Struct GraphStatistics 

pub struct GraphStatistics { /* private fields */ }

Core statistics about an RDF graph.

Tracks total triple count and the number of distinct subjects, predicates, and objects. Supports incremental updates as triples are added or removed.

Implementations

impl GraphStatistics

pub fn new() -> Self

Create a new, empty statistics instance.

pub fn add_triple(&mut self, subject: &str, predicate: &str, object: &str)

Record that a triple (subject, predicate, object) was added.

pub fn remove_triple(&mut self, subject: &str, predicate: &str, object: &str)

Record that a triple was removed. If the triple was never added, this is a no-op.

pub fn total_triples(&self) -> u64

Total number of triples.

pub fn distinct_subjects(&self) -> u64

Number of distinct subjects.

pub fn distinct_predicates(&self) -> u64

Number of distinct predicates.

pub fn distinct_objects(&self) -> u64

Number of distinct objects.

pub fn predicate_frequency(&self, predicate: &str) -> u64

Frequency of predicate (number of triples with that predicate).

pub fn top_predicates(&self, limit: usize) -> Vec<(String, u64)>

All predicates sorted by frequency (most frequent first).

pub fn estimate_cardinality( &self, subject: Option<&str>, predicate: Option<&str>, object: Option<&str>, ) -> u64

Estimate the number of triples for a given triple pattern.

None in a slot means “wildcard”. The estimate uses frequency data where available and falls back to uniform distribution otherwise.

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

Merge another GraphStatistics instance into this one (union semantics — no dedup).

Trait Implementations

impl Clone for GraphStatistics

fn clone(&self) -> GraphStatistics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GraphStatistics

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

Formats the value using the given formatter.

impl Default for GraphStatistics

fn default() -> GraphStatistics

Returns the “default value” for a type.