Various performance tweaks (#474)

* Store and reuse room list placeholder avatars and last messages

* Cache and reuse HomeScreenRooms

* Reduce RoomSummaryProvider diff collection time

* Promote more logs to info

* Slighty tweak RustTracing to make it easier to configure

* Move TimelineProvider and RoomTimelineController item processing to background queues

* Prevent the timeline from stopping an ogoing decelerating scroll when starting backpaginating

ElementX.xcodeproj/project.pbxproj

@@ -27,6 +27,7 @@
 		09713669577CDA8D012EE380 /* MatrixRustSDK in Frameworks */ = {isa = PBXBuildFile; productRef = 6647C55D93508C7CE9D954A5 /* MatrixRustSDK */; };
 		098CE03C6CC71A31F263FA33 /* ActivityCoordinator.swift in Sources */ = {isa = PBXBuildFile; fileRef = CA9D14D6F914324865C7DB9F /* ActivityCoordinator.swift */; };
 		09AAF04B27732046C755D914 /* SoftLogoutViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 32C5DAA1773F57653BF1C4F9 /* SoftLogoutViewModelTests.swift */; };
+		09BFDE37F0D0E586D26B17D7 /* Collections in Frameworks */ = {isa = PBXBuildFile; productRef = A20EA00CCB9DBE0FFB17DD09 /* Collections */; };
 		09C83DDDB07C28364F325209 /* MockRoomTimelineController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 52D7074991B3267B26D89B22 /* MockRoomTimelineController.swift */; };
 		0AE0AB1952F186EB86719B4F /* HomeScreenRoomCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = ED044D00F2176681CC02CD54 /* HomeScreenRoomCell.swift */; };
 		0BEFE400B4802FE8C9DB39B3 /* FilePreviewViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 62BDF0FF4F59AF6EA858B70B /* FilePreviewViewModel.swift */; };
@@ -136,6 +137,7 @@
 		3DA57CA0D609A6B37CA1DC2F /* BugReportService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6DC38E64A5ED3FDB201029A /* BugReportService.swift */; };
 		3ED2725734568F6B8CC87544 /* AttributedStringBuilder.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2A5C6FBF97B6EED3D4FA5EFF /* AttributedStringBuilder.swift */; };
 		3F2148F11164C7C5609984EB /* SwiftState in Frameworks */ = {isa = PBXBuildFile; productRef = 19CD5B074D7DD44AF4C58BB6 /* SwiftState */; };
+		3F327A62D233933F54F0F33A /* Collections in Frameworks */ = {isa = PBXBuildFile; productRef = BA93CD75CCE486660C9040BD /* Collections */; };
 		3F70E237CE4C3FAB02FC227F /* NotificationConstants.swift in Sources */ = {isa = PBXBuildFile; fileRef = C830A64609CBD152F06E0457 /* NotificationConstants.swift */; };
 		407DCE030E0F9B7C9861D38A /* GZIP in Frameworks */ = {isa = PBXBuildFile; productRef = 997C7385E1A07E061D7E2100 /* GZIP */; };
 		414F50CFCFEEE2611127DCFB /* RestorationToken.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3558A15CFB934F9229301527 /* RestorationToken.swift */; };
@@ -415,6 +417,7 @@
 		D59F046B15AA8E971053C1A6 /* RoomDetailsCoordinator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 813B198AE8833FD12E5A9C78 /* RoomDetailsCoordinator.swift */; };
 		D5C805F49B2C75DC3793E780 /* EmojiItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = 37A243E04B58DC6E41FDCD82 /* EmojiItem.swift */; };
 		D5EA4C6C80579279770D5804 /* ImageRoomTimelineView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0A45283CF1DB96E583BECA6 /* ImageRoomTimelineView.swift */; };
+		D63974A88CF2BC721F109C77 /* Collections in Frameworks */ = {isa = PBXBuildFile; productRef = AD544C0FA48DFFB080920061 /* Collections */; };
 		D6417E5A799C3C7F14F9EC0A /* SessionVerificationViewModelProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = B3069ADED46D063202FE7698 /* SessionVerificationViewModelProtocol.swift */; };
 		D79F0F852C6A4255D5E616D2 /* UserNotificationControllerProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8ED2D2F6A137A95EA50413BE /* UserNotificationControllerProtocol.swift */; };
 		D8359F67AF3A83516E9083C1 /* MockUserSession.swift in Sources */ = {isa = PBXBuildFile; fileRef = A4756C5A8C8649AD6C10C615 /* MockUserSession.swift */; };
@@ -475,6 +478,7 @@
 		FA9C427FFB11B1AA2DCC5602 /* RoomProxyProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 47111410B6E659A697D472B5 /* RoomProxyProtocol.swift */; };
 		FBCD77D557AACBE9B445133A /* MediaProxy.swift in Sources */ = {isa = PBXBuildFile; fileRef = E12C9E0B61A77C7F0EE7918C /* MediaProxy.swift */; };
