perf(tabs): release stale image and tab state

.gitea/workflows/pixel10.yml

@@ -118,6 +118,13 @@ jobs:
           dart pub global activate melos 7.8.1
           melos bootstrap
 
+      - name: Test Pixel 10 performance regressions
+        working-directory: apps/weblibre
+        run: >-
+          flutter test --no-pub
+          test/features/geckoview/utils/image_helper_test.dart
+          test/features/geckoview/domain/providers/tab_detail_state_test.dart
+
       - name: Generate bundled assets
         run: |
           melos run update-assets --no-select

apps/weblibre/lib/features/geckoview/domain/providers/tab_detail_state.dart

@@ -54,6 +54,14 @@ class TabProgressStates extends _$TabProgressStates {
 
     state = {...state}..[tabId] = progress;
   }
+
+  void removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
 }
 
 @Riverpod()
@@ -88,6 +96,17 @@ class TabThumbnails extends _$TabThumbnails {
 
     state = {...state}..[tabId] = thumbnail;
   }
+
+  void removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    // EquatableImage owns its ui.Image through a finalizer. Dropping the map
+    // reference is safer than disposing it here because an outgoing tab-preview
+    // frame may still hold the same wrapper briefly.
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
 }
 
 @Riverpod()
@@ -112,6 +131,14 @@ class TabHistoryStates extends _$TabHistoryStates {
 
     state = {...state}..[tabId] = history;
   }
+
+  void removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
 }
 
 @Riverpod()
@@ -142,6 +169,14 @@ class TabFindResultStates extends _$TabFindResultStates {
 
   FindResultState resultFor(String tabId) =>
       state[tabId] ?? FindResultState.$default();
+
+  void removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
 }
 
 @Riverpod()
@@ -170,6 +205,14 @@ class TabTranslationStates extends _$TabTranslationStates {
 
     state = {...state}..[tabId] = translation;
   }
+
+  void removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
 }
 
 @Riverpod()

apps/weblibre/lib/features/geckoview/domain/providers/tab_state.dart

@@ -36,6 +36,7 @@ import 'package:weblibre/features/geckoview/domain/entities/states/translation.d
 import 'package:weblibre/features/geckoview/domain/providers.dart';
 import 'package:weblibre/features/geckoview/domain/providers/selected_tab.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_detail_state.dart';
+import 'package:weblibre/features/geckoview/domain/providers/tab_list.dart';
 import 'package:weblibre/features/geckoview/features/find_in_page/domain/repositories/find_in_page.dart';
 import 'package:weblibre/features/geckoview/features/tabs/data/entities/isolation_context.dart';
 import 'package:weblibre/features/geckoview/features/tabs/data/entities/tab_mode.dart';
@@ -75,6 +76,14 @@ class TabStates extends _$TabStates {
     state = {...state}..[tabId] = next;
   }
 
+  void _removeAll(Set<String> tabIds) {
+    if (!state.keys.any(tabIds.contains)) {
+      return;
+    }
+
+    state = {...state}..removeWhere((tabId, _) => tabIds.contains(tabId));
+  }
+
   Future<void> _onTabContentStateChange(TabContentState contentState) async {
     final current = await patchedState(contentState.id);
 
@@ -187,6 +196,9 @@ class TabStates extends _$TabStates {
         bytes,
         targetWidth: thumbnailDecodeWidth,
         allowUpscaling: false,
+        // Periodic screenshots are almost always unique. Caching each decode
+        // retained up to 100 obsolete GPU images in the global icon LRU.
+        cacheResult: false,
       ),
     );
 
@@ -415,6 +427,29 @@ class TabStates extends _$TabStates {
       },
     );
 
