feat: 添加 DFCurrentValueFile 类和相关扩展，增强文件处理能力

Author: linhay

Sources/STFilePath/DownloadableFile/DFAnyFile.swift

@@ -57,3 +57,59 @@ public extension DFAnyFile {
     }
 
 }
+
+public final class DFCurrentValueFile<File: DownloadableFile & Sendable>: @unchecked Sendable, DownloadableFile {
+    public typealias Model = File.Model
+    
+    public let file: File
+    public var value: File.Model? {
+        set {
+            _value = newValue
+            save(newValue)
+        }
+        get { _value }
+    }
+    private var _value: File.Model?
+    private var task: Task<(), any Error>?
+    
+    public init(file: File, initialValue value: File.Model? = nil) {
+        self.file = file
+        self._value = value
+    }
+
+    public func fetch() async throws -> Model {
+        let value = try await file.fetch()
+        self._value = value
+        return value
+    }
+    
+    public func save(_ model: Model?) async throws {
+        try Task.checkCancellation()
+        self._value = model
+        try await file.save(model)
+    }
+
+    private func save(_ model: Model?) {
+        task?.cancel()
+        task = Task {
+            do {
+                try await save(model)
+            } catch let error as CancellationError {
+                debugPrint("Failed to save file: \(error)")
+            } catch {
+                debugPrint("Failed to save file: \(error)")
+            }
+        }
+    }
+    
+}
+
+
+public extension STFile {
+    
+    func toDFAnyFile() -> DFAnyFile<Data> {
+        .init(file: self)
+    }
+    
+}
+

Sources/STFilePath/DownloadableFile/DownloadableFile.swift

@@ -37,7 +37,7 @@ public protocol DownloadableFile: Sendable {
     /// - Parameter model: The model to save.
     /// - Throws: An error if the save operation fails.
     func save(_ model: Model?) async throws
-
+    
 }
 
 public extension DownloadableFile {
@@ -88,6 +88,10 @@ public extension DownloadableFile {
         }
     }
 
+    func currentValueFile(_ value: Model?) -> DFCurrentValueFile<Self> {
+        .init(file: self, initialValue: value)
+    }
+    
     /// [en] Maps the file data to a `Codable` type with default encoder and decoder settings.
     /// [zh] 使用默认的编码器和解码器设置将文件数据映射到 `Codable` 类型。
     /// - Parameters:
@@ -112,7 +116,7 @@ public extension DownloadableFile {
     /// [zh] 将文件的特定类型擦除为 `DFAnyFile`。
     /// - Returns: A `DFAnyFile` instance.
     /// - Throws: An error if the operation fails.
-    func eraseToAnyFile() async throws -> DFAnyFile<Model> {
+    func eraseToAnyFile() -> DFAnyFile<Model> {
         .init {
             try await self.fetch()
         } save: { model in

Sources/STFilePath/STPathAttributes.swift

@@ -40,19 +40,33 @@ public struct STPathNameComponents {
     public var isHidden: Bool { name.hasPrefix(".") }
 
     public init(_ name: String) {
-        let lastPathComponent = name.split(separator: "/", omittingEmptySubsequences: true).last ?? ""
-        let components = lastPathComponent.split(separator: ".", omittingEmptySubsequences: false)
-
-        // [en] If it is a hidden file and has only one dot, then the entire lastPathComponent is the file name.
-        // [zh] 如果是隐藏文件且只有一个点，那么整个 lastPathComponent 是文件名。
-        if components.count == 1 {
-            self.name = String(lastPathComponent)
+        let path = name
+        let pathComponents = path.split(separator: "/", omittingEmptySubsequences: true)
+        let lastPathComponent = pathComponents.last.map(String.init) ?? ""
+        if lastPathComponent.isEmpty {
+            self.name = ""
             self.extension = nil
+        } else if lastPathComponent.hasPrefix(".") {
+            // Hidden file, check for multiple dots
+            let dotComponents = lastPathComponent.dropFirst().split(separator: ".", omittingEmptySubsequences: false)
+            if dotComponents.count <= 1 {
+                self.name = lastPathComponent
+                self.extension = nil
+            } else {
+                let ext = dotComponents.last.map(String.init)
+                let namePart = "." + dotComponents.dropLast().joined(separator: ".")
+                self.name = namePart
+                self.extension = ext
+            }
         } else {
-            // [en] Otherwise, the part after the first dot is the file name, and the second part is the extension.
-            // [zh] 否则，除去第一个点的剩余部分是文件名，第二部分是扩展名。
-            self.name = (lastPathComponent.hasPrefix(".") ? "." : "") + components.dropLast().joined(separator: ".")
-            self.extension = components.last?.description
+            let dotComponents = lastPathComponent.split(separator: ".", omittingEmptySubsequences: false)
+            if dotComponents.count == 1 {
+                self.name = lastPathComponent
+                self.extension = nil
+            } else {
+                self.name = dotComponents.dropLast().joined(separator: ".")
+                self.extension = dotComponents.last.map(String.init)
+            }
         }
     }
 }