Method getBufferTag

src/common/classes/ClumpletReader.cpp:222–279

}

UCHAR ClumpletReader::getBufferTag() const
{
	const UCHAR* const buffer_end = getBufferEnd();
	const UCHAR* buffer_start = getBuffer();

	switch (kind)
	{
	case Tpb:
	case Tagged:
	case WideTagged:
		if (buffer_end - buffer_start == 0)
		{
			invalid_structure("empty buffer");
			return 0;
		}
		return buffer_start[0];
	case SpbStart:
	case UnTagged:
	case WideUnTagged:
	case SpbSendItems:
	case SpbReceiveItems:
	case SpbResponse:
	case InfoResponse:
	case InfoItems:
		usage_mistake("buffer is not tagged");
		return 0;
	case SpbAttach:
		if (buffer_end - buffer_start == 0)
		{
			invalid_structure("empty buffer");
			return 0;
		}
		switch (buffer_start[0])
		{
		case isc_spb_version1:
			// This is old SPB format, it's almost like DPB -
			// buffer's tag is the first byte.
			return buffer_start[0];
		case isc_spb_version:
			// Buffer's tag is the second byte
			if (buffer_end - buffer_start == 1)
			{
				invalid_structure("buffer too short", 1);
				return 0;
			}
			return buffer_start[1];
		case isc_spb_version3:
			// This is wide SPB attach format - buffer's tag is the first byte.
			return buffer_start[0];
		default:
			invalid_structure("spb in service attach should begin with isc_spb_version1 or isc_spb_version", buffer_start[0]);
			return 0;
		}
	default:
		fb_assert(false);
		return 0;
	}
}