Enhancing SFTP timeout handling

lib/core/utils/sftp_timeout.dart

@@ -0,0 +1,41 @@
+import 'dart:async';
+
+import 'package:dartssh2/dartssh2.dart';
+import 'package:fl_lib/fl_lib.dart';
+
+Duration sftpOperationTimeout(int seconds) {
+  return Duration(seconds: seconds <= 0 ? 5 : seconds);
+}
+
+Future<T> withSftpOpTimeout<T>(
+  String operation,
+  Future<T> future,
+  Duration timeout,
+) async {
+  try {
+    return await future.timeout(timeout);
+  } on TimeoutException catch (e, s) {
+    final error = TimeoutException('SFTP $operation timed out', timeout);
+    Loggers.app.warning(error.message, e, s);
+    throw error;
+  }
+}
+
+Future<SftpClient> withSftpSessionOpenTimeout(
+  String operation,
+  Future<SftpClient> future,
+  Duration timeout,
+) async {
+  try {
+    return await future.timeout(timeout);
+  } on TimeoutException catch (e, s) {
+    unawaited(
+      future.then((client) => client.close()).catchError((Object closeError) {
+        Loggers.app.warning('Failed to close timed out SFTP session', closeError);
+      }),
+    );
+    final error = TimeoutException('SFTP $operation timed out', timeout);
+    Loggers.app.warning(error.message, e, s);
+    throw error;
+  }
+}

lib/data/model/sftp/req.dart

@@ -1,4 +1,10 @@
-part of 'worker.dart';
+import 'package:fl_lib/fl_lib.dart';
+import 'package:server_box/core/utils/jump_chain.dart';
+import 'package:server_box/core/utils/refresh_interval.dart';
+import 'package:server_box/core/utils/server.dart';
+import 'package:server_box/data/model/server/server_private_info.dart';
+import 'package:server_box/data/res/default.dart';
+import 'package:server_box/data/res/store.dart';
 
 class SftpReq {
   final Spi spi;
@@ -87,106 +93,4 @@ class SftpTransferProgress {
   });
 }
 
-class SftpReqStatus {
-  final int id;
-  final SftpReq req;
-  final void Function() notifyListeners;
-  late SftpWorker worker;
-  final Completer? completer;
-
-  String get fileName => req.localPath.split(Pfs.seperator).last;
-
-  // status of the download
-  double? progress;
-  double? speedBytesPerSecond;
-  int? transferredBytes;
-  DateTime? _speedSampleTime;
-  int _speedSampleBytes = 0;
-  SftpWorkerStatus? status;
-  int? size;
-  Exception? error;
-  Duration? spentTime;
-
-  SftpReqStatus({
-    required this.req,
-    required this.notifyListeners,
-    this.completer,
-  }) : id = DateTime.now().microsecondsSinceEpoch {
-    worker = SftpWorker(onNotify: onNotify, req: req)..init();
-  }
-
-  @override
-  bool operator ==(Object other) => other is SftpReqStatus && id == other.id;
-
-  @override
-  int get hashCode => id ^ super.hashCode;
-
-  void dispose() {
-    worker._dispose();
-    completer?.complete(true);
-  }
-
-  void onNotify(dynamic event) {
-    var shouldDispose = false;
-    switch (event) {
-      case final SftpWorkerStatus val:
-        status = val;
-        if (status == SftpWorkerStatus.finished) {
-          dispose();
-        }
-        break;
-      case final double val:
-        progress = val;
-        break;
-      case final SftpTransferProgress val:
-        progress = val.percent;
-        transferredBytes = val.transferredBytes;
-        _initSpeedSampleIfNeeded(val.transferredBytes);
-        break;
-      case final int val:
-        size = val;
-        break;
-      case final Duration d:
-        spentTime = d;
-        break;
-      default:
-        error = Exception('sftp worker event: $event');
-        Loggers.app.warning(error);
-        shouldDispose = true;
-    }
-    notifyListeners();
-    if (shouldDispose) dispose();
-  }
-
-  void _initSpeedSampleIfNeeded(int transferredBytes) {
-    if (_speedSampleTime != null) return;
-    _speedSampleTime = DateTime.now();
-    _speedSampleBytes = transferredBytes;
-  }
-
-  bool refreshSpeed([DateTime? now]) {
-    if (status != SftpWorkerStatus.loading) return false;
-
-    final sampleTime = now ?? DateTime.now();
-    final sampleBytes = transferredBytes ?? 0;
-    final lastSampleTime = _speedSampleTime;
-    if (lastSampleTime == null) {
-      _speedSampleTime = sampleTime;
-      _speedSampleBytes = sampleBytes;
-      return false;
-    }
-
-    final elapsedMs = sampleTime.difference(lastSampleTime).inMilliseconds;
-    if (elapsedMs <= 0) return false;
-
-    final speed = (sampleBytes - _speedSampleBytes) * 1000 / elapsedMs;
-    _speedSampleTime = sampleTime;
-    _speedSampleBytes = sampleBytes;
-
-    if (speedBytesPerSecond == speed) return false;
-    speedBytesPerSecond = speed;
-    return true;
-  }
-}
-
 enum SftpWorkerStatus { preparing, sshConnectted, loading, finished }

