Add support to cache thumbnail images to disk

.github/workflows/linux.yml

@@ -28,7 +28,7 @@ jobs:
         with:
           channel: stable
       - name: Install dependencies
-        run: sudo apt-get update && sudo apt-get install -y libgtk-3-dev liblzma-dev libstdc++-12-dev ninja-build
+        run: sudo apt-get update && sudo apt-get install -y libgtk-3-dev liblzma-dev libstdc++-12-dev ninja-build libsqlite3-dev
       - name: Build
         run: flutter build linux --release
       - name: Package files

lib/api/client.dart

@@ -315,11 +315,11 @@ class EHApi extends __EHApi {
       ThumbnailAlign? align}) {
     final uri = Uri.parse(_combineBaseUrls(_dio.options.baseUrl, baseUrl));
     final queryParameters = <String, dynamic>{
-      r'max': max,
-      r'width': width,
-      r'height': height,
-      r'quality': quality,
-      r'force': force,
+      r'max': max?.toString(),
+      r'width': width?.toString(),
+      r'height': height?.toString(),
+      r'quality': quality?.toString(),
+      r'force': force?.toString(),
       r'method': method?.name,
       r'align': align?.name,
     };

lib/components/thumbnail.dart

@@ -84,6 +84,7 @@ class _Thumbnail extends State<Thumbnail> {
   Color? _iconColor;
   double? _iconSize;
   bool _disposed = false;
+  String? _originalUrl;
   void _onNsfwChanged(dynamic args) {
     final arguments = args as (String, bool)?;
     if (arguments == null) return;
@@ -134,6 +135,28 @@ class _Thumbnail extends State<Thumbnail> {
             .files[token]![0]!
             .id;
       }
+      _originalUrl ??= api.getThumbnailUrl(_fileId!,
+          max: widget._max,
+          width: widget._width,
+          height: widget._height,
+          method: ThumbnailMethod.contain,
+          align: ThumbnailAlign.center);
+      if (isImageCacheEnabled) {
+        try {
+          final cache = await imageCaches.getCache(_originalUrl!);
+          if (cache != null) {
+            setState(() {
+              _data = cache!.$1;
+              _uri = cache!.$3 ?? _originalUrl;
+              _isLoading = false;
+              _cancel = null;
+            });
+            return;
+          }
+        } catch (e) {
+          _log.warning("Failed to get cache for $_originalUrl: $e");
+        }
+      }
       final re = await api.getThumbnail(_fileId!,
           max: widget._max,
           width: widget._width,
@@ -148,6 +171,14 @@ class _Thumbnail extends State<Thumbnail> {
       _uri = re.response.realUri.toString();
       final data = Uint8List.fromList(re.data);
       if (!_cancel!.isCancelled) {
+        if (isImageCacheEnabled) {
+          try {
+            await imageCaches.putCache(
+                _originalUrl!, data, re.response.headers.map, _uri);
+          } catch (e) {
+            _log.warning("Failed to put cache for $_originalUrl: $e");
+          }
+        }
         setState(() {
           _isLoading = false;
           _data = data;

lib/globals.dart

@@ -22,6 +22,7 @@ import 'main.dart';
 import 'platform/clipboard.dart';
 import 'platform/display.dart';
 import 'platform/get_jar.dart';
+import 'platform/image_cache.dart';
 import 'platform/path.dart';
 import 'platform/set_title.dart';
 import 'tags.dart';
@@ -38,6 +39,7 @@ final dio = Dio()
 Config? _prefs;
 EHApi? _api;
 PersistCookieJar? _jar;
+ImageCaches? _imageCaches;
 
 Future<void> prepareJar() async {
   final jar = PersistCookieJar(storage: FileStorage(await getJarPath()));
@@ -66,6 +68,21 @@ Config get prefs {
   return _prefs!;
 }
 
