From 95137c0f7a6de7deaa1f0e1439767e16699d3ec0 Mon Sep 17 00:00:00 2001
From: Stefan Ceriu <stefanc@matrix.org>
Date: Wed, 11 Jan 2023 16:55:20 +0200
Subject: [PATCH] Move the RoomSummaryProvider id based room updated to the
 same serial dispatch queue as the normal diffing. Cleanup logging and
 RoomTimelineProvider diffing

---
 .../RoomSummary/RoomSummaryProvider.swift     | 33 +++++++++++----
 .../Timeline/RoomTimelineProvider.swift       | 40 ++++++++-----------
 2 files changed, 42 insertions(+), 31 deletions(-)

diff --git a/ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProvider.swift b/ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProvider.swift
index 938f1a206..b6b58a077 100644
--- a/ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProvider.swift
+++ b/ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProvider.swift
@@ -62,7 +62,28 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
     }
     
     func updateRoomsWithIdentifiers(_ identifiers: [String]) {
+        serialDispatchQueue.async { [weak self] in
+            guard let self else { return }
+            self.updateRoomsForIdentifiers(identifiers)
+        }
+    }
+    
+    func updateVisibleRange(_ range: ClosedRange<Int>) {
+        slidingSyncViewProxy.updateVisibleRange(range)
+    }
+    
+    // MARK: - Private
+    
+    /// Invoked from `updateRoomsWithIdentifiers` on the same dispatch queue as `updateRoomsWithDiffs`
+    private func updateRoomsForIdentifiers(_ identifiers: [String]) {
+        guard !identifiers.isEmpty else {
+            return
+        }
+        
+        MXLog.verbose("Updating \(identifiers.count) rooms")
+        
         guard statePublisher.value == .live else {
+            MXLog.verbose("Sliding sync not live yet, ignoring.")
             return
         }
         
@@ -91,16 +112,12 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
         }
 
         rooms = newSummaries
+        
+        MXLog.verbose("Finished updating \(identifiers.count) rooms")
     }
     
-    func updateVisibleRange(_ range: ClosedRange<Int>) {
-        slidingSyncViewProxy.updateVisibleRange(range)
-    }
-    
-    // MARK: - Private
-    
     fileprivate func updateRoomsWithDiffs(_ diffs: [SlidingSyncViewRoomsListDiff]) {
-        MXLog.info("Received \(diffs.count) diffs")
+        MXLog.verbose("Received \(diffs.count) diffs")
         
         rooms = diffs
             .reduce(rooms) { currentItems, diff in
@@ -119,7 +136,7 @@ class RoomSummaryProvider: RoomSummaryProviderProtocol {
                 return updatedItems
             }
         
-        MXLog.info("Finished applying diffs")
+        MXLog.verbose("Finished applying \(diffs.count) diffs")
     }
         
     private func buildRoomSummaryForIdentifier(_ identifier: String, invalidated: Bool) -> RoomSummary {
diff --git a/ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift b/ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift
index 95442b111..39de063ca 100644
--- a/ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift
+++ b/ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift
@@ -28,7 +28,6 @@ private class RoomTimelineListener: TimelineListener {
 
 class RoomTimelineProvider: RoomTimelineProviderProtocol {
     private let roomProxy: RoomProxyProtocol
-    private let serialDispatchQueue: DispatchQueue
     private var cancellables = Set<AnyCancellable>()
     
     let itemsPublisher = CurrentValueSubject<[TimelineItemProxy], Never>([])
@@ -41,7 +40,6 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
     
     init(roomProxy: RoomProxyProtocol) {
         self.roomProxy = roomProxy
-        serialDispatchQueue = DispatchQueue(label: "io.element.elementx.roomtimelineprovider")
         itemProxies = []
 
         Task {
@@ -50,8 +48,7 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
             roomTimelineListener
                 .itemsUpdatePublisher
                 .receive(on: DispatchQueue.main)
-//                .collect(.byTime(serialDispatchQueue, 0.25))
-                .sink { [weak self] in self?.updateItemsWithDiffs([$0]) }
+                .sink { [weak self] in self?.updateItemsWithDiff($0) }
                 .store(in: &cancellables)
             
             switch await roomProxy.addTimelineListener(listener: roomTimelineListener) {
@@ -138,27 +135,24 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
     
     // MARK: - Private
     
-    private func updateItemsWithDiffs(_ diffs: [TimelineDiff]) {
-        MXLog.verbose("Received timeline diffs")
+    private func updateItemsWithDiff(_ diff: TimelineDiff) {
+        MXLog.verbose("Received timeline diff")
         
-        itemProxies = diffs
-            .reduce(itemProxies) { currentItems, diff in
-                guard let collectionDiff = buildDiff(from: diff, on: currentItems) else {
-                    MXLog.error("Failed building CollectionDifference from \(diff)")
-                    return currentItems
-                }
-                
-                guard let updatedItems = currentItems.applying(collectionDiff) else {
-                    MXLog.error("Failed applying diff: \(collectionDiff)")
-                    return currentItems
-                }
-                
-                MXLog.verbose("Applied diff \(collectionDiff), new count: \(updatedItems.count)")
-                
-                return updatedItems
-            }
+        guard let collectionDiff = buildDiff(from: diff, on: itemProxies) else {
+            MXLog.error("Failed building CollectionDifference from \(diff)")
+            return
+        }
         
-        MXLog.verbose("Finished applying diffs")
+        guard let updatedItems = itemProxies.applying(collectionDiff) else {
+            MXLog.error("Failed applying diff: \(collectionDiff)")
+            return
+        }
+        
+        MXLog.verbose("Applied diff \(collectionDiff), new count: \(updatedItems.count)")
+        
+        itemProxies = updatedItems
+        
+        MXLog.verbose("Finished applying diff")
     }
      
     // swiftlint:disable:next cyclomatic_complexity function_body_length