Check Performance Degration Root Cause

CHANGELOG.md

@@ -5,7 +5,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## StreamChat
 ### ⚡ Performance
-- Improve performance of `ChatChannel` database model conversions more than 7 times [#3325](https://github.com/GetStream/stream-chat-swift/pull/3325)
 - Improve performance of `ChatChannel` and `ChatMessage` equality checks [#3335](https://github.com/GetStream/stream-chat-swift/pull/3335)
 ### ✅ Added
 - Expose `MissingConnectionId` + `InvalidURL` + `InvalidJSON` Errors [#3332](https://github.com/GetStream/stream-chat-swift/pull/3332)

Sources/StreamChat/Database/DTOs/ChannelDTO.swift

@@ -445,75 +445,70 @@ extension ChatChannel {
             )
             extraData = [:]
         }
-
-        let sortedMessageDTOs = dto.messages.sorted(by: { $0.createdAt.bridgeDate > $1.createdAt.bridgeDate })
+
         let reads: [ChatChannelRead] = try dto.reads.map { try $0.asModel() }
+
         let unreadCount: ChannelUnreadCount = {
-            guard let currentUserDTO = context.currentUser else {
+            guard let currentUser = context.currentUser else {
                 return .noUnread
             }
-            let currentUserRead = reads.first(where: { $0.user.id == currentUserDTO.user.id })
+
+            let currentUserRead = reads.first(where: { $0.user.id == currentUser.user.id })
+
             let allUnreadMessages = currentUserRead?.unreadMessagesCount ?? 0
-            // Therefore, no unread messages with mentions and we can skip the fetch
-            if allUnreadMessages == 0 {
+
+            // Fetch count of all mentioned messages after last read
+            // (this is not 100% accurate but it's the best we have)
+            let unreadMentionsRequest = NSFetchRequest<MessageDTO>(entityName: MessageDTO.entityName)
+            unreadMentionsRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
+                MessageDTO.channelMessagesPredicate(
+                    for: dto.cid,
+                    deletedMessagesVisibility: context.deletedMessagesVisibility ?? .visibleForCurrentUser,
+                    shouldShowShadowedMessages: context.shouldShowShadowedMessages ?? false
+                ),
+                NSPredicate(format: "createdAt > %@", currentUserRead?.lastReadAt.bridgeDate ?? DBDate(timeIntervalSince1970: 0)),
+                NSPredicate(format: "%@ IN mentionedUsers", currentUser.user)
+            ])
+
+            do {
+                return ChannelUnreadCount(
+                    messages: allUnreadMessages,
+                    mentions: try context.count(for: unreadMentionsRequest)
+                )
+            } catch {
+                log.error("Failed to fetch unread counts for channel `\(cid)`. Error: \(error)")
                 return .noUnread
             }
-            let unreadMentionsCount = sortedMessageDTOs
-                .prefix(allUnreadMessages)
-                .filter { $0.mentionedUsers.contains(currentUserDTO.user) }
-                .count
-            return ChannelUnreadCount(
-                messages: allUnreadMessages,
-                mentions: unreadMentionsCount
-            )
         }()
 
-        let latestMessages: [ChatMessage] = {
-            var messages = sortedMessageDTOs
-                .prefix(dto.managedObjectContext?.localCachingSettings?.chatChannel.latestMessagesLimit ?? 25)
+        let messages: [ChatMessage] = {
+            MessageDTO
+                .load(
+                    for: dto.cid,
+                    limit: dto.managedObjectContext?.localCachingSettings?.chatChannel.latestMessagesLimit ?? 25,
+                    deletedMessagesVisibility: dto.managedObjectContext?.deletedMessagesVisibility ?? .visibleForCurrentUser,
+                    shouldShowShadowedMessages: dto.managedObjectContext?.shouldShowShadowedMessages ?? false,
+                    context: context
+                )
                 .compactMap { try? $0.relationshipAsModel(depth: depth) }
-            if let oldest = dto.oldestMessageAt?.bridgeDate {
-                messages = messages.filter { $0.createdAt >= oldest }
-            }
-            if let truncated = dto.truncatedAt?.bridgeDate {
-                messages = messages.filter { $0.createdAt >= truncated }
-            }
-            return messages
         }()
 
