Function fetch_old_row

nodedb/src/control/trigger/dml_hook.rs:269–326

Fetch the current document as a field map (for OLD row bindings). Issues a PointGet to the Data Plane and deserializes the response. Returns an empty map if the document doesn't exist or can't be read.

(
    state: &SharedState,
    tenant_id: TenantId,
    collection: &str,
    document_id: &str,
)

/// Issues a PointGet to the Data Plane and deserializes the response.
/// Returns an empty map if the document doesn't exist or can't be read.
pub async fn fetch_old_row(
    state: &SharedState,
    tenant_id: TenantId,
    collection: &str,
    document_id: &str,
) -> HashMap<String, nodedb_types::Value> {
    let pk_bytes = document_id.as_bytes().to_vec();
    let surrogate = state
        .surrogate_assigner
        .lookup(collection, &pk_bytes)
        .ok()
        .flatten()
        .unwrap_or(nodedb_types::Surrogate::ZERO);
    let plan = crate::bridge::envelope::PhysicalPlan::Document(DocumentOp::PointGet {
        collection: collection.to_string(),
        document_id: document_id.to_string(),
        surrogate,
        pk_bytes,
        rls_filters: Vec::new(),
        system_as_of_ms: None,
        valid_at_ms: None,
    });
    let vshard_id = crate::types::VShardId::from_key(document_id.as_bytes());

    let resp = match crate::control::server::dispatch_utils::dispatch_to_data_plane(
        state,
        tenant_id,
        vshard_id,
        plan,
        TraceId::ZERO,
    )
    .await
    {
        Ok(r) => r,
        Err(_) => return HashMap::new(),
    };

    if resp.payload.is_empty() {
        return HashMap::new();
    }

    // Decode the response payload (MessagePack or JSON).
    let bytes = resp.payload.as_ref();
    if let Ok(serde_json::Value::Object(map)) = nodedb_types::json_from_msgpack(bytes) {
        return map
            .into_iter()
            .map(|(k, v)| (k, nodedb_types::Value::from(v)))
            .collect();
    }
    if let Ok(serde_json::Value::Object(map)) = sonic_rs::from_slice::<serde_json::Value>(bytes) {
        return map
            .into_iter()
            .map(|(k, v)| (k, nodedb_types::Value::from(v)))
            .collect();
    }

    HashMap::new()
}