fix: reduce idle CPU usage from 79% to near zero (#395)

* fix: reduce idle CPU usage from 79% to near zero (#394)

* perf: fix 15 performance bottlenecks from full codebase audit

* docs: remove performance audit tracking file

* fix: address PR review findings from CodeRabbit

Author: datlechin

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- High CPU usage (79%+) and energy consumption when idle (#394)
 - etcd connection failing with 404 when gRPC gateway uses a different API prefix (auto-detects `/v3/`, `/v3beta/`, `/v3alpha/`)
 - Data grid editing (delete rows, modify cells, add rows) not working in query tabs (#383)
 

LocalPackages/CodeEditSourceEditor/Sources/CodeEditSourceEditor/CodeSuggestion/Window/SuggestionController.swift

@@ -37,7 +37,7 @@ public final class SuggestionController: NSWindowController {
     /// Holds the observer for the window resign notifications
     private var windowResignObserver: NSObjectProtocol?
     /// Closes autocomplete when first responder changes away from the active text view
-    private var firstResponderObserver: NSObjectProtocol?
+    private var firstResponderKVO: NSKeyValueObservation?
     private var localEventMonitor: Any?
     private var sizeObservers: Set<AnyCancellable> = []
 
@@ -136,26 +136,22 @@ public final class SuggestionController: NSWindowController {
             self?.close()
         }
 
-        // Close when the active text view is removed (e.g., tab closed/switched)
-        if let existingObserver = firstResponderObserver {
-            NotificationCenter.default.removeObserver(existingObserver)
-        }
-        firstResponderObserver = NotificationCenter.default.addObserver(
-            forName: NSWindow.didUpdateNotification,
-            object: parentWindow,
-            queue: .main
-        ) { [weak self] _ in
-            guard let self else { return }
-            guard let textView = self.model.activeTextView else {
-                self.close()
-                return
-            }
-            // Close if text view removed from window or lost first responder
-            if textView.view.window == nil {
-                self.close()
-            } else if let firstResponder = textView.view.window?.firstResponder as? NSView,
-                      !firstResponder.isDescendant(of: textView.view) {
-                self.close()
+        // Close when first responder changes away from the active text view
+        firstResponderKVO?.invalidate()
+        firstResponderKVO = parentWindow.observe(\.firstResponder, options: [.new]) { [weak self] window, _ in
+            DispatchQueue.main.async { [weak self] in
+                guard let self else { return }
+                guard let textView = self.model.activeTextView else {
+                    self.close()
+                    return
+                }
+                if textView.view.window == nil {
+                    self.close()
+                } else if textView.view.window === window,
+                          let firstResponder = window.firstResponder as? NSView,
+                          !firstResponder.isDescendant(of: textView.view) {
+                    self.close()
+                }
             }
         }
 
@@ -174,10 +170,8 @@ public final class SuggestionController: NSWindowController {
             windowResignObserver = nil
         }
 
-        if let observer = firstResponderObserver {
-            NotificationCenter.default.removeObserver(observer)
-            firstResponderObserver = nil
-        }
+        firstResponderKVO?.invalidate()
+        firstResponderKVO = nil
 
         if popover != nil {
             popover?.close()

TablePro/ContentView.swift

@@ -18,6 +18,7 @@ struct ContentView: View {
     let payload: EditorTabPayload?
 
