/// <summary>
/// Creates a memory-mapped file from a file on disk.
/// </summary>
/// <param name="path">The path to file to map.</param>
/// <returns>A memory-mapped file.</returns>
public static FileMappingWrapper CreateFromFile(string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException("path wrong");
}
if (!File.Exists(path))
{
throw new ArgumentNullException("file doesn't exists");
}
using (var file = File.Open(path, FileMode.Open, FileAccess.ReadWrite))
{
FileMappingAccess rights = new FileMappingAccess();
FileMappingSecurity security = new FileMappingSecurity();
return(CreateFromFile(
file,
Guid.NewGuid().ToString(),
file.Length,
rights,
security,
HandleInheritability.Inheritable,
true // TODO: уточнить
));
}
}
/// <summary>
///
/// </summary>
/// <param name="fileStream"></param>
/// <param name="mapName"></param>
/// <param name="capacity"></param>
/// <param name="access"></param>
/// <param name="memoryMappedFileSecurity"></param>
/// <param name="inheritability"></param>
/// <param name="leaveOpen"></param>
/// <returns></returns>
public static FileMappingWrapper CreateFromFile(
FileStream fileStream,
string mapName,
long capacity,
FileMappingAccess access,
FileMappingSecurity memoryMappedFileSecurity,
HandleInheritability inheritability,
bool leaveOpen
)
{
if (fileStream == null || fileStream.SafeFileHandle.IsInvalid ||
string.IsNullOrEmpty(mapName))
{
throw new ArgumentNullException("fileStream or mapname is null");
}
SafeFileMappingHandle handle = new SafeFileMappingHandle(Win32.CreateFileMapping(
fileStream.SafeFileHandle,
IntPtr.Zero,
Win32.PAGE_READWRITE,
0,
unchecked ((UInt32)capacity),
mapName
)
);
if (handle.IsInvalid)
{
throw new Exception("Could not create memory-mapped file.");
}
// throws
// ArgumentException
// ArgumentNullException
// ArgumentOutOfRangeException
// ObjectDisposedException
// UnauthorizedAccessException
// IOException
var wrapper = new FileMappingWrapper(handle);
wrapper.fileSize = fileStream.Length;
return(wrapper);
}
public static extern SafeViewOfFileHandle MapViewOfFile(SafeFileMappingHandle hFileMappingObject,
[MarshalAs(UnmanagedType.U4)] FileMappingAccess dwDesiredAccess,
uint dwFileOffsetHigh,
uint dwFileOffsetLow,
uint dwNumberOfBytesToMap);
public static extern SafeFileMappingHandle OpenFileMapping([MarshalAs(UnmanagedType.U4)] FileMappingAccess dwDesiredAccess,
bool bInheritHandle,
string lpName);
