Function loadCacheData

src/core/cache.ts:267–305

()

/* ---- Disk cache load / save ---- */

export async function loadCacheData(): Promise<CacheData | null> {
  try {
    if (!fs.existsSync(CACHE_META) || !fs.existsSync(CACHE_FILE)) return null;
    if (fs.statSync(CACHE_META).size > MAX_CACHE_META_BYTES) {
      warnCore('Cache', 'Cache meta file exceeds size limit; ignoring and re-parsing');
      return null;
    }
    const meta = readCacheMetaPayload(JSON.parse(fs.readFileSync(CACHE_META, 'utf-8')) as unknown);
    if (!meta || meta.version !== CACHE_VERSION) return null; // old format – full re-parse

    const cacheSize = (await fs.promises.stat(CACHE_FILE)).size;
    if (cacheSize > MAX_CACHE_FILE_BYTES) {
      warnCore('Cache', `Cache file exceeds size limit (${cacheSize} bytes); ignoring and re-parsing`);
      return null;
    }

    // Read async to avoid blocking the event loop on the 200+ MB cache file
    const rawStr = await fs.promises.readFile(CACHE_FILE, 'utf-8');
    // Yield before the expensive JSON.parse so any pending IPC messages flush
    await new Promise<void>(r => setTimeout(r, 0));
    const raw = readSerializedCachePayload(JSON.parse(rawStr) as unknown);
    if (!raw) return null;
    // Yield after parse to let the event loop breathe
    await new Promise<void>(r => setTimeout(r, 0));
    const workspaces = new Map<string, Workspace>(raw.workspaces);
    const editLocIndex = new Map<string, Map<string, number>>();
    for (const [k, v] of raw.editLocIndex) {
      editLocIndex.set(k, new Map(v));
    }
    const sessionSourceIndex = new Map<string, SessionSource>(raw.sessionSourceIndex);
    return {
      result: { workspaces, sessions: raw.sessions, editLocIndex, sessionSourceIndex },
      dirMetas: meta.dirMetas,
    };
  } catch (e) {
    console.debug('Cache load failed, treating as miss:', e instanceof Error ? e.message : e);
    return null;
  }
}

export function saveCacheData(result: ParseResult, dirMetas: DirMetas): void {
  // Serialize immediately so the snapshot is captured before any in-memory