private FileStream WindowsCreateFile(string fileName, bool allowConcurrentWrite) { var fileShare = Win32FileNativeMethods.FILE_SHARE_READ; if (allowConcurrentWrite) { fileShare |= Win32FileNativeMethods.FILE_SHARE_WRITE; } if (CreateFileParameters.EnableFileDelete && PlatformDetector.CurrentOS != RuntimeOS.Windows) { fileShare |= Win32FileNativeMethods.FILE_SHARE_DELETE; } var handle = Win32FileNativeMethods.CreateFile( fileName, Win32FileNativeMethods.FileAccess.GenericWrite, fileShare, IntPtr.Zero, Win32FileNativeMethods.CreationDisposition.OpenAlways, CreateFileParameters.FileAttributes, IntPtr.Zero); if (handle.ToInt32() == -1) { Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error()); } var safeHandle = new SafeFileHandle(handle, true); var returnValue = new FileStream(safeHandle, FileAccess.Write, CreateFileParameters.BufferSize); returnValue.Seek(0, SeekOrigin.End); return(returnValue); }
private FileStream WindowsCreateFile(string fileName, bool allowFileSharedWriting) { int fileShare = Win32FileNativeMethods.FILE_SHARE_READ; if (allowFileSharedWriting) { fileShare |= Win32FileNativeMethods.FILE_SHARE_WRITE; } if (this.CreateFileParameters.EnableFileDelete && PlatformDetector.CurrentOS != RuntimeOS.Windows) { fileShare |= Win32FileNativeMethods.FILE_SHARE_DELETE; } Microsoft.Win32.SafeHandles.SafeFileHandle handle = null; FileStream fileStream = null; try { handle = Win32FileNativeMethods.CreateFile( fileName, Win32FileNativeMethods.FileAccess.GenericWrite, fileShare, IntPtr.Zero, Win32FileNativeMethods.CreationDisposition.OpenAlways, this.CreateFileParameters.FileAttributes, IntPtr.Zero); if (handle.IsInvalid) { Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error()); } fileStream = new FileStream(handle, FileAccess.Write, this.CreateFileParameters.BufferSize); fileStream.Seek(0, SeekOrigin.End); return(fileStream); } catch { if (fileStream != null) { fileStream.Dispose(); } if ((handle != null) && (!handle.IsClosed)) { handle.Close(); } throw; } }
private FileStream WindowsCreateFile(string fileName, bool allowFileSharedWriting) { int fileShare = Win32FileNativeMethods.FILE_SHARE_READ; if (allowFileSharedWriting) { fileShare |= Win32FileNativeMethods.FILE_SHARE_WRITE; } if (this.CreateFileParameters.EnableFileDelete && PlatformDetector.CurrentOS != RuntimeOS.Windows) { fileShare |= Win32FileNativeMethods.FILE_SHARE_DELETE; } Microsoft.Win32.SafeHandles.SafeFileHandle handle = null; FileStream fileStream = null; try { handle = Win32FileNativeMethods.CreateFile( fileName, Win32FileNativeMethods.FileAccess.GenericWrite | Win32FileNativeMethods.FileAccess.GenericRead, fileShare, IntPtr.Zero, Win32FileNativeMethods.CreationDisposition.OpenAlways, this.CreateFileParameters.FileAttributes, IntPtr.Zero); if (handle.IsInvalid) { Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error()); } #if !SILVERLIGHT && !MONO && !__IOS__ && !__ANDROID__ && NET4_5 // TODO: Beware there be dragons here, every time we create a file stream, it creates a byte array the size of the buffersize. // TODO: in MS .NET implementation, the file stream does write to its internal buffer if you are writing something that is bigger than its buffer size, // So, to prevent allocations, we set the buffer to 1, since then it will just write whats in the incoming buffer and not allocate a buffer if (this.CreateFileParameters.PoolingEnabled) { fileStream = new FileStream(handle, FileAccess.ReadWrite, 1); } else { fileStream = new FileStream(handle, FileAccess.ReadWrite, this.CreateFileParameters.BufferSize); } #else fileStream = new FileStream(handle, FileAccess.Write, this.CreateFileParameters.BufferSize); #endif fileStream.Seek(0, SeekOrigin.End); return(fileStream); } catch { if (fileStream != null) { fileStream.Dispose(); } if ((handle != null) && (!handle.IsClosed)) { handle.Close(); } throw; } }