perf(mobile): remove load of thumbnails in the image provider (immich-app#17773)

Remove loading of thumbnail in the image provider

* Removed the load of the thumbnail from the local and remote image provider as they shall provide the image, not the thumbnail. The thumbnail gets provided by the thumbnail provider.
* The thumbnail provider is used as the loadingBuilder and the image provider as the imageProvider. Therefore loading the thumbnail in the image provider loads it a second time which is completely redundant, uses precious time and yields no results.

Co-authored-by: Alex <[email protected]>

Author: 2 people

mobile/lib/providers/image/immich_local_image_provider.dart

@@ -53,50 +53,35 @@ class ImmichLocalImageProvider extends ImageProvider<ImmichLocalImageProvider> {
     ImageDecoderCallback decode,
     StreamController<ImageChunkEvent> chunkEvents,
   ) async* {
-    ui.ImmutableBuffer? buffer;
     try {
       final local = asset.local;
       if (local == null) {
         throw StateError('Asset ${asset.fileName} has no local data');
       }
 
-      var thumbBytes = await local
-          .thumbnailDataWithSize(const ThumbnailSize.square(256), quality: 80);
-      if (thumbBytes == null) {
-        throw StateError("Loading thumbnail for ${asset.fileName} failed");
-      }
-      buffer = await ui.ImmutableBuffer.fromUint8List(thumbBytes);
-      thumbBytes = null;
-      yield await decode(buffer);
-      buffer = null;
-
       switch (asset.type) {
         case AssetType.image:
           final File? file = await local.originFile;
           if (file == null) {
             throw StateError("Opening file for asset ${asset.fileName} failed");
           }
-          buffer = await ui.ImmutableBuffer.fromFilePath(file.path);
+          final buffer = await ui.ImmutableBuffer.fromFilePath(file.path);
           yield await decode(buffer);
-          buffer = null;
           break;
         case AssetType.video:
           final size = ThumbnailSize(width.ceil(), height.ceil());
-          thumbBytes = await local.thumbnailDataWithSize(size);
+          final thumbBytes = await local.thumbnailDataWithSize(size);
           if (thumbBytes == null) {
             throw StateError("Failed to load preview for ${asset.fileName}");
           }
-          buffer = await ui.ImmutableBuffer.fromUint8List(thumbBytes);
-          thumbBytes = null;
+          final buffer = await ui.ImmutableBuffer.fromUint8List(thumbBytes);
           yield await decode(buffer);
-          buffer = null;
           break;
         default:
           throw StateError('Unsupported asset type ${asset.type}');
       }
     } catch (error, stack) {
       log.severe('Error loading local image ${asset.fileName}', error, stack);
-      buffer?.dispose();
     } finally {
       chunkEvents.close();
     }

mobile/lib/providers/image/immich_remote_image_provider.dart

@@ -57,34 +57,13 @@ class ImmichRemoteImageProvider
         AppSettingsEnum.loadOriginal.defaultValue,
       );
 
-  /// Whether to load the preview thumbnail first or not
-  bool get _loadPreview => Store.get(
-        AppSettingsEnum.loadPreview.storeKey,
-        AppSettingsEnum.loadPreview.defaultValue,
-      );
-
   // Streams in each stage of the image as we ask for it
   Stream<ui.Codec> _codec(
     ImmichRemoteImageProvider key,
     CacheManager cache,
     ImageDecoderCallback decode,
     StreamController<ImageChunkEvent> chunkEvents,
   ) async* {
-    // Load a preview to the chunk events
-    if (_loadPreview) {
-      final preview = getThumbnailUrlForRemoteId(
-        key.assetId,
-        type: api.AssetMediaSize.thumbnail,
-      );
-
-      yield await ImageLoader.loadImageFromCache(
-        preview,
-        cache: cache,
-        decode: decode,
-        chunkEvents: chunkEvents,
-      );
-    }
-
     // Load the higher resolution version of the image
     final url = getThumbnailUrlForRemoteId(
       key.assetId,