Class MessageMoverNode

src/jrd/ExtEngineManager.cpp:279–338

Move parameters from a message to another, validating theirs values.

	// Move parameters from a message to another, validating theirs values.
	class MessageMoverNode : public CompoundStmtNode
	{
	public:
		MessageMoverNode(MemoryPool& pool, MessageNode* fromMessage, MessageNode* toMessage,
					MessageNode* aCheckMessageEof = nullptr)
			: CompoundStmtNode(pool),
			  checkMessageEof(aCheckMessageEof)
		{
			// Iterate over the format items, except the EOF item.
			for (USHORT i = 0; i < (fromMessage->format->fmt_count / 2) * 2; i += 2)
			{
				ParameterNode* flag = FB_NEW_POOL(pool) ParameterNode(pool);
				flag->messageNumber = fromMessage->messageNumber;
				flag->message = fromMessage;
				flag->argNumber = i + 1;

				ParameterNode* param = FB_NEW_POOL(pool) ParameterNode(pool);
				param->messageNumber = fromMessage->messageNumber;
				param->message = fromMessage;
				param->argNumber = i;
				param->argFlag = flag;

				AssignmentNode* assign = FB_NEW_POOL(pool) AssignmentNode(pool);
				assign->asgnFrom = param;
				statements.add(assign);

				flag = FB_NEW_POOL(pool) ParameterNode(pool);
				flag->messageNumber = toMessage->messageNumber;
				flag->message = toMessage;
				flag->argNumber = i + 1;

				param = FB_NEW_POOL(pool) ParameterNode(pool);
				param->messageNumber = toMessage->messageNumber;
				param->message = toMessage;
				param->argNumber = i;
				param->argFlag = flag;

				assign->asgnTo = param;
			}
		}

		const StmtNode* execute(thread_db* tdbb, Request* request, ExeState* exeState) const override
		{
			if (checkMessageEof &&
				request->req_operation == Request::req_evaluate &&
				(request->req_flags & req_proc_select))
			{
				const auto msg = request->getImpure<UCHAR>(checkMessageEof->impureOffset);
				const auto eof = (SSHORT*) (msg + (IPTR) checkMessageEof->format->fmt_desc.back().dsc_address);

				if (!*eof)
					request->req_operation = Request::req_return;
			}

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

	private: