Add logging to persistent store

Tusker/CoreData/MastodonCachePersistentStore.swift

@@ -10,6 +10,9 @@ import Foundation
 import CoreData
 import Pachyderm
 import Combine
+import OSLog
+
+fileprivate let logger = Logger(subsystem: Bundle.main.bundleIdentifier!, category: "PersistentStore")
 
 class MastodonCachePersistentStore: NSPersistentContainer {
     
@@ -49,7 +52,8 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         
         loadPersistentStores { (description, error) in
             if let error = error {
-                fatalError("Unable to load persistent store: \(error)")
+                logger.error("Unable to load persistent store: \(String(describing: error), privacy: .public)")
+                fatalError("Unable to load persistent store")
             }
         }
         
@@ -58,6 +62,18 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         NotificationCenter.default.addObserver(self, selector: #selector(managedObjectsDidChange), name: .NSManagedObjectContextObjectsDidChange, object: viewContext)
     }
     
+    func save(context: NSManagedObjectContext) {
+        guard context.hasChanges else {
+            return
+        }
+        do {
+            try context.save()
+        } catch {
+            logger.error("Unable to save managed object context: \(String(describing: error), privacy: .public)")
+            fatalError("Unable to save managed object context")
+        }
+    }
+    
     func status(for id: String, in context: NSManagedObjectContext? = nil) -> StatusMO? {
         let context = context ?? viewContext
         let request: NSFetchRequest<StatusMO> = StatusMO.fetchRequest()
@@ -84,9 +100,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         let context = context ?? backgroundContext
         context.perform {
             let statusMO = self.upsert(status: status, context: context)
-            if context.hasChanges {
-                try! context.save()
-            }
+            self.save(context: context)
             completion?(statusMO)
             self.statusSubject.send(status.id)
         }
@@ -95,9 +109,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
     @MainActor
     func addOrUpdateOnViewContext(status: Status) -> StatusMO {
         let statusMO = self.upsert(status: status, context: viewContext)
-        if viewContext.hasChanges {
-            try! viewContext.save()
-        }
+        self.save(context: viewContext)
         statusSubject.send(status.id)
         return statusMO
     }
@@ -105,9 +117,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
     func addAll(statuses: [Status], completion: (() -> Void)? = nil) {
         backgroundContext.perform {
             statuses.forEach { self.upsert(status: $0, context: self.backgroundContext) }
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             statuses.forEach { self.statusSubject.send($0.id) }
             completion?()
         }
@@ -146,9 +156,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
     func addOrUpdate(account: Account, completion: ((AccountMO) -> Void)? = nil) {
         backgroundContext.perform {
             let accountMO = self.upsert(account: account)
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             completion?(accountMO)
             self.accountSubject.send(account.id)
         }
@@ -180,9 +188,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
     func addOrUpdate(relationship: Relationship, completion: ((RelationshipMO) -> Void)? = nil) {
         backgroundContext.perform {
             let relationshipMO = self.upsert(relationship: relationship)
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             completion?(relationshipMO)
             self.relationshipSubject.send(relationship.id)
         }
@@ -191,9 +197,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
     func addAll(accounts: [Account], completion: (() -> Void)? = nil) {
         backgroundContext.perform {
             accounts.forEach { self.upsert(account: $0) }
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             completion?()
             accounts.forEach { self.accountSubject.send($0.id) }
         }
@@ -207,9 +211,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
             let accounts = notifications.filter { $0.kind != .mention }.map { $0.account }
             statuses.forEach { self.upsert(status: $0, context: self.backgroundContext) }
             accounts.forEach { self.upsert(account: $0) }
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             completion?()
             statuses.forEach { self.statusSubject.send($0.id) }
             accounts.forEach { self.accountSubject.send($0.id) }
@@ -232,9 +234,7 @@ class MastodonCachePersistentStore: NSPersistentContainer {
             updatedAccounts.forEach(self.accountSubject.send)
             updatedStatuses.forEach(self.statusSubject.send)
             
-            if self.backgroundContext.hasChanges {
-                try! self.backgroundContext.save()
-            }
+            self.save(context: self.backgroundContext)
             completion?()
         }
     }

Tusker/Screens/Timeline/HashtagTimelineViewController.swift

@@ -58,7 +58,7 @@ class HashtagTimelineViewController: TimelineTableViewController {
         } else {
             _ = SavedHashtag(hashtag: hashtag, context: context)
         }
-        try! context.save()
+        mastodonController.persistentContainer.save(context: context)
     }
 
 }

Tusker/Screens/Timeline/InstanceTimelineViewController.swift

@@ -94,7 +94,7 @@ class InstanceTimelineViewController: TimelineTableViewController {
             _ = SavedInstance(url: instanceURL, context: context)
             delegate?.didSaveInstance(url: instanceURL)
         }
-        try? context.save()
+        mastodonController.persistentContainer.save(context: context)
     }
 
 }

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -144,6 +144,12 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         }
     }
     
+    override func viewDidDisappear(_ animated: Bool) {
+        super.viewDidDisappear(animated)
+        
+        // TODO: prune offscreen rows
+    }
+    
     private func removeTimelineDescriptionCell() {
         var snapshot = dataSource.snapshot()
         snapshot.deleteSections([.header])

Tusker/Screens/Utilities/Previewing.swift

@@ -110,7 +110,7 @@ extension MenuActionProvider {
                     } else {
                         _ = SavedHashtag(hashtag: hashtag, context: context)
                     }
-                    try! context.save()
+                    mastodonController.persistentContainer.save(context: context)
                 })
             ]
         } else {

Tusker/Views/Poll/StatusPollView.swift

@@ -170,9 +170,7 @@ class StatusPollView: UIView {
                         return
                     }
                     status.poll = poll
-                    if container.viewContext.hasChanges {
-                        try! container.viewContext.save()
-                    }
+                    container.save(context: container.viewContext)
                     container.statusSubject.send(status.id)
                 }
             }