refactored names; fixed return values for hard links service

2025-02-22 00:30:42 +02:00
parent 9b68792ea9
commit 1ad07b1f51
15 changed files with 115 additions and 95 deletions
@@ -0,0 +1,113 @@
+using System.Collections.Concurrent;
+using System.Runtime.InteropServices;
+using Microsoft.Extensions.Logging;
+using Microsoft.Win32.SafeHandles;
+
+namespace Infrastructure.Verticals.Files;
+
+public class WindowsHardLinkFileService : IHardLinkFileService
+{
+    private readonly ILogger<WindowsHardLinkFileService> _logger;
+    private readonly ConcurrentDictionary<ulong, int> _fileIndexCounts = new();
+
+    public WindowsHardLinkFileService(ILogger<WindowsHardLinkFileService> logger)
+    {
+        _logger = logger;
+    }
+    
+    /// <inheritdoc/>
+    public long GetHardLinkCount(string filePath, bool ignoreRootDir)
+    {
+        try
+        {
+            using SafeFileHandle fileStream = File.OpenHandle(filePath);
+
+            if (!GetFileInformationByHandle(fileStream, out var file))
+            {
+                _logger.LogDebug("failed to get file handle {file}", filePath);
+                return -1;
+            }
+
+            if (!ignoreRootDir)
+            {
+                _logger.LogDebug("stat file | hardlinks: {nlink} | {file}", file.NumberOfLinks, filePath);
+                return file.NumberOfLinks == 1 ? 0 : 1;
+            }
+
+            // Get unique file ID (combination of high and low indices)
+            ulong fileIndex = ((ulong)file.FileIndexHigh << 32) | file.FileIndexLow;
+            
+            // Adjusted case: Check if there are links outside the ignored directory
+            int linksInIgnoredDir = _fileIndexCounts.TryGetValue(fileIndex, out int count)
+                ? count
+                : 1; // Default to 1 if not found
+
+            _logger.LogDebug("stat file {file} | links: {links} | ignored: {ignored}", filePath, file.NumberOfLinks, linksInIgnoredDir);
+            return file.NumberOfLinks - linksInIgnoredDir;
+        }
+        catch (Exception exception)
+        {
+            _logger.LogError(exception, "failed to stat file {file}", filePath);
+            return -1;
+        }
+    }
+
+    /// <inheritdoc/>
+    public void PopulateFileCounts(string directoryPath)
+    {
+        try
+        {
+            // Traverse all files and directories in the ignored path
+            foreach (var file in Directory.EnumerateFiles(directoryPath, "*", SearchOption.AllDirectories))
+            {
+                AddFileIndexToCount(file);
+            }
+
+            foreach (var dir in Directory.EnumerateDirectories(directoryPath, "*", SearchOption.AllDirectories))
+            {
+                AddFileIndexToCount(dir);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to populate file index counts from {dir}", directoryPath);
+        }
+    }
+
+    private void AddFileIndexToCount(string path)
+    {
+        try
+        {
+            using SafeFileHandle fileStream = File.OpenHandle(path);
+            if (GetFileInformationByHandle(fileStream, out var file))
+            {
+                ulong fileIndex = ((ulong)file.FileIndexHigh << 32) | file.FileIndexLow;
+                _fileIndexCounts.AddOrUpdate(fileIndex, 1, (_, count) => count + 1);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Couldn't stat {path} during file index counting", path);
+        }
+    }
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern bool GetFileInformationByHandle(
+        SafeFileHandle hFile,
+        out BY_HANDLE_FILE_INFORMATION lpFileInformation
+    );
+
+    private struct BY_HANDLE_FILE_INFORMATION
+    {
+        public uint FileAttributes;
+        public System.Runtime.InteropServices.ComTypes.FILETIME CreationTime;
+        public System.Runtime.InteropServices.ComTypes.FILETIME LastAccessTime;
+        public System.Runtime.InteropServices.ComTypes.FILETIME LastWriteTime;
+        public uint VolumeSerialNumber;
+        public uint FileSizeHigh;
+        public uint FileSizeLow;
+        public uint NumberOfLinks;
+        public uint FileIndexHigh;
+        public uint FileIndexLow;
+    }
+}