Method traverse_bfs

nodedb-graph/src/traversal.rs:28–91

BFS traversal. Returns all reachable node IDs within max_depth hops. `max_visited` caps the number of nodes visited to prevent supernode fan-out explosion. Pass [`DEFAULT_MAX_VISITED`] for the standard limit. `frontier_bitmap`: when `Some`, only nodes whose surrogate is present in the bitmap are eligible as traversal targets. Start nodes are not gated — only newly discovered frontier nodes are c

(
        &self,
        start_nodes: &[&str],
        label_filter: Option<&str>,
        direction: Direction,
        max_depth: usize,
        max_visited: usize,
        frontier_bitmap: Option<&

    /// bitmap are eligible as traversal targets. Start nodes are not gated — only
    /// newly discovered frontier nodes are checked.
    pub fn traverse_bfs(
        &self,
        start_nodes: &[&str],
        label_filter: Option<&str>,
        direction: Direction,
        max_depth: usize,
        max_visited: usize,
        frontier_bitmap: Option<&nodedb_types::SurrogateBitmap>,
    ) -> Vec<String> {
        let label_id = label_filter.and_then(|l| self.label_id(l));
        let mut visited: HashSet<u32> = HashSet::new();
        let mut queue: VecDeque<(u32, usize)> = VecDeque::new();

        for &node in start_nodes {
            if let Some(&id) = self.node_to_id.get(node)
                && visited.insert(id)
            {
                queue.push_back((id, 0));
            }
        }

        while let Some((node_id, depth)) = queue.pop_front() {
            if depth >= max_depth || visited.len() >= max_visited {
                continue;
            }

            // Track access for hot/cold partition decisions.
            self.record_access(node_id);

            if matches!(direction, Direction::Out | Direction::Both) {
                for (lid, dst) in self.dense_iter_out(node_id) {
                    if label_id.is_none_or(|f| f == lid)
                        && visited.len() < max_visited
                        && frontier_bitmap.is_none_or(|bm| {
                            bm.contains(nodedb_types::Surrogate::new(self.node_surrogate_raw(dst)))
                        })
                        && visited.insert(dst)
                    {
                        self.prefetch_node(dst);
                        queue.push_back((dst, depth + 1));
                    }
                }
            }
            if matches!(direction, Direction::In | Direction::Both) {
                for (lid, src) in self.dense_iter_in(node_id) {
                    if label_id.is_none_or(|f| f == lid)
                        && visited.len() < max_visited
                        && frontier_bitmap.is_none_or(|bm| {
                            bm.contains(nodedb_types::Surrogate::new(self.node_surrogate_raw(src)))
                        })
                        && visited.insert(src)
                    {
                        self.prefetch_node(src);
                        queue.push_back((src, depth + 1));
                    }
                }
            }
        }