+    ref.listen(tabListProvider, (previous, next) {
+      if (previous == null) {
+        // The first list can be a partial restore snapshot. There is no reliable
+        // removal signal until Gecko has emitted at least two snapshots.
+        return;
+      }
+
+      final activeTabIds = next.value.toSet();
+      final removedTabIds = previous.value
+          .where((tabId) => !activeTabIds.contains(tabId))
+          .toSet();
+      if (removedTabIds.isEmpty) {
+        return;
+      }
+
+      _removeAll(removedTabIds);
+      ref.read(tabProgressStatesProvider.notifier).removeAll(removedTabIds);
+      ref.read(tabThumbnailsProvider.notifier).removeAll(removedTabIds);
+      ref.read(tabHistoryStatesProvider.notifier).removeAll(removedTabIds);
+      ref.read(tabFindResultStatesProvider.notifier).removeAll(removedTabIds);
+      ref.read(tabTranslationStatesProvider.notifier).removeAll(removedTabIds);
+    });
+
     ref.onDispose(() async {
       for (final sub in subscriptions) {
         await sub.cancel();

apps/weblibre/lib/features/geckoview/domain/repositories/tab.dart

@@ -32,15 +32,18 @@ import 'package:weblibre/extensions/uri.dart';
 import 'package:weblibre/features/geckoview/domain/entities/states/tab.dart';
 import 'package:weblibre/features/geckoview/domain/entities/tab_container_selection.dart';
 import 'package:weblibre/features/geckoview/domain/providers.dart';
+import 'package:weblibre/features/geckoview/domain/providers/desktop_mode.dart';
 import 'package:weblibre/features/geckoview/domain/providers/pending_tab_selection.dart';
 import 'package:weblibre/features/geckoview/domain/providers/restore_complete.dart';
 import 'package:weblibre/features/geckoview/domain/providers/selected_tab.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_detail_state.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_list.dart';
+import 'package:weblibre/features/geckoview/domain/providers/tab_session.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/controllers/home_target_controller.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/providers.dart';
 import 'package:weblibre/features/geckoview/features/browser/domain/services/browser_data.dart';
+import 'package:weblibre/features/geckoview/features/find_in_page/domain/repositories/find_in_page.dart';
 import 'package:weblibre/features/geckoview/features/tabs/data/database/database.dart';
 import 'package:weblibre/features/geckoview/features/tabs/data/entities/isolation_context.dart';
 import 'package:weblibre/features/geckoview/features/tabs/data/entities/tab_mode.dart';
@@ -1211,6 +1214,21 @@ class TabRepository extends _$TabRepository {
     ref.listen(
       tabListProvider,
       (previous, next) async {
+        final activeTabIds = next.value.toSet();
+        final removedTabIds = previous?.value
+            .where((tabId) => !activeTabIds.contains(tabId))
+            .toSet();
+        if (removedTabIds != null) {
+          for (final tabId in removedTabIds) {
+            // These families are keepAlive so tab-specific state survives while
+            // a tab is merely in the background. Once Gecko confirms removal,
+            // keeping their services and listeners serves no purpose.
+            ref.invalidate(tabSessionProvider(tabId: tabId));
+            ref.invalidate(desktopModeProvider(tabId));
+            ref.invalidate(findInPageRepositoryProvider(tabId));
+          }
+        }
+
         if (_suppressNextReclose) {
           _suppressNextReclose = false;
           // Drop tombstones for the tabs that just came back via undo so

apps/weblibre/lib/features/geckoview/features/browser/presentation/screens/browser.dart

@@ -1000,6 +1000,20 @@ class BrowserScreen extends HookConsumerWidget {
     final pendingProxyLoadErrors = useRef(<String, _PendingProxyLoadError>{});
     final selectedTabIdForProxyPrompt = ref.watch(selectedTabProvider);
 
+    ref.listen(tabListProvider, (previous, next) {
+      if (previous == null) return;
+
+      final activeTabIds = next.value.toSet();
+      for (final tabId in previous.value.where(
+        (tabId) => !activeTabIds.contains(tabId),
+      )) {
+        // UI-scoped families intentionally survive while a tab is backgrounded,
+        // but must not retain listeners and text state after it is closed.
+        ref.invalidate(toolbarVisibilityControllerProvider(tabId));
+        ref.invalidate(findInPageControllerProvider(tabId));
+      }
+    });
+
     Future<void> handleProxyLoadError({
       required String tabId,
       required String? contextId,

apps/weblibre/lib/features/geckoview/features/browser/presentation/widgets/browser_modules/browser_view.dart

