Function build_pagerank_sql

nodedb-client/src/graph_dsl.rs:21–43

Build the `GRAPH ALGO PAGERANK …` DSL statement. Emits optional `ITERATIONS`, `DAMPING`, and `PERSONALIZATION {…}` clauses. The personalization map is serialized as a JSON `node_id → weight` object literal, which the server tokenizer captures as a single object token.

(
    collection: &str,
    personalization: Option<&HashMap<String, f64>>,
    damping: Option<f64>,
    max_iterations: Option<u32>,
)

/// The personalization map is serialized as a JSON `node_id → weight` object
/// literal, which the server tokenizer captures as a single object token.
pub(crate) fn build_pagerank_sql(
    collection: &str,
    personalization: Option<&HashMap<String, f64>>,
    damping: Option<f64>,
    max_iterations: Option<u32>,
) -> NodeDbResult<String> {
    let mut sql = format!(
        "GRAPH ALGO PAGERANK ON {}",
        quote_string_literal(collection)
    );
    if let Some(iters) = max_iterations {
        sql.push_str(&format!(" ITERATIONS {iters}"));
    }
    if let Some(d) = damping {
        sql.push_str(&format!(" DAMPING {d}"));
    }
    if let Some(p) = personalization.filter(|p| !p.is_empty()) {
        let json = sonic_rs::to_string(p)
            .map_err(|e| NodeDbError::storage(format!("personalization serialization: {e}")))?;
        sql.push_str(&format!(" PERSONALIZATION {json}"));
    }
    Ok(sql)
}

/// Parse a `(columns, rows)` PageRank result into `(node_id, rank)` pairs.
///