init

src/queue/lock.ts

@@ -0,0 +1,37 @@
+import { randomUUID } from 'crypto';
+import { redisConnection } from './connection';
+
+const DEFAULT_TTL = 30_000;
+const RETRY_INTERVAL = 50;
+
+/**
+ * Distributed Redis lock using SET NX EX. Serializes critical sections across
+ * api + worker processes — used for the operator wallet nonce
+ * (`chain:operator`), claim-watcher leader election (`watcher:claim`), etc.
+ */
+export async function withLock<T>(
+  key: string,
+  fn: () => Promise<T>,
+  ttl = DEFAULT_TTL,
+): Promise<T> {
+  const lockKey = `lock:${key}`;
+  const lockValue = randomUUID();
+  const ttlSeconds = Math.ceil(ttl / 1000);
+
+  while (true) {
+    const acquired = await redisConnection.set(lockKey, lockValue, 'EX', ttlSeconds, 'NX');
+    if (acquired === 'OK') break;
+    await new Promise((r) => setTimeout(r, RETRY_INTERVAL));
+  }
+
+  try {
+    return await fn();
+  } finally {
+    await redisConnection.eval(
+      `if redis.call("get", KEYS[1]) == ARGV[1] then return redis.call("del", KEYS[1]) else return 0 end`,
+      1,
+      lockKey,
+      lockValue,
+    );
+  }
+}