import { DirectoryEntry } from './xrootd.js';
interface CacheEntry {
entries: DirectoryEntry[];
cachedAt: Date;
}
export class DirectoryCache {
private cache: Map<string, CacheEntry>;
private cacheTTL: number; // milliseconds
private maxSize: number;
constructor(cacheTTLMinutes: number = 60, maxSize: number = 1000) {
this.cache = new Map();
this.cacheTTL = cacheTTLMinutes * 60 * 1000;
this.maxSize = maxSize;
}
get(path: string): DirectoryEntry[] | null {
const entry = this.cache.get(path);
if (!entry) {
return null;
}
const age = Date.now() - entry.cachedAt.getTime();
if (age > this.cacheTTL) {
// Expired
this.cache.delete(path);
return null;
}
return entry.entries;
}
set(path: string, entries: DirectoryEntry[]): void {
// LRU eviction: if cache is full, remove oldest entry
if (this.cache.size >= this.maxSize) {
const oldestKey = this.findOldestEntry();
if (oldestKey) {
this.cache.delete(oldestKey);
}
}
this.cache.set(path, {
entries,
cachedAt: new Date(),
});
}
invalidate(path: string): void {
this.cache.delete(path);
}
clear(): void {
this.cache.clear();
}
getStats(): { size: number; hitRate?: number } {
return {
size: this.cache.size,
};
}
private findOldestEntry(): string | null {
let oldestKey: string | null = null;
let oldestTime = Date.now();
for (const [key, entry] of Array.from(this.cache.entries())) {
const time = entry.cachedAt.getTime();
if (time < oldestTime) {
oldestTime = time;
oldestKey = key;
}
}
return oldestKey;
}
// Cleanup expired entries periodically
cleanup(): void {
const now = Date.now();
const keysToDelete: string[] = [];
for (const [key, entry] of Array.from(this.cache.entries())) {
const age = now - entry.cachedAt.getTime();
if (age > this.cacheTTL) {
keysToDelete.push(key);
}
}
keysToDelete.forEach(key => this.cache.delete(key));
}
}
