internal unsafe MemoryMapFile(String fileName, String fileMappingName) {
//
// Use native API to create the file directly.
//
SafeFileHandle fileHandle = Win32Native.UnsafeCreateFile(fileName, FileStream.GENERIC_READ, FileShare.Read, null, FileMode.Open, 0, IntPtr.Zero);
int lastError = Marshal.GetLastWin32Error();
if (fileHandle.IsInvalid)
{
BCLDebug.Assert(false, "Failed to create file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
int highSize;
int lowSize = Win32Native.GetFileSize(fileHandle, out highSize);
if (lowSize == Win32Native.INVALID_FILE_SIZE)
{
BCLDebug.Assert(false, "Failed to get the file size of " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
fileSize = (((long) highSize) << 32) | ((uint) lowSize);
if (fileSize == 0)
{
// we cannot map zero size file. the caller should check for the file size.
fileHandle.Close();
return;
}
SafeFileMappingHandle fileMapHandle = Win32Native.CreateFileMapping(fileHandle, IntPtr.Zero, PAGE_READONLY, 0, 0, fileMappingName);
fileHandle.Close();
lastError = Marshal.GetLastWin32Error();
if (fileMapHandle.IsInvalid) {
BCLDebug.Assert(false, "Failed to create file mapping for file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
viewOfFileHandle = Win32Native.MapViewOfFile(fileMapHandle, SECTION_MAP_READ, 0, 0, UIntPtr.Zero);
lastError = Marshal.GetLastWin32Error();
if (viewOfFileHandle.IsInvalid) {
BCLDebug.Assert(false, "Failed to map a view of file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
bytes = (byte*)viewOfFileHandle.DangerousGetHandle ();
fileMapHandle.Close();
}