@@ -111,8 +111,16 @@ class _BrowserViewState extends ConsumerState<BrowserView>
   static const _pointerThrottleInterval = Duration(milliseconds: 32);
   DateTime _lastPointerEvent = DateTime(0);
   Offset _accumulatedDelta = Offset.zero;
+  bool _screenshotCaptureInFlight = false;
 
   Future<void> _timerTick(Timer timer) async {
+    // Timer.periodic does not await async callbacks. A slow Gecko capture used
+    // to overlap the next tick, multiplying GPU readbacks, bitmap encoders and
+    // thumbnail events exactly while the device was already under load.
+    if (_screenshotCaptureInFlight) {
+      return;
+    }
+
     // Skip the (expensive) Gecko render-to-bitmap while a full-cover route
     // (settings, tab tray, search, …) occludes the browser. The screenshot
     // would force an off-screen render the user can't see and competes for the
@@ -133,15 +141,17 @@ class _BrowserViewState extends ConsumerState<BrowserView>
       return;
     }
 
+    _screenshotCaptureInFlight = true;
+    try {
       await ref
           .read(selectedTabSessionProvider)
-        .requestScreenshot(requireImageResult: false)
-        .onError((error, stackTrace) {
+          .requestScreenshot(requireImageResult: false);
+    } catch (error, stackTrace) {
       logger.e(error, stackTrace: stackTrace);
       timer.cancel();
-
-          return null;
-        });
+    } finally {
+      _screenshotCaptureInFlight = false;
+    }
   }
 
   @override

apps/weblibre/lib/features/geckoview/features/pwa/domain/providers.dart

@@ -27,6 +27,7 @@ import 'package:weblibre/core/logger.dart';
 import 'package:weblibre/extensions/uri.dart';
 import 'package:weblibre/features/geckoview/domain/providers.dart';
 import 'package:weblibre/features/geckoview/domain/providers/selected_tab.dart';
+import 'package:weblibre/features/geckoview/domain/providers/tab_list.dart';
 import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
 import 'package:weblibre/features/geckoview/features/pwa/domain/pwa_installability.dart';
 import 'package:weblibre/features/web_search/domain/controllers/sandbox_capture_controller.dart';
@@ -66,6 +67,21 @@ class PwaManifestState extends _$PwaManifestState {
       },
     );
 
+    ref.listen(tabListProvider, (previous, next) {
+      if (previous == null) return;
+
+      final activeTabIds = next.value.toSet();
+      final removedTabIds = previous.value
+          .where((tabId) => !activeTabIds.contains(tabId))
+          .toSet();
+      if (!removedTabIds.any(state.containsKey)) {
+        return;
+      }
+
+      state = {...state}
+        ..removeWhere((tabId, _) => removedTabIds.contains(tabId));
+    });
+
     return {};
   }
 }

apps/weblibre/lib/features/geckoview/utils/image_helper.dart

@@ -42,6 +42,7 @@ Future<EquatableImage?> tryDecodeImage(
   int? targetWidth,
   int? targetHeight,
   bool allowUpscaling = true,
+  bool cacheResult = true,
 }) async {
   // The decode options are part of the identity of the result, not just of the
   // request: the same bytes decoded at a thumbnail's target width and at an
@@ -55,12 +56,14 @@ Future<EquatableImage?> tryDecodeImage(
     allowUpscaling: allowUpscaling,
   );
 
+  if (cacheResult) {
     final cached = _cache.get(identity);
     if (cached?.value != null) {
       return cached;
     } else if (cached != null) {
       _cache.remove(identity);
     }
+  }
 
   try {
     final codec = await instantiateImageCodec(
@@ -74,7 +77,9 @@ Future<EquatableImage?> tryDecodeImage(
     final image = EquatableImage(frameInfo.image, identity: identity);
 
     if (image.value != null && image.value!.width > 0) {
+      if (cacheResult) {
         _cache.set(identity, image);
+      }
       return image;
     }
   } catch (e, s) {
@@ -87,7 +92,9 @@ Future<EquatableImage?> tryDecodeImage(
           targetHeight: targetHeight,
         );
         if (svgImage != null) {
+          if (cacheResult) {
             _cache.set(identity, svgImage);
+          }
           return svgImage;
         }
       } catch (svgError, svgStackTrace) {

apps/weblibre/pubspec.yaml

@@ -2,7 +2,7 @@ name: weblibre
 description: "The Privacy-Focused & AI-Powered Research Browser"
 publish_to: 'none'
 resolution: workspace
-version: 0.30.0-alpha-3+40
+version: 0.30.0-alpha-3+41
 
 environment:
   sdk: '>=3.8.0 <4.0.0'

apps/weblibre/test/features/geckoview/domain/providers/tab_detail_state_test.dart

