fixes and improvements related to Core Data usage #1443

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed issue where relay metadata is never updated. [#1472](https://github.com/planetary-social/nos/issues/1472)
 - Updated the copy on the 3 dots note menu. [#1028](https://github.com/planetary-social/nos/issues/1028)
 - Added functionality to share notes link through the 3 dots note menu. [#1272](https://github.com/planetary-social/nos/issues/1272)
+- Fixes and improvements related to Core Data usage. [#1443](https://github.com/planetary-social/nos/issues/1443)
 
 ### Internal Changes
 - Use NIP-92 media metadata to display media in the proper orientation. Currently behind the “Enable new media display” feature flag. [#1172](https://github.com/planetary-social/nos/issues/1172)

Nos/Controller/PersistenceController.swift

@@ -2,24 +2,24 @@ import CoreData
 import Logger
 import Dependencies
 
-class PersistenceController {
+final class PersistenceController {
 
     @Dependency(\.currentUser) var currentUser
     @Dependency(\.crashReporting) var crashReporting
 
     /// Increment this to delete core data on update
-    static let version = 3
-    static let versionKey = "NosPersistenceControllerVersion"
+    private static let version = 3
+    private static let versionKey = "NosPersistenceControllerVersion"
 
     static var preview: PersistenceController = {
         let controller = PersistenceController(inMemory: true)
-        let viewContext = controller.container.viewContext
+        let viewContext = controller.viewContext
         return controller
     }()
 
     static var empty: PersistenceController = {
         let result = PersistenceController(inMemory: true)
-        let viewContext = result.container.viewContext
+        let viewContext = result.viewContext
         return result
     }()
 
@@ -28,22 +28,18 @@ class PersistenceController {
     }
 
     /// A context for parsing Nostr events from relays.
-    lazy var parseContext = {
-        newBackgroundContext()
-    }()
+    private(set) lazy var parseContext = newBackgroundContext()
 
     /// A context for Views to do expensive queries that we want to keep off the viewContext.
-    lazy var backgroundViewContext = {
-        self.newBackgroundContext()
-    }()
+    private(set) lazy var backgroundViewContext = newBackgroundContext()
 
     var sqliteURL: URL? {
         container.persistentStoreDescriptions.first?.url
     }
 
     private(set) var container: NSPersistentContainer
-    private var model: NSManagedObjectModel
-    private var inMemory: Bool
+    private let model: NSManagedObjectModel
+    private let inMemory: Bool
 
     init(containerName: String = "Nos", inMemory: Bool = false, erase: Bool = false) {
         self.inMemory = inMemory
@@ -53,57 +49,19 @@ class PersistenceController {
         setUp(erasingPrevious: erase)
     }
 
-    func tearDown() throws {
-        for store in container.persistentStoreCoordinator.persistentStores {
-            try container.persistentStoreCoordinator.remove(store)
-        }
-
-        try container.persistentStoreDescriptions.forEach { storeDescription in
-            try container.persistentStoreCoordinator.destroyPersistentStore(
-                at: storeDescription.url!, 
-                ofType: NSSQLiteStoreType, 
-                options: nil
-            )
-        }
-
-        viewContext.reset()
-        backgroundViewContext.reset()
-        parseContext.reset() 
-    }
-
-    func setUp(erasingPrevious: Bool) {
+    private func setUp(erasingPrevious: Bool) {
         if inMemory {
             container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
         } 
 
         loadPersistentStores(from: container, erasingPrevious: erasingPrevious)
 
-        container.viewContext.automaticallyMergesChangesFromParent = true
-        let mergeType = NSMergePolicyType.mergeByPropertyStoreTrumpMergePolicyType
-        container.viewContext.mergePolicy = NSMergePolicy(merge: mergeType)
-    }
-
-    #if DEBUG
-    func resetForTesting() {
-        container = NSPersistentContainer(name: "Nos", managedObjectModel: model)
-        if !inMemory {
-            container.loadPersistentStores(completionHandler: { (storeDescription, _) in
-                guard let storeURL = storeDescription.url else {
-                    Log.error("Could not get store URL")
-                    return
-                }
-                Self.clearCoreData(store: storeURL, in: self.container)
-            })
-        }
-        setUp(erasingPrevious: true)
-        viewContext.reset()
-        backgroundViewContext.reset()
-        parseContext.reset() 
+        viewContext.automaticallyMergesChangesFromParent = true
+        viewContext.mergePolicy = NSMergePolicy.mergeByPropertyStoreTrump
     }
-    #endif
 
     private func loadPersistentStores(from container: NSPersistentContainer, erasingPrevious: Bool) {
-        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
+        container.loadPersistentStores { storeDescription, error in
 
             // Drop database if necessary
             if Self.loadVersionFromDisk() < Self.version || erasingPrevious {
@@ -124,7 +82,7 @@ class PersistenceController {
                 }
                 fatalError("Could not initialize database \(error), \(error.userInfo)")
             }
-        })
+        }
     }
 
     @MainActor
@@ -135,7 +93,7 @@ class PersistenceController {
         }
     }
 
-    static func clearCoreData(store storeURL: URL, in container: NSPersistentContainer) {
+    private static func clearCoreData(store storeURL: URL, in container: NSPersistentContainer) {
         Log.info("Dropping Core Data...")
         do {
             try container.persistentStoreCoordinator.destroyPersistentStore(at: storeURL, type: .sqlite)
@@ -144,56 +102,22 @@ class PersistenceController {
         }
     }
 
