Improve performance of state system

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.8
+// swift-tools-version: 5.10
 //
 //  Package.swift
 //  Meta
@@ -11,6 +11,10 @@ import PackageDescription
 /// The Meta package is the foundation of the Aparoksha project.
 let package = Package(
     name: "Meta",
+    platforms: [
+        .macOS(.v10_15),
+        .iOS(.v13)
+    ],
     products: [
         .library(
             name: "Meta",

Sources/Model/Data Flow/State.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import Observation
 
 /// A property wrapper for properties in a view that should be stored throughout view updates.
 @propertyWrapper
@@ -18,8 +19,8 @@ public struct State<Value>: StateProtocol {
         }
         nonmutating set {
             rawValue = newValue
-            content.storage.update = true
+            StateManager.updateState(id: id)
-            UpdateManager.updateViews(force: forceUpdates)
+            StateManager.updateViews(force: forceUpdates)
         }
     }
 
@@ -32,46 +33,45 @@ public struct State<Value>: StateProtocol {
         }
     }
 
-    // swiftlint:disable force_cast
     /// Get and set the value without updating the views.
     public var rawValue: Value {
         get {
-            content.storage.value as! Value
+            guard let value = StateManager.getState(id: id) as? Value else {
+                let initialValue = getInitialValue()
+                StateManager.setState(id: id, value: initialValue)
+                return initialValue
+            }
+            return value
         }
         nonmutating set {
-            content.storage.value = newValue
+            StateManager.setState(id: id, value: newValue)
-            writeValue?(newValue)
         }
     }
-    // swiftlint:enable force_cast
 
-    /// The stored value.
+    /// Whether the value is an observable object.
-    let content: StateContent
+    var isObservable: Bool {
+        if #available(macOS 14, *), #available(iOS 17, *) {
+            return Value.self as? Observable.Type != nil
+        } else {
+            return false
+        }
+    }
+
+    /// The state's identifier for the stored value.
+    var id: UUID = .init()
 
     /// Whether to force update the views when the value changes.
-    public var forceUpdates: Bool
+    var forceUpdates: Bool
 
-    /// The function for updating the value in the settings file.
+    /// The closure for initializing the state property's value.
-    private var writeValue: ((Value) -> Void)?
+    var getInitialValue: () -> Value
-
-    /// The value with an erased type.
-    public var value: Any {
-        get {
-            wrappedValue
-        }
-        nonmutating set {
-            if let newValue = newValue as? Value {
-                content.storage.value = newValue
-            }
-        }
-    }
 
     /// Initialize a property representing a state in the view with an autoclosure.
     /// - Parameters:
     ///     - wrappedValue: The wrapped value.
     ///     - forceUpdates: Whether to force update all available views when the property gets modified.
     public init(wrappedValue: @autoclosure @escaping () -> Value, forceUpdates: Bool = false) {
-        content = .init(getInitialValue: wrappedValue)
+        getInitialValue = wrappedValue
         self.forceUpdates = forceUpdates
     }
 

