feat(concurrency): update HomeViewModel, make fetched result vc deleg…

…ate call concurrency safe
Pocket · Jul 23, 2024 · 43e3090 · 43e3090
1 parent 889a67a
commit 43e3090
Showing 1 changed file with 63 additions and 51 deletions.
diff --git a/PocketKit/Sources/PocketKit/Home/HomeViewModel.swift b/PocketKit/Sources/PocketKit/Home/HomeViewModel.swift
@@ -964,62 +964,74 @@ extension HomeViewModel {
 }
 
 extension HomeViewModel: NSFetchedResultsControllerDelegate {
-    func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChangeContentWith snapshot: NSDiffableDataSourceSnapshotReference) {
-        var newSnapshot = buildSnapshot()
-
-        if controller == recentSavesController {
-            let reloadedItemIdentifiers: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .recentSaves($0 as! NSManagedObjectID) })
-            let reconfiguredItemdIdentifiers: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .recentSaves($0 as! NSManagedObjectID) })
-            newSnapshot.reloadItems(reloadedItemIdentifiers)
-            newSnapshot.reconfigureItems(reconfiguredItemdIdentifiers)
-            updateRecentSavesWidget()
-        }
+    nonisolated func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChangeContentWith snapshot: NSDiffableDataSourceSnapshotReference) {
+        let isRecentSaves = controller is NSFetchedResultsController<SavedItem>
+        let isRecommendations = controller is RichFetchedResultsController<Recommendation>
+        let isSharedWithYou =  controller is RichFetchedResultsController<SharedWithYouItem>
 
-        if isOffline {
-            // If we are offline don't try and do anything with Slates, and let the snapshot show the offline
-            setRecommendationsWidgetOffline()
-            self.snapshot = newSnapshot
-            return
-        }
+        let reloadedRecentSaves: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .recentSaves($0 as! NSManagedObjectID) })
+        let reconfiguredRecentSaves: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .recentSaves($0 as! NSManagedObjectID) })
 
-        if controller == recomendationsController {
-            let existingItemIdentifiers = newSnapshot.itemIdentifiers
-
-            // Gather all variations a recomendation could exist in for reloaded identifiers
-            var reloadedItemIdentifiers: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .recommendationHero($0 as! NSManagedObjectID) })
-            reloadedItemIdentifiers.append(contentsOf: snapshot.reloadedItemIdentifiers.compactMap({ .recommendationCarousel($0 as! NSManagedObjectID) }))
-            // Filter to just the ones that exist in our snapshot
-            reloadedItemIdentifiers = reloadedItemIdentifiers.filter({ existingItemIdentifiers.contains($0) })
-            // Tell the new snapshot to reload just the ones that exist
-            newSnapshot.reloadItems(reloadedItemIdentifiers)
-
-            // Gather all variations a recomendation could exist in for reconfigured identifiers
-            var reconfiguredItemIdentifiers: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .recommendationHero($0 as! NSManagedObjectID) })
-            reconfiguredItemIdentifiers.append(contentsOf: snapshot.reconfiguredItemIdentifiers.compactMap({ .recommendationCarousel($0 as! NSManagedObjectID) }))
-            // Filter to just the ones that exist in our snapshot
-            reconfiguredItemIdentifiers = reconfiguredItemIdentifiers.filter({ existingItemIdentifiers.contains($0) })
-            // Tell the new snapshot to reconfigure just the ones that exist
-            newSnapshot.reconfigureItems(reconfiguredItemIdentifiers)
-            updateRecommendationsWidget()
-        }
+        let reloadedHeroRecommendations: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .recommendationHero($0 as! NSManagedObjectID) })
+        let reconfiguredHeroRecommendations: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .recommendationHero($0 as! NSManagedObjectID) })
+
+        let reloadedCarouselRecommendations: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .recommendationCarousel($0 as! NSManagedObjectID) })
+        let reconfiguredCarouselRecommendations: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .recommendationCarousel($0 as! NSManagedObjectID) })
+
+        let reloadedSharedWithYou: [Cell] = snapshot.reloadedItemIdentifiers.compactMap({ .sharedWithYou($0 as! NSManagedObjectID) })
+        let reconfiguredSharedWithYou: [Cell] = snapshot.reconfiguredItemIdentifiers.compactMap({ .sharedWithYou($0 as! NSManagedObjectID) })
+
+        Task { @MainActor in
+            var newSnapshot = buildSnapshot()
+
+            if isRecentSaves {
+                newSnapshot.reloadItems(reloadedRecentSaves)
+                newSnapshot.reconfigureItems(reconfiguredRecentSaves)
+                updateRecentSavesWidget()
+            }
 
-        if controller == sharedWithYouController {
-            let existingItemIdentifiers = newSnapshot.itemIdentifiers
-            let reloadedItems: [Cell] =
-            snapshot
-                .reloadedItemIdentifiers
-                .compactMap { .sharedWithYou($0 as! NSManagedObjectID) }
-                .filter { existingItemIdentifiers.contains($0) }
-            let reconfiguredItems: [Cell] =
-            snapshot
-                .reconfiguredItemIdentifiers
-                .compactMap { .sharedWithYou($0 as! NSManagedObjectID) }
-                .filter { existingItemIdentifiers.contains($0) }
-            newSnapshot.reloadItems(reloadedItems)
-            newSnapshot.reconfigureItems(reconfiguredItems)
+            if isOffline {
+                // If we are offline don't try and do anything with Slates, and let the snapshot show the offline
+                setRecommendationsWidgetOffline()
+                self.updateSnapshot(newSnapshot)
+                return
+            }
+
+            if isRecommendations {
+                let existingItemIdentifiers = newSnapshot.itemIdentifiers
+
+                // Gather all variations a recomendation could exist in for reloaded identifiers
+                var reloadedItemIdentifiers = reloadedHeroRecommendations
+                reloadedItemIdentifiers.append(contentsOf: reloadedCarouselRecommendations)
+                // Filter to just the ones that exist in our snapshot
+                reloadedItemIdentifiers = reloadedItemIdentifiers.filter({ existingItemIdentifiers.contains($0) })
+                // Tell the new snapshot to reload just the ones that exist
+                newSnapshot.reloadItems(reloadedItemIdentifiers)
+
+                // Gather all variations a recomendation could exist in for reconfigured identifiers
+                var reconfiguredItemIdentifiers = reconfiguredHeroRecommendations
+                reconfiguredItemIdentifiers.append(contentsOf: reconfiguredCarouselRecommendations)
+                // Filter to just the ones that exist in our snapshot
+                reconfiguredItemIdentifiers = reconfiguredItemIdentifiers.filter({ existingItemIdentifiers.contains($0) })
+                // Tell the new snapshot to reconfigure just the ones that exist
+                newSnapshot.reconfigureItems(reconfiguredItemIdentifiers)
+                updateRecommendationsWidget()
+            }
+
+            if isSharedWithYou {
+                let existingItemIdentifiers = newSnapshot.itemIdentifiers
+                let reloadedItems = reloadedSharedWithYou.filter { existingItemIdentifiers.contains($0) }
+                let reconfiguredItems = reconfiguredSharedWithYou.filter { existingItemIdentifiers.contains($0) }
+                newSnapshot.reloadItems(reloadedItems)
+                newSnapshot.reconfigureItems(reconfiguredItems)
+            }
+
+            self.updateSnapshot(newSnapshot)
         }
+    }
 
-        self.snapshot = newSnapshot
+    private func updateSnapshot(_ snapshot: Snapshot) {
+        self.snapshot = snapshot
     }
 }