import { logger } from './logger.js';
interface CacheItem<T> {
value: T;
expiresAt: number;
}
export class TTLCache<T> {
private cache = new Map<string, CacheItem<T>>();
private defaultTTL: number;
private maxSize: number;
constructor(defaultTTL = 300000, maxSize = 500) {
this.defaultTTL = defaultTTL; // 5 minutes default
this.maxSize = maxSize;
}
set(key: string, value: T, ttl?: number): void {
// LRU eviction if cache is full
if (this.cache.size >= this.maxSize) {
const firstKey = this.cache.keys().next().value;
if (firstKey) {
this.cache.delete(firstKey);
logger.debug('Cache evicted oldest entry', { key: firstKey });
}
}
this.cache.set(key, {
value,
expiresAt: Date.now() + (ttl ?? this.defaultTTL),
});
logger.debug('Cache set', { key, ttl: ttl ?? this.defaultTTL });
}
get(key: string): T | undefined {
const item = this.cache.get(key);
if (!item) {
logger.debug('Cache miss', { key });
return undefined;
}
if (Date.now() > item.expiresAt) {
this.cache.delete(key);
logger.debug('Cache expired', { key });
return undefined;
}
logger.debug('Cache hit', { key });
return item.value;
}
has(key: string): boolean {
return this.get(key) !== undefined;
}
invalidate(key: string): void {
this.cache.delete(key);
logger.debug('Cache invalidated', { key });
}
clear(): void {
this.cache.clear();
logger.debug('Cache cleared');
}
invalidatePattern(pattern: RegExp): void {
let count = 0;
for (const key of Array.from(this.cache.keys())) {
if (pattern.test(key)) {
this.cache.delete(key);
count++;
}
}
logger.debug('Cache pattern invalidated', { pattern: pattern.toString(), count });
}
get size(): number {
return this.cache.size;
}
}
