Function distance

nodedb-vector/src/distance/mod.rs:17–38

(a: &[f32], b: &[f32], metric: DistanceMetric)

/// falls back to scalar implementations on other architectures.
#[inline]
pub fn distance(a: &[f32], b: &[f32], metric: DistanceMetric) -> f32 {
    assert_eq!(
        a.len(),
        b.len(),
        "distance: length mismatch (a.len()={}, b.len()={})",
        a.len(),
        b.len()
    );
    let rt = simd::runtime();
    match metric {
        DistanceMetric::L2 => (rt.l2_squared)(a, b),
        DistanceMetric::Cosine => (rt.cosine_distance)(a, b),
        DistanceMetric::InnerProduct => (rt.neg_inner_product)(a, b),
        DistanceMetric::Manhattan => manhattan(a, b),
        DistanceMetric::Chebyshev => chebyshev(a, b),
        DistanceMetric::Hamming => hamming_f32(a, b),
        DistanceMetric::Jaccard => jaccard(a, b),
        DistanceMetric::Pearson => pearson(a, b),
        // Unknown future metric — fall back to L2.
        _ => (rt.l2_squared)(a, b),
    }
}

/// Batch distance: compute distances from `query` to each candidate.
///