Class ExtMessageNode

src/jrd/ExtEngineManager.cpp:123–154

External message node.

	// External message node.
	class ExtMessageNode : public MessageNode
	{
	public:
		ExtMessageNode(thread_db* tdbb, MemoryPool& pool, CompilerScratch* csb, USHORT message, const Format* aFormat)
			: MessageNode(pool),
			  format(aFormat)
		{
			setup(tdbb, csb, message, format->fmt_count);
		}

		virtual USHORT setupDesc(thread_db* tdbb, CompilerScratch* csb, USHORT index,
			dsc* desc, ItemInfo* itemInfo)
		{
			*desc = format->fmt_desc[index];
			return type_alignments[desc->dsc_dtype];
		}

		virtual const StmtNode* execute(thread_db* tdbb, Request* request, ExeState* exeState) const
		{
			if (request->req_operation == Request::req_evaluate)
			{
				// Clear the message. This is important for external routines.
				UCHAR* msg = request->getImpure<UCHAR>(impureOffset);
				memset(msg, 0, format->fmt_length);
			}

			return MessageNode::execute(tdbb, request, exeState);
		}

	public:
		const Format* format;
	};

	// Initialize output parameters with their domains default value or NULL.
	// Kind of blr_init_variable, but for parameters.