Function BTR_next_index

src/jrd/btr.cpp:2104–2173

bool BTR_next_index(thread_db* tdbb, jrd_rel* relation, jrd_tra* transaction, index_desc* idx, WIN* window)
{
/**************************************
 *
 *	B T R _ n e x t _ i n d e x
 *
 **************************************
 *
 * Functional description
 *	Get next index for relation.  Index ids
 *  recently changed from UCHAR to SHORT
 *
 **************************************/
	SET_TDBB(tdbb);

	USHORT id;
	if (idx->idx_id == idx_invalid)
	{
		id = 0;
		window->win_bdb = NULL;
	}
	else
		id = idx->idx_id + 1;

	index_root_page* root;
	if (window->win_bdb)
		root = (index_root_page*) window->win_buffer;
	else
	{
		RelationPages* const relPages = transaction ?
			relation->getPages(tdbb, transaction->tra_number) : relation->getPages(tdbb);

		if (!(root = fetch_root(tdbb, window, relation, relPages)))
			return false;
	}

	for (; id < root->irt_count; ++id)
	{
		const index_root_page::irt_repeat* irt_desc = root->irt_rpt + id;
		if (irt_desc->getTransaction() && transaction)
		{
			const TraNumber trans = irt_desc->getTransaction();
			CCH_RELEASE(tdbb, window);
			const int trans_state = TRA_wait(tdbb, transaction, trans, jrd_tra::tra_wait);
			if ((trans_state == tra_dead) || (trans_state == tra_committed))
			{
				// clean up this left-over index
				root = (index_root_page*) CCH_FETCH(tdbb, window, LCK_write, pag_root);
				irt_desc = root->irt_rpt + id;

				if (irt_desc->getTransaction() == trans)
					BTR_delete_index(tdbb, window, id);
				else
					CCH_RELEASE(tdbb, window);

				root = (index_root_page*) CCH_FETCH(tdbb, window, LCK_read, pag_root);
				continue;
			}