 		FBF09B6C900415800DDF2A21 /* EmojiProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6C113E0CB7E15E9765B1817A /* EmojiProvider.swift */; };
+		FC10228E73323BDC09526F97 /* Collections in Frameworks */ = {isa = PBXBuildFile; productRef = 9C73F37731C9FDED1BB24C1C /* Collections */; };
 		FCD3F2B82CAB29A07887A127 /* KeychainAccess in Frameworks */ = {isa = PBXBuildFile; productRef = 2B43F2AF7456567FE37270A7 /* KeychainAccess */; };
 		FE4593FC2A02AAF92E089565 /* ElementAnimations.swift in Sources */ = {isa = PBXBuildFile; fileRef = EF1593DD87F974F8509BB619 /* ElementAnimations.swift */; };
 		FE8D76708280968F7A670852 /* MockUserNotificationController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9080CDD3881D0D1B2F280A7C /* MockUserNotificationController.swift */; };
@@ -1077,6 +1081,7 @@
 				3F2148F11164C7C5609984EB /* SwiftState in Frameworks */,
 				60ED66E63A169E47489348A8 /* GZIP in Frameworks */,
 				EC280623A42904341363EAAF /* Sentry in Frameworks */,
+				09BFDE37F0D0E586D26B17D7 /* Collections in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1088,6 +1093,7 @@
 				53DEF39F0C4DE02E3FC56D91 /* SwiftyBeaver in Frameworks */,
 				F06CE9132855E81EBB6DDC32 /* KeychainAccess in Frameworks */,
 				67D6E0700A9C1E676F6231F8 /* Kingfisher in Frameworks */,
+				D63974A88CF2BC721F109C77 /* Collections in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1108,6 +1114,7 @@
 				492274DA6691EE985C2FCCAA /* GZIP in Frameworks */,
 				F0F82C3C848C865C3098AA52 /* Sentry in Frameworks */,
 				3A64A93A651A3CB8774ADE8E /* SnapshotTesting in Frameworks */,
+				3F327A62D233933F54F0F33A /* Collections in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1128,6 +1135,7 @@
 				6298AB0906DDD3525CD78C6B /* SwiftState in Frameworks */,
 				407DCE030E0F9B7C9861D38A /* GZIP in Frameworks */,
 				8F2FAA98457750D9D664136F /* Sentry in Frameworks */,
+				FC10228E73323BDC09526F97 /* Collections in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -2474,6 +2482,7 @@
 				1BCD21310B997A6837B854D6 /* GZIP */,
 				67E7A6F388D3BF85767609D9 /* Sentry */,
 				21C83087604B154AA30E9A8F /* SnapshotTesting */,
+				BA93CD75CCE486660C9040BD /* Collections */,
 			);
 			productName = UITests;
 			productReference = F506C6ADB1E1DA6638078E11 /* UITests.xctest */;
@@ -2528,6 +2537,7 @@
 				9573B94B1C86C6DF751AF3FD /* SwiftState */,
 				997C7385E1A07E061D7E2100 /* GZIP */,
 				7731767AE437BA3BD2CC14A8 /* Sentry */,
+				9C73F37731C9FDED1BB24C1C /* Collections */,
 			);
 			productName = ElementX;
 			productReference = 4CD6AC7546E8D7E5C73CEA48 /* ElementX.app */;
@@ -2557,6 +2567,7 @@
 				19CD5B074D7DD44AF4C58BB6 /* SwiftState */,
 				2B788C81F6369D164ADEB917 /* GZIP */,
 				886A0A498FA01E8EDD451D05 /* Sentry */,
+				A20EA00CCB9DBE0FFB17DD09 /* Collections */,
 			);
 			productName = IntegrationTests;
 			productReference = 9C7F7DE62D33C6A26CBFCD72 /* IntegrationTests.xctest */;
@@ -2580,6 +2591,7 @@
 				AC5D19D7A65EB05A9704FB44 /* SwiftyBeaver */,
 				800631D7250B7F93195035F1 /* KeychainAccess */,
 				940C605265DD82DA0C655E23 /* Kingfisher */,
+				AD544C0FA48DFFB080920061 /* Collections */,
 			);
 			productName = NSE;
 			productReference = 0D8F620C8B314840D8602E3F /* NSE.appex */;
@@ -2700,6 +2712,7 @@
 			packageReferences = (
 				AC3475112CA40C2C6E78D1EB /* XCRemoteSwiftPackageReference "matrix-analytics-events" */,
 				4CE94127E27181B8B72188F0 /* XCRemoteSwiftPackageReference "AppAuth-iOS" */,
+				F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */,
 				C13F55E4518415CB4C278E73 /* XCRemoteSwiftPackageReference "DTCoreText" */,
 				D5F7D47BBAAE0CF1DDEB3034 /* XCRemoteSwiftPackageReference "DeviceKit" */,
 				701C7BEF8F70F7A83E852DCC /* XCRemoteSwiftPackageReference "GZIP" */,
@@ -4002,6 +4015,14 @@
 				minimumVersion = 1.10.0;
 			};
 		};
+		F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */ = {
+			isa = XCRemoteSwiftPackageReference;
+			repositoryURL = "https://github.com/apple/swift-collections";
+			requirement = {
+				kind = upToNextMajorVersion;
+				minimumVersion = 1.0.4;
+			};
+		};
 /* End XCRemoteSwiftPackageReference section */
 
