refactor: simplify background worker (#21558)

* chore: log hash starting

* chore: android - bump the min worker delay

* remove local sync only task and always enqueue background workers

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>

mobile/ios/Runner/Background/BackgroundWorker.g.swift

@@ -73,9 +73,8 @@ class BackgroundWorkerPigeonCodec: FlutterStandardMessageCodec, @unchecked Senda
 
 /// Generated protocol from Pigeon that represents a handler of messages from Flutter.
 protocol BackgroundWorkerFgHostApi {
-  func enableSyncWorker() throws
-  func enableUploadWorker() throws
-  func disableUploadWorker() throws
+  func enable() throws
+  func disable() throws
 }
 
 /// Generated setup class from Pigeon to handle messages through the `binaryMessenger`.
@@ -84,44 +83,31 @@ class BackgroundWorkerFgHostApiSetup {
   /// Sets up an instance of `BackgroundWorkerFgHostApi` to handle messages through the `binaryMessenger`.
   static func setUp(binaryMessenger: FlutterBinaryMessenger, api: BackgroundWorkerFgHostApi?, messageChannelSuffix: String = "") {
     let channelSuffix = messageChannelSuffix.count > 0 ? ".\(messageChannelSuffix)" : ""
-    let enableSyncWorkerChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFgHostApi.enableSyncWorker\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+    let enableChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFgHostApi.enable\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
-      enableSyncWorkerChannel.setMessageHandler { _, reply in
+      enableChannel.setMessageHandler { _, reply in
         do {
-          try api.enableSyncWorker()
+          try api.enable()
           reply(wrapResult(nil))
         } catch {
           reply(wrapError(error))
         }
       }
     } else {
-      enableSyncWorkerChannel.setMessageHandler(nil)
+      enableChannel.setMessageHandler(nil)
     }
-    let enableUploadWorkerChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFgHostApi.enableUploadWorker\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+    let disableChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFgHostApi.disable\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
-      enableUploadWorkerChannel.setMessageHandler { _, reply in
+      disableChannel.setMessageHandler { _, reply in
         do {
-          try api.enableUploadWorker()
+          try api.disable()
           reply(wrapResult(nil))
         } catch {
           reply(wrapError(error))
         }
       }
     } else {
-      enableUploadWorkerChannel.setMessageHandler(nil)
-    }
-    let disableUploadWorkerChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFgHostApi.disableUploadWorker\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
-    if let api = api {
-      disableUploadWorkerChannel.setMessageHandler { _, reply in
-        do {
-          try api.disableUploadWorker()
-          reply(wrapResult(nil))
-        } catch {
-          reply(wrapError(error))
-        }
-      }
-    } else {
-      disableUploadWorkerChannel.setMessageHandler(nil)
+      disableChannel.setMessageHandler(nil)
     }
   }
 }
@@ -167,7 +153,6 @@ class BackgroundWorkerBgHostApiSetup {
 }
 /// Generated protocol from Pigeon that represents Flutter messages that can be called from Swift.
 protocol BackgroundWorkerFlutterApiProtocol {
-  func onLocalSync(maxSeconds maxSecondsArg: Int64?, completion: @escaping (Result<Void, PigeonError>) -> Void)
   func onIosUpload(isRefresh isRefreshArg: Bool, maxSeconds maxSecondsArg: Int64?, completion: @escaping (Result<Void, PigeonError>) -> Void)
   func onAndroidUpload(completion: @escaping (Result<Void, PigeonError>) -> Void)
   func cancel(completion: @escaping (Result<Void, PigeonError>) -> Void)
@@ -182,24 +167,6 @@ class BackgroundWorkerFlutterApi: BackgroundWorkerFlutterApiProtocol {
   var codec: BackgroundWorkerPigeonCodec {
     return BackgroundWorkerPigeonCodec.shared
   }
-  func onLocalSync(maxSeconds maxSecondsArg: Int64?, completion: @escaping (Result<Void, PigeonError>) -> Void) {
-    let channelName: String = "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFlutterApi.onLocalSync\(messageChannelSuffix)"
-    let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
-    channel.sendMessage([maxSecondsArg] as [Any?]) { response in
-      guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName: channelName)))
-        return
-      }
-      if listResponse.count > 1 {
-        let code: String = listResponse[0] as! String
-        let message: String? = nilOrValue(listResponse[1])
-        let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(PigeonError(code: code, message: message, details: details)))
-      } else {
-        completion(.success(()))
-      }
-    }
-  }
   func onIosUpload(isRefresh isRefreshArg: Bool, maxSeconds maxSecondsArg: Int64?, completion: @escaping (Result<Void, PigeonError>) -> Void) {
     let channelName: String = "dev.flutter.pigeon.immich_mobile.BackgroundWorkerFlutterApi.onIosUpload\(messageChannelSuffix)"
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)

mobile/ios/Runner/Background/BackgroundWorker.swift

@@ -1,7 +1,7 @@
 import BackgroundTasks
 import Flutter
 
-enum BackgroundTaskType { case localSync, refreshUpload, processingUpload }
+enum BackgroundTaskType { case refresh, processing }
 