         let latestMessageFromUser: ChatMessage? = {
-            guard let currentUserId = context.currentUser?.user.id else { return nil }
-            return try? sortedMessageDTOs
-                .first(where: { messageDTO in
-                    guard messageDTO.user.id == currentUserId else { return false }
-                    guard messageDTO.localMessageState == nil else { return false }
-                    return messageDTO.type != MessageType.ephemeral.rawValue
-                })?
+            guard let currentUser = context.currentUser else { return nil }
+
+            return try? MessageDTO
+                .loadLastMessage(
+                    from: currentUser.user.id,
+                    in: dto.cid,
+                    context: context
+                )?
                 .relationshipAsModel(depth: depth)
         }()
-
-        let watchers = dto.watchers
-            .sorted { lhs, rhs in
-                let lhsActivity = lhs.lastActivityAt?.bridgeDate ?? .distantPast
-                let rhsActivity = rhs.lastActivityAt?.bridgeDate ?? .distantPast
-                if lhsActivity == rhsActivity {
-                    return lhs.id > rhs.id
-                }
-                return lhsActivity > rhsActivity
-            }
-            .prefix(context.localCachingSettings?.chatChannel.lastActiveWatchersLimit ?? 100)
+
+        let watchers = UserDTO.loadLastActiveWatchers(cid: cid, context: context)
             .compactMap { try? $0.asModel() }
 
-        let members = dto.members
-            .sorted { lhs, rhs in
-                let lhsActivity = lhs.user.lastActivityAt?.bridgeDate ?? .distantPast
-                let rhsActivity = rhs.user.lastActivityAt?.bridgeDate ?? .distantPast
-                if lhsActivity == rhsActivity {
-                    return lhs.id > rhs.id
-                }
-                return lhsActivity > rhsActivity
-            }
-            .prefix(context.localCachingSettings?.chatChannel.lastActiveMembersLimit ?? 100)
+        let members = MemberDTO.loadLastActiveMembers(cid: cid, context: context)
             .compactMap { try? $0.asModel() }
 
         let muteDetails: MuteDetails? = {
@@ -555,7 +550,7 @@ extension ChatChannel {
             reads: reads,
             cooldownDuration: Int(dto.cooldownDuration),
             extraData: extraData,
-            latestMessages: latestMessages,
+            latestMessages: messages,
             lastMessageFromCurrentUser: latestMessageFromUser,
             pinnedMessages: pinnedMessages,
             muteDetails: muteDetails,

Sources/StreamChat/Database/DTOs/MemberModelDTO.swift

@@ -92,6 +92,17 @@ extension MemberDTO {
         new.id = memberId
         return new
     }
+
+    static func loadLastActiveMembers(cid: ChannelId, context: NSManagedObjectContext) -> [MemberDTO] {
+        let request = NSFetchRequest<MemberDTO>(entityName: MemberDTO.entityName)
+        request.predicate = NSPredicate(format: "channel.cid == %@", cid.rawValue)
+        request.sortDescriptors = [
+            ChannelMemberListSortingKey.lastActiveSortDescriptor,
+            ChannelMemberListSortingKey.defaultSortDescriptor
+        ]
+        request.fetchLimit = context.localCachingSettings?.chatChannel.lastActiveMembersLimit ?? 100
+        return load(by: request, context: context)
+    }
 }
 
 extension NSManagedObjectContext {

Sources/StreamChat/Database/DTOs/MessageDTO.swift

@@ -516,6 +516,19 @@ class MessageDTO: NSManagedObject {
         return (try? context.count(for: request)) ?? 0
     }
 
+    static func loadLastMessage(from userId: String, in cid: String, context: NSManagedObjectContext) -> MessageDTO? {
+        let request = NSFetchRequest<MessageDTO>(entityName: entityName)
+        request.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [
+            channelPredicate(with: cid),
+            .init(format: "user.id == %@", userId),
+            .init(format: "type != %@", MessageType.ephemeral.rawValue),
+            messageSentPredicate()
+        ])
+        request.sortDescriptors = [NSSortDescriptor(keyPath: \MessageDTO.createdAt, ascending: false)]
+        request.fetchLimit = 1
+        return load(by: request, context: context).first
+    }
+
     static func loadSendingMessages(context: NSManagedObjectContext) -> [MessageDTO] {
         let request = NSFetchRequest<MessageDTO>(entityName: MessageDTO.entityName)
         request.sortDescriptors = [NSSortDescriptor(keyPath: \MessageDTO.locallyCreatedAt, ascending: false)]
@@ -1296,28 +1309,21 @@ private extension ChatMessage {
 
         if let currentUser = context.currentUser {
             isSentByCurrentUser = currentUser.user.id == dto.user.id
-            if !dto.ownReactions.isEmpty {
-                currentUserReactions = Set(
-                    MessageReactionDTO
-                        .loadReactions(ids: dto.ownReactions, context: context)
-                        .compactMap { try? $0.asModel() }
-                )
-            } else {
-                currentUserReactions = []
-            }
+            currentUserReactions = Set(
+                MessageReactionDTO
+                    .loadReactions(ids: dto.ownReactions, context: context)
+                    .compactMap { try? $0.asModel() }
+            )
         } else {
             isSentByCurrentUser = false
             currentUserReactions = []
         }
 
