Function count_possible_sources

devtools/topology.c:46–71

What nodes can reach n without going through exclude? */

/* What nodes can reach n without going through exclude? */
static size_t count_possible_sources(const struct gossmap *map,
				     struct gossmap_node *n,
				     struct gossmap_node *exclude,
				     bool is_last_node)
{
	const struct dijkstra *dij;
	size_t distance_budget, num;

	dij = dijkstra(tmpctx, map, n, AMOUNT_MSAT(0), 0,
		       channel_usable_to_excl, route_score_shorter, exclude);

	if (is_last_node)
		distance_budget = ROUTING_MAX_HOPS - 1;
	else
		distance_budget = ROUTING_MAX_HOPS - 2;

	assert(dijkstra_distance(dij, gossmap_node_idx(map, n)) == 0);
	assert(dijkstra_distance(dij, gossmap_node_idx(map, exclude)) == UINT_MAX);

	num = 0;
	for (n = gossmap_first_node(map); n; n = gossmap_next_node(map, n)) {
		if (dijkstra_distance(dij, gossmap_node_idx(map, n)) <= distance_budget)
			num++;
	}
	return num;
}

/* Note: dijkstra() sets dir to the neighbor side; i.e. c->half[dir].node_idx is the
 * neighbor. */