perf: ⚡ async icon loading via isolates with fallback queue

sqmw · sqmw · commit 53157f8918c9 · 2026-01-24T17:31:56.000+08:00
diff --git a/lib/screens/desk_tidy_home_page.dart b/lib/screens/desk_tidy_home_page.dart
@@ -2,6 +2,7 @@ import 'dart:io';
 import 'dart:math' as math;
 import 'dart:ui';
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
@@ -56,6 +57,7 @@ class _DeskTidyHomePageState extends State<DeskTidyHomePage>
   Timer? _dragEndTimer;
   Timer? _autoRefreshTimer;
   bool _isRefreshing = false;
+  int _shortcutLoadToken = 0;
   List<ShortcutItem> _shortcuts = [];
   List<AppCategory> _categories = [];
   String? _activeCategoryId;
@@ -443,8 +445,13 @@ class _DeskTidyHomePageState extends State<DeskTidyHomePage>
       }
 
       const requestIconSize = 256;
+      final existingIcons = <String, Uint8List?>{};
+      for (final shortcut in _shortcuts) {
+        existingIcons[shortcut.path] = shortcut.iconData;
+      }
 
-      final shortcutFutures = shortcutsPaths.map((shortcutPath) async {
+      final shortcutItems = <ShortcutItem>[];
+      for (final shortcutPath in shortcutsPaths) {
         final name = shortcutPath.split('\\').last.replaceAll('.lnk', '');
 
         String targetPath = shortcutPath;
@@ -459,32 +466,22 @@ class _DeskTidyHomePageState extends State<DeskTidyHomePage>
 
         // Don't treat folder shortcuts as "apps".
         if (isFolderShortcut) {
-          return null;
+          continue;
         }
 
-        final primaryIcon = await extractIconAsync(
-          shortcutPath,
-          size: requestIconSize,
-        );
-        final iconData =
-            primaryIcon ??
-            await extractIconAsync(targetPath, size: requestIconSize);
-
-        return ShortcutItem(
-          name: name,
-          path: shortcutPath,
-          iconPath: '',
-          description: '桌面快捷方式',
-          targetPath: targetPath,
-          iconData: iconData,
+        shortcutItems.add(
+          ShortcutItem(
+            name: name,
+            path: shortcutPath,
+            iconPath: '',
+            description: '桌面快捷方式',
+            targetPath: targetPath,
+            iconData: existingIcons[shortcutPath],
+          ),
         );
-      }).toList();
-
-      final shortcutItems = (await Future.wait(
-        shortcutFutures,
-      )).whereType<ShortcutItem>().toList();
+      }
 
-      // 插入已启用的系统项目
+      // 插入已启用的系统项目（先用占位图标，后续异步补齐）
       final systemItemsToLoad = <SystemItemType>[];
       if (_showThisPC) systemItemsToLoad.add(SystemItemType.thisPC);
       if (_showRecycleBin) systemItemsToLoad.add(SystemItemType.recycleBin);
@@ -493,32 +490,40 @@ class _DeskTidyHomePageState extends State<DeskTidyHomePage>
       if (_showUserFiles) systemItemsToLoad.add(SystemItemType.userFiles);
 
       for (final type in systemItemsToLoad) {
-        final info = SystemItemInfo.all[type]!;
-        final icon = await extractIconAsync(
-          info.iconResource,
-          size: requestIconSize,
+        final virtualPath = SystemItemInfo.virtualPath(type);
+        shortcutItems.add(
+          ShortcutItem.system(
+            type,
+            iconData: existingIcons[virtualPath],
+          ),
         );
-        shortcutItems.add(ShortcutItem.system(type, iconData: icon));
       }
 
       // 按名称自然排序（字母顺序），使系统项目与普通应用自然混合
       shortcutItems.sort((a, b) {
         return a.name.toLowerCase().compareTo(b.name.toLowerCase());
       });
 
-      // 只在数据变化时更新UI，实现无感更新
-      if (forceReloadIcons || !_shortcutsEqual(_shortcuts, shortcutItems)) {
-        final searchIndex = _buildSearchIndex(shortcutItems);
-        setState(() {
-          _shortcuts = shortcutItems;
-          _searchIndexByPath = searchIndex;
-        });
-        _syncCategoriesWithShortcuts(shortcutItems);
-      }
+      final searchIndex = _buildSearchIndex(shortcutItems);
+      setState(() {
+        _shortcuts = shortcutItems;
+        _searchIndexByPath = searchIndex;
+      });
+      _syncCategoriesWithShortcuts(shortcutItems);
 
       if (shouldShowLoading) {
         setState(() => _isLoading = false);
       }
+
+      final loadToken = ++_shortcutLoadToken;
+      unawaited(
+        _hydrateShortcutIcons(
+          shortcutItems,
+          loadToken,
+          requestIconSize,
+          forceReloadIcons,
+        ),
+      );
     } catch (e) {
       print('加载快捷方式失败: $e');
       if (shouldShowLoading) {
@@ -529,6 +534,74 @@ class _DeskTidyHomePageState extends State<DeskTidyHomePage>
     }
   }
 
