Move hard link helper functions to their own class

osu.Game/Database/LegacyImportManager.cs

@@ -72,7 +72,7 @@ namespace osu.Game.Database
             string testExistingPath = stableStorage.GetFullPath(stableStorage.GetFiles(string.Empty).First());
             string testDestinationPath = desktopGameHost.Storage.GetFullPath(test_filename);
 
-            return RealmFileStore.CreateHardLink(testDestinationPath, testExistingPath, IntPtr.Zero);
+            return HardLinkHelper.CreateHardLink(testDestinationPath, testExistingPath, IntPtr.Zero);
         }
 
         public virtual async Task<int> GetImportCount(StableContent content, CancellationToken cancellationToken)

osu.Game/Database/RealmFileStore.cs

@@ -4,9 +4,6 @@
 using System;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
-using System.Runtime.InteropServices.ComTypes;
-using Microsoft.Win32.SafeHandles;
 using osu.Framework;
 using osu.Framework.Extensions;
 using osu.Framework.IO.Stores;
@@ -14,6 +11,7 @@ using osu.Framework.Logging;
 using osu.Framework.Platform;
 using osu.Framework.Testing;
 using osu.Game.Extensions;
+using osu.Game.IO;
 using osu.Game.Models;
 using Realms;
 
@@ -68,7 +66,7 @@ namespace osu.Game.Database
             if (RuntimeInfo.OS == RuntimeInfo.Platform.Windows && data is FileStream fs && preferHardLinks)
             {
                 // attempt to do a fast hard link rather than copy.
-                if (CreateHardLink(Storage.GetFullPath(file.GetStoragePath()), fs.Name, IntPtr.Zero))
+                if (HardLinkHelper.CreateHardLink(Storage.GetFullPath(file.GetStoragePath()), fs.Name, IntPtr.Zero))
                     return;
             }
 
@@ -128,63 +126,5 @@ namespace osu.Game.Database
 
             Logger.Log($@"Finished realm file store cleanup ({removedFiles} of {totalFiles} deleted)");
         }
-
-        #region Windows hard link support
-
-        // For future use (to detect if a file is a hard link with other references existing on disk).
-        public static int GetFileLinkCount(string filePath)
-        {
-            int result = 0;
-            SafeFileHandle handle = CreateFile(filePath, FileAccess.Read, FileShare.Read, IntPtr.Zero, FileMode.Open, FileAttributes.Archive, IntPtr.Zero);
-
-            ByHandleFileInformation fileInfo;
-
-            if (GetFileInformationByHandle(handle, out fileInfo))
-                result = (int)fileInfo.NumberOfLinks;
-            CloseHandle(handle);
-
-            return result;
-        }
-
-        [DllImport("Kernel32.dll", CharSet = CharSet.Unicode)]
-        public static extern bool CreateHardLink(
-            string lpFileName,
-            string lpExistingFileName,
-            IntPtr lpSecurityAttributes
-        );
-
-        [StructLayout(LayoutKind.Sequential)]
-        private struct ByHandleFileInformation
-        {
-            public readonly uint FileAttributes;
-            public readonly FILETIME CreationTime;
-            public readonly FILETIME LastAccessTime;
-            public readonly FILETIME LastWriteTime;
-            public readonly uint VolumeSerialNumber;
-            public readonly uint FileSizeHigh;
-            public readonly uint FileSizeLow;
-            public readonly uint NumberOfLinks;
-            public readonly uint FileIndexHigh;
-            public readonly uint FileIndexLow;
-        }
-
-        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
-        private static extern SafeFileHandle CreateFile(
-            string lpFileName,
-            [MarshalAs(UnmanagedType.U4)] FileAccess dwDesiredAccess,
-            [MarshalAs(UnmanagedType.U4)] FileShare dwShareMode,
-            IntPtr lpSecurityAttributes,
-            [MarshalAs(UnmanagedType.U4)] FileMode dwCreationDisposition,
-            [MarshalAs(UnmanagedType.U4)] FileAttributes dwFlagsAndAttributes,
-            IntPtr hTemplateFile);
-
-        [DllImport("kernel32.dll", SetLastError = true)]
-        private static extern bool GetFileInformationByHandle(SafeFileHandle handle, out ByHandleFileInformation lpFileInformation);
-
-        [DllImport("kernel32.dll", SetLastError = true)]
-        [return: MarshalAs(UnmanagedType.Bool)]
-        private static extern bool CloseHandle(SafeHandle hObject);
-
-        #endregion
     }
 }

osu.Game/IO/HardLinkHelper.cs

@@ -0,0 +1,68 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.ComTypes;
+using Microsoft.Win32.SafeHandles;
+
+namespace osu.Game.IO
+{
+    internal static class HardLinkHelper
+    {
+        // For future use (to detect if a file is a hard link with other references existing on disk).
+        public static int GetFileLinkCount(string filePath)
+        {
+            int result = 0;
+            SafeFileHandle handle = CreateFile(filePath, FileAccess.Read, FileShare.Read, IntPtr.Zero, FileMode.Open, FileAttributes.Archive, IntPtr.Zero);
+
+            ByHandleFileInformation fileInfo;
+
+            if (GetFileInformationByHandle(handle, out fileInfo))
+                result = (int)fileInfo.NumberOfLinks;
+            CloseHandle(handle);
+
+            return result;
+        }
+
+        [DllImport("Kernel32.dll", CharSet = CharSet.Unicode)]
+        public static extern bool CreateHardLink(
+            string lpFileName,
+            string lpExistingFileName,
+            IntPtr lpSecurityAttributes
+        );
+
+        [StructLayout(LayoutKind.Sequential)]
+        private struct ByHandleFileInformation
+        {
+            public readonly uint FileAttributes;
+            public readonly FILETIME CreationTime;
+            public readonly FILETIME LastAccessTime;
+            public readonly FILETIME LastWriteTime;
+            public readonly uint VolumeSerialNumber;
+            public readonly uint FileSizeHigh;
+            public readonly uint FileSizeLow;
+            public readonly uint NumberOfLinks;
+            public readonly uint FileIndexHigh;
+            public readonly uint FileIndexLow;
+        }
+
+        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
+        private static extern SafeFileHandle CreateFile(
+            string lpFileName,
+            [MarshalAs(UnmanagedType.U4)] FileAccess dwDesiredAccess,
+            [MarshalAs(UnmanagedType.U4)] FileShare dwShareMode,
+            IntPtr lpSecurityAttributes,
+            [MarshalAs(UnmanagedType.U4)] FileMode dwCreationDisposition,
+            [MarshalAs(UnmanagedType.U4)] FileAttributes dwFlagsAndAttributes,
+            IntPtr hTemplateFile);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        private static extern bool GetFileInformationByHandle(SafeFileHandle handle, out ByHandleFileInformation lpFileInformation);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool CloseHandle(SafeHandle hObject);
+    }
+}