Sources/Model/Data Flow/StateManager.swift

@@ -0,0 +1,106 @@
+//
+//  StateManager.swift
+//  Meta
+//
+//  Created by david-swift on 21.06.24.
+//
+
+import Foundation
+
+/// This type manages view updates.
+public enum StateManager {
+
+    /// Whether to block updates in general.
+    public static var blockUpdates = false
+    /// Whether to save state.
+    public static var saveState = true
+    /// The functions handling view updates.
+    static var updateHandlers: [(Bool) -> Void] = []
+    /// The state.
+    static var state: [State] = []
+
+    /// Information about a piece of state.
+    struct State {
+
+        /// The state's identifiers.
+        var ids: [UUID]
+        /// The state value.
+        var value: Any?
+        /// Whether to update in the next iteration.
+        var update = false
+
+    }
+
+    /// Update all of the views.
+    /// - Parameter force: Whether to force all views to update.
+    ///
+    /// Nothing happens if ``UpdateManager/blockUpdates`` is true.
+    static func updateViews(force: Bool = false) {
+        if !blockUpdates {
+            for handler in updateHandlers {
+                handler(force)
+            }
+        }
+    }
+
+    /// Add a handler that is called when the user interface should update.
+    /// - Parameter handler: The handler. The parameter defines whether the whole UI should be force updated.
+    public static func addUpdateHandler(handler: @escaping (Bool) -> Void) {
+        updateHandlers.append(handler)
+    }
+
+    /// Set the state value for a certain ID.
+    /// - Parameters:
+    ///   - id: The identifier.
+    ///   - value: The new value.
+    static func setState(id: UUID, value: Any?) {
+        if saveState {
+            guard let index = state.firstIndex(where: { $0.ids.contains(id) }) else {
+                state.append(.init(ids: [id], value: value))
+                return
+            }
+            state[safe: index]?.value = value
+        }
+    }
+
+    /// Get the state value for a certain ID.
+    /// - Parameter id: The identifier.
+    /// - Returns: The value.
+    static func getState(id: UUID) -> Any? {
+        state[safe: state.firstIndex { $0.ids.contains(id) }]?.value
+    }
+
+    /// Mark the state of a certain id as updated.
+    /// - Parameter id: The identifier.
+    static func updateState(id: UUID) {
+        if saveState {
+            state[safe: state.firstIndex { $0.ids.contains(id) }]?.update = true
+        }
+    }
+
+    /// Mark the state of a certain id as not updated.
+    /// - Parameter id: The identifier.
+    static func updatedState(id: UUID) {
+        if saveState {
+            state[safe: state.firstIndex { $0.ids.contains(id) }]?.update = false
+        }
+    }
+
+    /// Get whether to update the state of a certain id.
+    /// - Parameter id: The identifier.
+    /// - Returns: Whether to update the state.
+    static func getUpdateState(id: UUID) -> Bool {
+        state[safe: state.firstIndex { $0.ids.contains(id) }]?.update ?? false
+    }
+
+    /// Change the identifier for a certain state value.
+    /// - Parameters:
+    ///   - oldID: The old identifier.
+    ///   - newID: The new identifier.
+    static func changeID(old oldID: UUID, new newID: UUID) {
+        if saveState {
+            state[safe: state.firstIndex { $0.ids.contains(oldID) }]?.ids.append(newID)
+        }
+    }
+
+}

Sources/Model/Data Flow/StateProtocol.swift

@@ -5,10 +5,14 @@
 //  Created by david-swift on 26.05.24.
 //
 
+import Foundation
+
 /// An interface for accessing `State` without specifying the generic type.
 protocol StateProtocol {
 
-    /// The `StateContent`.
+    /// The identifier for the state property's value.
-    var content: StateContent { get }
+    var id: UUID { get set }
+    /// Whether the state value is an observable object.
+    var isObservable: Bool { get }
 
 }

Sources/Model/Data Flow/UpdateManager.swift

@@ -1,34 +0,0 @@
-//
-//  UpdateManager.swift
-//  Meta
-//
-//  Created by david-swift on 26.05.24.
-//
-
-/// This type manages view updates.
-public enum UpdateManager {
-
-    /// Whether to block updates in general.
-    public static var blockUpdates = false
-    /// The functions handling view updates.
-    static var updateHandlers: [(Bool) -> Void] = []
-
-    /// Update all of the views.
-    /// - Parameter force: Whether to force all views to update.
-    ///
-    /// Nothing happens if ``UpdateManager/blockUpdates`` is true.
-    static func updateViews(force: Bool = false) {
-        if !blockUpdates {
-            for handler in updateHandlers {
-                handler(force)
-            }
-        }
-    }
-
-    /// Add a handler that is called when the user interface should update.
-    /// - Parameter handler: The handler. The parameter defines whether the whole UI should be force updated.
-    public static func addUpdateHandler(handler: @escaping (Bool) -> Void) {
-        updateHandlers.append(handler)
-    }
-
-}

Sources/Model/Extensions/Array.swift

@@ -20,6 +20,8 @@ extension Array: AnyView where Element == AnyView {
         type: WidgetType.Type,
         modifiers: [(AnyView) -> AnyView] = []
     ) -> String {
+        let oldValue = StateManager.saveState
+        StateManager.saveState = false
         var description = ""
         for view in self where view.renderable(type: type, modifiers: modifiers) {
             description += view.getDebugTree(parameters: parameters, type: type, modifiers: modifiers) + "\n"
@@ -27,6 +29,7 @@ extension Array: AnyView where Element == AnyView {
         if !description.isEmpty {
             description.removeLast()
         }
+        StateManager.saveState = oldValue
         return description
     }
 

