Struct GraphLabelRegistry 

pub struct GraphLabelRegistry {
    pub labels: BTreeMap<String, u32>,
    pub kinds: BTreeMap<String, LabelKind>,
    pub sequences: BTreeMap<u32, u64>,
    pub dropped_label_ids: BTreeSet<u32>,
    pub next_label_id: u32,
}

Per-graph AGE label registry: label name -> label id plus the per-label id sequences. Serializable so engines can persist it in catalog metadata and restore deterministic id allocation.

Fields

labels: BTreeMap<String, u32>

Label name -> AGE label id. Vertex and edge labels share the namespace-wide counter; the reserved names for ids 1 / 2 are not stored here (empty labels map onto them implicitly).

kinds: BTreeMap<String, LabelKind>

Label name -> vertex or edge kind. Registries persisted before kinds were recorded fill this map from the stored entities.

sequences: BTreeMap<u32, u64>

Label id -> last allocated per-label sequence value.

dropped_label_ids: BTreeSet<u32>

AGE label ids whose relations were removed through drop_label. Tombstones are persisted because edge rows can outlive the vertex label relations that owned their endpoints. Registries written before this field existed deserialize as an empty set.

next_label_id: u32

Next label id handed to a previously unseen label.

Implementations

impl GraphLabelRegistry

pub fn contains_label(&self, label: &str) -> bool

Whether label names a registered user label or a reserved default label.

pub fn label_kind(&self, label: &str) -> Option<LabelKind>

The kind of a registered or default label. A user label persisted before kinds were recorded, and whose entities are all gone, reports as a vertex label until its next use records the kind.

pub fn register_label( &mut self, label: &str, kind: LabelKind, ) -> GraphStoreResult<Option<u32>>

Register an empty user label ahead of any entity, as create_vlabel / create_elabel do. Returns the new label id; None when the name is already a label of this graph.

pub fn remove_label(&mut self, label: &str) -> Option<u32>

Forget a label. Default labels leave a durable tombstone so the graph can continue to exist without their AGE relations. Returns the released label id, or None when the label is not registered.

pub fn labels(&self) -> Vec<GraphLabelInfo>

Every present label of the graph in ag_label order: surviving defaults first, then user labels by ascending label id.

pub fn merge(&mut self, other: &GraphLabelRegistry)

Merge another registry (e.g. persisted metadata) into this one, keeping the larger sequence values and label id watermark.

Trait Implementations

impl Clone for GraphLabelRegistry

fn clone(&self) -> GraphLabelRegistry

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GraphLabelRegistry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for GraphLabelRegistry

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for GraphLabelRegistry

where GraphLabelRegistry: Default,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for GraphLabelRegistry

impl PartialEq for GraphLabelRegistry

fn eq(&self, other: &GraphLabelRegistry) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for GraphLabelRegistry

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for GraphLabelRegistry