+  Future<void> _hydrateShortcutIcons(
+    List<ShortcutItem> baseItems,
+    int loadToken,
+    int requestIconSize,
+    bool forceReloadIcons,
+  ) async {
+    final updatedIcons = <String, Uint8List?>{};
+    final tasks = <Future<void>>[];
+
+    for (final item in baseItems) {
+      if (!forceReloadIcons && item.iconData != null) {
+        continue;
+      }
+      tasks.add(() async {
+        try {
+          Uint8List? icon;
+          if (item.isSystemItem && item.systemItemType != null) {
+            final info = SystemItemInfo.all[item.systemItemType]!;
+            icon = await extractIconAsync(
+              info.iconResource,
+              size: requestIconSize,
+            );
+          } else {
+            final primary = await extractIconAsync(
+              item.path,
+              size: requestIconSize,
+            );
+            final targetPath =
+                item.targetPath.isNotEmpty ? item.targetPath : item.path;
+            icon = primary ??
+                await extractIconAsync(targetPath, size: requestIconSize);
+          }
+
+          if (icon != null && icon.isNotEmpty) {
+            updatedIcons[item.path] = icon;
+          }
+        } catch (_) {
+          // Ignore icon failures to keep UI responsive.
+        }
+      }());
+    }
+
+    if (tasks.isEmpty) return;
+    await Future.wait(tasks);
+
+    if (!mounted || loadToken != _shortcutLoadToken) return;
+    if (updatedIcons.isEmpty) return;
+
+    final updated = baseItems.map((item) {
+      final icon = updatedIcons[item.path];
+      if (icon == null) return item;
+      return ShortcutItem(
+        name: item.name,
+        path: item.path,
+        iconPath: item.iconPath,
+        description: item.description,
+        targetPath: item.targetPath,
+        iconData: icon,
+        isSystemItem: item.isSystemItem,
+        systemItemType: item.systemItemType,
+      );
+    }).toList();
+
+    setState(() {
+      _shortcuts = updated;
+    });
+  }
+
   void _syncCategoriesWithShortcuts(List<ShortcutItem> shortcuts) {
     final existingPaths = shortcuts.map((e) => e.path).toSet();
     bool changed = false;
diff --git a/lib/utils/desktop_helper.dart b/lib/utils/desktop_helper.dart
@@ -41,6 +41,7 @@ const int _iconCacheVersion = 9;
 const int _iconCacheCapacity = 64;
 final LinkedHashMap<String, Uint8List?> _iconCache =
     LinkedHashMap<String, Uint8List?>();
+final Map<String, Future<Uint8List?>> _iconInFlight = {};
 
 class _IconTask {
   final String path;
@@ -55,6 +56,14 @@ final Queue<_IconTask> _iconTaskQueue = Queue<_IconTask>();
 int _activeIconIsolates = 0;
 // Limit concurrent isolates to avoid creating too many DCs at once.
 const int _maxIconIsolates = 3;
+final Queue<_IconTask> _mainIconTaskQueue = Queue<_IconTask>();
+bool _mainIconDrainScheduled = false;
+
+void _debugLog(String message) {
+  if (kDebugMode) {
+    debugPrint(message);
+  }
+}
 
 math.Point<int> getPrimaryScreenSize() {
   final w = GetSystemMetrics(SM_CXSCREEN);
@@ -1065,6 +1074,8 @@ Uint8List? extractIcon(String filePath, {int size = 64}) {
   // Try to locate the icon resource via shell, then extract a high-res icon via
   // PrivateExtractIconsW (handles PNG-in-ICO as well). Fallback to SHGetFileInfo
   // HICON if needed.
+  final comReady = _ensureComReady();
+  try {
   final desiredSize = size.clamp(16, 256);
 
   final primaryKey = _cacheKeyForFile(filePath, desiredSize);
@@ -1125,14 +1136,12 @@ Uint8List? extractIcon(String filePath, {int size = 64}) {
     calloc.free(pathPtr);
     if (hr == 0) {
       calloc.free(shFileInfo);
-      _writeIconCache(primaryKey, null);
       return null;
     }
 
     final iconHandle = shFileInfo.ref.hIcon;
     calloc.free(shFileInfo);
     if (iconHandle == 0) {
-      _writeIconCache(primaryKey, null);
       return null;
     }
 
@@ -1145,6 +1154,11 @@ Uint8List? extractIcon(String filePath, {int size = 64}) {
       : primaryKey;
   _writeIconCache(finalKey, cachedValue);
   return cachedValue;
+  } finally {
+    if (comReady) {
+      CoUninitialize();
+    }
+  }
 }
 
 Uint8List? _extractJumboIconPng(String filePath, int desiredSize) {
@@ -1639,7 +1653,11 @@ Future<Uint8List?> extractIconAsync(String filePath, {int size = 64}) {
   final cached = _readIconCache(cacheKey);
   if (cached.found) return Future.value(cached.value);
 
