/**
* Cache Manager
*
* Caches fetched samples locally to avoid re-fetching on every run.
* Stores JSON files in .vector-memory/benchmark-cache/
*/
import { existsSync, mkdirSync, readdirSync, rmSync } from "fs";
import { join } from "path";
import type { RawSample } from "./types";
const DEFAULT_CACHE_DIR = ".vector-memory/benchmark-cache";
const DEFAULT_EXPIRY_MS = 7 * 24 * 60 * 60 * 1000; // 7 days
/**
* Cache entry stored on disk.
*/
export interface CacheEntry {
/** Source name */
source: string;
/** Timestamp when fetched */
fetchedAt: number;
/** Cached samples */
samples: RawSample[];
/** Version for cache invalidation */
version: number;
}
const CACHE_VERSION = 1;
/**
* Manages caching of fetched samples.
*/
export class CacheManager {
private readonly cacheDir: string;
private readonly expiryMs: number;
constructor(cacheDir: string = DEFAULT_CACHE_DIR, expiryMs: number = DEFAULT_EXPIRY_MS) {
this.cacheDir = cacheDir;
this.expiryMs = expiryMs;
}
/**
* Get cached samples for a source.
* Returns null if not cached or expired.
*/
async get(source: string, maxAgeMs?: number): Promise<RawSample[] | null> {
const filePath = this.getCachePath(source);
if (!existsSync(filePath)) {
return null;
}
try {
const file = Bun.file(filePath);
const entry: CacheEntry = await file.json();
// Check version
if (entry.version !== CACHE_VERSION) {
return null;
}
// Check expiry
const maxAge = maxAgeMs ?? this.expiryMs;
const age = Date.now() - entry.fetchedAt;
if (age > maxAge) {
return null;
}
return entry.samples;
} catch {
// Invalid cache file
return null;
}
}
/**
* Store samples in cache.
*/
async set(source: string, samples: RawSample[]): Promise<void> {
this.ensureCacheDir();
const entry: CacheEntry = {
source,
fetchedAt: Date.now(),
samples,
version: CACHE_VERSION,
};
const filePath = this.getCachePath(source);
await Bun.write(filePath, JSON.stringify(entry, null, 2));
}
/**
* Clear cache for a source, or all sources if not specified.
*/
async clear(source?: string): Promise<void> {
if (source) {
const filePath = this.getCachePath(source);
if (existsSync(filePath)) {
rmSync(filePath);
}
} else {
if (existsSync(this.cacheDir)) {
rmSync(this.cacheDir, { recursive: true });
}
}
}
/**
* List all cached sources.
*/
list(): string[] {
if (!existsSync(this.cacheDir)) {
return [];
}
return readdirSync(this.cacheDir)
.filter((f) => f.endsWith(".json"))
.map((f) => f.replace(".json", ""));
}
/**
* Get cache info for a source.
*/
async getInfo(
source: string
): Promise<{ fetchedAt: Date; sampleCount: number; expired: boolean } | null> {
const filePath = this.getCachePath(source);
if (!existsSync(filePath)) {
return null;
}
try {
const file = Bun.file(filePath);
const entry: CacheEntry = await file.json();
return {
fetchedAt: new Date(entry.fetchedAt),
sampleCount: entry.samples.length,
expired: Date.now() - entry.fetchedAt > this.expiryMs,
};
} catch {
return null;
}
}
private getCachePath(source: string): string {
// Sanitize source name for filesystem
const safeName = source.replace(/[^a-zA-Z0-9-_]/g, "-");
return join(this.cacheDir, `${safeName}.json`);
}
private ensureCacheDir(): void {
if (!existsSync(this.cacheDir)) {
mkdirSync(this.cacheDir, { recursive: true });
}
}
}
