dotnet-installer/test/Microsoft.DotNet.Tools.Tests.Utilities/TempFileSystem/DisposableFile.cs
2015-12-14 17:39:29 -08:00

83 lines
3.4 KiB
C#

// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
using System;
using System.IO;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;
namespace Microsoft.DotNet.Tools.Test.Utilities
{
public sealed class DisposableFile : TempFile, IDisposable
{
public DisposableFile(string path)
: base(path)
{
}
public DisposableFile(string prefix = null, string extension = null, string directory = null, string callerSourcePath = null, int callerLineNumber = 0)
: base(prefix, extension, directory, callerSourcePath, callerLineNumber)
{
}
public void Dispose()
{
if (Path != null && File.Exists(Path))
{
try
{
File.Delete(Path);
}
catch (UnauthorizedAccessException)
{
try
{
// the file might still be memory-mapped, delete on close:
DeleteFileOnClose(Path);
}
catch (IOException ex)
{
throw new InvalidOperationException(string.Format(@"
The file '{0}' seems to have been opened in a way that prevents us from deleting it on close.
Is the file loaded as an assembly (e.g. via Assembly.LoadFile)?
{1}: {2}", Path, ex.GetType().Name, ex.Message), ex);
}
catch (UnauthorizedAccessException)
{
// We should ignore this exception if we got it the second time,
// the most important reason is that the file has already been
// scheduled for deletion and will be deleted when all handles
// are closed.
}
}
}
}
[DllImport("kernel32.dll", PreserveSig = false)]
private static extern void SetFileInformationByHandle(SafeFileHandle handle, int fileInformationClass, ref uint fileDispositionInfoDeleteFile, int bufferSize);
private const int FileDispositionInfo = 4;
internal static void PrepareDeleteOnCloseStreamForDisposal(FileStream stream)
{
// tomat: Set disposition to "delete" on the stream, so to avoid ForeFront EndPoint
// Protection driver scanning the file. Note that after calling this on a file that's open with DeleteOnClose,
// the file can't be opened again, not even by the same process.
uint trueValue = 1;
SetFileInformationByHandle(stream.SafeFileHandle, FileDispositionInfo, ref trueValue, sizeof(uint));
}
/// <summary>
/// Marks given file for automatic deletion when all its handles are closed.
/// Note that after doing this the file can't be opened again, not even by the same process.
/// </summary>
internal static void DeleteFileOnClose(string fullPath)
{
using (var stream = new FileStream(fullPath, FileMode.Open, FileAccess.ReadWrite, FileShare.Delete | FileShare.ReadWrite, 8, FileOptions.DeleteOnClose))
{
PrepareDeleteOnCloseStreamForDisposal(stream);
}
}
}
}