Fix #8277: Crash on old devices due to too many filter lists enabled (#…

…8283)

Sources/Brave/Frontend/Browser/Helpers/LaunchHelper.swift

@@ -87,6 +87,26 @@ public actor LaunchHelper {
     let remainingModes = ContentBlockerManager.BlockingMode.allCases.filter({ !loadedBlockModes.contains($0) })
 
     Task.detached(priority: .low) {
+      // Let's disable filter lists if we have reached a maxumum amount
+      let enabledSources = await AdBlockStats.shared.enabledSources
+      if enabledSources.count > AdBlockStats.maxNumberOfAllowedFilterLists {
+        let toDisableSources = enabledSources[AdBlockStats.maxNumberOfAllowedFilterLists...]
+
+        for source in toDisableSources {
+          switch source {
+          case .adBlock:
+            // This should never be in the list because the order of enabledSources places this as the first item
+            continue
+          case .filterList(let componentId):
+            ContentBlockerManager.log.debug("Disabling filter list \(source.debugDescription)")
+            await FilterListStorage.shared.ensureFilterList(for: componentId, isEnabled: false)
+          case .filterListURL(let uuid):
+            ContentBlockerManager.log.debug("Disabling custom filter list \(source.debugDescription)")
+            await CustomFilterListStorage.shared.ensureFilterList(for: uuid, isEnabled: false)
+          }
+        }
+      }
+
       let signpostID = Self.signpost.makeSignpostID()
       let state = Self.signpost.beginInterval("nonBlockingLaunchTask", id: signpostID)
       await FilterListResourceDownloader.shared.start(with: adBlockService)

Sources/Brave/Frontend/Settings/Features/ShieldsPrivacy/FilterLists/FilterListsView.swift

@@ -41,6 +41,7 @@ struct FilterListsView: View {
       } header: {
         Text(Strings.customFilterLists)
       }
+      .listRowBackground(Color(.secondaryBraveGroupedBackground))
       .toggleStyle(SwitchToggleStyle(tint: .accentColor))
 
       Section {
@@ -52,10 +53,9 @@ struct FilterListsView: View {
           Text(Strings.filterListsDescription)
             .textCase(.none)
         }
-      }
+      }.listRowBackground(Color(.secondaryBraveGroupedBackground))
     }
     .toggleStyle(SwitchToggleStyle(tint: .accentColor))
-    .listRowBackground(Color(.secondaryBraveGroupedBackground))
     .animation(.default, value: customFilterListStorage.filterListsURLs)
     .listBackgroundColor(Color(UIColor.braveGroupedBackground))
     .listStyle(.insetGrouped)

Sources/Brave/WebFilters/CustomFilterListStorage.swift

@@ -32,6 +32,17 @@ import Data
       }
     }
   }
+
+  /// Ensures that the settings for a filter list are stored
+  /// - Parameters:
+  ///   - uuid: The uuid of the filter list to update
+  ///   - isEnabled: A boolean indicating if the filter list is enabled or not
+  public func ensureFilterList(for uuid: String, isEnabled: Bool) {
+    // Enable the setting
+    if let index = filterListsURLs.firstIndex(where: { $0.setting.uuid == uuid }) {
+      filterListsURLs[index].setting.isEnabled = isEnabled
+    }
+  }
 
   func update(filterListId id: ObjectIdentifier, with result: Result<Date, Error>) {
     guard let index = filterListsURLs.firstIndex(where: { $0.id == id }) else {

Sources/Brave/WebFilters/FilterListCustomURLDownloader.swift

@@ -128,14 +128,10 @@ actor FilterListCustomURLDownloader: ObservableObject {
       return
     }
 
-    do {
-      try await AdBlockStats.shared.compileDelayed(
-        filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
-        isAlwaysAggressive: true, delayed: true
-      )
-    } catch {
-      // Don't handle cancellation errors
-    }
+    await AdBlockStats.shared.compile(
+      filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
+      isAlwaysAggressive: true
+    )
   }
 
   /// Start fetching the resource for the given filter list. Once a new version is downloaded, the file will be processed using the `handle` method

Sources/Brave/WebFilters/FilterListResourceDownloader.swift

@@ -194,16 +194,10 @@ public actor FilterListResourceDownloader {
       return
     }
 
