[document-updater] wrap doc locks in project lock (#35416)

* [document-updater] wrap doc locks in project lock

* [document-updater] use BlockingProject as redis key prefix

* [redis-wrapper] update comment

GitOrigin-RevId: 0ce50e76386871e6c29481494febc8d6b37e7df5

services/document-updater/app/js/ProjectLockManager.js

@@ -0,0 +1,21 @@
+const Settings = require('@overleaf/settings')
+const redis = require('@overleaf/redis-wrapper')
+const rclient = redis.createClient(Settings.redis.lock)
+const keys = Settings.redis.lock.key_schema
+const RedisLocker = require('@overleaf/redis-wrapper/RedisLocker')
+
+// Project level lock used to serialise processing of a project's pending
+// updates (the `BlockingProject:{project_id}` key). Acquired before the per-doc
+// `Blocking:{doc_id}` lock - never the other way around - to avoid deadlocks.
+module.exports = new RedisLocker({
+  rclient,
+  getKey(projectId) {
+    return keys.projectBlockingKey({ project_id: projectId })
+  },
+  wrapTimeoutError(err, projectId) {
+    err.project_id = projectId
+    return err
+  },
+  metricsPrefix: 'project',
+  lockTTLSeconds: Settings.redisLockTTLSeconds,
+})