Function cacheable

packages/redis/cachable.ts:187–295

(
  fnOrName: T | string,
  fnOrExpireInSec: number | T,
  expireInSecOrOptions?: number | CacheableOptions,
  maybeOptions?: CacheableOptions
)

// Implementation for cacheable (Redis-only - async)
export function cacheable<T extends (...args: any) => any>(
  fnOrName: T | string,
  fnOrExpireInSec: number | T,
  expireInSecOrOptions?: number | CacheableOptions,
  maybeOptions?: CacheableOptions
) {
  const name = typeof fnOrName === 'string' ? fnOrName : fnOrName.name;
  const fn =
    typeof fnOrName === 'function'
      ? fnOrName
      : typeof fnOrExpireInSec === 'function'
        ? fnOrExpireInSec
        : null;

  let expireInSec: number | null = null;
  let options: CacheableOptions = {};

  // Parse parameters based on function signature
  if (typeof fnOrName === 'function') {
    // Overload 1: cacheable(fn, expireInSec, options?)
    expireInSec = typeof fnOrExpireInSec === 'number' ? fnOrExpireInSec : null;
    if (expireInSecOrOptions && typeof expireInSecOrOptions === 'object') {
      options = expireInSecOrOptions;
    }
  } else {
    // Overload 2: cacheable(name, fn, expireInSec, options?)
    expireInSec =
      typeof expireInSecOrOptions === 'number' ? expireInSecOrOptions : null;
    if (maybeOptions) {
      options = maybeOptions;
    }
  }

  if (typeof fn !== 'function') {
    throw new Error('fn is not a function');
  }

  if (typeof expireInSec !== 'number') {
    throw new Error('expireInSec is not a number');
  }

  const cachePrefix = `cachable:${name}`;
  const getKey = (...args: Parameters<T>) =>
    `${cachePrefix}:${stringify(args)}`.replaceAll(/\s/g, '');

  const lruCache = new LRUCache<string, any>({
    max: CACHEABLE_LRU_MAX,
    ttl: CACHEABLE_LRU_TTL_MS,
  });

  // L1 LRU (60s) + L2 Redis. clear() deletes Redis + local LRU; other nodes may serve stale from LRU for up to 60s.
  const cachedFn = async (
    ...args: Parameters<T>
  ): Promise<Awaited<ReturnType<T>>> => {
    const key = getKey(...args);

    // L1: in-memory LRU first (offloads Redis on hot keys)
    const lruHit = lruCache.get(key);