     @State private var currentSession: ConnectionSession?
+    @State private var closingSessionId: UUID?
     @State private var columnVisibility: NavigationSplitViewVisibility = .all
     @State private var showNewConnectionSheet = false
     @State private var showEditConnectionSheet = false
@@ -70,6 +71,7 @@ struct ContentView: View {
             // Right sidebar toggle is handled by MainContentView (has the binding)
             // Left sidebar toggle uses native NSSplitViewController.toggleSidebar via responder chain
             .onChange(of: DatabaseManager.shared.currentSessionId, initial: true) { _, newSessionId in
+                guard closingSessionId == nil else { return }
                 let ourConnectionId = payload?.connectionId
                 if ourConnectionId != nil {
                     guard newSessionId == ourConnectionId else { return }
@@ -102,59 +104,9 @@ struct ContentView: View {
                     columnVisibility = .detailOnly
                 }
             }
-            .onChange(of: (payload?.connectionId ?? currentSession?.id).flatMap { DatabaseManager.shared.connectionStatusVersions[$0] }, initial: true) { _, _ in
-                let sessions = DatabaseManager.shared.activeSessions
-                let connectionId = payload?.connectionId ?? currentSession?.id ?? DatabaseManager.shared.currentSessionId
-                guard let sid = connectionId else {
-                    if currentSession != nil { currentSession = nil }
-                    return
-                }
-                guard let newSession = sessions[sid] else {
-                    if currentSession?.id == sid {
-                        rightPanelState?.teardown()
-                        rightPanelState = nil
-                        sessionState?.coordinator.teardown()
-                        sessionState = nil
-                        currentSession = nil
-                        columnVisibility = .detailOnly
-                        AppState.shared.isConnected = false
-                        AppState.shared.safeModeLevel = .silent
-                        AppState.shared.editorLanguage = .sql
-                        AppState.shared.currentDatabaseType = nil
-                        AppState.shared.supportsDatabaseSwitching = true
-
-                        // Close all native tab windows for this connection and
-                        // force AppKit to deallocate them instead of pooling.
-                        let tabbingId = "com.TablePro.main.\(sid.uuidString)"
-                        DispatchQueue.main.async {
-                            for window in NSApp.windows where window.tabbingIdentifier == tabbingId {
-                                window.isReleasedWhenClosed = true
-                                window.close()
-                            }
-                        }
-                    }
-                    return
-                }
-                if let existing = currentSession,
-                   existing.isContentViewEquivalent(to: newSession) {
-                    return
-                }
-                currentSession = newSession
-                if rightPanelState == nil {
-                    rightPanelState = RightPanelState()
-                }
-                if sessionState == nil {
-                    sessionState = SessionStateFactory.create(
-                        connection: newSession.connection,
-                        payload: payload
-                    )
-                }
-                AppState.shared.isConnected = true
-                AppState.shared.safeModeLevel = newSession.connection.safeModeLevel
-                AppState.shared.editorLanguage = PluginManager.shared.editorLanguage(for: newSession.connection.type)
-                AppState.shared.currentDatabaseType = newSession.connection.type
-                AppState.shared.supportsDatabaseSwitching = PluginManager.shared.supportsDatabaseSwitching(
-                    for: newSession.connection.type)
+            .task { handleConnectionStatusChange() }
+            .onReceive(NotificationCenter.default.publisher(for: .connectionStatusDidChange)) { _ in
+                handleConnectionStatusChange()
             }
             .onReceive(NotificationCenter.default.publisher(for: NSWindow.didBecomeKeyNotification)) { notification in
                 // Only process notifications for our own window to avoid every
@@ -378,6 +330,63 @@ struct ContentView: View {
         )
     }
 