-    let isImportant = await AdBlockStats.shared.criticalSources.contains(source)
-
-    do {
-      try await AdBlockStats.shared.compileDelayed(
-        filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
-        isAlwaysAggressive: isAlwaysAggressive, delayed: !isImportant
-      )
-    } catch {
-      // Don't handle cancellation errors
-    }
+    await AdBlockStats.shared.compile(
+      filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
+      isAlwaysAggressive: isAlwaysAggressive
+    )
   }
 
   /// Register all enabled filter lists with the `AdBlockService`

Sources/Brave/WebFilters/ShieldStats/Adblock/AdBlockStats.swift

@@ -11,7 +11,13 @@ import os.log
 /// This object holds on to our adblock engines and returns information needed for stats tracking as well as some conveniences
 /// for injected scripts needed during web navigation and cosmetic filters models needed by the `SelectorsPollerScript.js` script.
 public actor AdBlockStats {
-  static let maxNumberOfAllowedFilterLists = 30
+  /// The max number of enabled filter lists depending on the amount memory available to the device
+  static var maxNumberOfAllowedFilterLists: Int = {
+    let memory = Int(ProcessInfo.processInfo.physicalMemory / 1073741824)
+    ContentBlockerManager.log.debug("Memory: \(memory)")
+    return min(5 * memory, 40)
+  }()
+
   typealias CosmeticFilterModelTuple = (isAlwaysAggressive: Bool, model: CosmeticFilterModel)
   public static let shared = AdBlockStats()
 
@@ -63,33 +69,13 @@ public actor AdBlockStats {
     await removeDisabledEngines()
   }
 
-  public func compileDelayed(
-    filterListInfo: CachedAdBlockEngine.FilterListInfo, resourcesInfo: CachedAdBlockEngine.ResourcesInfo,
-    isAlwaysAggressive: Bool, delayed: Bool
-  ) async throws {
-    if delayed {
-      Task.detached(priority: .background) {
-        ContentBlockerManager.log.debug("Delaying \(filterListInfo.source.debugDescription)")
-        await self.compile(
-          filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
-          isAlwaysAggressive: isAlwaysAggressive
-        )
-      }
-    } else {
-      await self.compile(
-        filterListInfo: filterListInfo, resourcesInfo: resourcesInfo,
-        isAlwaysAggressive: isAlwaysAggressive
-      )
-    }
-  }
-
   /// Create and add an engine from the given resources.
   /// If an engine already exists for the given source, it will be replaced.
   ///
   /// - Note: This method will ensure syncronous compilation
   public func compile(
     filterListInfo: CachedAdBlockEngine.FilterListInfo, resourcesInfo: CachedAdBlockEngine.ResourcesInfo, 
-    isAlwaysAggressive: Bool
+    isAlwaysAggressive: Bool, ignoreMaximum: Bool = false
   ) async {
     await currentCompileTask?.value
 
@@ -99,7 +85,7 @@ public actor AdBlockStats {
     }
 
     currentCompileTask = Task {
-      if reachedMaxLimit && cachedEngines[filterListInfo.source] == nil {
+      if !ignoreMaximum && reachedMaxLimit && cachedEngines[filterListInfo.source] == nil {
         ContentBlockerManager.log.error("Failed to compile engine for \(filterListInfo.source.debugDescription): Reached maximum!")
         return
       }
@@ -171,22 +157,18 @@ public actor AdBlockStats {
   /// Remove all engines that have disabled sources
   func ensureEnabledEngines() async {
     do {
-      var count = 0
-
       for source in await enabledSources {
         guard cachedEngines[source] == nil else { continue }
         guard let availableFilterList = availableFilterLists[source] else { continue }
         guard let resourcesInfo = self.resourcesInfo else { continue }
 
-        try await compileDelayed(
+        await compile(
           filterListInfo: availableFilterList.filterListInfo,
           resourcesInfo: resourcesInfo,
-          isAlwaysAggressive: availableFilterList.isAlwaysAggressive,
-          delayed: count > 5
+          isAlwaysAggressive: availableFilterList.isAlwaysAggressive
         )
 
         // Sleep for 1ms. This drastically reduces memory usage without much impact to usability
-        count += 1
         try await Task.sleep(nanoseconds: 1000000)
       }
     } catch {