Sources/Model/User Interface/View/AnyView.swift

@@ -26,12 +26,17 @@ extension AnyView {
         type: WidgetType.Type,
         modifiers: [(AnyView) -> AnyView] = []
     ) -> String {
+        let oldValue = StateManager.saveState
+        StateManager.saveState = false
+        defer {
+            StateManager.saveState = oldValue
+        }
         if let body = getModified(modifiers: modifiers) as? Body {
             return body.getBodyDebugTree(parameters: parameters, type: type, modifiers: modifiers)
         } else if let widget = getModified(modifiers: modifiers) as? Widget {
             return widget.getViewDescription(parameters: parameters, type: type, modifiers: modifiers)
         }
-        return """
+        let string = """
         \(Self.self) {
             \(indented: viewContent
                 .map { view in
@@ -40,6 +45,7 @@ extension AnyView {
                 .getBodyDebugTree(parameters: parameters, type: type, modifiers: modifiers))
         }
         """
+        return string
     }
 
     func getModified(modifiers: [(AnyView) -> AnyView]) -> AnyView {

Sources/Model/User Interface/View/Widget.swift

@@ -43,6 +43,11 @@ extension Widget {
         type: WidgetType.Type,
         modifiers: [(AnyView) -> AnyView]
     ) -> String {
+        let oldValue = StateManager.saveState
+        StateManager.saveState = false
+        defer {
+            StateManager.saveState = oldValue
+        }
         var content = ""
         for element in debugTreeContent {
             if content.isEmpty {

Sources/View/StateWrapper.swift

@@ -11,7 +11,7 @@ import Observation
 public struct StateWrapper: ConvenienceWidget {
 
     /// The content.
-    var content: Body
+    var content: () -> Body
     /// The state information (from properties with the `State` wrapper).
     var state: [String: StateProtocol] = [:]
 
@@ -24,7 +24,7 @@ public struct StateWrapper: ConvenienceWidget {
 
     /// The debug tree's content.
     public var debugTreeContent: [(String, body: Body)] {
-        [("content", body: content)]
+        [("content", body: content())]
     }
 
     /// The identifier of the field storing whether to update the wrapper's content.
@@ -33,7 +33,7 @@ public struct StateWrapper: ConvenienceWidget {
     /// Initialize a `StateWrapper`.
     /// - Parameter content: The view content.
     public init(@ViewBuilder content: @escaping () -> Body) {
-        self.content = content()
+        self.content = content
     }
 
     /// Initialize a `StateWrapper`.
@@ -41,7 +41,7 @@ public struct StateWrapper: ConvenienceWidget {
     ///   - content: The view content.
     ///   - state: The state information.
     init(content: @escaping () -> Body, state: [String: StateProtocol]) {
-        self.content = content()
+        self.content = content
         self.state = state
     }
 
@@ -60,18 +60,19 @@ public struct StateWrapper: ConvenienceWidget {
         var updateProperties = storage.fields[updateID] as? Bool ?? false
         storage.fields[updateID] = false
         for property in state {
-            if let storage = storage.state[property.key]?.content.storage {
+            if let oldID = storage.state[property.key]?.id {
-                property.value.content.storage = storage
+                StateManager.changeID(old: oldID, new: property.value.id)
+                storage.state[property.key]?.id = property.value.id
             }
-            if property.value.content.storage.update {
+            if StateManager.getUpdateState(id: property.value.id) {
                 updateProperties = true
-                property.value.content.storage.update = false
+                StateManager.updatedState(id: property.value.id)
             }
         }
         guard let storages = storage.content[.mainContent] else {
             return
         }
-        content.update(storages, modifiers: modifiers, updateProperties: updateProperties, type: type)
+        content().update(storages, modifiers: modifiers, updateProperties: updateProperties, type: type)
     }
 
     /// Get a view storage.
@@ -80,22 +81,28 @@ public struct StateWrapper: ConvenienceWidget {
     ///     - type: The type of the widgets.
     /// - Returns: The view storage.
     public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-        let content = content.storages(modifiers: modifiers, type: type)
+        let content = content().storages(modifiers: modifiers, type: type)
         let storage = ViewStorage(nil, content: [.mainContent: content])
         storage.state = state
-        observe(storage: storage)
+        if #available(macOS 14, *), #available(iOS 17, *), state.contains(where: { $0.value.isObservable }) {
+            observe(storage: storage)
+        }
         return storage
     }
 