+final _globalLog = Logger("global");
+
+Future<void> prepareImageCaches() async {
+  _imageCaches = ImageCaches();
+  try {
+    await _imageCaches!.init();
+  } catch (e) {
+    _globalLog.warning("Failed to initiailzed image caches: $e");
+  }
+}
+
+ImageCaches get imageCaches => _imageCaches!;
+
+bool get isImageCacheEnabled => prefs.getBool("enableImageCache") ?? true;
+
 void initApi(String baseUrl) {
   _api = EHApi(dio, baseUrl: baseUrl);
 }

lib/l10n/app_en.arb

@@ -195,5 +195,6 @@
     "dlUseAvgSpeed": "Show average speed in task details.",
     "refresh": "Refresh",
     "originalImg": "Original image",
-    "overwriteDefaultConfig": "Overwrite default config"
+    "overwriteDefaultConfig": "Overwrite default config",
+    "enableImageCache": "Cache images to disk."
 }

lib/l10n/app_zh.arb

@@ -195,5 +195,6 @@
     "dlUseAvgSpeed": "在任务详情中显示平均速度。",
     "refresh": "刷新",
     "originalImg": "原图",
-    "overwriteDefaultConfig": "覆盖默认设置"
+    "overwriteDefaultConfig": "覆盖默认设置",
+    "enableImageCache": "将图片缓存到本地硬盘。"
 }

lib/main.dart

@@ -251,6 +251,7 @@ void main() async {
   if (prefs.getBool("preventScreenCapture") ?? false) {
     await platformDisplay.enableProtect();
   }
+  await prepareImageCaches();
   GoRouter.optionURLReflectsImperativeAPIs = true;
   runApp(const MainApp());
 }

lib/platform/image_cache.dart

@@ -0,0 +1 @@
+export './image_cache_ffi.dart' if (dart.library.html) './image_cache_web.dart';

lib/platform/image_cache_ffi.dart

@@ -0,0 +1,149 @@
+import 'dart:convert';
+import 'dart:io' as io;
+import 'dart:typed_data';
+import 'package:file/file.dart';
+import 'package:file/local.dart';
+import 'package:logging/logging.dart';
+import 'package:path/path.dart' as path;
+import 'package:path_provider/path_provider.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import '../globals.dart';
+import '../utils.dart';
+
+const _imagesTable = """CREATE TABLE images (
+url TEXT,
+path TEXT,
+last_used INT,
+headers TEXT,
+realUrl TEXT,
+PRIMARY KEY(url)
+);""";
+const _allTables = ['images'];
+
+final _log = Logger("ImageCachesDb");
+
+class ImageCaches {
+  Database? _db;
+  final _fs = const LocalFileSystem();
+  Directory? _cacheDir;
+  String? _exeDir;
+  final Set<String> _existingTable = {};
+  bool _inited = false;
+  ImageCaches();
+  Future<String?> _desktopFilePath() async {
+    final String? exe = await platformPath.getCurrentExe();
+    if (exe == null) return null;
+    _exeDir = path.dirname(exe);
+    return path.join(_exeDir!, "image_caches.db");
+  }
+
+  Future<String> get _filePath async {
+    if (isWindows || isLinux) {
+      try {
+        final tmp = await _desktopFilePath();
+        if (tmp != null) return tmp;
+      } catch (e) {
+        _log.warning("Failed to get database file location.");
+      }
+    }
+    final io.Directory appSupportDir = await getApplicationSupportDirectory();
+    return path.join(appSupportDir.path, "image_caches.db");
+  }
+
+  Future<Directory> get cacheDir async {
+    if (_cacheDir != null) return _cacheDir!;
+    if ((isWindows || isLinux) && _exeDir != null) {
+      return _cacheDir = _fs.directory(path.join(_exeDir!, "image_caches"));
+    }
+    final io.Directory cacheDir = await getApplicationCacheDirectory();
+    return _cacheDir = _fs.directory(path.join(cacheDir.path, "image_caches"));
+  }
+
+  Future<void> _createDir() async {
+    final dir = await cacheDir;
+    if (!(await dir.exists())) {
+      await dir.create(recursive: true);
+    }
+  }
+
+  Future<bool> _checkDatabase() async {
+    await _updateExistsTable();
+    final v = await _db!.getVersion();
+    _log.fine("Database version: $v");
+    if (_allTables.length != _existingTable.length ||
+        !_allTables.every((e) => _existingTable.contains(e))) {
+      return false;
+    }
+    return true;
+  }
+
+  Future<void> _createTable() async {
+    if (!_existingTable.contains("images")) {
+      await _db!.execute(_imagesTable);
+    }
+    await _updateExistsTable();
+  }
+
+  Future<void> _updateExistsTable() async {
+    _existingTable.clear();
+    final cur = await _db!
+        .query("sqlite_master", where: 'type = ?', whereArgs: ['table']);
+    for (final c in cur) {
+      _existingTable.add(c["name"]! as String);
+    }
+  }
+
+  Future<void> init() async {
+    sqfliteFfiInit();
+    _db = await databaseFactoryFfi.openDatabase(await _filePath);
+    await _createDir();
+    if (!(await _checkDatabase())) await _createTable();
+    _inited = true;
+  }
+
+  Future<(Uint8List, Map<String, List<String>>, String?)?> getCache(
+      String uri) async {
+    if (!_inited) return null;
+    final d = await _db!.query("images", where: 'url = ?', whereArgs: [uri]);
+    if (d.isEmpty) return null;
+    final data = d.first;
+    final path = data["path"] as String;
+    final header = data["headers"] as String;
+    final realUrl = data["readUrl"] as String?;
+    final lastUsed = DateTime.now().millisecondsSinceEpoch;
+    try {
+      await _db!.rawUpdate(
+          "UPDATE images SET last_used = ? WHERE url = ?;", [lastUsed, uri]);
+    } catch (e) {
+      _log.warning("Failed to set last_used to $lastUsed for $uri.");
+    }
+    final f = _fs.file(path);
+    final da = await f.readAsBytes();
+    final h = jsonDecode(header) as Map<String, dynamic>;
+    return (
+      da,
+      h.map((k, v) => MapEntry(k, (v as List<dynamic>).cast<String>())),
+      realUrl
+    );
+  }
+
+  Future<void> putCache(String uri, Uint8List data,
+      Map<String, List<String>> headers, String? realUri) async {
+    if (!_inited) return;
+    final u = Uri.parse(uri);
+    final dir = await cacheDir;
+    final p = path.join(dir.path, u.host.isEmpty ? "nohost" : u.host,
+        u.path.substring(1) + u.query);
+    final d = _fs.directory(path.dirname(p));
+    if (!(await d.exists())) {
+      await d.create(recursive: true);
+    }
+    final f = _fs.file(p);
+    await f.writeAsBytes(data.toList());
+    final lastUsed = DateTime.now().millisecondsSinceEpoch;
+    final header = jsonEncode(headers);
+    await _db!.rawInsert(
+        "INSERT OR REPLACE INTO images VALUES (?, ?, ?, ?, ?);",
+        [uri, p, lastUsed, header, realUri]);
+  }
+}