 /* Begin XCSwiftPackageProductDependency section */
@@ -4130,6 +4151,16 @@
 			package = 701C7BEF8F70F7A83E852DCC /* XCRemoteSwiftPackageReference "GZIP" */;
 			productName = GZIP;
 		};
+		9C73F37731C9FDED1BB24C1C /* Collections */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */;
+			productName = Collections;
+		};
+		A20EA00CCB9DBE0FFB17DD09 /* Collections */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */;
+			productName = Collections;
+		};
 		A5A56C4F47C368EBE5C5E870 /* DesignKit */ = {
 			isa = XCSwiftPackageProductDependency;
 			productName = DesignKit;
@@ -4164,11 +4195,21 @@
 			package = 25B4484A6A20B9F1705DEEDA /* XCRemoteSwiftPackageReference "SwiftyBeaver" */;
 			productName = SwiftyBeaver;
 		};
+		AD544C0FA48DFFB080920061 /* Collections */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */;
+			productName = Collections;
+		};
 		B1E8B697DF78FE7F61FC6CA4 /* MatrixRustSDK */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = 80B898A3AD2AC63F3ABFC218 /* XCRemoteSwiftPackageReference "matrix-rust-components-swift" */;
 			productName = MatrixRustSDK;
 		};
+		BA93CD75CCE486660C9040BD /* Collections */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = F76A08D0EA29A07A54F4EB4D /* XCRemoteSwiftPackageReference "swift-collections" */;
+			productName = Collections;
+		};
 		BC01130651CB23340B899032 /* DeviceKit */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = D5F7D47BBAAE0CF1DDEB3034 /* XCRemoteSwiftPackageReference "DeviceKit" */;

ElementX.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -108,6 +108,15 @@
         "version" : "7.30.2"
       }
     },
+    {
+      "identity" : "swift-collections",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-collections",
+      "state" : {
+        "revision" : "937e904258d22af6e447a0b72c0bc67583ef64a2",
+        "version" : "1.0.4"
+      }
+    },
     {
       "identity" : "swift-snapshot-testing",
       "kind" : "remoteSourceControl",

