Method fetchRecord

src/jrd/recsrc/MergeJoin.cpp:505–532

}

bool MergeJoin::fetchRecord(thread_db* tdbb, FB_SIZE_T index) const
{
	Request* const request = tdbb->getRequest();
	Impure* const impure = request->getImpure<Impure>(m_impure);
	Impure::irsb_mrg_repeat* tail = &impure->irsb_mrg_rpt[index];

	const SSHORT m = tail->irsb_mrg_order;
	tail = &impure->irsb_mrg_rpt[m];
	const SortedStream* const sort_rsb = m_args[m];

	SLONG record = tail->irsb_mrg_equal_current;
	++record;

	if (record > tail->irsb_mrg_equal_end)
	{
		if (index == 0 || !fetchRecord(tdbb, index - 1))
			return false;

		record = tail->irsb_mrg_equal;
	}

	tail->irsb_mrg_equal_current = record;

	MergeFile* const mfb = &tail->irsb_mrg_file;
	sort_rsb->mapData(tdbb, request, getData(tdbb, mfb, record));

	return true;
}