lib/platform/image_cache_web.dart

@@ -0,0 +1,45 @@
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
+import 'dart:typed_data';
+import 'package:web/web.dart';
+
+class ImageCaches {
+  Cache? cache;
+  ImageCaches();
+  Future<void> init() async {
+    cache = await window.caches.open("image_caches").toDart;
+  }
+
+  Future<(Uint8List, Map<String, List<String>>, String?)?> getCache(
+      String uri) async {
+    if (cache == null) return null;
+    final init = RequestInit(credentials: 'include');
+    final req = Request(URL(uri), init);
+    final opts = CacheQueryOptions(ignoreVary: true);
+    final re = await cache!.match(req, opts).toDart;
+    if (re == null || re!.body == null) return null;
+    final ab = await re!.arrayBuffer().toDart;
+    final buffer = ab.toDart;
+    final he = re!.headers;
+    final forEach = he.getProperty("forEach".toJS) as JSFunction?;
+    Map<String, List<String>> h = {};
+    void forE(JSString value, JSString key, Headers headers) {
+      h[key.toDart] = value.toDart.split(",");
+    }
+
+    forEach?.callAsFunction(he, forE.toJS);
+    return (buffer.asUint8List(), h, null);
+  }
+
+  Future<void> putCache(String uri, Uint8List data,
+      Map<String, List<String>> headers, String? realUri) async {
+    if (cache == null) return;
+    final he = JSObject();
+    for (final e in headers.entries) {
+      he.setProperty(e.key.toJS, e.value.map((e) => e.toJS).toList().toJS);
+    }
+    final opts = ResponseInit(status: 200, statusText: 'OK', headers: he);
+    final res = Response(data.toJS, opts);
+    await cache!.put(uri.toJS, res).toDart;
+  }
+}

lib/settings.dart

@@ -25,6 +25,7 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
   bool _oriShowTranslatedTag = false;
   bool _oriUseTitleJpn = false;
   bool _oriDlUseAvgSpeed = false;
+  bool _oriEnableImageCache = false;
   bool _displayAd = false;
   Lang _lang = Lang.system;
   bool _preventScreenCapture = false;
@@ -32,6 +33,7 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
   bool _showTranslatedTag = false;
   bool _useTitleJpn = false;
   bool _dlUseAvgSpeed = false;
+  bool _enableImageCache = false;
   @override
   void initState() {
     super.initState();
@@ -92,6 +94,14 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
       _oriDlUseAvgSpeed = false;
       _dlUseAvgSpeed = false;
     }
+    try {
+      _oriEnableImageCache = prefs.getBool("enableImageCache") ?? true;
+      _enableImageCache = _oriEnableImageCache;
+    } catch (e) {
+      _log.warning("Failed to get enableImageCache:", e);
+      _oriEnableImageCache = true;
+      _enableImageCache = true;
+    }
   }
 
   void fallback(BuildContext context) {
@@ -110,6 +120,7 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
       _showTranslatedTag = _oriLang.toLocale().languageCode == "zh";
       _preventScreenCapture = false;
       _dlUseAvgSpeed = false;
+      _enableImageCache = true;
     });
   }
 
@@ -178,6 +189,14 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
         _oriDlUseAvgSpeed = _dlUseAvgSpeed;
       }
     }
+    if (_enableImageCache != _oriEnableImageCache) {
+      if (!await prefs.setBool("enableImageCache", _enableImageCache)) {
+        re = false;
+        _log.warning("Failed to save enableImageCache.");
+      } else {
+        _oriEnableImageCache = _enableImageCache;
+      }
+    }
     return re;
   }
 
@@ -331,6 +350,21 @@ class _SettingsPage extends State<SettingsPage> with ThemeModeWidget {
                                     .dlUseAvgSpeed),
                               ),
                             ),
+                            Container(
+                              padding: const EdgeInsets.symmetric(vertical: 8),
+                              child: CheckboxMenuButton(
+                                value: _enableImageCache,
+                                onChanged: (bool? value) {
+                                  if (value != null) {
+                                    setState(() {
+                                      _enableImageCache = value;
+                                    });
+                                  }
+                                },
+                                child: Text(AppLocalizations.of(context)!
+                                    .enableImageCache),
+                              ),
+                            ),
                             Row(
                               mainAxisAlignment: MainAxisAlignment.center,
                               children: [

pubspec.lock

@@ -875,6 +875,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "7.0.0"
+  sqflite_common:
+    dependency: transitive
+    description:
+      name: sqflite_common
+      sha256: "3da423ce7baf868be70e2c0976c28a1bb2f73644268b7ffa7d2e08eab71f16a4"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.4"
+  sqflite_common_ffi:
+    dependency: "direct main"
+    description:
+      name: sqflite_common_ffi
+      sha256: "4d6137c29e930d6e4a8ff373989dd9de7bac12e3bc87bce950f6e844e8ad3bb5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.3"
+  sqlite3:
+    dependency: transitive
+    description:
+      name: sqlite3
+      sha256: b384f598b813b347c5a7e5ffad82cbaff1bec3d1561af267041e66f6f0899295
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.3"
   stack_trace:
     dependency: transitive
     description:
@@ -931,6 +955,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.8.15"
+  synchronized:
+    dependency: transitive
+    description:
+      name: synchronized
+      sha256: "539ef412b170d65ecdafd780f924e5be3f60032a1128df156adad6c5b373d558"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.0+1"
   term_glyph:
     dependency: transitive
     description:
@@ -1028,7 +1060,7 @@ packages:
     source: hosted
     version: "1.1.0"
   web:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: web
       sha256: "97da13628db363c635202ad97068d47c5b8aa555808e7a9411963c533b449b27"

pubspec.yaml

@@ -38,10 +38,12 @@ dependencies:
   photo_view: ^0.15.0
   retrofit: ^4.0.1
   shared_preferences: ^2.2.0
+  sqflite_common_ffi: ^2.3.3
   super_clipboard: ^0.8.15
   super_context_menu: ^0.8.15
   ua_parser_js: ^1.0.1
   user_agent_analyzer: ^5.0.0
+  web: ^0.5.0
   web_socket_channel: ^3.0.0
   window_manager: ^0.3.6
 
@@ -59,6 +61,7 @@ dev_dependencies:
   build_runner: ^2.4.6
   retrofit_generator: ^8.1.0
   json_serializable: ^6.7.1
+  sqflite_common_ffi: ^2.3.3
 
 flutter:
   generate: true