Method search

nodedb-vector/src/delta/index.rs:64–87

Brute-force scan over fresh vectors (excluding tombstones), returning the top-`k` results sorted ascending by distance.

(&self, query: &[f32], k: usize, metric: DistanceMetric)

    /// Brute-force scan over fresh vectors (excluding tombstones), returning
    /// the top-`k` results sorted ascending by distance.
    pub fn search(&self, query: &[f32], k: usize, metric: DistanceMetric) -> Vec<(u32, f32)> {
        if k == 0 {
            return Vec::new();
        }

        let mut scored: Vec<(u32, f32)> = self
            .fresh
            .iter()
            .filter(|(id, _)| !self.tombstones.contains(id))
            .map(|(id, vec)| (*id, distance(query, vec, metric)))
            .collect();

        // Partial sort: cheapest path to top-k.
        if k < scored.len() {
            scored.select_nth_unstable_by(k, |a, b| {
                a.1.partial_cmp(&b.1).unwrap_or(std::cmp::Ordering::Equal)
            });
            scored.truncate(k);
        }

        scored.sort_unstable_by(|a, b| a.1.partial_cmp(&b.1).unwrap_or(std::cmp::Ordering::Equal));

        scored
    }

    /// Drain all staged fresh vectors for patching into the main HNSW.
    /// After this call `fresh_len()` returns 0.