nandi.uk
This repository has no description
1.1 kB
40 lines
1import { IDistributedLockService } from './IDistributedLockService';
2
3/**
4 * In-memory distributed locking service for development and testing.
5 *
6 * Provides lock functionality using in-memory state. This is suitable for:
7 * - Local development with a single worker
8 * - Unit/integration tests
9 * - Mock persistence mode
10 *
11 * NOT suitable for production with multiple workers/instances.
12 */
13export class InMemoryDistributedLockService implements IDistributedLockService {
14 private locks: Map<string, boolean> = new Map();
15
16 async withLock<T>(
17 key: string,
18 ttl: number,
19 fn: () => Promise<T>,
20 ): Promise<T> {
21 // Simple lock acquisition - throws if already locked
22 if (this.locks.get(key)) {
23 throw new Error(`Lock already held for key: ${key}`);
24 }
25
26 this.locks.set(key, true);
27
28 // Set TTL to auto-release lock (safety mechanism)
29 const timeout = setTimeout(() => {
30 this.locks.delete(key);
31 }, ttl);
32
33 try {
34 return await fn();
35 } finally {
36 clearTimeout(timeout);
37 this.locks.delete(key);
38 }
39 }
40}