private unsafe static int ReadFileNative(IntPtr hFile, byte[] bytes, int offset, int count, bool isPipe, out int bytesRead, bool useFileAPIs)
{
Debug.Assert(offset >= 0, "offset >= 0");
Debug.Assert(count >= 0, "count >= 0");
Debug.Assert(bytes != null, "bytes != null");
// Don't corrupt memory when multiple threads are erroneously writing
// to this stream simultaneously.
if (bytes.Length - offset < count)
throw new IndexOutOfRangeException(SR.IndexOutOfRange_IORaceCondition);
Contract.EndContractBlock();
// You can't use the fixed statement on an array of length 0.
if (bytes.Length == 0)
{
bytesRead = 0;
return Interop.Errors.ERROR_SUCCESS;
}
bool readSuccess;
fixed (byte* p = bytes)
{
if (useFileAPIs)
{
readSuccess = (0 != Interop.Kernel32.ReadFile(hFile, p + offset, count, out bytesRead, IntPtr.Zero));
}
else
{
// If the code page could be Unicode, we should use ReadConsole instead, e.g.
int charsRead;
readSuccess = Interop.Kernel32.ReadConsole(hFile, p + offset, count / BytesPerWChar, out charsRead, IntPtr.Zero);
bytesRead = charsRead * BytesPerWChar;
}
}
if (readSuccess)
return Interop.Errors.ERROR_SUCCESS;
// For pipes that are closing or broken, just stop.
// (E.g. ERROR_NO_DATA ("pipe is being closed") is returned when we write to a console that is closing;
// ERROR_BROKEN_PIPE ("pipe was closed") is returned when stdin was closed, which is mot an error, but EOF.)
int errorCode = Marshal.GetLastWin32Error();
if (errorCode == Interop.Errors.ERROR_NO_DATA || errorCode == Interop.Errors.ERROR_BROKEN_PIPE)
return Interop.Errors.ERROR_SUCCESS;
return errorCode;
}
