Refactor: move the higher level platform lock code to its own package

app/lib/entity/sqlite/database.dart

@@ -17,6 +17,7 @@ import 'package:nc_photos/object_extension.dart';
 import 'package:nc_photos/platform/k.dart' as platform_k;
 import 'package:np_codegen/np_codegen.dart';
 import 'package:np_collection/np_collection.dart';
+import 'package:np_platform_lock/np_platform_lock.dart';
 
 part 'database.g.dart';
 part 'database/nc_album_extension.dart';

app/lib/entity/sqlite/database_extension.dart

@@ -122,7 +122,7 @@ extension SqliteDbExtension on SqliteDb {
   ///
   /// Do NOT call this when using [isolate], call [useInIsolate] instead
   Future<T> use<T>(Future<T> Function(SqliteDb db) block) async {
-    return await platform.Lock.synchronized(k.appDbLockId, () async {
+    return await PlatformLock.synchronized(k.appDbLockId, () async {
       return await transaction(() async {
         return await block(this);
       });
@@ -135,7 +135,7 @@ extension SqliteDbExtension on SqliteDb {
   ///
   /// This function does not start a transaction, see [use] instead
   Future<T> useNoTransaction<T>(Future<T> Function(SqliteDb db) block) async {
-    return await platform.Lock.synchronized(k.appDbLockId, () async {
+    return await PlatformLock.synchronized(k.appDbLockId, () async {
       return await block(this);
     });
   }
@@ -145,7 +145,7 @@ extension SqliteDbExtension on SqliteDb {
   Future<U> isolate<T, U>(T args, ComputeWithDbCallback<T, U> callback) async {
     // we need to acquire the lock here as method channel is not supported in
     // background isolates
-    return await platform.Lock.synchronized(k.appDbLockId, () async {
+    return await PlatformLock.synchronized(k.appDbLockId, () async {
       // in unit tests we use an in-memory db, which mean there's no way to
       // access it in other isolates
       if (platform_k.isUnitTest) {

app/lib/mobile/lock.dart

@@ -1,32 +0,0 @@
-import 'package:nc_photos/platform/k.dart' as platform_k;
-import 'package:nc_photos/web/lock.dart' as web;
-import 'package:np_platform_lock/np_platform_lock.dart' as plugin;
-
-class Lock {
-  static Future<T> synchronized<T>(int lockId, Future<T> Function() fn) async {
-    if (platform_k.isAndroid) {
-      return _synchronizedAndroid(lockId, fn);
-    } else if (platform_k.isDesktop) {
-      return _synchronizedDesktop(lockId, fn);
-    } else {
-      throw UnimplementedError();
-    }
-  }
-
-  static Future<T> _synchronizedAndroid<T>(
-      int lockId, Future<T> Function() fn) async {
-    while (!await plugin.Lock.tryLock(lockId)) {
-      await Future.delayed(const Duration(milliseconds: 50));
-    }
-    try {
-      return await fn();
-    } finally {
-      await plugin.Lock.unlock(lockId);
-    }
-  }
-
-  // this is mainly used to run test cases
-  static Future<T> _synchronizedDesktop<T>(
-          int lockId, Future<T> Function() fn) =>
-      web.Lock.synchronized(lockId, fn);
-}

app/lib/mobile/platform.dart

@@ -2,6 +2,5 @@ export 'db_util.dart';
 export 'download.dart';
 export 'file_saver.dart';
 export 'google_gps_map.dart';
-export 'lock.dart';
 export 'notification.dart';
 export 'universal_storage.dart';

app/lib/web/lock.dart

@@ -1,9 +0,0 @@
-import 'package:synchronized/synchronized.dart' as dart;
-
-// Isolates are not supported on web
-class Lock {
-  static Future<T> synchronized<T>(int lockId, Future<T> Function() fn) =>
-      (_locks[lockId] ??= dart.Lock(reentrant: true)).synchronized(fn);
-
-  static final _locks = <int, dart.Lock>{};
-}

app/lib/web/platform.dart

@@ -2,6 +2,5 @@ export 'db_util.dart';
 export 'download.dart';
 export 'file_saver.dart';
 export 'google_gps_map.dart';
-export 'lock.dart';
 export 'notification.dart';
 export 'universal_storage.dart';