 /*
  * DEBUG: Testing Background Tasks in Xcode
@@ -9,10 +9,6 @@ enum BackgroundTaskType { case localSync, refreshUpload, processingUpload }
  * To test background task functionality during development:
  * 1. Pause the application in Xcode debugger
  * 2. In the debugger console, enter one of the following commands:
-
- ## For local sync (short-running sync):
- 
- e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateLaunchForTaskWithIdentifier:@"app.alextran.immich.background.localSync"]
  
  ## For background refresh (short-running sync):
  
@@ -24,8 +20,6 @@ enum BackgroundTaskType { case localSync, refreshUpload, processingUpload }
 
  * To simulate task expiration (useful for testing expiration handlers):
  
- e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateExpirationForTaskWithIdentifier:@"app.alextran.immich.background.localSync"]
- 
  e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateExpirationForTaskWithIdentifier:@"app.alextran.immich.background.refreshUpload"]
  
  e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateExpirationForTaskWithIdentifier:@"app.alextran.immich.background.processingUpload"]
@@ -120,17 +114,9 @@ class BackgroundWorker: BackgroundWorkerBgHostApi {
    * This method acts as a bridge between the native iOS background task system and Flutter.
    */
   func onInitialized() throws {
-    switch self.taskType {
-    case .refreshUpload, .processingUpload:
-      flutterApi?.onIosUpload(isRefresh: self.taskType == .refreshUpload,
-                              maxSeconds: maxSeconds.map { Int64($0) }, completion: { result in
-        self.handleHostResult(result: result)
-      })
-    case .localSync:
-      flutterApi?.onLocalSync(maxSeconds: maxSeconds.map { Int64($0) }, completion: { result in
-        self.handleHostResult(result: result)
-      })
-    }
+    flutterApi?.onIosUpload(isRefresh: self.taskType == .refresh, maxSeconds: maxSeconds.map { Int64($0) }, completion: { result in
+      self.handleHostResult(result: result)
+    })
   }
 
   /**
@@ -177,6 +163,10 @@ class BackgroundWorker: BackgroundWorkerBgHostApi {
    * - Parameter success: Indicates whether the background task completed successfully
    */
   private func complete(success: Bool) {
+    if(isComplete) {
+      return
+    }
+    
     isComplete = true
     engine.destroyContext()
     completionHandler(success)

mobile/ios/Runner/Background/BackgroundWorkerApiImpl.swift

@@ -1,77 +1,40 @@
 import BackgroundTasks
 
 class BackgroundWorkerApiImpl: BackgroundWorkerFgHostApi {
-  func enableSyncWorker() throws {
-    BackgroundWorkerApiImpl.scheduleLocalSync()
-    print("BackgroundUploadImpl:enableSyncWorker Local Sync worker scheduled")
-  }
-  
-  func enableUploadWorker() throws {
-    BackgroundWorkerApiImpl.updateUploadEnabled(true)
-    
-    BackgroundWorkerApiImpl.scheduleRefreshUpload()
-    BackgroundWorkerApiImpl.scheduleProcessingUpload()
-    print("BackgroundUploadImpl:enableUploadWorker Scheduled background upload tasks")
-  }
-  
-  func disableUploadWorker() throws {
-    BackgroundWorkerApiImpl.updateUploadEnabled(false)
-    BackgroundWorkerApiImpl.cancelUploadTasks()
-    print("BackgroundUploadImpl:disableUploadWorker Disabled background upload tasks")
-  }
-  
-  public static let backgroundUploadEnabledKey = "immich:background:backup:enabled"
-  
-  private static let localSyncTaskID = "app.alextran.immich.background.localSync"
-  private static let refreshUploadTaskID = "app.alextran.immich.background.refreshUpload"
-  private static let processingUploadTaskID = "app.alextran.immich.background.processingUpload"
 