-        latestReactions = {
-            guard !dto.latestReactions.isEmpty else { return Set() }
-            return Set(
-                MessageReactionDTO
-                    .loadReactions(ids: dto.latestReactions, context: context)
-                    .compactMap { try? $0.asModel() }
-            )
-        }()
+        latestReactions = Set(
+            MessageReactionDTO
+                .loadReactions(ids: dto.latestReactions, context: context)
+                .compactMap { try? $0.asModel() }
+        )
 
         threadParticipants = dto.threadParticipants.array
             .compactMap { $0 as? UserDTO }
@@ -1331,10 +1337,8 @@ private extension ChatMessage {
             .sorted { $0.id.index < $1.id.index }
 
         latestReplies = {
-            guard dto.replyCount > 0 else { return [] }
-            return dto.replies
-                .sorted(by: { $0.createdAt.bridgeDate > $1.createdAt.bridgeDate })
-                .prefix(5)
+            guard !dto.replies.isEmpty else { return [] }
+            return MessageDTO.loadReplies(for: dto.id, limit: 5, context: context)
                 .compactMap { try? ChatMessage(fromDTO: $0, depth: depth) }
         }()
 

Sources/StreamChat/Database/DTOs/UserDTO.swift

@@ -115,6 +115,17 @@ extension UserDTO {
         new.teams = []
         return new
     }
+
+    static func loadLastActiveWatchers(cid: ChannelId, context: NSManagedObjectContext) -> [UserDTO] {
+        let request = NSFetchRequest<UserDTO>(entityName: UserDTO.entityName)
+        request.sortDescriptors = [
+            UserListSortingKey.lastActiveSortDescriptor,
+            UserListSortingKey.defaultSortDescriptor
+        ]
+        request.predicate = NSPredicate(format: "ANY watchedChannels.cid == %@", cid.rawValue)
+        request.fetchLimit = context.localCachingSettings?.chatChannel.lastActiveWatchersLimit ?? 100
+        return load(by: request, context: context)
+    }
 }
 
 extension NSManagedObjectContext: UserDatabaseSession {

Sources/StreamChat/Query/Sorting/ChannelMemberListSortingKey.swift

@@ -33,6 +33,11 @@ extension ChannelMemberListSortingKey {
         return .init(keyPath: dateKeyPath, ascending: false)
     }()
 
+    static let lastActiveSortDescriptor: NSSortDescriptor = {
+        let dateKeyPath: KeyPath<MemberDTO, DBDate?> = \MemberDTO.user.lastActivityAt
+        return .init(keyPath: dateKeyPath, ascending: false)
+    }()
+
     func sortDescriptor(isAscending: Bool) -> NSSortDescriptor {
         .init(key: rawValue, ascending: isAscending)
     }

Sources/StreamChat/Query/Sorting/UserListSortingKey.swift

@@ -39,6 +39,11 @@ extension UserListSortingKey {
         return .init(keyPath: stringKeyPath, ascending: false)
     }()
 
+    static let lastActiveSortDescriptor: NSSortDescriptor = {
+        let dateKeyPath: KeyPath<UserDTO, DBDate?> = \UserDTO.lastActivityAt
+        return .init(keyPath: dateKeyPath, ascending: false)
+    }()
+
     func sortDescriptor(isAscending: Bool) -> NSSortDescriptor? {
         .init(key: rawValue, ascending: isAscending)
     }

Tests/StreamChatTests/Database/DTOs/ChannelDTO_Tests.swift

@@ -1322,7 +1322,7 @@ final class ChannelDTO_Tests: XCTestCase {
         XCTAssertEqual(channel.unreadCount.messages, 0)
     }
 
-    func test_asModel_populatesLatestMessage_withoutFilteringDeletedMessages() throws {
+    func test_asModel_populatesLatestMessage() throws {
         // GIVEN
         database = DatabaseContainer_Spy(
             kind: .inMemory,
@@ -1411,7 +1411,7 @@ final class ChannelDTO_Tests: XCTestCase {
         // THEN
         XCTAssertEqual(
             Set(channel.latestMessages.map(\.id)),
-            Set([message1.id, deletedMessageFromCurrentUser.id, deletedMessageFromAnotherUser.id])
+            Set([message1.id, deletedMessageFromCurrentUser.id, shadowedMessageFromAnotherUser.id])
         )
     }