Caching the room proxies and their messages. Improved performance throughout.

2026-11-03 16:10:20 +00:00 · 2022-03-31 15:37:52 +03:00
parent b50bf724a3
commit 49f7678ce8
22 changed files with 191 additions and 189 deletions
@@ -91,8 +91,6 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
    // MARK: - Private
    
    func updateRoomsList() {
-        parameters.userSession.getRoomList { [weak self] rooms in
-            self?.viewModel.updateWithRoomList(rooms)
-        }
+        self.viewModel.updateWithRoomList(parameters.userSession.rooms)
    }
 }
@@ -67,7 +67,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
        self.roomList = roomList
        
        state.rooms = roomList.map { roomProxy in
-            roomFromProxy(roomProxy)
+            buildRoomFromProxy(roomProxy)
        }
        
        roomUpdateListeners.removeAll()
@@ -75,10 +75,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
        roomList.forEach({ roomProxy  in
            roomProxy.callbacks.sink { [weak self] callback in
                switch callback {
-                case .updatedLastMessage:
+                case .updatedMessages:
                    self?.loadLastMessageForRoomWithIdentifier(roomProxy.id)
-                default:
-                    break
                }
            }
            .store(in: &roomUpdateListeners)
@@ -92,9 +90,19 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
    // MARK: - Private
    
    private func loadRoomDataForIdentifier(_ roomIdentifier: String) {
-        loadAvatarForRoomWithIdentifier(roomIdentifier)
-        loadRoomDisplayNameForRoomWithIdentifier(roomIdentifier)
-        loadLastMessageForRoomWithIdentifier(roomIdentifier)
+        let room = state.rooms.first(where: { $0.id == roomIdentifier })
+        
+        if room?.avatar == nil {
+            loadAvatarForRoomWithIdentifier(roomIdentifier)
+        }
+        
+        if room?.displayName == nil {
+            loadRoomDisplayNameForRoomWithIdentifier(roomIdentifier)
+        }
+        
+        if room?.lastMessage == nil {
+            loadLastMessageForRoomWithIdentifier(roomIdentifier)
+        }
    }
    
    private func loadAvatarForRoomWithIdentifier(_ roomIdentifier: String) {
@@ -149,22 +157,12 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
            return
        }
        
-        if let lastMessage = room.lastMessage {
-            self.updateLastMessage(lastMessage, forRoomWithIdentifier: roomIdentifier)
-        } else {
-            room.paginateBackwards(count: 1) { result in
-                switch result {
-                case .success(let messages):
-                    guard let lastMessage = messages.last else {
-                        return
-                    }
-                    
-                    self.updateLastMessage(lastMessage.body, forRoomWithIdentifier: roomIdentifier)
-                default:
-                    break
-                }
-            }
+        if let lastMessage = room.messages.last {
+            self.updateLastMessage(lastMessage.body, forRoomWithIdentifier: roomIdentifier)
+            return
        }
+        
+        room.paginateBackwards(count: 1, callback: nil)
    }
    
    private func updateLastMessage(_ lastMessage: String, forRoomWithIdentifier roomIdentifier: String) {
@@ -174,15 +172,18 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
        
        self.state.rooms[index].lastMessage = lastMessage
    }
+    
+    private func buildRoomFromProxy(_ roomProxy: RoomProxyProtocol) -> HomeScreenRoom {
+        let avatar = mediaProvider.imageForURL(roomProxy.avatarURL)
        
