Function xdr_packed_message

src/remote/protocol.cpp:1609–1740

static bool_t xdr_packed_message( RemoteXdr* xdrs, RMessage* message, const rem_fmt* format)
{
/**************************************
 *
 *	x d r _ p a c k e d _ m e s s a g e
 *
 **************************************
 *
 * Functional description
 *	Map a formatted message.
 *
 **************************************/

	if (xdrs->x_op == XDR_FREE)
		return TRUE;

	const rem_port* const port = xdrs->x_public;

	if (!message || !format)
		return FALSE;

	// If we are running a symmetric version of the protocol, just slop
	// the bits and don't sweat the translations

	if (port->port_flags & PORT_symmetric)
		return xdr_opaque(xdrs, reinterpret_cast<SCHAR*>(message->msg_address), format->fmt_length);

	// Optimize the message by transforming NULL indicators into a bitmap
	// and then skipping the NULL items

	class NullBitmap : private HalfStaticArray<UCHAR, 4>
	{
	public:
		explicit NullBitmap(USHORT size)
		{
			resize(size);
		}

		void setNull(USHORT id)
		{
			data[id >> 3] |= (1 << (id & 7));
		}

		bool isNull(USHORT id) const
		{
			return data[id >> 3] & (1 << (id & 7));
		}

		UCHAR* getData()
		{
			return data;
		}
	};

	fb_assert(format->fmt_desc.getCount() % 2 == 0);
	const USHORT flagBytes = (format->fmt_desc.getCount() / 2 + 7) / 8;
	NullBitmap nulls(flagBytes);