Use FoundationEssentials file attributes for replacement directories

Author: Hokila

Sources/FoundationEssentials/FileManager/FileManager+Directories.swift

@@ -71,9 +71,9 @@ extension _FileManagerImpl {
         let temporaryItemsDirectory = temporaryDirectory.appending(component: "TemporaryItems", directoryHint: .isDirectory)
         let referenceDirectory = reference.deletingPathExtension()
         let useTemporaryDirectory: Bool
-        if let temporaryVolumeIdentifier = try? temporaryDirectory.resourceValues(forKeys: [.volumeIdentifierKey]).volumeIdentifier,
-           let referenceVolumeIdentifier = try? reference.resourceValues(forKeys: [.volumeIdentifierKey]).volumeIdentifier {
-            useTemporaryDirectory = temporaryVolumeIdentifier.isEqual(referenceVolumeIdentifier)
+        if let temporaryVolumeIdentifier = systemNumber(for: temporaryDirectory),
+           let referenceVolumeIdentifier = systemNumber(for: reference) {
+            useTemporaryDirectory = temporaryVolumeIdentifier == referenceVolumeIdentifier
         } else {
             useTemporaryDirectory = !fileManager.isWritableFile(atPath: referenceDirectory.path)
         }
@@ -91,6 +91,14 @@ extension _FileManagerImpl {
                 attempt += 1
             }
         }
+
+        func systemNumber(for url: URL) -> UInt? {
+            guard let attributes = try? fileManager.attributesOfItem(atPath: url.path),
+                  let value = attributes[.systemNumber] else {
+                return nil
+            }
+            return _readFileAttributePrimitive(value, as: UInt.self)
+        }
     }
 
     private func itemReplacementDirectoryName(forAttempt attempt: Int) -> String {