request cancellation

mobile/lib/infrastructure/repositories/asset_media.repository.dart

@@ -1,45 +1,211 @@
+import 'dart:async';
 import 'dart:ffi';
-import 'dart:typed_data';
-import 'dart:ui';
+import 'dart:io';
 import 'dart:ui' as ui;
 
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/foundation.dart';
+import 'package:immich_mobile/providers/image/cache/remote_image_cache_manager.dart';
 import 'package:immich_mobile/providers/infrastructure/platform.provider.dart';
-import 'package:photo_manager/photo_manager.dart';
 import 'package:ffi/ffi.dart';
+import 'package:immich_mobile/services/api.service.dart';
+import 'package:logging/logging.dart';
 
-class AssetMediaRepository {
-  const AssetMediaRepository();
+abstract class ImageRequest {
+  static int _nextRequestId = 0;
 
-  Future<ui.Codec> getLocalThumbnail(String localId, ui.Size size) async {
-    final info = await thumbnailApi.getThumbnailBuffer(localId, width: size.width.toInt(), height: size.height.toInt());
+  final int requestId = _nextRequestId++;
+  bool _isCancelled = false;
 
-    final pointer = Pointer<Uint8>.fromAddress(info['pointer']!);
-    final actualWidth = info['width']!;
-    final actualHeight = info['height']!;
-    final actualSize = actualWidth * actualHeight * 4;
+  get isCancelled => _isCancelled;
 
+  ImageRequest();
+
+  Future<ImageInfo?> load(ImageDecoderCallback decode, {double scale = 1.0});
+
+  void cancel() {
+    if (isCancelled) {
+      return;
+    }
+    _isCancelled = true;
+    return _onCancelled();
+  }
+
+  void _onCancelled();
+}
+
+class LocalImageRequest extends ImageRequest {
+  final String localId;
+  final int width;
+  final int height;
+
+  LocalImageRequest({required this.localId, required ui.Size size})
+    : width = size.width.toInt(),
+      height = size.height.toInt();
+
+  @override
+  Future<ImageInfo?> load(ImageDecoderCallback decode, {double scale = 1.0}) async {
+    if (_isCancelled) {
+      return null;
+    }
+
+    final Map<String, int> info = await thumbnailApi.requestImage(
+      localId,
+      requestId: requestId,
+      width: width,
+      height: height,
+    );
+
+    final address = info['pointer'];
+    if (address == null) {
+      return null;
+    }
+
+    final pointer = Pointer<Uint8>.fromAddress(address);
     try {
+      if (_isCancelled) {
+        return null;
+      }
+
+      final actualWidth = info['width']!;
+      final actualHeight = info['height']!;
+      final actualSize = actualWidth * actualHeight * 4;
+
       final buffer = await ImmutableBuffer.fromUint8List(pointer.asTypedList(actualSize));
+      if (_isCancelled) {
+        return null;
+      }
+
       final descriptor = ui.ImageDescriptor.raw(
         buffer,
         width: actualWidth,
         height: actualHeight,
         pixelFormat: ui.PixelFormat.rgba8888,
       );
-      return await descriptor.instantiateCodec();
+      final codec = await descriptor.instantiateCodec();
+      if (_isCancelled) {
+        return null;
+      }
+
+      final frame = await codec.getNextFrame();
+      return ImageInfo(image: frame.image, scale: scale);
     } finally {
       malloc.free(pointer);
     }
   }
 