@@ -0,0 +1,34 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:riverpod/riverpod.dart';
+import 'package:weblibre/features/geckoview/domain/providers/tab_detail_state.dart';
+
+void main() {
+  test('closed tab progress is pruned without touching active tabs', () {
+    final container = ProviderContainer();
+    addTearDown(container.dispose);
+
+    final notifier = container.read(tabProgressStatesProvider.notifier);
+    notifier.update('closed-tab', 80);
+    notifier.update('active-tab', 40);
+
+    notifier.removeAll({'closed-tab', 'unknown-tab'});
+
+    expect(container.read(tabProgressStatesProvider), {'active-tab': 40});
+  });
+
+  test('pruning unrelated ids does not publish a new map', () {
+    final container = ProviderContainer();
+    addTearDown(container.dispose);
+
+    final notifier = container.read(tabProgressStatesProvider.notifier);
+    notifier.update('active-tab', 40);
+    final before = container.read(tabProgressStatesProvider);
+
+    notifier.removeAll({'unknown-tab'});
+
+    expect(
+      identical(container.read(tabProgressStatesProvider), before),
+      isTrue,
+    );
+  });
+}

apps/weblibre/test/features/geckoview/utils/image_helper_test.dart

@@ -75,6 +75,27 @@ void main() {
     });
   });
 
+  testWidgets('tryDecodeImage can bypass the global image cache', (
+    tester,
+  ) async {
+    await tester.runAsync(() async {
+      clearImageCache();
+      final svgBytes = Uint8List.fromList(utf8.encode(_svgIcon));
+
+      final first = await tryDecodeImage(svgBytes, cacheResult: false);
+      final second = await tryDecodeImage(svgBytes, cacheResult: false);
+
+      expect(first, isNotNull);
+      expect(second, isNotNull);
+      expect(first, equals(second));
+      expect(identical(first, second), isFalse);
+
+      // These are deliberately distinct uncached image resources.
+      first!.dispose();
+      second!.dispose();
+    });
+  });
+
   test('ImageIdentity compares structurally, not by a folded hash', () {
     const a = (
       digest: 0x0123456789ABCDEF,

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/ext/Bitmap.kt

@@ -9,32 +9,42 @@ package eu.weblibre.flutter_mozilla_components.ext
 import android.graphics.Bitmap
 import android.os.Build
 import java.io.ByteArrayOutputStream
+import kotlin.math.roundToInt
 
 fun Bitmap.resize(maxWidth: Int, maxHeight: Int): Bitmap {
-    var width = this.width
-    var height = this.height
-
-    val aspectRatio: Float = width.toFloat() / height.toFloat()
-
-    if (width > height) {
-        width = maxWidth
-        height = (width / aspectRatio).toInt()
-    } else {
-        height = maxHeight
-        width = (height * aspectRatio).toInt()
+    require(maxWidth > 0 && maxHeight > 0) {
+        "Bitmap bounds must be positive"
     }
 
-    return Bitmap.createScaledBitmap(this, width, height, true)
+    if (width <= maxWidth && height <= maxHeight) {
+        return this
+    }
+
+    val scale = minOf(
+        maxWidth.toFloat() / width.toFloat(),
+        maxHeight.toFloat() / height.toFloat(),
+    )
+    val targetWidth = (width * scale).roundToInt().coerceAtLeast(1)
+    val targetHeight = (height * scale).roundToInt().coerceAtLeast(1)
+
+    return Bitmap.createScaledBitmap(this, targetWidth, targetHeight, true)
 }
 
