Add thumb queue

mobile/lib/image/provider/local_thumbnail_img.dart

@@ -7,6 +7,19 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
 import 'package:photo_manager/photo_manager.dart';
 import "package:photos/image/in_memory_image_cache.dart";
+import "package:photos/utils/standalone/task_queue.dart";
+
+final thumbnailQueue = TaskQueue<String>(
+  maxConcurrentTasks: 15,
+  taskTimeout: const Duration(minutes: 1),
+  maxQueueSize: 1000, // Limit the queue to 50 pending tasks
+);
+
+final mediumThumbnailQueue = TaskQueue<String>(
+  maxConcurrentTasks: 5,
+  taskTimeout: const Duration(minutes: 1),
+  maxQueueSize: 1000, // Limit the queue to 50 pending tasks
+);
 
 class LocalThumbnailProvider extends ImageProvider<LocalThumbnailProviderKey> {
   final LocalThumbnailProviderKey key;
@@ -36,6 +49,11 @@ class LocalThumbnailProvider extends ImageProvider<LocalThumbnailProviderKey> {
     );
   }
 
+  static Future<void> cancelRequest(LocalThumbnailProviderKey key) async {
+    thumbnailQueue.removeTask('${key.asset.id}-small');
+    mediumThumbnailQueue.removeTask('${key.asset.id}-medium');
+  }
+
   Stream<ui.Codec> _codec(
     LocalThumbnailProviderKey key,
     ImageDecoderCallback decode,
@@ -56,10 +74,16 @@ class LocalThumbnailProvider extends ImageProvider<LocalThumbnailProviderKey> {
     Uint8List? thumbBytes =
         enteImageCache.getThumbByID(asset.id, key.smallThumbWidth);
     if (thumbBytes == null) {
-      thumbBytes = await asset.thumbnailDataWithSize(
-        ThumbnailSize(key.smallThumbWidth, key.smallThumbHeight),
-        quality: 75,
-      );
+      final Completer<Uint8List?> future = Completer();
+      await thumbnailQueue.addTask('${asset.id}-small', () async {
+        final thumbBytes = await asset.thumbnailDataWithSize(
+          ThumbnailSize(key.smallThumbWidth, key.smallThumbHeight),
+          quality: 75,
+        );
+        enteImageCache.putThumbByID(asset.id, thumbBytes, key.smallThumbWidth);
+        future.complete(thumbBytes);
+      });
+      thumbBytes = await future.future;
       enteImageCache.putThumbByID(asset.id, thumbBytes, key.smallThumbWidth);
     }
     if (thumbBytes != null) {
@@ -71,10 +95,16 @@ class LocalThumbnailProvider extends ImageProvider<LocalThumbnailProviderKey> {
     }
 
     if (normalThumbBytes == null) {
-      normalThumbBytes = await asset.thumbnailDataWithSize(
-        ThumbnailSize(key.width, key.height),
-        quality: 50,
-      );
+      final Completer<Uint8List?> future = Completer();
+      await mediumThumbnailQueue.addTask('${asset.id}-medium', () async {
+        normalThumbBytes = await asset.thumbnailDataWithSize(
+          ThumbnailSize(key.width, key.height),
+          quality: 50,
+        );
+        enteImageCache.putThumbByID(asset.id, normalThumbBytes, key.height);
+        future.complete(normalThumbBytes);
+      });
+      normalThumbBytes = await future.future;
       enteImageCache.putThumbByID(asset.id, normalThumbBytes, key.height);
     }
     if (normalThumbBytes == null) {
@@ -82,7 +112,7 @@ class LocalThumbnailProvider extends ImageProvider<LocalThumbnailProviderKey> {
         "$runtimeType biThumb ${asset.title} failed",
       );
     }
-    final buffer = await ui.ImmutableBuffer.fromUint8List(normalThumbBytes);
+    final buffer = await ui.ImmutableBuffer.fromUint8List(normalThumbBytes!);
     final codec = await decode(buffer);
     yield codec;
     chunkEvents.close().ignore();

mobile/lib/image/thumnail/local_thumb_service.dart

@@ -1,6 +1,3 @@
-import "dart:typed_data";
-
-import "package:photos/image/provider/local_thumbnail_img.dart";
 import "package:photos/utils/standalone/task_queue.dart";
 
 class LocalThumbnailService {
@@ -9,8 +6,4 @@ class LocalThumbnailService {
     taskTimeout: const Duration(minutes: 1),
     maxQueueSize: 100, // Limit the queue to 50 pending tasks
   );
-
-  Future<Uint8List?> _cached(LocalThumbnailProviderKey key) async {
-    return null;
-  }
 }

mobile/lib/ui/viewer/file/thumbnail_widget.dart

@@ -71,6 +71,7 @@ class _ThumbnailWidgetState extends State<ThumbnailWidget> {
   ImageProvider? _imageProvider;
   int? optimizedImageHeight;
   int? optimizedImageWidth;
+  LocalThumbnailProviderKey? localImageProviderKey;
 
   @override
   void initState() {
@@ -81,7 +82,13 @@ class _ThumbnailWidgetState extends State<ThumbnailWidget> {
   @override
   void dispose() {
     super.dispose();
+
     Future.delayed(const Duration(milliseconds: 10), () {
+      if (!mounted) {
+        if (localImageProviderKey != null) {
+          LocalThumbnailProvider.cancelRequest(localImageProviderKey!);
+        }
+      }
       // Cancel request only if the widget has been unmounted
       if (!mounted && widget.file.isRemoteFile && !_hasLoadedThumbnail) {
         removePendingGetThumbnailRequestIfAny(widget.file);
@@ -125,13 +132,12 @@ class _ThumbnailWidgetState extends State<ThumbnailWidget> {
         ).image;
         _hasLoadedThumbnail = true;
       } else {
-        _imageProvider = LocalThumbnailProvider(
-          LocalThumbnailProviderKey(
-            asset: widget.file.asset!,
-            height: widget.thumbnailSize,
-            width: widget.thumbnailSize,
-          ),
+        localImageProviderKey = LocalThumbnailProviderKey(
+          asset: widget.file.asset!,
+          height: widget.thumbnailSize,
+          width: widget.thumbnailSize,
         );
+        _imageProvider = LocalThumbnailProvider(localImageProviderKey!);
       }
     }
     Widget? image;

mobile/lib/utils/standalone/task_queue.dart

@@ -8,13 +8,16 @@ class _QueueItem<T> {
   final Future<void> Function() task;
   final Completer<void> completer;
   DateTime lastUpdated;
+  int counter;
 
   _QueueItem(this.id, this.task)
       : lastUpdated = DateTime.now(),
+        counter = 1,
         completer = Completer<void>();
 
   void updateTimestamp() {
     lastUpdated = DateTime.now();
+    counter++;
   }
 
   bool isTimedOut(Duration timeout) {
@@ -148,8 +151,11 @@ class TaskQueue<T> {
 
     if (_taskMap.containsKey(id)) {
       final item = _taskMap[id]!;
+      item.counter--;
+      if (item.counter > 0) {
+        return false;
+      }
       _priorityQueue.remove(item);
-
       // Complete the future with a cancellation error
       if (!item.completer.isCompleted) {
         item.completer.completeError(Exception('Task $id was cancelled'));