NTFSSecurity/AlphaFS/Filesystem/File Class/File.GetChangeTime.cs

/*  Copyright (C) 2008-2016 Peter Palotas, Jeffrey Jangli, Alexandr Normuradov
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using Microsoft.Win32.SafeHandles;
using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.AccessControl;

namespace Alphaleonis.Win32.Filesystem
{
   public static partial class File
   {
      #region GetChangeTime

      /// <summary>[AlphaFS] Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <param name="path">The file for which to obtain creation date and time information.</param>
      /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
      [SecurityCritical]
      public static DateTime GetChangeTime(string path, PathFormat pathFormat)
      {
         return GetChangeTimeCore(false, null, null, path, false, pathFormat);
      }


      /// <summary>[AlphaFS] Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <param name="path">The file for which to obtain creation date and time information.</param>
      [SecurityCritical]
      public static DateTime GetChangeTime(string path)
      {
         return GetChangeTimeCore(false, null, null, path, false, PathFormat.RelativePath);
      }

      /// <summary>[AlphaFS] Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <param name="safeHandle">An open handle to the file or directory from which to retrieve information.</param>
      [SecurityCritical]
      public static DateTime GetChangeTime(SafeFileHandle safeHandle)
      {
         return GetChangeTimeCore(false, null, safeHandle, null, false, PathFormat.LongFullPath);
      }

      /// <summary>[AlphaFS] Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <param name="transaction">The transaction.</param>
      /// <param name="path">The file for which to obtain creation date and time information.</param>
      /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeTransacted(KernelTransaction transaction, string path, PathFormat pathFormat)
      {
         return GetChangeTimeCore(false, transaction, null, path, false, pathFormat);
      }

      /// <summary>[AlphaFS] Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <param name="transaction">The transaction.</param>
      /// <param name="path">The file for which to obtain creation date and time information.</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeTransacted(KernelTransaction transaction, string path)
      {
         return GetChangeTimeCore(false, transaction, null, path, false, PathFormat.RelativePath);
      }

      #endregion // GetChangeTime

      #region GetChangeTimeUtc

      /// <summary>[AlphaFS] Gets the change date and time, in Coordinated Universal Time (UTC) format, of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in UTC time.</returns>
      /// <param name="path">The file for which to obtain change date and time information, in Coordinated Universal Time (UTC) format.</param>
      /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeUtc(string path, PathFormat pathFormat)
      {
         return GetChangeTimeCore(false, null, null, path, true, pathFormat);
      }

      /// <summary>[AlphaFS] Gets the change date and time, in Coordinated Universal Time (UTC) format, of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in UTC time.</returns>
      /// <param name="path">The file for which to obtain change date and time information, in Coordinated Universal Time (UTC) format.</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeUtc(string path)
      {
         return GetChangeTimeCore(false, null, null, path, true, PathFormat.RelativePath);
      }

      /// <summary>[AlphaFS] Gets the change date and time, in Coordinated Universal Time (UTC) format, of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in UTC time.</returns>
      /// <param name="safeHandle">An open handle to the file or directory from which to retrieve information.</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeUtc(SafeFileHandle safeHandle)
      {
         return GetChangeTimeCore(false, null, safeHandle, null, true, PathFormat.LongFullPath);
      }

      /// <summary>[AlphaFS] Gets the change date and time, in Coordinated Universal Time (UTC) format, of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in UTC time.</returns>
      /// <param name="transaction">The transaction.</param>
      /// <param name="path">The file for which to obtain change date and time information, in Coordinated Universal Time (UTC) format.</param>
      /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeUtcTransacted(KernelTransaction transaction, string path, PathFormat pathFormat)
      {
         return GetChangeTimeCore(false, transaction, null, path, true, pathFormat);
      }

      /// <summary>[AlphaFS] Gets the change date and time, in Coordinated Universal Time (UTC) format, of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in UTC time.</returns>
      /// <param name="transaction">The transaction.</param>
      /// <param name="path">The file for which to obtain change date and time information, in Coordinated Universal Time (UTC) format.</param>
      [SecurityCritical]
      public static DateTime GetChangeTimeUtcTransacted(KernelTransaction transaction, string path)
      {
         return GetChangeTimeCore(false, transaction, null, path, true, PathFormat.RelativePath);
      }

      #endregion // GetChangeTimeUtc

      #region Internal Methods

      /// <summary>Gets the change date and time of the specified file.</summary>
      /// <returns>A <see cref="System.DateTime"/> structure set to the change date and time for the specified file. This value is expressed in local time.</returns>
      /// <remarks><para>Use either <paramref name="path"/> or <paramref name="safeHandle"/>, not both.</para></remarks>
      /// <exception cref="ArgumentException"/>
      /// <exception cref="ArgumentNullException"/>
      /// <exception cref="PlatformNotSupportedException"/>
      /// <param name="isFolder">Specifies that <paramref name="path"/> is a file or directory.</param>
      /// <param name="transaction">The transaction.</param>
      /// <param name="safeHandle">An open handle to the file or directory from which to retrieve information.</param>
      /// <param name="path">The file or directory for which to obtain creation date and time information.</param>
      /// <param name="getUtc"><see langword="true"/> gets the Coordinated Universal Time (UTC), <see langword="false"/> gets the local time.</param>
      /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
      [SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "Disposing is under control.")]
      [SecurityCritical]
      internal static DateTime GetChangeTimeCore(bool isFolder, KernelTransaction transaction, SafeFileHandle safeHandle, string path, bool getUtc, PathFormat pathFormat)
      {
         if (!NativeMethods.IsAtLeastWindowsVista)
            throw new PlatformNotSupportedException(Resources.Requires_Windows_Vista_Or_Higher);

         bool callerHandle = safeHandle != null;
         if (!callerHandle)
         {
            if (pathFormat != PathFormat.LongFullPath && Utils.IsNullOrWhiteSpace(path))
               throw new ArgumentNullException("path");

            string pathLp = Path.GetExtendedLengthPathCore(transaction, path, pathFormat, GetFullPathOptions.RemoveTrailingDirectorySeparator | GetFullPathOptions.CheckInvalidPathChars);

            safeHandle = CreateFileCore(transaction, pathLp, isFolder ? ExtendedFileAttributes.BackupSemantics : ExtendedFileAttributes.Normal, null, FileMode.Open, FileSystemRights.ReadData, FileShare.ReadWrite, true, PathFormat.LongFullPath);
         }


         try
         {
            NativeMethods.IsValidHandle(safeHandle);
            
            using (var safeBuffer = new SafeGlobalMemoryBufferHandle(IntPtr.Size + Marshal.SizeOf(typeof(NativeMethods.FILE_BASIC_INFO))))
            {
               NativeMethods.FILE_BASIC_INFO fbi;

               if (!NativeMethods.GetFileInformationByHandleEx_FileBasicInfo(safeHandle, NativeMethods.FileInfoByHandleClass.FileBasicInfo, out fbi, (uint)safeBuffer.Capacity))
                  NativeError.ThrowException(Marshal.GetLastWin32Error());

               safeBuffer.StructureToPtr(fbi, true);
               NativeMethods.FILETIME changeTime = safeBuffer.PtrToStructure<NativeMethods.FILE_BASIC_INFO>(0).ChangeTime;

               return getUtc
                  ? DateTime.FromFileTimeUtc(changeTime)
                  : DateTime.FromFileTime(changeTime);
            }
         }
         finally
         {
            // Handle is ours, dispose.
            if (!callerHandle && safeHandle != null)
               safeHandle.Close();
         }
      }

      #endregion // Internal Methods
   }
}