interface CacheEntry<T> {
data: T;
expiresAt: number;
lastAccessed: number;
}
const store = new Map<string, CacheEntry<unknown>>();
const MAX_ENTRIES = 500;
const DEFAULT_TTL_MS = 60 * 60 * 1000; // 1 hour
let hits = 0;
let misses = 0;
function evictOldest(): void {
let oldestKey: string | null = null;
let oldestTime = Infinity;
for (const [key, entry] of store) {
if (entry.lastAccessed < oldestTime) {
oldestTime = entry.lastAccessed;
oldestKey = key;
}
}
if (oldestKey) {
store.delete(oldestKey);
}
}
export function getCached<T>(key: string): T | null {
const entry = store.get(key);
if (!entry) {
misses++;
return null;
}
if (Date.now() > entry.expiresAt) {
store.delete(key);
misses++;
return null;
}
entry.lastAccessed = Date.now();
hits++;
return entry.data as T;
}
export function setCache<T>(key: string, data: T, ttlMs: number = DEFAULT_TTL_MS): void {
while (store.size >= MAX_ENTRIES) {
evictOldest();
}
store.set(key, {
data,
expiresAt: Date.now() + ttlMs,
lastAccessed: Date.now(),
});
}
export function clearCache(): void {
store.clear();
hits = 0;
misses = 0;
}
export function cacheStats(): { size: number; hits: number; misses: number } {
return { size: store.size, hits, misses };
}
