System.IO.FileStream.SetLengthCore C# (CSharp) Method

        private void SetLengthCore(long value)
        {
            Debug.Assert(value >= 0, "value >= 0");
            long origPos = _filePosition;

            VerifyOSHandlePosition();
            if (_filePosition != value)
                SeekCore(value, SeekOrigin.Begin);
            if (!Interop.Kernel32.SetEndOfFile(_fileHandle))
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode == Interop.Errors.ERROR_INVALID_PARAMETER)
                    throw new ArgumentOutOfRangeException(nameof(value), SR.ArgumentOutOfRange_FileLengthTooBig);
                throw Win32Marshal.GetExceptionForWin32Error(errorCode);
            }
            // Return file pointer to where it was before setting length
            if (origPos != value)
            {
                if (origPos < value)
                    SeekCore(origPos, SeekOrigin.Begin);
                else
                    SeekCore(0, SeekOrigin.End);
            }
        }