Method build_rag_response

nodedb/src/data/executor/handlers/graph_rag.rs:184–231

Encode a `GraphRagResponse` from RRF-fused results. Shared by both 2-source (`execute_graph_rag_fusion`) and 3-source (`execute_graph_rag_fusion_triple`) fusion pipelines.

(
        &self,
        task: &ExecutionTask,
        p: RagResponseParams<'_>,
    )

    /// Shared by both 2-source (`execute_graph_rag_fusion`) and 3-source
    /// (`execute_graph_rag_fusion_triple`) fusion pipelines.
    pub(in crate::data::executor) fn build_rag_response(
        &self,
        task: &ExecutionTask,
        p: RagResponseParams<'_>,
    ) -> Response {
        let results: Vec<GraphRagResult> = p
            .fused
            .iter()
            .map(|f| {
                let (vector_rank, vector_distance) = p
                    .vector_scores
                    .get(f.document_id.as_str())
                    .map(|(rank, dist)| (Some(*rank), Some(*dist)))
                    .unwrap_or((None, None));
                let hop_distance = p.hop_distances.get(f.document_id.as_str()).copied();
                GraphRagResult {
                    node_id: f.document_id.clone(),
                    rrf_score: f.rrf_score,
                    vector_rank,
                    vector_distance,
                    hop_distance,
                }
            })
            .collect();

        let response_body = GraphRagResponse {
            results,
            metadata: GraphRagMetadata {
                vector_candidates: p.vector_candidate_count,
                graph_expanded: p.graph_expanded_count,
                truncated: p.bfs_truncated,
                watermark_lsn: self.watermark.as_u64(),
            },
        };

        match encode(&response_body) {
            Ok(payload) => self.response_with_payload(task, payload),
            Err(e) => {
                warn!(core = self.core_id, error = %e, "{} serialization failed", p.op_name);
                self.response_error(
                    task,
                    ErrorCode::Internal {
                        detail: e.to_string(),
                    },
                )
            }
        }
    }

    /// BFS traversal that also tracks hop distances from start nodes.
    pub(in crate::data::executor) fn bfs_with_distances(