Function create_pseudo_root_node

src/vector_store.rs:160–254

(
    quantization_metric: &QuantizationMetric,
    storage_type: StorageType,
    prop_file: &RwLock<File>,
    version_hash: VersionNumber,
    offset_counter: &HNSWIndexFileOffsetCounter,
    cache

/// the root when traversing the index.
#[allow(clippy::too_many_arguments)]
pub fn create_pseudo_root_node(
    quantization_metric: &QuantizationMetric,
    storage_type: StorageType,
    prop_file: &RwLock<File>,
    version_hash: VersionNumber,
    offset_counter: &HNSWIndexFileOffsetCounter,
    cache: &HNSWIndexCache,
    values_range: (f32, f32),
    hnsw_params: &HNSWHyperParams,
    distance_metric: DistanceMetric,
    metadata_schema: &MetadataSchema,
    vec: Vec<f32>,
    vec_hash: InternalId,
) -> Result<SharedLatestNode, WaCustomError> {
    let vector_list = Arc::new(quantization_metric.quantize(&vec, storage_type, values_range)?);

    let mut prop_file_guard = prop_file.write().unwrap();
    let location = write_prop_value_to_file(&vec_hash, &vector_list, &mut prop_file_guard)?;

    let prop_value = Arc::new(NodePropValue {
        id: vec_hash,
        vec: vector_list,
        location,
    });

    let prop_metadata = {
        let mbits = metadata_schema.pseudo_root_dimensions(HIGH_WEIGHT);
        let metadata = Arc::new(Metadata::from(mbits));
        // A pseudo root node is similar to a base replica node. Hence
        // the replica_id and prop_value's id are same.
        let replica_id = vec_hash;
        let location =
            write_prop_metadata_to_file(replica_id, metadata.clone(), &mut prop_file_guard)?;
        Some(Arc::new(NodePropMetadata {
            replica_id: vec_hash,
            vec: metadata,
            location,
        }))
    };

    drop(prop_file_guard);

    let file_id = offset_counter.file_id();

    let mut root = LazyItem::new(
        ProbNode::new(
            HNSWLevel(0),
            version_hash,
            prop_value.clone(),
            prop_metadata.clone(),
            ptr::null_mut(),
            ptr::null_mut(),
            hnsw_params.level_0_neighbors_count,
            distance_metric,
        ),
        file_id,
        offset_counter.next_level_0_offset(),
    );