-  private static func updateUploadEnabled(_ isEnabled: Bool) {
-    return UserDefaults.standard.set(isEnabled, forKey: BackgroundWorkerApiImpl.backgroundUploadEnabledKey)
+  func enable() throws {
+    BackgroundWorkerApiImpl.scheduleRefreshWorker()
+    BackgroundWorkerApiImpl.scheduleProcessingWorker()
+    print("BackgroundUploadImpl:enbale Background worker scheduled")
   }
-
-  private static func cancelUploadTasks() {
-    BackgroundWorkerApiImpl.updateUploadEnabled(false)
-    BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: refreshUploadTaskID);
-    BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: processingUploadTaskID);
+  
+  func disable() throws {
+    BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: BackgroundWorkerApiImpl.refreshTaskID);
+    BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: BackgroundWorkerApiImpl.processingTaskID);
+    print("BackgroundUploadImpl:disableUploadWorker Disabled background workers")
   }
+  
+  private static let refreshTaskID = "app.alextran.immich.background.refreshUpload"
+  private static let processingTaskID = "app.alextran.immich.background.processingUpload"
 
   public static func registerBackgroundWorkers() {
       BGTaskScheduler.shared.register(
-          forTaskWithIdentifier: processingUploadTaskID, using: nil) { task in
+          forTaskWithIdentifier: processingTaskID, using: nil) { task in
           if task is BGProcessingTask {
             handleBackgroundProcessing(task: task as! BGProcessingTask)
           }
       }
 
       BGTaskScheduler.shared.register(
-          forTaskWithIdentifier: refreshUploadTaskID, using: nil) { task in
+          forTaskWithIdentifier: refreshTaskID, using: nil) { task in
           if task is BGAppRefreshTask {
-            handleBackgroundRefresh(task: task as! BGAppRefreshTask, taskType: .refreshUpload)
+            handleBackgroundRefresh(task: task as! BGAppRefreshTask)
           }
       }
-    
-    BGTaskScheduler.shared.register(
-        forTaskWithIdentifier: localSyncTaskID, using: nil) { task in
-        if task is BGAppRefreshTask {
-          handleBackgroundRefresh(task: task as! BGAppRefreshTask, taskType: .localSync)
-        }
-    }
   }
   
-  private static func scheduleLocalSync() {
-    let backgroundRefresh = BGAppRefreshTaskRequest(identifier: localSyncTaskID)
-      backgroundRefresh.earliestBeginDate = Date(timeIntervalSinceNow: 5 * 60) // 5 mins
-
-      do {
-          try BGTaskScheduler.shared.submit(backgroundRefresh)
-      } catch {
-          print("Could not schedule the local sync task \(error.localizedDescription)")
-      }
-  }
-  
-  private static func scheduleRefreshUpload() {
-    let backgroundRefresh = BGAppRefreshTaskRequest(identifier: refreshUploadTaskID)
+  private static func scheduleRefreshWorker() {
+    let backgroundRefresh = BGAppRefreshTaskRequest(identifier: refreshTaskID)
       backgroundRefresh.earliestBeginDate = Date(timeIntervalSinceNow: 5 * 60) // 5 mins
 
       do {
@@ -81,8 +44,8 @@ class BackgroundWorkerApiImpl: BackgroundWorkerFgHostApi {
       }
   }
 
-  private static func scheduleProcessingUpload() {
-    let backgroundProcessing = BGProcessingTaskRequest(identifier: processingUploadTaskID)
+  private static func scheduleProcessingWorker() {
+    let backgroundProcessing = BGProcessingTaskRequest(identifier: processingTaskID)
     
     backgroundProcessing.requiresNetworkConnectivity = true
     backgroundProcessing.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) // 15 mins
@@ -94,29 +57,16 @@ class BackgroundWorkerApiImpl: BackgroundWorkerFgHostApi {
     }
   }
   
-  private static func handleBackgroundRefresh(task: BGAppRefreshTask, taskType: BackgroundTaskType) {
-    let maxSeconds: Int?
-    
-    switch taskType {
-    case .localSync:
-      maxSeconds = 15
-      scheduleLocalSync()
-    case .refreshUpload:
-      maxSeconds = 20
-      scheduleRefreshUpload()
-    case .processingUpload:
-      print("Unexpected background refresh task encountered")
-      return;
-    }
-
+  private static func handleBackgroundRefresh(task: BGAppRefreshTask) {
+    scheduleRefreshWorker()
     // Restrict the refresh task to run only for a maximum of (maxSeconds) seconds
-    runBackgroundWorker(task: task, taskType: taskType, maxSeconds: maxSeconds)
+    runBackgroundWorker(task: task, taskType: .refresh, maxSeconds: 20)
   }
   
   private static func handleBackgroundProcessing(task: BGProcessingTask) {
-    scheduleProcessingUpload()
+    scheduleProcessingWorker()
     // There are no restrictions for processing tasks. Although, the OS could signal expiration at any time
-    runBackgroundWorker(task: task, taskType: .processingUpload, maxSeconds: nil)
+    runBackgroundWorker(task: task, taskType: .processing, maxSeconds: nil)
   }
   
   /**