UserMessageList: use @FetchRequest to prevent the N^2 behavior that was happening in calls to allPrivateMessages

Meshtastic/Extensions/CoreData/UserEntityExtension.swift

@@ -10,12 +10,20 @@ import CoreData
 import MeshtasticProtobufs
 
 extension UserEntity {
+	var messagePredicate: NSPredicate {
+		return NSPredicate(format: "((toUser == %@) OR (fromUser == %@)) AND toUser != nil AND fromUser != nil AND isEmoji == false AND admin = false AND portNum != 10", self, self)
+	}
+
+	var messageFetchRequest: NSFetchRequest<MessageEntity> {
+		let fetchRequest = MessageEntity.fetchRequest()
+		fetchRequest.sortDescriptors = [NSSortDescriptor(key: "messageTimestamp", ascending: true)]
+		fetchRequest.predicate = messagePredicate
+		return fetchRequest
+	}
 
 	var messageList: [MessageEntity] {
 		let context = PersistenceController.shared.container.viewContext
-		let fetchRequest = MessageEntity.fetchRequest()
-		fetchRequest.sortDescriptors = [NSSortDescriptor(key: "messageTimestamp", ascending: true)]
-		fetchRequest.predicate = NSPredicate(format: "((toUser == %@) OR (fromUser == %@)) AND toUser != nil AND fromUser != nil AND isEmoji == false AND admin = false AND portNum != 10", self, self)
+		let fetchRequest = messageFetchRequest
 
 		return (try? context.fetch(fetchRequest)) ?? [MessageEntity]()
 	}
@@ -26,9 +34,8 @@ extension UserEntity {
 
 		// Most recent DM for this user (descending, limit 1)
 		let context = PersistenceController.shared.container.viewContext
-		let fetchRequest = MessageEntity.fetchRequest()
+		let fetchRequest = messageFetchRequest
 		fetchRequest.sortDescriptors = [NSSortDescriptor(key: "messageTimestamp", ascending: false)]
-		fetchRequest.predicate = NSPredicate(format: "((toUser == %@) OR (fromUser == %@)) AND toUser != nil AND fromUser != nil AND isEmoji == false AND admin = false AND portNum != 10", self, self)
 		fetchRequest.fetchLimit = 1
 
 		return (try? context.fetch(fetchRequest))?.first
@@ -48,9 +55,10 @@ extension UserEntity {
 		// (For our own node, set skipLastMessageCheck=true, because we don't update lastMessage on our own connected node.)
 		guard self.lastMessage != nil || skipLastMessageCheck else { return 0; }
 
-		let fetchRequest = MessageEntity.fetchRequest()
-		// sort is irrelvant.
-		fetchRequest.predicate = NSPredicate(format: "((toUser == %@) OR (fromUser == %@)) AND toUser != nil AND fromUser != nil AND isEmoji == false AND admin = false AND portNum != 10 AND read == false", self, self)
+		let fetchRequest = messageFetchRequest
+		fetchRequest.sortDescriptors = [] // sort is irrelvant.
+		fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [fetchRequest.predicate!, NSPredicate(format: "read == false")])
+
 		return (try? context.count(for: fetchRequest)) ?? 0
 	}
 

Meshtastic/Views/Messages/UserMessageList.swift

@@ -21,17 +21,21 @@ struct UserMessageList: View {
 	@State private var messageToHighlight: Int64 = 0
 	@State private var redrawTapbacksTrigger = UUID()
 	@AppStorage("preferredPeripheralNum") private var preferredPeripheralNum = -1
-	
-	private var allPrivateMessages: [MessageEntity] {
-		// Cast user.messageList to an array for easier indexing and ForEach.
-		return user.messageList.compactMap { $0 as MessageEntity }
+	@FetchRequest private var allPrivateMessages: FetchedResults<MessageEntity>
+
+	init(user: UserEntity) {
+		self.user = user
+
+		// Configure fetch request here
+		let request: NSFetchRequest<MessageEntity> = user.messageFetchRequest
+		_allPrivateMessages = FetchRequest(fetchRequest: request)
 	}
-	
+
 	func handleInteractionComplete() {
 		markMessagesAsRead()
 		redrawTapbacksTrigger = UUID()
 	}
-	
+
 	func markMessagesAsRead() {
 		do {
 			for unreadMessage in allPrivateMessages.filter({ !$0.read }) {
@@ -51,19 +55,22 @@ struct UserMessageList: View {
 			Logger.data.error("Failed to read direct messages: \(error.localizedDescription, privacy: .public)")
 		}
 	}
-	
+
 	var body: some View {
+		// Cast user.messageList to an array for easier indexing and ForEach.
+		let messages = allPrivateMessages.compactMap { $0 as MessageEntity }
+
 		VStack {
 			ScrollViewReader { scrollView in
 				ScrollView {
 					LazyVStack {
-						ForEach(allPrivateMessages.indices, id: \.self) { index in
-							let message = allPrivateMessages[index]
-							let previousMessage = index > 0 ? allPrivateMessages[index - 1] : nil
+						ForEach(messages.indices, id: \.self) { index in
+							let message = messages[index]
+							let previousMessage = index > 0 ? messages[index - 1] : nil
 							
 							UserMessageRow(
 								message: message,
-								allMessages: allPrivateMessages,
+								allMessages: messages,
 								previousMessage: previousMessage,
 								preferredPeripheralNum: preferredPeripheralNum,
 								user: user,