-    func loadSampleData(context: NSManagedObjectContext) async throws {
-        guard let sampleFile = Bundle.current.url(forResource: "sample_data", withExtension: "json") else {
-            Log.error("Error: bad sample file location")
-            return
-        }
-
-        guard let sampleData = try? Data(contentsOf: sampleFile) else {
-            print("Error: Debug data not found")
-            return
-        }
-
-        Event.deleteAll(context: context)
-        context.reset()
-
-        guard let events = try? EventProcessor.parse(jsonData: sampleData, from: nil, in: context) else {
-            print("Error: Could not parse events")
-            return
-        }
-
-        print("Successfully preloaded \(events.count) events")
-
-        let verifiedEvents = Event.all(context: context)
-        print("Successfully fetched \(verifiedEvents.count) events")
-
-        // Force follow sample data users; This will be wiped if you sync with a relay.
-        let authors = Author.all(context: context)
-        let follows = try context.fetch(Follow.followsRequest(sources: authors))
-
-        if let publicKey = currentUser.publicKeyHex {
-            let currentAuthor = try Author.findOrCreate(by: publicKey, context: context)
-            currentAuthor.follows = Set(follows)
-        }
-    }
-
     func newBackgroundContext() -> NSManagedObjectContext {
         let context = container.newBackgroundContext()
         context.automaticallyMergesChangesFromParent = true
         context.mergePolicy = NSMergePolicy.mergeByPropertyStoreTrump
         return context
     }
 
-    static func loadVersionFromDisk() -> Int {
+    private static func loadVersionFromDisk() -> Int {
         UserDefaults.standard.integer(forKey: Self.versionKey)
     }
 
-    static func saveVersionToDisk(_ newVersion: Int) {
+    private static func saveVersionToDisk(_ newVersion: Int) {
         UserDefaults.standard.set(newVersion, forKey: Self.versionKey)
     }
 
-    /// Cleans up uneeded entities from the database. Our local database is really just a cache, and we need to 
+    /// Cleans up unneeded entities from the database. Our local database is really just a cache, and we need to
     /// invalidate old items to keep it from growing indefinitely.
     /// 
     /// This should only be called once right at app launch.
@@ -230,3 +154,58 @@ class PersistenceController {
         }
     }
 }
+
+#if DEBUG
+extension PersistenceController {
+    func loadSampleData(context: NSManagedObjectContext) async throws {
+        guard let sampleFile = Bundle.current.url(forResource: "sample_data", withExtension: "json") else {
+            Log.error("Error: bad sample file location")
+            return
+        }
+
+        guard let sampleData = try? Data(contentsOf: sampleFile) else {
+            print("Error: Debug data not found")
+            return
+        }
+
+        Event.deleteAll(context: context)
+        context.reset()
+
+        guard let events = try? EventProcessor.parse(jsonData: sampleData, from: nil, in: context) else {
+            print("Error: Could not parse events")
+            return
+        }
+
+        print("Successfully preloaded \(events.count) events")
+
+        let verifiedEvents = Event.all(context: context)
+        print("Successfully fetched \(verifiedEvents.count) events")
+
+        // Force follow sample data users; This will be wiped if you sync with a relay.
+        let authors = Author.all(context: context)
+        let follows = try context.fetch(Follow.followsRequest(sources: authors))
+
+        if let publicKey = currentUser.publicKeyHex {
+            let currentAuthor = try Author.findOrCreate(by: publicKey, context: context)
+            currentAuthor.follows = Set(follows)
+        }
+    }
+
+    func resetForTesting() {
+        container = NSPersistentContainer(name: "Nos", managedObjectModel: model)
+        if !inMemory {
+            container.loadPersistentStores(completionHandler: { (storeDescription, _) in
+                guard let storeURL = storeDescription.url else {
+                    Log.error("Could not get store URL")
+                    return
+                }
+                Self.clearCoreData(store: storeURL, in: self.container)
+            })
+        }
+        setUp(erasingPrevious: true)
+        viewContext.reset()
+        backgroundViewContext.reset()
+        parseContext.reset()
+    }
+}
+#endif

Nos/Controller/SearchController.swift

@@ -49,9 +49,7 @@ class SearchController: ObservableObject {
     /// The timer for showing the "not finding results" view. Resets any time the query is changed.
     private var timer: Timer?
 
-    private lazy var context: NSManagedObjectContext = {
-        persistenceController.viewContext
-    }()
+    private lazy var context = persistenceController.viewContext
 
     /// The amount of time, in seconds, to remain in the `.loading` state until switching to `.stillLoading`.
     private let stillLoadingTime: TimeInterval = 10
@@ -141,7 +139,7 @@ class SearchController: ObservableObject {
         authorResults = []
     }
 
-    func note(fromPublicKey publicKeyString: String) -> Event? {
+    private func note(fromPublicKey publicKeyString: String) -> Event? {
         let strippedString = publicKeyString.trimmingCharacters(
             in: NSCharacterSet.whitespacesAndNewlines
         )