-    private func roomFromProxy(_ roomProxy: RoomProxyProtocol) -> HomeScreenRoom {
-        HomeScreenRoom(id: roomProxy.id,
-                       displayName: roomProxy.name,
-                       topic: roomProxy.topic,
-                       lastMessage: roomProxy.lastMessage,
-                       isDirect: roomProxy.isDirect,
-                       isEncrypted: roomProxy.isEncrypted,
-                       isSpace: roomProxy.isSpace,
-                       isTombstoned: roomProxy.isTombstoned)
+        return HomeScreenRoom(id: roomProxy.id,
+                              displayName: roomProxy.name,
+                              topic: roomProxy.topic,
+                              lastMessage: roomProxy.messages.last?.body,
+                              avatar: avatar,
+                              isDirect: roomProxy.isDirect,
+                              isEncrypted: roomProxy.isEncrypted,
+                              isSpace: roomProxy.isSpace,
+                              isTombstoned: roomProxy.isTombstoned)
    }
 }
@@ -38,9 +38,7 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
        self.timelineController = timelineController
        self.timelineViewFactory = timelineViewFactory
        
-        super.init(initialViewState: RoomScreenViewState(roomTitle: roomName ?? "💥"))
-        
-        buildTimelineViews()
+        super.init(initialViewState: RoomScreenViewState(roomTitle: roomName ?? "Unknown room 💥"))
        
        timelineController.callbacks.sink { [weak self] callback in
            guard let self = self else { return }
@@ -57,6 +55,8 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
                self.state.items[viewIndex] = timelineViewFactory.buildTimelineViewFor(timelineItem)
            }
        }.store(in: &cancellables)
+        
+        buildTimelineViews()
    }
    
    // MARK: - Public
@@ -80,8 +80,10 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
    // MARK: - Private
    
    private func buildTimelineViews() {
-        state.items = timelineController.timelineItems.map { item  in
+        let stateItems = timelineController.timelineItems.map { item  in
            timelineViewFactory.buildTimelineViewFor(item)
        }
+        
+        state.items = stateItems
    }
 }
@@ -30,7 +30,7 @@ struct EmoteRoomTimelineView: View {

 struct EmoteRoomTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -51,7 +51,7 @@ struct EventBasedTimelineView: View {

 struct EventBasedTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -35,7 +35,7 @@ struct FormattedBodyText: View {

 struct FormattedBodyText_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
        
    }
@@ -35,7 +35,7 @@ struct ImageRoomTimelineView: View {

 struct ImageRoomTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
     
@@ -30,7 +30,7 @@ struct NoticeRoomTimelineView: View {

 struct NoticeRoomTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -36,7 +36,7 @@ struct PlaceholderAvatarImage: View {

 struct PlaceholderAvatarImage_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -44,7 +44,7 @@ struct LabelledDivider: View {

 struct SeparatorRoomTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -27,7 +27,7 @@ struct TextRoomTimelineView: View {

 struct TextRoomTimelineView_Previews: PreviewProvider {
    static var previews: some View {
-        body
+        body.preferredColorScheme(.light)
        body.preferredColorScheme(.dark)
    }
    
@@ -59,9 +59,16 @@ struct TimelineView: View {
                tableViewObserver = TableViewObserver(tableView: tableView,
                                                      topDetectionOffset: (tableView.bounds.size.height / 3.0))
                
+                tableViewObserver.scrollToBottom()
+                
                // Check if there are enough items. Otherwise ask for more
                attemptBackPagination()
            }
+            .onAppear(perform: {
+                if timelineItems != context.viewState.items {
+                    timelineItems = context.viewState.items
+                }
+            })
            .onReceive(tableViewObserver.scrollViewDidReachTop, perform: {
                if context.viewState.isBackPaginating {
                    return
@@ -202,6 +209,20 @@ private class TableViewObserver: NSObject, UITableViewDelegate {
        return (scrollView.contentOffset.y + scrollView.adjustedContentInset.top) <= topDetectionOffset
    }
    
+    func scrollToBottom() {
+        guard let tableView = tableView,
+              tableView.numberOfSections > 0  else {
+                  return
+        }
+        
+        let currentItemCount = tableView.numberOfRows(inSection: 0)
+        guard currentItemCount > 1 else {
+            return
+        }
+        
+        tableView.scrollToRow(at: .init(row: currentItemCount - 1, section: 0), at: .bottom, animated: false)
+    }
+    
    // MARK: - UIScrollViewDelegate

    func scrollViewDidScroll(_ scrollView: UIScrollView) {