Improve performance for Logs

ApplicationLibrary/Views/Log/LogTextView.swift

@@ -206,9 +206,25 @@ class LogCoordinator {
                 context.coordinator.cachedAttributedString = attributedString
                 textView.attributedText = attributedString
             case let .incremental(from: startIndex):
-                let attributedString = buildAttributedString(logs: logs, monoFont: Self.monoFont, defaultColor: Self.defaultColor, searchText: searchText, baseAttributedString: context.coordinator.cachedAttributedString, startIndex: startIndex)
-                context.coordinator.cachedAttributedString = attributedString
-                textView.attributedText = attributedString
+                // Build only the new logs, not the entire attributed string
+                let newLogsAttributedString = buildAttributedString(logs: logs, monoFont: Self.monoFont, defaultColor: Self.defaultColor, searchText: searchText, baseAttributedString: nil, startIndex: startIndex)
+
+                // Append to existing text storage instead of replacing
+                let textStorage = textView.textStorage
+
+                // Add newline separator before appending if there's existing content
+                if textStorage.length > 0 {
+                    let newline = NSAttributedString(string: "\n", attributes: [
+                        .foregroundColor: Self.defaultColor,
+                        .font: Self.monoFont,
+                    ])
+                    textStorage.append(newline)
+                }
+
+                textStorage.append(newLogsAttributedString)
+
+                // Update cache to full content
+                context.coordinator.cachedAttributedString = NSAttributedString(attributedString: textStorage)
             }
         }
 
@@ -254,6 +270,7 @@ class LogCoordinator {
 
         func updateNSView(_ scrollView: NSScrollView, context: Context) {
             guard let textView = scrollView.documentView as? NSTextView else { return }
+            guard let textStorage = textView.textStorage else { return }
 
             let lastCount = context.coordinator.lastLogsCount
             let updateStrategy = context.coordinator.shouldUpdate(logs: logs, searchText: searchText)
@@ -264,11 +281,25 @@ class LogCoordinator {
             case .fullRebuild:
                 let attributedText = buildAttributedString(logs: logs, monoFont: Self.monoFont, defaultColor: Self.defaultColor, searchText: searchText)
                 context.coordinator.cachedAttributedString = attributedText
-                textView.textStorage?.setAttributedString(attributedText)
+                textStorage.setAttributedString(attributedText)
             case let .incremental(from: startIndex):
-                let attributedText = buildAttributedString(logs: logs, monoFont: Self.monoFont, defaultColor: Self.defaultColor, searchText: searchText, baseAttributedString: context.coordinator.cachedAttributedString, startIndex: startIndex)
-                context.coordinator.cachedAttributedString = attributedText
-                textView.textStorage?.setAttributedString(attributedText)
+                // Build only the new logs, not the entire attributed string
+                let newLogsAttributedString = buildAttributedString(logs: logs, monoFont: Self.monoFont, defaultColor: Self.defaultColor, searchText: searchText, baseAttributedString: nil, startIndex: startIndex)
+
+                // Add newline separator before appending if there's existing content
+                if textStorage.length > 0 {
+                    let newline = NSAttributedString(string: "\n", attributes: [
+                        .foregroundColor: Self.defaultColor,
+                        .font: Self.monoFont,
+                    ])
+                    textStorage.append(newline)
+                }
+
+                // Append to existing text storage instead of replacing
+                textStorage.append(newLogsAttributedString)
+
+                // Update cache to full content
+                context.coordinator.cachedAttributedString = NSAttributedString(attributedString: textStorage)
             }
 
             let shouldScroll = shouldAutoScroll && logs.count != lastCount

ApplicationLibrary/Views/Log/LogView.swift

@@ -34,7 +34,7 @@ private struct LogViewContent: View {
                 previewContent
             } else if viewModel.isEmpty {
                 emptyContent
-            } else if viewModel.filteredLogs.isEmpty {
+            } else if viewModel.visibleLogs.isEmpty {
                 emptyContent
             } else {
                 logScrollView
@@ -113,7 +113,7 @@ private struct LogViewContent: View {
             ScrollViewReader { reader in
                 ScrollView {
                     LazyVStack(alignment: .leading, spacing: 8) {
-                        ForEach(viewModel.filteredLogs) { logEntry in
+                        ForEach(viewModel.visibleLogs) { logEntry in
                             Text(highlightedText(for: logEntry.message))
                                 .font(logFont)
                                 .focusable()
@@ -127,7 +127,7 @@ private struct LogViewContent: View {
                 .onAppear {
                     scrollToLastEntry(reader)
                 }
-                .onChangeCompat(of: viewModel.filteredLogs.count) { _ in
+                .onChangeCompat(of: viewModel.visibleLogs.count) { _ in
                     if !viewModel.isPaused {
                         scrollToLastEntry(reader)
                     }
@@ -135,7 +135,7 @@ private struct LogViewContent: View {
             }
         #else
             LogTextView(
-                logs: viewModel.filteredLogs,
+                logs: viewModel.visibleLogs,
                 font: logFont,
                 shouldAutoScroll: !viewModel.isPaused,
                 searchText: viewModel.searchText
@@ -166,7 +166,7 @@ private struct LogViewContent: View {
 
     #if os(tvOS)
         private func scrollToLastEntry(_ reader: ScrollViewProxy) {
-            guard let lastEntry = viewModel.filteredLogs.last else { return }
+            guard let lastEntry = viewModel.visibleLogs.last else { return }
             withAnimation {
                 reader.scrollTo(lastEntry.id, anchor: .bottom)
             }

ApplicationLibrary/Views/Log/LogViewModel.swift

@@ -25,9 +25,21 @@ public class LogViewModel: ObservableObject {
     private var lastEffectiveLevel: Int?
     private var lastSearchText = ""
 
+    // Performance optimization: limit visible logs to prevent UI lag
+    private static let maxVisibleLogs = 1000
+
     public var isEmpty: Bool { commandClient.logList.isEmpty }
     public var isConnected: Bool { commandClient.isConnected }
 
+    // Only show last N logs for performance, but keep all in filteredLogs for export
+    public var visibleLogs: [LogEntry] {
+        if filteredLogs.count <= Self.maxVisibleLogs {
+            return filteredLogs
+        } else {
+            return Array(filteredLogs.suffix(Self.maxVisibleLogs))
+        }
+    }
+
     public init(commandClient: CommandClient) {
         self.commandClient = commandClient