+    // MARK: - Connection Status
+
+    private func handleConnectionStatusChange() {
+        guard closingSessionId == nil else { return }
+        let sessions = DatabaseManager.shared.activeSessions
+        let connectionId = payload?.connectionId ?? currentSession?.id ?? DatabaseManager.shared.currentSessionId
+        guard let sid = connectionId else {
+            if currentSession != nil { currentSession = nil }
+            return
+        }
+        guard let newSession = sessions[sid] else {
+            if currentSession?.id == sid {
+                closingSessionId = sid
+                rightPanelState?.teardown()
+                rightPanelState = nil
+                sessionState?.coordinator.teardown()
+                sessionState = nil
+                currentSession = nil
+                columnVisibility = .detailOnly
+                AppState.shared.isConnected = false
+                AppState.shared.safeModeLevel = .silent
+                AppState.shared.editorLanguage = .sql
+                AppState.shared.currentDatabaseType = nil
+                AppState.shared.supportsDatabaseSwitching = true
+
+                let tabbingId = "com.TablePro.main.\(sid.uuidString)"
+                DispatchQueue.main.async {
+                    for window in NSApp.windows where window.tabbingIdentifier == tabbingId {
+                        window.isReleasedWhenClosed = true
+                        window.close()
+                    }
+                }
+            }
+            return
+        }
+        if let existing = currentSession,
+           existing.isContentViewEquivalent(to: newSession) {
+            return
+        }
+        currentSession = newSession
+        if rightPanelState == nil {
+            rightPanelState = RightPanelState()
+        }
+        if sessionState == nil {
+            sessionState = SessionStateFactory.create(
+                connection: newSession.connection,
+                payload: payload
+            )
+        }
+        AppState.shared.isConnected = true
+        AppState.shared.safeModeLevel = newSession.connection.safeModeLevel
+        AppState.shared.editorLanguage = PluginManager.shared.editorLanguage(for: newSession.connection.type)
+        AppState.shared.currentDatabaseType = newSession.connection.type
+        AppState.shared.supportsDatabaseSwitching = PluginManager.shared.supportsDatabaseSwitching(
+            for: newSession.connection.type)
+    }
+
     // MARK: - Actions
 
     private func connectToDatabase(_ connection: DatabaseConnection) {

TablePro/Core/AI/InlineSuggestionManager.swift

@@ -58,7 +58,6 @@ final class InlineSuggestionManager {
     func install(controller: TextViewController, schemaProvider: SQLSchemaProvider?) {
         self.controller = controller
         self.schemaProvider = schemaProvider
-        installScrollObserver()
     }
 
     func editorDidFocus() {
@@ -87,11 +86,7 @@ final class InlineSuggestionManager {
         removeGhostLayer()
 
         removeKeyEventMonitor()
-
-        if let observer = _scrollObserver.withLock({ $0 }) {
-            NotificationCenter.default.removeObserver(observer)
-            _scrollObserver.withLock { $0 = nil }
-        }
+        removeScrollObserver()
 
         schemaProvider = nil
         controller = nil
@@ -337,6 +332,7 @@ final class InlineSuggestionManager {
 
         textView.layer?.addSublayer(layer)
         ghostLayer = layer
+        installScrollObserver()
     }
 
     private func removeGhostLayer() {
@@ -346,28 +342,28 @@ final class InlineSuggestionManager {
 
     // MARK: - Accept / Dismiss
 
-    /// Accept the current suggestion by inserting it at the cursor
     private func acceptSuggestion() {
         guard let suggestion = currentSuggestion,
               let textView = controller?.textView else { return }
 
         let offset = suggestionOffset
         removeGhostLayer()
         currentSuggestion = nil
+        removeScrollObserver()
 
         textView.replaceCharacters(
             in: NSRange(location: offset, length: 0),
             with: suggestion
         )
     }
 
-    /// Dismiss the current suggestion without inserting
     func dismissSuggestion() {
         debounceTimer?.invalidate()
         currentTask?.cancel()
         currentTask = nil
         removeGhostLayer()
         currentSuggestion = nil
+        removeScrollObserver()
     }
 
     // MARK: - Key Event Monitor
@@ -421,6 +417,7 @@ final class InlineSuggestionManager {
     // MARK: - Scroll Observer
 
     private func installScrollObserver() {
+        guard _scrollObserver.withLock({ $0 }) == nil else { return }
         guard let scrollView = controller?.scrollView else { return }
         let contentView = scrollView.contentView
 
@@ -430,15 +427,22 @@ final class InlineSuggestionManager {
                 object: contentView,
                 queue: .main
             ) { [weak self] _ in
-                guard self?.currentSuggestion != nil else { return }
                 Task { @MainActor [weak self] in
                     guard let self else { return }
                     if let suggestion = self.currentSuggestion {
-                        // Reposition the ghost layer after scroll
                         self.showGhostText(suggestion, at: self.suggestionOffset)
                     }
                 }
             }
         }
     }
+
+    private func removeScrollObserver() {
+        _scrollObserver.withLock {
+            if let observer = $0 {
+                NotificationCenter.default.removeObserver(observer)
+            }
+            $0 = nil
+        }
+    }
 }

