Function add_node

src/jrd/btr.cpp:2641–2770

static ULONG add_node(thread_db* tdbb,
					  WIN* window,
					  index_insertion* insertion,
					  temporary_key* new_key,
					  RecordNumber* new_record_number,
					  ULONG* original_page,
					  ULONG* sibling_page)
{
/**************************************
 *
 *	a d d _ n o d e
 *
 **************************************
 *
 * Functional description
 *	Insert a node in an index.  This recurses to the leaf level.
 *	If a split occurs, return the new index page number and its
 *	leading string.
 *
 **************************************/

	SET_TDBB(tdbb);
	btree_page* bucket = (btree_page*) window->win_buffer;

	// For leaf level guys, loop thru the leaf buckets until insertion
	// point is found (should be instant)
	if (bucket->btr_level == insertion->iib_btr_level)
	{
		while (true)
		{
			const ULONG split = insert_node(tdbb, window, insertion, new_key,
				new_record_number, original_page, sibling_page);

			if (split != NO_VALUE_PAGE)
				return split;

			bucket = (btree_page*) CCH_HANDOFF(tdbb, window, bucket->btr_sibling, LCK_write, pag_index);
		}
	}

	// If we're above the leaf level, find the appropriate node in the chain of sibling pages.
	// Hold on to this position while we recurse down to the next level, in case there's a
	// split at the lower level, in which case we need to insert the new page at this level.
	ULONG page;
	while (true)
	{
		page = find_page(bucket, insertion->iib_key, insertion->iib_descriptor,
						 insertion->iib_number);

		if (page != END_BUCKET)
			break;

		bucket = (btree_page*) CCH_HANDOFF(tdbb, window, bucket->btr_sibling, LCK_read, pag_index);
	}

	BtrPageGCLock lockCurrent(tdbb);
	lockCurrent.disablePageGC(tdbb, window->win_page);