// src/utils/fileCache.ts
import crypto from 'crypto';
import fs from 'fs/promises';
import path from 'path';
export interface CacheEntry<T> {
data: T;
timestamp: number;
fileHash: string;
filePath: string;
}
export interface CacheOptions {
maxAge: number;
checkFileChanges: boolean;
}
export class FileBasedCache<T> {
private cache = new Map<string, CacheEntry<T>>();
private rootDirectory: string;
private options: CacheOptions = {
maxAge: 10 * 60 * 1000, // 10분
checkFileChanges: true,
};
constructor(rootDirectory: string) {
this.rootDirectory = rootDirectory;
}
private static generateCacheKey(filePath: string, namespace: string = 'default'): string {
return crypto.createHash('md5').update(`${namespace}:${filePath}`).digest('hex');
}
async get(filePath: string, namespace?: string): Promise<T | null> {
const key = FileBasedCache.generateCacheKey(filePath, namespace);
const entry = this.cache.get(key);
if (!entry) {
return null;
}
if (Date.now() - entry.timestamp > this.options.maxAge) {
this.cache.delete(key);
return null;
}
if (this.options.checkFileChanges) {
const hasChanged = await this.hasFileChanged(entry);
if (hasChanged) {
this.cache.delete(key);
return null;
}
}
return entry.data;
}
async set(filePath: string, data: T, namespace?: string): Promise<void> {
const key = FileBasedCache.generateCacheKey(filePath, namespace);
let fileHash = '';
try {
fileHash = await this.getFileHash(filePath);
} catch (error) {
console.warn(`Failed to hash file: ${filePath}`, error);
}
const entry: CacheEntry<T> = {
data,
timestamp: Date.now(),
fileHash,
filePath,
};
this.cache.set(key, entry);
}
private async hasFileChanged(entry: CacheEntry<T>): Promise<boolean> {
try {
const currentHash = await this.getFileHash(entry.filePath);
return currentHash !== entry.fileHash;
} catch {
return true;
}
}
private async getFileHash(filePath: string): Promise<string> {
const fullPath = path.resolve(this.rootDirectory, filePath);
const stats = await fs.stat(fullPath);
if (stats.size < 1024 * 1000) {
// 1000KB 미만
const content = await fs.readFile(fullPath, 'utf-8');
return crypto
.createHash('md5')
.update(content + stats.mtime.toISOString())
.digest('hex');
} else {
// 큰 파일은 메타데이터만 사용
return crypto
.createHash('md5')
.update(stats.size + stats.mtime.toISOString())
.digest('hex');
}
}
cleanup(maxAge: number = 30 * 60 * 1000): void {
const now = Date.now();
for (const [key, entry] of this.cache) {
if (now - entry.timestamp > maxAge) {
this.cache.delete(key);
}
}
}
}
