From f71e1ac03a784e89105efe75c93a14448b5caf55 Mon Sep 17 00:00:00 2001
From: Adria Navarro <adria@budibase.com>
Date: Wed, 29 Nov 2023 13:56:25 +0100
Subject: [PATCH] Allow locks without TTL

---
 packages/backend-core/src/redis/redlockImpl.ts | 17 +++++++++++++++--
 packages/types/src/sdk/locks.ts                |  4 ++--
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/packages/backend-core/src/redis/redlockImpl.ts b/packages/backend-core/src/redis/redlockImpl.ts
index 266f1fe989..cccb981399 100644
--- a/packages/backend-core/src/redis/redlockImpl.ts
+++ b/packages/backend-core/src/redis/redlockImpl.ts
@@ -4,6 +4,7 @@ import { LockOptions, LockType } from "@budibase/types"
 import * as context from "../context"
 import env from "../environment"
 import { logWarn } from "../logging"
+import { Duration } from "../utils"
 
 async function getClient(
   type: LockType,
@@ -105,12 +106,21 @@ export async function doWithLock<T>(
   task: () => Promise<T>
 ): Promise<RedlockExecution<T>> {
   const redlock = await getClient(opts.type, opts.customOptions)
-  let lock
+  let lock: Redlock.Lock | undefined
+  let interval
   try {
     const name = getLockName(opts)
 
+    let ttl = opts.ttl || Duration.fromSeconds(15).toMs()
+
     // create the lock
-    lock = await redlock.lock(name, opts.ttl)
+    lock = await redlock.lock(name, ttl)
+
+    if (!opts.ttl) {
+      interval = setInterval(() => {
+        lock!.extend(ttl)
+      }, ttl / 2)
+    }
 
     // perform locked task
     // need to await to ensure completion before unlocking
@@ -134,5 +144,8 @@ export async function doWithLock<T>(
     if (lock) {
       await lock.unlock()
     }
+    if (interval) {
+      clearInterval(interval)
+    }
   }
 }
diff --git a/packages/types/src/sdk/locks.ts b/packages/types/src/sdk/locks.ts
index a35e7b379b..080574b735 100644
--- a/packages/types/src/sdk/locks.ts
+++ b/packages/types/src/sdk/locks.ts
@@ -36,9 +36,9 @@ export interface LockOptions {
    */
   name: LockName
   /**
-   * The ttl to auto-expire the lock if not unlocked manually
+   * The ttl to auto-expire the lock if not unlocked manually. If undefined, the lock will be autoextending while the process is running.
    */
-  ttl: number
+  ttl?: number
   /**
    * The individual resource to lock. This is useful for locking around very specific identifiers, e.g. a document that is prone to conflicts
    */