mastercache/src/cache/locks.ts

Multi-tier cache module for Node.js. Redis, Upstash, CloudfareKV, File, in-memory and others drivers

import { Mutex, withTimeout, type MutexInterface } from 'async-mutex';

export class Locks {
  /**
   * A map that will hold active locks for each key
   */
  #locks = new Map<string, MutexInterface>();

  /**
   * For a given key, get or create a new lock
   *
   * @param key Key to get or create a lock for
   * @param timeout Time to wait to acquire the lock
   */
  getOrCreateForKey(key: string, timeout?: number) {
    let lock = this.#locks.get(key);
    if (!lock) {
      lock = new Mutex();
      this.#locks.set(key, lock);
    }

    return timeout ? withTimeout(lock, timeout) : lock;
  }

  release(key: string, releaser: MutexInterface.Releaser) {
    releaser();
    this.#locks.delete(key);
  }
}