Function run

nodedb/src/engine/graph/algo/diameter.rs:26–47

Run Diameter/Eccentricity computation on the CSR index. `params.mode`: "EXACT" or "APPROXIMATE" (default). Returns `(diameter, radius)` as a single row.

(csr: &CsrIndex, params: &AlgoParams)

/// `params.mode`: "EXACT" or "APPROXIMATE" (default).
/// Returns `(diameter, radius)` as a single row.
pub fn run(csr: &CsrIndex, params: &AlgoParams) -> AlgoResultBatch {
    let n = csr.node_count();
    if n == 0 {
        return AlgoResultBatch::new(GraphAlgorithm::Diameter);
    }

    let mode = params
        .mode
        .as_deref()
        .unwrap_or("APPROXIMATE")
        .to_uppercase();

    let (diameter, radius) = if mode == "EXACT" {
        compute_exact(csr, n)
    } else {
        compute_approximate(csr, n)
    };

    let mut batch = AlgoResultBatch::new(GraphAlgorithm::Diameter);
    batch.push_diameter(diameter, radius);
    batch
}

/// Exact computation: BFS from every node, compute all eccentricities.
fn compute_exact(csr: &CsrIndex, n: usize) -> (i64, i64) {