refactor: overhaul FileSystemCompression class

Added extension methods: DirectoryInfo.Compress()
FileInfo.Compress()

Reworked methods:
SetCompression() (formerly EnableCompression())

src/Common/FileSystemCompression.cs

@@ -4,35 +4,155 @@
 /// - Goz https://stackoverflow.com/users/131140/goz
 
 using System;
+using System.IO;
 using System.Runtime.InteropServices;
-using Microsoft.Win32.SafeHandles;
+using PInvoke;
 
 namespace HXE.Common
 {
     internal static class FileSystemCompression
     {
-        private const int FSCTL_SET_COMPRESSION = 0x9C040;
-        private const short COMPRESSION_FORMAT_DEFAULT = 1;
-
-        [DllImport("kernel32.dll", SetLastError = true)]
-        private static extern int DeviceIoControl(
-            SafeFileHandle hDevice,
-            int dwIoControlCode,
-            ref short lpInBuffer,
-            int nInBufferSize,
-            IntPtr lpOutBuffer,
-            int nOutBufferSize,
-            ref int lpBytesReturned,
-            IntPtr lpOverlapped);
-
-        public static bool EnableCompression(SafeFileHandle handle)
+        private static class Constants
         {
-            int lpBytesReturned = 0;
-            short lpInBuffer = COMPRESSION_FORMAT_DEFAULT;
+            public const int FSCTL_SET_COMPRESSION = 0x9C040;
+            public const short COMPRESSION_FORMAT_DEFAULT = 1;
+        }
+
+        // TODO: Duplicate as non-extension "CompressDirectory()"
+        /// <summary>
+        ///     Compress the directory represented by the DirectoryInfo object.
+        /// </summary>
+        /// <param name="directoryInfo">The directory to enable compression for.</param>
+        /// <param name="compressFiles"></param> // TODO
+        /// <param name="recurse"></param> // TODO
+        /// <param name="progress"></param> // TODO
+        /// <exception cref="DirectoryNotFoundException">
+        /// The path encapsulated in the System.IO.DirectoryInfo object is invalid, such<br/>
+        /// as being on an unmapped drive.
+        /// </exception>
+        /// <exception cref="System.Security.SecurityException">The caller does not have the required permission.</exception>
+        /// <exception cref="FileNotFoundException">The file is not found.</exception>
+        /// <exception cref="UnauthorizedAccessException">file path is read-only.</exception>
+        /// <exception cref="Win32Exception">DeviceIoControl operation failed. See <see cref="Win32Exception.NativeErrorCode"/> for exception data.</exception>
+        public static void Compress(this DirectoryInfo directoryInfo, bool compressFiles = true, bool recurse = false, IProgress<int> progress = null)
+        {
+            /* Progress */
+            bool withProgress = progress != null;
+            int itemsCompleted = 0;
+            int itemsTotal = 1;
+
+            void UpdateProgress(int n)
+            {
+                if (withProgress) return; // not necessary, but it's here just in case.
+                itemsCompleted += n;
+                progress.Report(itemsCompleted * 100 / itemsTotal);
+            }
+
+            /* Get files, subdirectories */
+            SearchOption searchOption = recurse ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly;
+            DirectoryInfo[] directories = recurse ? directoryInfo.GetDirectories(
+                searchPattern: "*",
+                searchOption: searchOption
+                ) : null;
+            FileInfo[] files = compressFiles ? directoryInfo.GetFiles(
+                searchPattern: "*",
+                searchOption: searchOption
+                ) : null;
+
+            /* Add files, directories count to itemsTotal; Update progress */
+            if (withProgress)
+            {
+                if (files != null)
+                {
+                    itemsTotal += files.Length;
+                }
+                if (directories != null)
+                {
+                    itemsTotal += directories.Length;
+                }
+
+                UpdateProgress(0);