app/pubspec.lock

@@ -1004,6 +1004,13 @@ packages:
       relative: true
     source: path
     version: "0.0.1"
+  np_platform_util:
+    dependency: transitive
+    description:
+      path: "../np_platform_util"
+      relative: true
+    source: path
+    version: "0.0.1"
   np_string:
     dependency: "direct main"
     description:
@@ -1504,7 +1511,7 @@ packages:
     source: hosted
     version: "1.2.0"
   synchronized:
-    dependency: "direct main"
+    dependency: transitive
     description:
       name: synchronized
       sha256: "5fcbd27688af6082f5abd611af56ee575342c30e87541d0245f7ff99faa02c60"

app/pubspec.yaml

@@ -127,7 +127,6 @@ dependencies:
   smooth_corner: ^1.1.0
   sqlite3: any
   sqlite3_flutter_libs: ^0.5.15
-  synchronized: ^3.1.0
   to_string:
     git:
       url: https://gitlab.com/nkming2/dart-to-string

np_platform_lock/lib/src/lock.dart

@@ -1,17 +1,9 @@
-import 'package:flutter/services.dart';
+import 'package:np_platform_lock/src/raw_lock.dart';
-import 'package:np_platform_lock/src/k.dart' as k;
 
-class Lock {
+class PlatformLock {
-  static Future<bool> tryLock(int lockId) async {
+  static Future<T> synchronized<T>(int lockId, Future<T> Function() fn) =>
-    return (await _channel.invokeMethod<bool>("tryLock", <String, dynamic>{
+      RawLockInterface().synchronized(lockId, fn);
-      "lockId": lockId,
-    }))!;
-  }
 
-  static Future<void> unlock(int lockId) =>
+  static Future<void> forceUnlock(int lockId) =>
-      _channel.invokeMethod("unlock", <String, dynamic>{
+      RawLockInterface().forceUnlock(lockId);
-        "lockId": lockId,
-      });
-
-  static const _channel = MethodChannel("${k.libId}/lock");
 }

np_platform_lock/lib/src/native/lock.dart

@@ -0,0 +1,17 @@
+import 'package:flutter/services.dart';
+import 'package:np_platform_lock/src/k.dart' as k;
+
+class Lock {
+  static Future<bool> tryLock(int lockId) async {
+    return (await _channel.invokeMethod<bool>("tryLock", <String, dynamic>{
+      "lockId": lockId,
+    }))!;
+  }
+
+  static Future<void> unlock(int lockId) =>
+      _channel.invokeMethod("unlock", <String, dynamic>{
+        "lockId": lockId,
+      });
+
+  static const _channel = MethodChannel("${k.libId}/lock");
+}

np_platform_lock/lib/src/native/raw_lock.dart

@@ -0,0 +1,41 @@
+import 'package:np_platform_lock/src/native/lock.dart';
+import 'package:np_platform_lock/src/raw_lock.dart';
+import 'package:np_platform_lock/src/web/raw_lock.dart' as web;
+import 'package:np_platform_util/np_platform_util.dart';
+
+class RawLock implements RawLockInterface {
+  RawLock._();
+
+  factory RawLock() => _inst;
+
+  @override
+  Future<T> synchronized<T>(int lockId, Future<T> Function() fn) async {
+    if (isUnitTest) {
+      return _synchronizedTest(lockId, fn);
+    } else {
+      return _synchronized(lockId, fn);
+    }
+  }
+
+  @override
+  Future<void> forceUnlock(int lockId) {
+    return Lock.unlock(lockId);
+  }
+
+  Future<T> _synchronized<T>(int lockId, Future<T> Function() fn) async {
+    while (!await Lock.tryLock(lockId)) {
+      await Future.delayed(const Duration(milliseconds: 50));
+    }
+    try {
+      return await fn();
+    } finally {
+      await Lock.unlock(lockId);
+    }
+  }
+
+  // this is mainly used to run test cases
+  Future<T> _synchronizedTest<T>(int lockId, Future<T> Function() fn) =>
+      web.RawLock().synchronized(lockId, fn);
+
+  static final _inst = RawLock._();
+}

