hits + stats.misses) || 0,
};
}
// Helper method for caching provider responses
async getOrSet<T>(
key: string,
fetcher: () => Promise<T>,
ttl?: number
): Promise<{ value: T; cached: boolean }> {
const cached = this.get<T>(key);
if (cached !== undefined) {
logger.debug(`Cache hit for key: ${key}`);
return { value: cached, cached: true };
}
logger.debug(`Cache miss for key: ${key}`);
const value = await fetcher();
this.set(key, value, ttl);
return { value, cached: false };
}
}