-fun Bitmap.toWebPBytes(): ByteArray {
+fun Bitmap.toWebPBytes(
+    lossless: Boolean = true,
+    quality: Int = 100,
+): ByteArray {
     val stream = ByteArrayOutputStream()
     val compressFormat = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+        if (lossless) {
             Bitmap.CompressFormat.WEBP_LOSSLESS
+        } else {
+            Bitmap.CompressFormat.WEBP_LOSSY
+        }
     } else {
         @Suppress("DEPRECATION")
         Bitmap.CompressFormat.WEBP
     }
-    compress(compressFormat, 100, stream)
+    compress(compressFormat, quality.coerceIn(0, 100), stream)
     return stream.toByteArray()
 }

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/middleware/FlutterEventMiddleware.kt

@@ -19,6 +19,15 @@ import eu.weblibre.flutter_mozilla_components.pigeons.ImageSrcHitResult
 import eu.weblibre.flutter_mozilla_components.pigeons.PhoneHitResult
 import eu.weblibre.flutter_mozilla_components.pigeons.UnknownHitResult
 import eu.weblibre.flutter_mozilla_components.pigeons.VideoHitResult
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import mozilla.components.browser.state.action.BrowserAction
 import mozilla.components.browser.state.action.ContentAction
 import mozilla.components.browser.state.action.LastAccessAction
@@ -45,6 +54,53 @@ class FlutterEventMiddleware(private val flutterEvents: GeckoStateEvents) : Midd
         requireNotNull(GlobalComponents.components) { "Components not initialized" }
     }
 
+    /**
+     * Thumbnail scaling and WebP encoding are CPU-heavy and this middleware is
+     * normally invoked on the browser/UI dispatch path. Keep that work off the
+     * frame-critical thread and serialize it so periodic captures cannot build
+     * up a queue of competing bitmap encoders.
+     */
+    private val thumbnailEncodingScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+    private val thumbnailEncodingMutex = Mutex()
+    private var thumbnailEncodingJob: Job? = null
+
+    private fun forwardThumbnail(action: ContentAction.UpdateThumbnailAction) {
+        // Only the newest selected-tab preview is useful. Cancellation does not
+        // interrupt Bitmap.compress itself, so the mutex also prevents a newer
+        // request from starting a second encoder before the old one unwinds.
+        thumbnailEncodingJob?.cancel()
+        thumbnailEncodingJob = thumbnailEncodingScope.launch {
+            thumbnailEncodingMutex.withLock {
+                if (!isActive) return@withLock
+
+                val resized = action.thumbnail.resize(maxWidth = 720, maxHeight = 720)
+                try {
+                    // Thumbnails are displayed at a few hundred logical pixels;
+                    // lossless 1280x800 WebP added CPU and channel traffic with
+                    // no visible benefit.
+                    val bytes = resized.toWebPBytes(lossless = false, quality = 82)
+                    if (!isActive) return@withLock
+
+                    runOnUiThread {
+                        flutterEvents.onThumbnailChange(
+                            EventSequence.next(),
+                            action.sessionId,
+                            bytes,
+                        ) { _ -> }
+                    }
+                } catch (error: CancellationException) {
+                    throw error
+                } catch (error: Exception) {
+                    Log.e("FlutterEventMiddleware", "Failed to encode thumbnail", error)
+                } finally {
+                    if (resized !== action.thumbnail && !resized.isRecycled) {
+                        resized.recycle()
+                    }
+                }
+            }
+        }
+    }
+    
     @Suppress("ComplexMethod")
     override fun invoke(
         store: Store<BrowserState, BrowserAction>,
@@ -53,12 +109,7 @@ class FlutterEventMiddleware(private val flutterEvents: GeckoStateEvents) : Midd
     ) {
         when (action) {
             is ContentAction.UpdateThumbnailAction -> {
-                val resized = action.thumbnail.resize(maxWidth = 1280, maxHeight = 800);
-                val bytes = resized.toWebPBytes()
-
-                runOnUiThread {
-                    flutterEvents.onThumbnailChange(EventSequence.next(), action.sessionId, bytes) { _ -> }
-                }
+                forwardThumbnail(action)
             }
             //UpdateReaderConnectRequiredAction seems to be the only event that is called predictable
             //after a hot reload