ElementX/Sources/Other/Logging/RustTracing.swift

@@ -14,48 +14,60 @@
 // limitations under the License.
 //
 
+import Collections
 import MatrixRustSDK
 
 // This exposes the full Rust side tracing subscriber filter for more flexibility.
 // We can filter by level, crate and even file. See more details here:
 // https://docs.rs/tracing-subscriber/0.2.7/tracing_subscriber/filter/struct.EnvFilter.html#examples
 struct TracingConfiguration {
-    static var release = TracingConfiguration(common: .info)
+    static var release = TracingConfiguration(overrides: [.common: .info])
-    static var debug = TracingConfiguration()
+    static var debug = TracingConfiguration(overrides: [.common: .info])
-    static var full = TracingConfiguration(common: .info,
+    static func custom(overrides: [Target: LogLevel]) -> TracingConfiguration {
-                                           targets: [
+        TracingConfiguration(overrides: overrides)
-                                               .hyper: .warn,
+    }
-                                               .sled: .warn,
+    
-                                               .matrix_sdk_sled: .warn,
+    enum LogLevel: String { case error, warn, info, debug, trace }
-                                               .matrix_sdk_http_client: .trace,
-                                               .matrix_sdk_ffi_uniffi_api: .warn,
-                                               .matrix_sdk_ffi: .warn,
-                                               .matrix_sdk_sliding_sync: .warn,
-                                               .matrix_sdk_base_sliding_sync: .warn,
-                                               .matrix_sdk_crypto: .trace
-                                           ])
     
     enum Target: String {
+        case common = ""
+        
         case hyper, sled, matrix_sdk_sled, matrix_sdk_ffi, matrix_sdk_crypto
+        
         case matrix_sdk_http_client = "matrix_sdk::http_client"
         case matrix_sdk_ffi_uniffi_api = "matrix_sdk_ffi::uniffi_api"
         case matrix_sdk_sliding_sync = "matrix_sdk::sliding_sync"
         case matrix_sdk_base_sliding_sync = "matrix_sdk_base::sliding_sync"
     }
     
-    enum LogLevel: String { case error, warn, info, debug, trace }
+    let targets: OrderedDictionary<Target, LogLevel> = [
-    
+        .common: .warn,
-    var common = LogLevel.warn
-    var targets: [Target: LogLevel] = [
         .hyper: .warn,
         .sled: .warn,
         .matrix_sdk_sled: .warn,
         .matrix_sdk_crypto: .debug,
-        .matrix_sdk_http_client: .debug
+        .matrix_sdk_http_client: .debug,
+        .matrix_sdk_sliding_sync: .trace,
+        .matrix_sdk_base_sliding_sync: .trace
     ]
     
+    var overrides = [Target: LogLevel]()
+    
     var filter: String {
-        "\(common),\(targets.map { "\($0.key.rawValue)=\($0.value.rawValue)" }.joined(separator: ","))"
+        var newTargets = targets
+        for (target, logLevel) in overrides {
+            newTargets.updateValue(logLevel, forKey: target)
+        }
+        
+        let components = newTargets.map { (target: Target, logLevel: LogLevel) in
+            guard !target.rawValue.isEmpty else {
+                return logLevel.rawValue
+            }
+            
+            return "\(target.rawValue)=\(logLevel.rawValue)"
+        }
+        
+        return components.joined(separator: ",")
     }
 }
 

ElementX/Sources/Screens/HomeScreen/HomeScreenModels.swift

@@ -95,6 +95,9 @@ struct HomeScreenViewStateBindings {
 }
 
 struct HomeScreenRoom: Identifiable, Equatable {
+    private static let placeholderLastMessage = AttributedString("Last message")
+    private static let placeholderAvatar = UIImage(systemName: "photo")
+    
     /// The list item identifier can be a real room identifier, a custom one for invalidated entries
     /// or a completely unique one for empty items and skeletons
     let id: String
@@ -102,11 +105,11 @@ struct HomeScreenRoom: Identifiable, Equatable {
     /// The real room identifier this item points to
     let roomId: String?
     
-    let name: String
+    var name = ""
     
-    let hasUnreads: Bool
+    var hasUnreads = false
     
-    let timestamp: String?
+    var timestamp: String?
     
     var lastMessage: AttributedString?
     