+  final existing = _iconInFlight[cacheKey];
+  if (existing != null) return existing;
+
   final completer = Completer<Uint8List?>();
+  _iconInFlight[cacheKey] = completer.future;
   _iconTaskQueue.add(_IconTask(filePath, desiredSize, cacheKey, completer));
   _drainIconTasks();
   return completer.future;
@@ -1649,22 +1667,30 @@ void _drainIconTasks() {
   while (_activeIconIsolates < _maxIconIsolates && _iconTaskQueue.isNotEmpty) {
     final task = _iconTaskQueue.removeFirst();
     _activeIconIsolates++;
+    final path = task.path;
+    final size = task.size;
 
-    Isolate.run<Uint8List?>(() => extractIcon(task.path, size: task.size))
+    _runIconIsolate(path, size)
         .then((data) {
-          // Fallback: if isolate extraction fails/returns empty, retry in main
-          // isolate to avoid missing icons (may block briefly but recovers).
-          Uint8List? result = data;
-          if (result == null || result.isEmpty) {
-            result = extractIcon(task.path, size: task.size);
+          final result = (data == null || data.isEmpty) ? null : data;
+          if (result != null) {
+            _writeIconCache(task.cacheKey, result);
+            task.completer.complete(result);
+            _iconInFlight.remove(task.cacheKey);
+          } else {
+            _debugLog(
+              'icon isolate empty: ${task.path} size=${task.size}',
+            );
+            _mainIconTaskQueue.add(task);
+            _scheduleMainIconDrain();
           }
-          _writeIconCache(task.cacheKey, result);
-          task.completer.complete(result);
         })
-        .catchError((_, __) {
-          final result = extractIcon(task.path, size: task.size);
-          _writeIconCache(task.cacheKey, result);
-          task.completer.complete(result);
+        .catchError((err, st) {
+          _debugLog(
+            'icon isolate error: ${task.path} size=${task.size} err=$err\n$st',
+          );
+          _mainIconTaskQueue.add(task);
+          _scheduleMainIconDrain();
         })
         .whenComplete(() {
           _activeIconIsolates--;
@@ -1673,6 +1699,33 @@ void _drainIconTasks() {
   }
 }
 
+void _scheduleMainIconDrain() {
+  if (_mainIconDrainScheduled) return;
+  _mainIconDrainScheduled = true;
+  Future<void>(() async {
+    while (_mainIconTaskQueue.isNotEmpty) {
+      final task = _mainIconTaskQueue.removeFirst();
+      Uint8List? result;
+      try {
+        result = extractIcon(task.path, size: task.size);
+      } catch (_) {
+        _debugLog(
+          'icon main fallback error: ${task.path} size=${task.size}',
+        );
+        result = null;
+      }
+      _writeIconCache(task.cacheKey, result);
+      if (!task.completer.isCompleted) {
+        task.completer.complete(result);
+      }
+      _iconInFlight.remove(task.cacheKey);
+      // Yield between tasks to keep UI responsive.
+      await Future<void>.delayed(const Duration(milliseconds: 8));
+    }
+    _mainIconDrainScheduled = false;
+  });
+}
+
 _IconCacheResult _readIconCache(String key) {
   if (!_iconCache.containsKey(key)) return const _IconCacheResult(found: false);
   return _IconCacheResult(found: true, value: _iconCache[key]);
@@ -1697,6 +1750,44 @@ String _cacheKeyForSystemIndex(int index, int size) =>
 String _cacheKeyForFile(String filePath, int size) =>
     'v$_iconCacheVersion|file:${path.normalize(filePath)}|$size';
 
+bool _ensureComReady() {
+  final hr = CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
+  return hr == S_OK || hr == S_FALSE;
+}
+
+Uint8List? _extractIconIsolate(String path, int size) {
+  return extractIcon(path, size: size);
+}
+
+Future<Uint8List?> _runIconIsolate(String path, int size) async {
+  final port = ReceivePort();
+  await Isolate.spawn(
+    _iconIsolateEntry,
+    <Object>[port.sendPort, path, size],
+  );
+  final message = await port.first;
+  port.close();
+  if (message is TransferableTypedData) {
+    return message.materialize().asUint8List();
+  }
+  if (message is Uint8List) {
+    return message;
+  }
+  return null;
+}
+
+void _iconIsolateEntry(List<Object> args) {
+  final sendPort = args[0] as SendPort;
+  final path = args[1] as String;
+  final size = args[2] as int;
+  final bytes = _extractIconIsolate(path, size);
+  if (bytes == null || bytes.isEmpty) {
+    sendPort.send(null);
+    return;
+  }
+  sendPort.send(TransferableTypedData.fromList([bytes]));
+}
+
 List<String> getClipboardFilePaths() {
   if (!Platform.isWindows) return [];
   if (OpenClipboard(NULL) == 0) return [];