     /// Observe the observable properties accessed in the view.
     /// - Parameter storage: The view storage
+    @available(macOS, introduced: 14)
+    @available(iOS, introduced: 17)
     func observe(storage: ViewStorage) {
         withObservationTracking {
-            _ = content.getDebugTree(parameters: true, type: AnyView.self)
+            _ = content().getDebugTree(parameters: true, type: AnyView.self)
         } onChange: {
-            storage.fields[updateID] = true
+            Task {
-            UpdateManager.updateViews()
+                StateManager.updateState(id: storage.state.first?.value.id ?? .init())
-            observe(storage: storage)
+                StateManager.updateViews()
+                observe(storage: storage)
+            }
         }
     }
 

Tests/DemoApp/DemoApp.swift

@@ -1,15 +1,18 @@
 import Foundation
 import Meta
+import Observation
 import SampleBackends
 
+@available(macOS 14, *)
+@available(iOS 17, *)
 struct DemoView: View {
 
-    @State private var test = "Label"
+    @State private var test = TestModel()
 
-     var view: Body {
+    var view: Body {
         Backend1.TestWidget1()
-        Backend1.Button(test) {
+        Backend1.Button(test.test) {
-            test = "\(Int.random(in: 1...10))"
+            test.test = "\(Int.random(in: 1...10))"
         }
         TestView()
         testContent
@@ -23,29 +26,55 @@ struct DemoView: View {
 
 }
 
-struct TestView: SimpleView {
+struct TestView: View {
+
+    @State private var test = "Label"
 
     var view: Body {
         Backend2.TestWidget4()
+        Backend1.Button(test) {
+            Task {
+                try await Task.sleep(nanoseconds: 100_000_000)
+                test = "\(Int.random(in: 1...10))"
+            }
+        }
     }
 
 }
 
-let backendType = Backend1.BackendWidget.self
+@available(macOS 14, *)
-let modifiers: [(AnyView) -> AnyView] = [
+@available(iOS 17, *)
-    { $0 as? Backend2.TestWidget2 != nil ? [Backend1.TestWidget1()] : $0 }
+@Observable
-]
+class TestModel {
+
+    var test = "Label"
 
-print(DemoView().getDebugTree(parameters: true, type: backendType, modifiers: modifiers))
-let storage = DemoView().storage(modifiers: modifiers, type: backendType)
-for round in 0...2 {
-    print("#\(round)")
-    DemoView().updateStorage(storage, modifiers: modifiers, updateProperties: true, type: backendType)
 }
 
-UpdateManager.addUpdateHandler { _ in
+@main
-    print("#Handler")
+@available(macOS 14, *)
-    DemoView().updateStorage(storage, modifiers: modifiers, updateProperties: false, type: backendType)
+@available(iOS 17, *)
-}
+struct DemoApp {
 
-sleep(2)
+    static func main() {
+        let backendType = Backend1.BackendWidget.self
+        let modifiers: [(AnyView) -> AnyView] = [
+            { $0 as? Backend2.TestWidget2 != nil ? [Backend1.TestWidget1()] : $0 }
+        ]
+
+        print(DemoView().getDebugTree(parameters: true, type: backendType, modifiers: modifiers))
+        let storage = DemoView().storage(modifiers: modifiers, type: backendType)
+        for round in 0...2 {
+            print("#\(round)")
+            DemoView().updateStorage(storage, modifiers: modifiers, updateProperties: true, type: backendType)
+        }
+
+        StateManager.addUpdateHandler { _ in
+            DemoView().updateStorage(storage, modifiers: modifiers, updateProperties: false, type: backendType)
+        }
+
+        sleep(2)
+        DemoView().updateStorage(storage, modifiers: modifiers, updateProperties: true, type: backendType)
+    }
+
+}

Tests/SampleBackends/Backend1.swift

@@ -74,8 +74,9 @@ public enum Backend1 {
         }
 
         public func container<WidgetType>(modifiers: [(any AnyView) -> any AnyView], type: WidgetType.Type) -> ViewStorage {
+            print("Init button")
             Task {
-                try await Task.sleep(for: .seconds(1))
+                try await Task.sleep(nanoseconds: 1_000_000_000)
                 action()
             }
             return .init(nil)
@@ -83,9 +84,9 @@ public enum Backend1 {
 
         public func update<WidgetType>(_ storage: ViewStorage, modifiers: [(any AnyView) -> any AnyView], updateProperties: Bool, type: WidgetType.Type) {
             if updateProperties {
-                print("Update button")
+                print("Update button (label = \(label))")
             } else {
-                print("Do not update button")
+                print("Do not update button (label = \(label))")
             }
         }