@@ -122,8 +125,8 @@ struct HomeScreenRoom: Identifiable, Equatable {
                        name: "Placeholder room name",
                        hasUnreads: false,
                        timestamp: "Now",
-                       lastMessage: AttributedString("Last message"),
+                       lastMessage: Self.placeholderLastMessage,
-                       avatar: UIImage(systemName: "photo"),
+                       avatar: Self.placeholderAvatar,
                        isPlaceholder: true)
     }
 }

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -31,6 +31,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     
     private let visibleItemRangePublisher = CurrentValueSubject<Range<Int>, Never>(0..<0)
     
+    private var roomsForIdentifiers = [String: HomeScreenRoom]()
+    
     var callback: ((HomeScreenViewModelAction) -> Void)?
     
     // MARK: - Setup
@@ -178,7 +180,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     // MARK: - Private
     
     private func loadDataForRoomIdentifier(_ identifier: String) {
-        guard let room = state.rooms.first(where: { $0.roomId == identifier }),
+        guard let room = roomsForIdentifiers[identifier],
               room.avatar == nil,
               let avatarURL = room.avatarURL else {
             return
@@ -206,6 +208,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             return
         }
         
+        MXLog.info("Updating rooms")
+        
         var rooms = [HomeScreenRoom]()
         
         // Try merging together results from both the visibleRoomsSummaryProvider and the allRoomsSummaryProvider
@@ -235,24 +239,34 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         }
         
         state.rooms = rooms
+        
+        MXLog.info("Finished updating rooms")
     }
     
     private func buildRoom(with details: RoomSummaryDetails) -> HomeScreenRoom {
-        let avatarImage = details.avatarURL.flatMap { userSession.mediaProvider.imageFromURL($0, avatarSize: .room(on: .home)) }
+        var room: HomeScreenRoom! = roomsForIdentifiers[details.id]
         
-        var timestamp: String?
+        if room == nil {
-        if let lastMessageTimestamp = details.lastMessageTimestamp {
+            room = HomeScreenRoom(id: details.id,
-            timestamp = lastMessageTimestamp.formatted(date: .omitted, time: .shortened)
+                                  roomId: details.id,
+                                  avatarURL: details.avatarURL)
         }
         
-        return HomeScreenRoom(id: details.id,
+        room.name = details.name
-                              roomId: details.id,
+        room.hasUnreads = details.unreadNotificationCount > 0
-                              name: details.name,
+        room.lastMessage = details.lastMessage
-                              hasUnreads: details.unreadNotificationCount > 0,
+        
-                              timestamp: timestamp,
+        if let avatarURL = details.avatarURL {
-                              lastMessage: details.lastMessage,
+            room.avatar = userSession.mediaProvider.imageFromURL(avatarURL, avatarSize: .room(on: .home))
-                              avatarURL: details.avatarURL,
+        }
-                              avatar: avatarImage)
+        
+        if let lastMessageTimestamp = details.lastMessageTimestamp {
+            room.timestamp = lastMessageTimestamp.formatted(date: .omitted, time: .shortened)
+        }
+        
+        roomsForIdentifiers[details.id] = room
+        
+        return room
     }
     
     private func updateVisibleRange(_ range: Range<Int>) {

ElementX/Sources/Screens/RoomScreen/View/TimelineTableViewController.swift

@@ -69,7 +69,6 @@ class TimelineTableViewController: UIViewController {
         didSet {
             // Paginate again if the threshold hasn't been satisfied.
             paginateBackwardsPublisher.send(())
-            applySnapshot()
         }
     }
         

ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProvider.swift

@@ -56,7 +56,7 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
             .store(in: &cancellables)
         
         slidingSyncViewProxy.diffPublisher
-            .collect(.byTime(serialDispatchQueue, 0.1))
+            .collect(.byTime(serialDispatchQueue, 0.025))
             .sink { [weak self] in self?.updateRoomsWithDiffs($0) }
             .store(in: &cancellables)
     }
@@ -80,7 +80,7 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
             return
         }
         
-        MXLog.verbose("Updating \(identifiers.count) rooms")
+        MXLog.info("Updating \(identifiers.count) rooms")
         
         guard statePublisher.value == .live else {
             MXLog.warning("Sliding sync not live yet, ignoring update.")
@@ -117,7 +117,7 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
     }
     
     fileprivate func updateRoomsWithDiffs(_ diffs: [SlidingSyncViewRoomsListDiff]) {
-        MXLog.verbose("Received \(diffs.count) diffs")
+        MXLog.info("Received \(diffs.count) diffs")
         
         rooms = diffs
             .reduce(rooms) { currentItems, diff in
@@ -136,7 +136,7 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
                 return updatedItems
             }
         