TablePro/Core/Database/DatabaseManager.swift

@@ -312,12 +312,14 @@ final class DatabaseManager {
     private func setSession(_ session: ConnectionSession, for connectionId: UUID) {
         activeSessions[connectionId] = session
         connectionStatusVersions[connectionId, default: 0] &+= 1
+        NotificationCenter.default.post(name: .connectionStatusDidChange, object: connectionId)
     }
 
     /// Remove a session and clean up its per-connection version counter.
     private func removeSessionEntry(for connectionId: UUID) {
         activeSessions.removeValue(forKey: connectionId)
         connectionStatusVersions.removeValue(forKey: connectionId)
+        NotificationCenter.default.post(name: .connectionStatusDidChange, object: connectionId)
     }
 
     #if DEBUG

TablePro/Core/Services/Formatting/SQLFormatterService.swift

@@ -108,13 +108,13 @@ struct SQLFormatterService: SQLFormatterProtocol {
     /// Get or create the keyword uppercasing regex for a given database type
     private static func keywordRegex(for dialect: DatabaseType) -> NSRegularExpression? {
         keywordRegexLock.lock()
-        defer { keywordRegexLock.unlock() }
-
         if let cached = keywordRegexCache[dialect] {
+            keywordRegexLock.unlock()
             return cached
         }
+        keywordRegexLock.unlock()
 
-        let provider = MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
+        let provider = resolveDialectProvider(for: dialect)
         let allKeywords = provider.keywords.union(provider.functions).union(provider.dataTypes)
         let escapedKeywords = allKeywords.map { NSRegularExpression.escapedPattern(for: $0) }
         let pattern = "\\b(\(escapedKeywords.joined(separator: "|")))\\b"
@@ -123,10 +123,24 @@ struct SQLFormatterService: SQLFormatterProtocol {
             return nil
         }
 
+        keywordRegexLock.lock()
+        defer { keywordRegexLock.unlock() }
+        if let cached = keywordRegexCache[dialect] {
+            return cached
+        }
         keywordRegexCache[dialect] = regex
         return regex
     }
 
+    private static func resolveDialectProvider(for dialect: DatabaseType) -> SQLDialectProvider {
+        if Thread.isMainThread {
+            return MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
+        }
+        return DispatchQueue.main.sync {
+            MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
+        }
+    }
+
     // MARK: - Public API
 
     func format(
@@ -152,8 +166,7 @@ struct SQLFormatterService: SQLFormatterProtocol {
             throw SQLFormatterError.invalidCursorPosition(cursor, max: sqlLength)
         }
 
-        // Get dialect provider
-        let dialectProvider = MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
+        let dialectProvider = Self.resolveDialectProvider(for: dialect)
 
         // Format the SQL
         let formatted = formatSQL(sql, dialect: dialectProvider, databaseType: dialect, options: options)

TablePro/Core/Services/Infrastructure/AnalyticsService.swift

@@ -69,6 +69,7 @@ final class AnalyticsService {
             while !Task.isCancelled {
                 await self?.sendHeartbeat()
                 try? await Task.sleep(for: .seconds(self?.heartbeatInterval ?? 86_400))
+                guard self != nil else { return }
             }
         }
     }

TablePro/Core/Services/Infrastructure/AppNotifications.swift

@@ -17,6 +17,7 @@ extension Notification.Name {
     // MARK: - Connections
 
     static let connectionUpdated = Notification.Name("connectionUpdated")
+    static let connectionStatusDidChange = Notification.Name("connectionStatusDidChange")
     static let databaseDidConnect = Notification.Name("databaseDidConnect")
 
     // MARK: - SQL Favorites

TablePro/Core/Services/Licensing/LicenseManager.swift

@@ -94,6 +94,7 @@ final class LicenseManager {
 
             while !Task.isCancelled {
                 try? await Task.sleep(for: .seconds(self?.revalidationInterval ?? 604_800))
+                guard self != nil else { return }
                 await self?.revalidate()
             }
         }