Method internalGetRecord

src/jrd/recsrc/IndexTableScan.cpp:156–355

}

bool IndexTableScan::internalGetRecord(thread_db* tdbb) const
{
	JRD_reschedule(tdbb);

	Request* const request = tdbb->getRequest();
	record_param* const rpb = &request->req_rpb[m_stream];
	Impure* const impure = request->getImpure<Impure>(m_impure);

	if (!(impure->irsb_flags & irsb_open))
	{
		rpb->rpb_number.setValid(false);
		return false;
	}

	if (impure->irsb_flags & irsb_first)
	{
		impure->irsb_flags &= ~irsb_first;
		setPage(tdbb, impure, NULL);

		impure->irsb_iterator = m_index->retrieval->irb_list ?
			FB_NEW_POOL(*tdbb->getDefaultPool()) IndexScanListIterator(tdbb, m_index->retrieval) :
			nullptr;

		USHORT dummy = 0;		// exclude upper/lower bits are not used here,
								// i.e. additional forced include not needed
		if (!BTR_make_bounds(tdbb, m_index->retrieval, impure->irsb_iterator,
							 impure->irsb_nav_lower, impure->irsb_nav_upper, dummy))
		{
			rpb->rpb_number.setValid(false);
			return false;
		}
	}

	// If this is the first time, start at the beginning
	if (!impure->irsb_nav_page)
	{
		// initialize for a retrieval
		if (!setupBitmaps(tdbb, impure))
		{
			rpb->rpb_number.setValid(false);
			return false;
		}
	}

	index_desc* const idx = (index_desc*) ((SCHAR*) impure + m_offset);

	// find the last fetched position from the index
	const USHORT pageSpaceID = m_relation->getPages(tdbb)->rel_pg_space_id;
	win window(pageSpaceID, impure->irsb_nav_page);

	const IndexRetrieval* const retrieval = m_index->retrieval;
	const USHORT flags = retrieval->irb_generic & (irb_descending | irb_partial | irb_starting);

	do
	{
		UCHAR* nextPointer = getPosition(tdbb, impure, &window);
		if (!nextPointer)
		{