-        MXLog.verbose("Finished applying \(diffs.count) diffs")
+        MXLog.info("Finished applying \(diffs.count) diffs")
     }
         
     private func buildRoomSummaryForIdentifier(_ identifier: String, invalidated: Bool) -> RoomSummary {

ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift

@@ -29,6 +29,7 @@ private class RoomTimelineListener: TimelineListener {
 class RoomTimelineProvider: RoomTimelineProviderProtocol {
     private let roomProxy: RoomProxyProtocol
     private var cancellables = Set<AnyCancellable>()
+    private let serialDispatchQueue: DispatchQueue
     
     let itemsPublisher = CurrentValueSubject<[TimelineItemProxy], Never>([])
     
@@ -40,6 +41,7 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
     
     init(roomProxy: RoomProxyProtocol) {
         self.roomProxy = roomProxy
+        serialDispatchQueue = DispatchQueue(label: "io.element.elementx.roomtimelineprovider")
         itemProxies = []
 
         Task {
@@ -47,8 +49,8 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
             
             roomTimelineListener
                 .itemsUpdatePublisher
-                .receive(on: DispatchQueue.main)
+                .collect(.byTime(serialDispatchQueue, 0.025))
-                .sink { [weak self] in self?.updateItemsWithDiff($0) }
+                .sink { [weak self] in self?.updateItemsWithDiffs($0) }
                 .store(in: &cancellables)
             
             switch await roomProxy.addTimelineListener(listener: roomTimelineListener) {
@@ -63,22 +65,25 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
     
     // MARK: - Private
     
-    private func updateItemsWithDiff(_ diff: TimelineDiff) {
+    private func updateItemsWithDiffs(_ diffs: [TimelineDiff]) {
         MXLog.verbose("Received timeline diff")
         
-        guard let collectionDiff = buildDiff(from: diff, on: itemProxies) else {
+        itemProxies = diffs
-            MXLog.error("Failed building CollectionDifference from \(diff)")
+            .reduce(itemProxies) { currentItems, diff in
-            return
+                guard let collectionDiff = buildDiff(from: diff, on: currentItems) else {
-        }
+                    MXLog.error("Failed building CollectionDifference from \(diff)")
-        
+                    return currentItems
-        guard let updatedItems = itemProxies.applying(collectionDiff) else {
+                }
-            MXLog.error("Failed applying diff: \(collectionDiff)")
+                
-            return
+                guard let updatedItems = currentItems.applying(collectionDiff) else {
-        }
+                    MXLog.error("Failed applying diff: \(collectionDiff)")
-        
+                    return currentItems
-        MXLog.verbose("Applied diff \(collectionDiff), new count: \(updatedItems.count)")
+                }
-        
+                
-        itemProxies = updatedItems
+                MXLog.verbose("Applied diff \(collectionDiff), new count: \(updatedItems.count)")
+                
+                return updatedItems
+            }
         
         MXLog.verbose("Finished applying diff")
     }

ElementX/Sources/Services/Timeline/TimelineController/RoomTimelineController.swift

@@ -21,10 +21,11 @@ import UniformTypeIdentifiers
 
 class RoomTimelineController: RoomTimelineControllerProtocol {
     private let userId: String
+    private let roomProxy: RoomProxyProtocol
     private let timelineProvider: RoomTimelineProviderProtocol
     private let timelineItemFactory: RoomTimelineItemFactoryProtocol
     private let mediaProvider: MediaProviderProtocol
-    let roomProxy: RoomProxyProtocol
+    private let serialDispatchQueue: DispatchQueue
     
     private var cancellables = Set<AnyCancellable>()
     private var timelineItemsUpdateTask: Task<Void, Never>? {
@@ -51,10 +52,11 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
         self.timelineItemFactory = timelineItemFactory
         self.mediaProvider = mediaProvider
         self.roomProxy = roomProxy
+        serialDispatchQueue = DispatchQueue(label: "io.element.elementx.roomtimelineprovider")
         
         self.timelineProvider
             .itemsPublisher
-            .receive(on: DispatchQueue.main)
+            .receive(on: serialDispatchQueue)
             .sink { [weak self] _ in
                 guard let self else { return }
                 