+            }
+
+            /* Compress root directory */
+            Kernel32.SafeObjectHandle hDirectory = Kernel32.CreateFile(
+                filename: directoryInfo.FullName,
+                access: Kernel32.ACCESS_MASK.GenericRight.GENERIC_READ | Kernel32.ACCESS_MASK.GenericRight.GENERIC_WRITE,
+                share: Kernel32.FileShare.None,
+                securityAttributes: Kernel32.SECURITY_ATTRIBUTES.Create(),
+                creationDisposition: Kernel32.CreationDisposition.OPEN_EXISTING,
+                flagsAndAttributes: Kernel32.CreateFileFlags.FILE_FLAG_BACKUP_SEMANTICS,
+                templateFile: null
+            );
+
+            SetCompression(hDirectory);
+            hDirectory.Close();
+            if (withProgress)
+                UpdateProgress(itemsCompleted++);
+
+            /* Compress sub-directories */
+            if (recurse)
+            {
+                foreach (DirectoryInfo directory in directories)
+                {
+                    directory.Compress();
+                    if (withProgress)
+                        UpdateProgress(itemsCompleted++);
+                }
+            }
+
+            /* Compress files*/
+            if (compressFiles)
+            {
+                foreach (FileInfo file in files)
+                {
+                    file.Compress();
+                    if (withProgress)
+                        UpdateProgress(itemsCompleted++);
+                }
+            }
+        }
+
+        // TODO: Duplicate as non-extension "CompressFile()"
+        /// <summary>
+        ///     Set filesystem compression for the file
+        /// </summary>
+        /// <param name="fileInfo">A FileInfo object indicating the file to compress.</param>
+        /// <exception cref="System.Security.SecurityException">The caller does not have the required permission.</exception>
+        /// <exception cref="FileNotFoundException">The file is not found.</exception>
+        /// <exception cref="UnauthorizedAccessException">path is read-only or is a directory.</exception>
+        /// <exception cref="DirectoryNotFoundException">The specified path is invalid, such as being on an unmapped drive.</exception>
+        /// <exception cref="Win32Exception">DeviceIoControl operation failed. See <see cref="Win32Exception.NativeErrorCode"/> for exception data.</exception>
+        public static void Compress(this FileInfo fileInfo)
+        {
+            FileStream fileStream = fileInfo.Open(mode: FileMode.Open, access: FileAccess.ReadWrite, share: FileShare.None);
+            SetCompression((Kernel32.SafeObjectHandle)(SafeHandle)fileStream.SafeFileHandle);
+            fileStream.Dispose();
+        }
+
+        /// <summary>
+        ///     P/Invoke DeviceIoControl with the FSCTL_SET_COMPRESSION
+        /// </summary>
+        /// <param name="handle"></param> //TODO
+        /// <exception cref="Win32Exception">DeviceIoControl operation failed. See <see cref="Win32Exception.NativeErrorCode"/> for exception data.</exception>
+        public static unsafe void SetCompression(Kernel32.SafeObjectHandle handle)
+        {
+            short lpInBuffer = Constants.COMPRESSION_FORMAT_DEFAULT;
+            bool success = Kernel32.DeviceIoControl(
+                hDevice: handle,
+                dwIoControlCode: Constants.FSCTL_SET_COMPRESSION,
+                inBuffer: &lpInBuffer,
+                nInBufferSize: sizeof(short), // sizeof(typeof(lpInBuffer.GetType()))
+                outBuffer: (void*)IntPtr.Zero,
+                nOutBufferSize: 0,
+                pBytesReturned: out _,
+                lpOverlapped: (Kernel32.OVERLAPPED*)IntPtr.Zero
+                );
 
-            return DeviceIoControl(handle, FSCTL_SET_COMPRESSION,
-                ref lpInBuffer, sizeof(short), IntPtr.Zero, 0,
-                ref lpBytesReturned, IntPtr.Zero) != 0;
+            if (!success)
+            {
+                throw new Win32Exception(Kernel32.GetLastError());
+            }
         }
     }
 }