Revert "fix: prevent channel monitor loss when remote backup fails"

Author: pwltr

lib/android/src/main/java/com/reactnativeldk/classes/LdkPersister.kt

@@ -23,12 +23,29 @@ class LdkPersister {
 
             val isNew = !file.exists()
 
-            // Always write locally first
-            val serialized = data.write()
-            file.writeBytes(serialized)
+            if (BackupClient.skipRemoteBackup) {
+                file.writeBytes(data.write())
+                if (isNew) {
+                    LdkEventEmitter.send(EventTypes.new_channel, body)
+                }
+                return ChannelMonitorUpdateStatus.LDKChannelMonitorUpdateStatus_Completed
+            }
+
+            BackupClient.addToPersistQueue(BackupClient.Label.CHANNEL_MONITOR(channelId=channelId), data.write()) { error ->
+                if (error != null) {
+                    LdkEventEmitter.send(EventTypes.native_log, "Failed to persist channel (${channelId}) to remote backup: $error")
+                    return@addToPersistQueue
+                }
+
+                try {
+                    file.writeBytes(data.write())
+                } catch (e: Exception) {
+                    //If this fails we can't do much but LDK will retry on startup
+                    LdkEventEmitter.send(EventTypes.native_log, "Failed to locally persist channel (${channelId}) to disk")
+                    return@addToPersistQueue
+                }
 
-            // Update chain monitor on main thread to avoid threading issues
-            LdkModule.reactContext?.runOnUiThread {
+                //Update chain monitor with successful persist
                 val res = LdkModule.chainMonitor?.channel_monitor_updated(channelFundingOutpoint, data._latest_update_id)
                 if (res == null || !res.is_ok) {
                     LdkEventEmitter.send(EventTypes.native_log, "Failed to update chain monitor with persisted channel (${channelId})")
@@ -40,16 +57,7 @@ class LdkPersister {
                 }
             }
 
-            // Kick off remote backup asynchronously; never block/skip local persist
-            if (!BackupClient.skipRemoteBackup) {
-                BackupClient.addToPersistQueue(BackupClient.Label.CHANNEL_MONITOR(channelId=channelId), serialized) { error ->
-                    if (error != null) {
-                        LdkEventEmitter.send(EventTypes.native_log, "Failed to persist channel (${channelId}) to remote backup: $error")
-                    }
-                }
-            }
-
-            return ChannelMonitorUpdateStatus.LDKChannelMonitorUpdateStatus_Completed
+            return ChannelMonitorUpdateStatus.LDKChannelMonitorUpdateStatus_InProgress
         } catch (e: Exception) {
             return ChannelMonitorUpdateStatus.LDKChannelMonitorUpdateStatus_UnrecoverableError
         }

lib/ios/Classes/LdkPersist.swift

@@ -27,17 +27,33 @@ class LdkPersister: Persist {
             }
 
             let isNew = !FileManager().fileExists(atPath: channelStoragePath.path)
-
-            // Always write locally first
-            let serialized = Data(data.write())
-            try serialized.write(to: channelStoragePath)
-
-            // Notify chain monitor on main thread to avoid threading issues
-            DispatchQueue.main.async {
-                let res = Ldk.chainMonitor?.channelMonitorUpdated(
-                    fundingTxo: channelFundingOutpoint,
-                    completedUpdateId: data.getLatestUpdateId()
-                )
+            
+            // If we're not remotely backing up no need to update status later
+            if BackupClient.skipRemoteBackup {
+                try Data(data.write()).write(to: channelStoragePath)
+                if isNew {
+                    LdkEventEmitter.shared.send(withEvent: .new_channel, body: body)
+                }
+                return ChannelMonitorUpdateStatus.Completed
+            }
+                         
+            BackupClient.addToPersistQueue(.channelMonitor(id: channelIdHex), data.write()) { error in
+                if let error {
+                    LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed persist channel on remote server (\(channelIdHex)). \(error.localizedDescription)")
+                    return
+                }
+                
+                // Callback for when the persist queue queue entry is processed
+                do {
+                    try Data(data.write()).write(to: channelStoragePath)
+                } catch {
+                    // If this fails we can't do much but LDK will retry on startup
+                    LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed to locally persist channel (\(channelIdHex)). \(error.localizedDescription)")
+                    return
+                }
+                                
+                // Update chainmonitor with successful persist
+                let res = Ldk.chainMonitor?.channelMonitorUpdated(fundingTxo: channelFundingOutpoint, completedUpdateId: data.getLatestUpdateId())
                 if let error = res?.getError() {
                     LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed to update chain monitor for channel (\(channelIdHex)) Error \(error.getValueType()).")
                 } else {
@@ -47,19 +63,10 @@ class LdkPersister: Persist {
                     }
                 }
             }
-
-            // Kick off remote backup asynchronously; log but never block/skip local persist
-            if !BackupClient.skipRemoteBackup {
-                BackupClient.addToPersistQueue(.channelMonitor(id: channelIdHex), [UInt8](serialized)) { error in
-                    if let error {
-                        LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed persist channel on remote server (\(channelIdHex)). \(error.localizedDescription)")
-                    }
-                }
-            }
-
-            return ChannelMonitorUpdateStatus.Completed
+            
+            return ChannelMonitorUpdateStatus.InProgress
         } catch {
-            LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed to locally persist channel (\(channelIdHex)). \(error.localizedDescription)")
+            LdkEventEmitter.shared.send(withEvent: .native_log, body: "Error. Failed to persist channel (\(channelIdHex)) to disk Error \(error.localizedDescription).")
             return ChannelMonitorUpdateStatus.UnrecoverableError
         }
     }

lib/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@synonymdev/react-native-ldk",
   "title": "React Native LDK",
-  "version": "0.0.161",
+  "version": "0.0.160",
   "description": "React Native wrapper for LDK",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",