np_platform_lock/lib/src/raw_lock.dart

@@ -0,0 +1,17 @@
+import 'package:np_platform_lock/src/native/raw_lock.dart'
+    if (dart.library.html) 'package:np_platform_lock/src/web/raw_lock.dart';
+
+abstract class RawLockInterface {
+  factory RawLockInterface() => RawLock();
+
+  /// Safely run [fn] with an async lock
+  Future<T> synchronized<T>(int lockId, Future<T> Function() fn);
+
+  /// Forcefully unlock an async lock
+  ///
+  /// This function is mostly for development use only, for example, to fix a
+  /// dangling lock after hot reload. This should not be used in production code
+  ///
+  /// This method may not be supported by all implementations
+  Future<void> forceUnlock(int lockId);
+}

np_platform_lock/lib/src/web/raw_lock.dart

@@ -0,0 +1,19 @@
+import 'package:np_platform_lock/src/raw_lock.dart';
+import 'package:synchronized/synchronized.dart';
+
+class RawLock implements RawLockInterface {
+  RawLock._();
+
+  factory RawLock() => _inst;
+
+  @override
+  Future<T> synchronized<T>(int lockId, Future<T> Function() fn) =>
+      (_locks[lockId] ??= Lock(reentrant: true)).synchronized(fn);
+
+  @override
+  Future<void> forceUnlock(int lockId) => Future.value();
+
+  static final _inst = RawLock._();
+
+  final _locks = <int, Lock>{};
+}

np_platform_lock/pubspec.yaml

@@ -11,6 +11,9 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
+  np_platform_util:
+    path: ../np_platform_util
+  synchronized: ^3.1.0
 
 dev_dependencies:
   np_lints:

np_platform_util/.gitignore

@@ -0,0 +1,30 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+# Libraries should not include pubspec.lock, per https://dart.dev/guides/libraries/private-files#pubspeclock.
+/pubspec.lock
+**/doc/api/
+.dart_tool/
+.packages
+build/

np_platform_util/.metadata

@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 4d9e56e694b656610ab87fcf2efbcd226e0ed8cf
+  channel: stable
+
+project_type: package

np_platform_util/analysis_options.yaml

@@ -0,0 +1 @@
+include: package:np_lints/np.yaml

np_platform_util/lib/np_platform_util.dart

@@ -0,0 +1,3 @@
+library np_platform_util;
+
+export 'src/env.dart';

np_platform_util/lib/src/env.dart

@@ -0,0 +1,60 @@
+import 'dart:io';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+enum NpPlatform {
+  android,
+  fuchsia,
+  iOs,
+  linux,
+  macOs,
+  web,
+  windows,
+  ;
+
+  bool get isMobile => this == android || this == iOs;
+  bool get isDesktop =>
+      this == fuchsia || this == linux || this == macOs || this == windows;
+}
+
+/// Get the current running platform
+///
+/// This function does not take the current context into account
+NpPlatform getRawPlatform() {
+  if (kIsWeb) {
+    return NpPlatform.web;
+  } else {
+    return defaultTargetPlatform.toPlatform();
+  }
+}
+
+/// Get the current platform from [context]
+NpPlatform getThemePlatform(BuildContext context) {
+  if (kIsWeb) {
+    return NpPlatform.web;
+  } else {
+    return Theme.of(context).platform.toPlatform();
+  }
+}
+
+final isUnitTest = !kIsWeb && Platform.environment.containsKey("FLUTTER_TEST");
+
+extension on TargetPlatform {
+  NpPlatform toPlatform() {
+    switch (this) {
+      case TargetPlatform.android:
+        return NpPlatform.android;
+      case TargetPlatform.iOS:
+        return NpPlatform.iOs;
+      case TargetPlatform.linux:
+        return NpPlatform.linux;
+      case TargetPlatform.macOS:
+        return NpPlatform.macOs;
+      case TargetPlatform.windows:
+        return NpPlatform.windows;
+      case TargetPlatform.fuchsia:
+        return NpPlatform.fuchsia;
+    }
+  }
+}

np_platform_util/pubspec.yaml

@@ -0,0 +1,17 @@
+name: np_platform_util
+description: A new Flutter plugin project.
+version: 0.0.1
+homepage:
+publish_to: none
+
+environment:
+  sdk: '>=2.19.6 <3.0.0'
+  flutter: ">=3.3.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+dev_dependencies:
+  np_lints:
+    path: ../np_lints