Merge branch 'main' into muukii/store-reader-2

Package.swift

@@ -12,6 +12,7 @@ let package = Package(
   ],
   products: [
     .library(name: "Verge", targets: ["Verge"]),
+    .library(name: "VergeTiny", targets: ["VergeTiny"]),
     .library(name: "VergeNormalizationDerived", targets: ["VergeNormalizationDerived"]),
     .library(name: "VergeRx", targets: ["VergeRx"]),
     .library(name: "VergeClassic", targets: ["VergeClassic"]),
@@ -45,6 +46,7 @@ let package = Package(
     // macro exports
     .target(name: "VergeMacros", dependencies: ["VergeMacrosPlugin"]),
 
+    .target(name: "VergeTiny", dependencies: []),
     .target(
       name: "Verge",
       dependencies: [
@@ -96,6 +98,10 @@ let package = Package(
         .enableExperimentalFeature("StrictConcurrency")
       ]
     ),
+    .testTarget(
+      name: "VergeTinyTests",
+      dependencies: ["VergeTiny"]
+    ),
     .testTarget(
       name: "VergeMacrosTests",
       dependencies: [

Sources/VergeTiny/Source.swift

@@ -0,0 +1,243 @@
+//
+// Copyright (c) 2021 Hiroshi Kimura(Muukii) <[email protected]>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+import Foundation
+
+public struct DynamicProperty<T> {
+
+  public var value: T? {
+    get {
+
+      storage.lock.lock()
+
+      // Do not directly cast using `as?`.
+      guard let value = storage.synchronized_value(for: key) else {
+        storage.lock.unlock()
+        return nil
+      }
+
+      storage.lock.unlock()
+
+      return value as? T
+    }
+    nonmutating set {
+      storage.lock.lock()
+      storage.synchronized_setValue(newValue as Any, for: key)
+      storage.lock.unlock()
+    }
+  }
+
+  public let key: String
+  private let storage: DynamicPropertyStorage.Storage<Any>
+
+  init(key: String, storage: DynamicPropertyStorage.Storage<Any>) {
+    self.key = key
+    self.storage = storage
+  }
+
+  private func _doIfChanged(
+    value: T,
+    compare: (T, T) -> Bool,
+    perform: (T) -> Void
+  ) {
+
+    storage.lock.lock()
+
+    // Do not directly cast using `as?`.
+    // To detect storage does not have value for key when T is optinal type.
+    guard let cachedRawValue = storage.synchronized_value(for: key) else {
+      storage.synchronized_setValue(value, for: key)
+      storage.lock.unlock()
+      perform(value)
+      return
+    }
+
+    let cachedValue = cachedRawValue as! T
+
+    guard compare(cachedValue, value) == false else {
+      storage.lock.unlock()
+      return
+    }
+
+    storage.synchronized_setValue(value, for: key)
+
+    storage.lock.unlock()
+
+    perform(value)
+
+  }
+
+  /// [Experimental]
+  /// should be renamed
+  public func doIfChanged(
+    _ value: T,
+    _ compare: (T, T) -> Bool,
+    _ perform: (T) -> Void
+  ) {
+
+    _doIfChanged(
+      value: value,
+      compare: compare,
+      perform: perform
+    )
+
+  }
+
+  /// [Experimental]
+  /// should be renamed
+  public func doIfChanged(
+    _ value: T,
+    _ perform: (T) -> Void
+  ) where T : Equatable {
+
+    _doIfChanged(
+      value: value,
+      compare: ==,
+      perform: perform
+    )
+
+  }
+
+}
+
+public final class DynamicPropertyStorage {
+
+  final class Storage<T> {
+
+    let lock = NSLock()
+
+    var rawStorage: [String : T] = [:]
+
+    func synchronized_value(for key: String) -> T? {
+
+      guard let value = rawStorage[key] else {
+        return nil
+      }
+
+      return value
+    }
+
+    func synchronized_setValue(_ value: T, for key: String) {
+      rawStorage[key] = value
+    }
+
+    func synchronized_removeValue(for key: String) {
+      rawStorage.removeValue(forKey: key)
+    }
+  }
+
+  struct CodeLocation: Hashable {
+    let file: String
+    let line: UInt
+    let column: UInt
+
+    func makeKey() -> String {
+      "\(file).\(line).\(column)"
+    }
+  }
+
+  private let _anyStorage: Storage<Any> = .init()
+
+  public init() {
+
+  }
+
+  public func defineProperty<T>(
+    file: StaticString = #file,
+    line: UInt = #line,
+    column: UInt = #column,
+    _ type: T.Type
+  ) -> DynamicProperty<T> {
+
+    let codeLocation = CodeLocation(file: file.description, line: line, column: column)
+
+    return .init(key: codeLocation.makeKey(), storage: _anyStorage)
+
+  }
+
+  /// [Experimental]
+  /// should be renamed
+  public func doIfChanged<T>(
+    file: StaticString = #file,
+    line: UInt = #line,
+    column: UInt = #column,
+    _ value: T,
+    _ compare: (T, T) -> Bool,
+    _ perform: (T) -> Void
+  ) {
+
+    let property = defineProperty(file: file, line: line, column: column, T.self)
+
+    property.doIfChanged(
+      value,
+      compare,
+      perform
+    )
+
+  }
+
+  /// [Experimental]
+  /// should be renamed
+  public func doIfChanged<T>(
+    file: StaticString = #file,
+    line: UInt = #line,
+    column: UInt = #column,
+    _ value: T,
+    _ perform: (T) -> Void
+  ) where T : Equatable {
+
+    let property = defineProperty(file: file, line: line, column: column, T.self)
+
+    property.doIfChanged(
+      value,
+      perform
+    )
+
+  }
+
+}
+
+nonisolated(unsafe) private var _storageKey: Void?
+
+extension NSObject {
+
+  public var associatedProperties: DynamicPropertyStorage {
+
+    objc_sync_enter(self)
+    defer {
+      objc_sync_exit(self)
+    }
+
+    if let associated = objc_getAssociatedObject(self, &_storageKey)
+        as? DynamicPropertyStorage
+    {
+      return associated
+    } else {
+      let associated = DynamicPropertyStorage()
+      objc_setAssociatedObject(self, &_storageKey, associated, .OBJC_ASSOCIATION_RETAIN)
+      return associated
+    }
+
+  }
+
+}
+
+