lib/data/model/sftp/status.dart

@@ -0,0 +1,122 @@
+import 'dart:async';
+
+import 'package:fl_lib/fl_lib.dart';
+import 'package:server_box/data/model/sftp/req.dart';
+import 'package:server_box/data/model/sftp/worker.dart';
+
+class SftpReqStatus {
+  final int id;
+  final SftpReq req;
+  final void Function() notifyListeners;
+  late SftpWorker worker;
+  final Completer? completer;
+
+  String get fileName => req.localPath.split(Pfs.seperator).last;
+
+  // status of the download
+  double? progress;
+  double? speedBytesPerSecond;
+  int? transferredBytes;
+  DateTime? _speedSampleTime;
+  int _speedSampleBytes = 0;
+  SftpWorkerStatus? status;
+  int? size;
+  Exception? error;
+  Duration? spentTime;
+  bool _disposed = false;
+
+  SftpReqStatus({
+    required this.req,
+    required this.notifyListeners,
+    this.completer,
+  }) : id = DateTime.now().microsecondsSinceEpoch {
+    worker = SftpWorker(onNotify: onNotify, req: req);
+    unawaited(_initWorker());
+  }
+
+  @override
+  bool operator ==(Object other) => other is SftpReqStatus && id == other.id;
+
+  @override
+  int get hashCode => id.hashCode;
+
+  void dispose() {
+    if (_disposed) return;
+    _disposed = true;
+    worker.dispose();
+    if (completer?.isCompleted == false) {
+      completer?.complete(true);
+    }
+  }
+
+  Future<void> _initWorker() async {
+    try {
+      await worker.init();
+    } catch (e, s) {
+      Loggers.app.warning('Failed to initialize SFTP worker', e, s);
+      onNotify(e);
+    }
+  }
+
+  void onNotify(dynamic event) {
+    var shouldDispose = false;
+    switch (event) {
+      case final SftpWorkerStatus val:
+        status = val;
+        if (status == SftpWorkerStatus.finished) {
+          dispose();
+        }
+        break;
+      case final double val:
+        progress = val;
+        break;
+      case final SftpTransferProgress val:
+        progress = val.percent;
+        transferredBytes = val.transferredBytes;
+        _initSpeedSampleIfNeeded(val.transferredBytes);
+        break;
+      case final int val:
+        size = val;
+        break;
+      case final Duration d:
+        spentTime = d;
+        break;
+      default:
+        error = Exception('sftp worker event: $event');
+        Loggers.app.warning(error);
+        shouldDispose = true;
+    }
+    notifyListeners();
+    if (shouldDispose) dispose();
+  }
+
+  void _initSpeedSampleIfNeeded(int transferredBytes) {
+    if (_speedSampleTime != null) return;
+    _speedSampleTime = DateTime.now();
+    _speedSampleBytes = transferredBytes;
+  }
+
+  bool refreshSpeed([DateTime? now]) {
+    if (status != SftpWorkerStatus.loading) return false;
+
+    final sampleTime = now ?? DateTime.now();
+    final sampleBytes = transferredBytes ?? 0;
+    final lastSampleTime = _speedSampleTime;
+    if (lastSampleTime == null) {
+      _speedSampleTime = sampleTime;
+      _speedSampleBytes = sampleBytes;
+      return false;
+    }
+
+    final elapsedMs = sampleTime.difference(lastSampleTime).inMilliseconds;
+    if (elapsedMs <= 0) return false;
+
+    final speed = (sampleBytes - _speedSampleBytes) * 1000 / elapsedMs;
+    _speedSampleTime = sampleTime;
+    _speedSampleBytes = sampleBytes;
+
+    if (speedBytesPerSecond == speed) return false;
+    speedBytesPerSecond = speed;
+    return true;
+  }
+}