-  Future<Uint8List?> getThumbnail(String id, {int quality = 80, ui.Size size = const ui.Size.square(256)}) =>
-      AssetEntity(
-        id: id,
-        // The below fields are not used in thumbnailDataWithSize but are required
-        // to create an AssetEntity instance. It is faster to create a dummy AssetEntity
-        // instance than to fetch the asset from the device first.
-        typeInt: AssetType.image.index,
-        width: size.width.toInt(),
-        height: size.height.toInt(),
-      ).thumbnailDataWithSize(ThumbnailSize(size.width.toInt(), size.height.toInt()), quality: quality);
+  @override
+  Future<void> _onCancelled() {
+    return thumbnailApi.cancelImageRequest(requestId);
+  }
+}
+
+class RemoteImageRequest extends ImageRequest {
+  static final log = Logger('RemoteImageRequest');
+  static final cacheManager = RemoteImageCacheManager();
+  static final client = HttpClient();
+  String uri;
+  Map<String, String> headers;
+  HttpClientRequest? _request;
+
+  RemoteImageRequest({required this.uri, required this.headers});
+
+  @override
+  Future<ImageInfo?> load(ImageDecoderCallback decode, {double scale = 1.0}) async {
+    if (_isCancelled) {
+      return null;
+    }
+
+    try {
+      // The DB calls made by the cache manager are a *massive* bottleneck (6+ seconds) with high concurrency.
+      // Since it isn't possible to cancel these operations, we only prefer the cache when they can be avoided.
+      // The DB hit is left as a fallback for offline use.
+      final cachedFileBuffer = await _loadCachedFile(uri, inMemoryOnly: true);
+      if (cachedFileBuffer != null) {
+        return _decodeBuffer(cachedFileBuffer, decode, scale);
+      }
+
+      final buffer = await _downloadImage(uri);
+      if (buffer == null || _isCancelled) {
+        return null;
+      }
+      return await _decodeBuffer(buffer, decode, scale);
+    } catch (e) {
+      if (e is HttpException && (e.message.endsWith('aborted') || e.message.startsWith('Connection closed'))) {
+        return null;
+      }
+      log.severe('Failed to load remote image', e);
+      final buffer = await _loadCachedFile(uri, inMemoryOnly: false);
+      if (buffer != null) {
+        return _decodeBuffer(buffer, decode, scale);
+      }
+      rethrow;
+    } finally {
+      _request = null;
+    }
+  }
+
+  Future<ImmutableBuffer?> _downloadImage(String url) async {
+    final request = _request = await client.getUrl(Uri.parse(url));
+    if (_isCancelled) {
+      return null;
+    }
+
+    final headers = ApiService.getRequestHeaders();
+    for (final entry in headers.entries) {
+      request.headers.set(entry.key, entry.value);
+    }
+    final response = await request.close();
+    if (_isCancelled) {
+      return null;
+    }
+
+    final bytes = await consolidateHttpClientResponseBytes(response);
+    _cacheFile(url, bytes);
+    if (_isCancelled) {
+      return null;
+    }
+    return await ImmutableBuffer.fromUint8List(bytes);
+  }
+
+  Future<void> _cacheFile(String url, Uint8List bytes) async {
+    try {
+      await cacheManager.putFile(url, bytes);
+    } catch (e) {
+      log.severe('Failed to cache image', e);
+    }
+  }
+
+  Future<ImmutableBuffer?> _loadCachedFile(String url, {required bool inMemoryOnly}) async {
+    if (_isCancelled) {
+      return null;
+    }
+    final file = await (inMemoryOnly ? cacheManager.getFileFromMemory(url) : cacheManager.getFileFromCache(url));
+    if (_isCancelled || file == null) {
+      return null;
+    }
+    return await ImmutableBuffer.fromFilePath(file.file.path);
+  }
+
+  Future<ImageInfo?> _decodeBuffer(ImmutableBuffer buffer, ImageDecoderCallback decode, scale) async {
+    if (_isCancelled) {
+      buffer.dispose();
+      return null;
+    }
+    final codec = await decode(buffer);
+    if (_isCancelled) {
+      buffer.dispose();
+      codec.dispose();
+      return null;
+    }
+    final frame = await codec.getNextFrame();
+    return ImageInfo(image: frame.image, scale: scale);
+  }
+
+  @override
+  void _onCancelled() {
+    _request?.abort();
+    _request = null;
+  }
 }