@@ -236,14 +238,8 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
         updateTimelineItems()
     }
     
-    private func updateTimelineItems() {
-        timelineItemsUpdateTask = Task {
-            await asyncUpdateTimelineItems()
-        }
-    }
-    
     // swiftlint:disable:next cyclomatic_complexity
-    private func asyncUpdateTimelineItems() async {
+    private func updateTimelineItems() {
         var newTimelineItems = [RoomTimelineItemProtocol]()
         var canBackPaginate = true
         var isBackPaginating = false

ElementX/SupportingFiles/target.yml

@@ -124,6 +124,7 @@ targets:
     - package: SwiftState
     - package: GZIP
     - package: Sentry
+    - package: Collections
 
     sources:
     - path: ../Sources

IntegrationTests/SupportingFiles/target.yml

@@ -43,6 +43,7 @@ targets:
     - package: SwiftState
     - package: GZIP
     - package: Sentry
+    - package: Collections
 
     info:
       path: ../SupportingFiles/Info.plist

NSE/SupportingFiles/target.yml

@@ -36,6 +36,7 @@ targets:
       - package: SwiftyBeaver
       - package: KeychainAccess
       - package: Kingfisher
+      - package: Collections
 
     info:
       path: ../SupportingFiles/Info.plist

UITests/SupportingFiles/target.yml

@@ -40,6 +40,7 @@ targets:
     - package: GZIP
     - package: Sentry
     - package: SnapshotTesting
+    - package: Collections
 
     info:
       path: ../SupportingFiles/Info.plist

UnitTests/Sources/TracingConfigurationTests.swift

@@ -19,32 +19,18 @@ import XCTest
 @testable import ElementX
 
 class TracingConfigurationTests: XCTestCase {
-    func testReleaseConfiguration() {
+    func testConfiguration() {
-        let filterComponents = TracingConfiguration.release.filter.components(separatedBy: ",")
+        let configuration = TracingConfiguration(overrides: [.common: .trace,
-        XCTAssertTrue(filterComponents.contains("info"))
+                                                             .matrix_sdk_base_sliding_sync: .error,
-        XCTAssertTrue(filterComponents.contains("hyper=warn"))
+                                                             .matrix_sdk_http_client: .warn,
-        XCTAssertTrue(filterComponents.contains("sled=warn"))
+                                                             .matrix_sdk_crypto: .info,
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_sled=warn"))
+                                                             .hyper: .debug])
-    }
+        
-    
+        let filterComponents = configuration.filter.components(separatedBy: ",")
-    func testDebugConfiguration() {
+        XCTAssertEqual(filterComponents.first, "trace")
-        let filterComponents = TracingConfiguration.debug.filter.components(separatedBy: ",")
+        XCTAssertTrue(filterComponents.contains("matrix_sdk_base::sliding_sync=error"))
-        XCTAssertTrue(filterComponents.contains("warn"))
+        XCTAssertTrue(filterComponents.contains("matrix_sdk::http_client=warn"))
-        XCTAssertTrue(filterComponents.contains("hyper=warn"))
+        XCTAssertTrue(filterComponents.contains("matrix_sdk_crypto=info"))
-        XCTAssertTrue(filterComponents.contains("sled=warn"))
+        XCTAssertTrue(filterComponents.contains("hyper=debug"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_sled=warn"))
-    }
-    
-    func testFullConfiguration() {
-        let filterComponents = TracingConfiguration.full.filter.components(separatedBy: ",")
-        XCTAssertTrue(filterComponents.contains("info"))
-        XCTAssertTrue(filterComponents.contains("hyper=warn"))
-        XCTAssertTrue(filterComponents.contains("sled=warn"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_sled=warn"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk::http_client=trace"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_ffi::uniffi_api=warn"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_ffi=warn"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk::sliding_sync=warn"))
-        XCTAssertTrue(filterComponents.contains("matrix_sdk_base::sliding_sync=warn"))
     }
 }

project.yml

@@ -83,3 +83,6 @@ packages:
   SnapshotTesting:
     url: https://github.com/pointfreeco/swift-snapshot-testing
     majorVersion: 1.10.0
+  Collections:
+    url: https://github.com/apple/swift-collections
+    majorVersion: 1.0.4