22  * Roll nodes[1] into nodes[0] by advancing nodes[1] to the end of a contiguous
23  * span of nodes. This makes nodes[0]->last the end of that contiguous used span
24  * of indexes that started at the original nodes[1]->start.
26  * If there is an interior hole, nodes[1] is now the first node starting the
27  * next used span. A hole span is between nodes[0]->last and nodes[1]->start.
29  * If there is a tailing hole, nodes[1] is now NULL. A hole span is between
30  * nodes[0]->last and last_index.
32  * If the contiguous used range span to last_index, nodes[1] is set to NULL.
37 	struct interval_tree_node *cur = state->nodes[1];  in interval_tree_span_iter_next_gap()
39 	state->nodes[0] = cur;  in interval_tree_span_iter_next_gap()
41 		if (cur->last > state->nodes[0]->last)  in interval_tree_span_iter_next_gap()
42 			state->nodes[0] = cur;  in interval_tree_span_iter_next_gap()
45 	} while (cur && (state->nodes[0]->last >= cur->start ||  in interval_tree_span_iter_next_gap()
46 			 state->nodes[0]->last + 1 == cur->start));  in interval_tree_span_iter_next_gap()
47 	state->nodes[1] = cur;  in interval_tree_span_iter_next_gap()
57 	iter->nodes[0] = NULL;  in interval_tree_span_iter_first()
58 	iter->nodes[1] =  in interval_tree_span_iter_first()
60 	if (!iter->nodes[1]) {  in interval_tree_span_iter_first()
61 		/* No nodes intersect the span, whole span is hole */  in interval_tree_span_iter_first()
67 	if (iter->nodes[1]->start > first_index) {  in interval_tree_span_iter_first()
70 		iter->last_hole = iter->nodes[1]->start - 1;  in interval_tree_span_iter_first()
80 	iter->last_used = iter->nodes[0]->last;  in interval_tree_span_iter_first()
83 		iter->nodes[0] = NULL;  in interval_tree_span_iter_first()
84 		iter->nodes[1] = NULL;  in interval_tree_span_iter_first()
91 	if (!iter->nodes[0] && !iter->nodes[1]) {  in interval_tree_span_iter_next()
98 		iter->last_used = iter->nodes[0]->last;  in interval_tree_span_iter_next()
101 			iter->nodes[0] = NULL;  in interval_tree_span_iter_next()
102 			iter->nodes[1] = NULL;  in interval_tree_span_iter_next()
108 	if (!iter->nodes[1]) {  in interval_tree_span_iter_next()
110 		iter->start_hole = iter->nodes[0]->last + 1;  in interval_tree_span_iter_next()
112 		iter->nodes[0] = NULL;  in interval_tree_span_iter_next()
117 	/* must have both nodes[0] and [1], interior hole */  in interval_tree_span_iter_next()
118 	iter->start_hole = iter->nodes[0]->last + 1;  in interval_tree_span_iter_next()
119 	iter->last_hole = iter->nodes[1]->start - 1;  in interval_tree_span_iter_next()