Struct NamedGraphManager 

pub struct NamedGraphManager { /* private fields */ }

High-level manager for named RDF graphs within a single dataset

Provides a Jena-compatible API for creating, querying, and managing named graphs. Each graph is identified by a GraphName key.

Example

use oxirs_core::named_graph::NamedGraphManager;
use oxirs_core::model::{GraphName, NamedNode, Literal, Triple};

let mut mgr = NamedGraphManager::new();
let graph_iri = NamedNode::new("http://example.org/graph1").expect("valid IRI");
let key = GraphName::NamedNode(graph_iri.clone());

// Create a named graph (auto-created on first insert)
mgr.add_named_graph(key.clone());

// Insert a triple into that graph
let subj = NamedNode::new("http://example.org/s").expect("valid IRI");
let pred = NamedNode::new("http://example.org/p").expect("valid IRI");
let obj  = Literal::new("hello");
let triple = Triple::new(subj, pred, obj);
mgr.insert_triple(&key, triple).expect("operation should succeed");

assert_eq!(mgr.triple_count_in(&key), 1);

Implementations

impl NamedGraphManager

pub fn new() -> Self

Create a new empty dataset manager

pub fn with_capacity(named_graph_capacity: usize) -> Self

Create a dataset manager with an initial capacity hint for named graphs

pub fn default_graph(&self) -> &Graph

Returns a shared reference to the default (unnamed) graph

pub fn default_graph_mut(&mut self) -> &mut Graph

Returns an exclusive reference to the default (unnamed) graph

pub fn add_named_graph(&mut self, name: GraphName) -> bool

Create (or ensure the existence of) a named graph

Returns true if the graph was newly created, false if it already existed. Has no effect on the default graph key.

pub fn remove_named_graph(&mut self, name: &GraphName) -> Option<Graph>

Remove a named graph from the dataset

Returns the removed Graph if it existed, None otherwise. Calling this with the default graph key clears the default graph and returns the old contents.

pub fn get_named_graph(&self, name: &GraphName) -> Option<&Graph>

Returns a shared reference to the named graph with the given key

Returns None if no such graph exists. Use the default-graph key to access the default graph.

pub fn get_or_create_named_graph_mut(&mut self, name: &GraphName) -> &mut Graph

Returns an exclusive reference to the named graph with the given key, creating an empty graph entry if it does not exist yet.

pub fn get_named_graph_mut(&mut self, name: &GraphName) -> Option<&mut Graph>

Returns an exclusive reference to an existing named graph

Returns None if the graph does not exist (unlike get_or_create_named_graph_mut).

pub fn contains_named_graph(&self, name: &GraphName) -> bool

Returns true if a named graph with the given key exists

pub fn list_named_graphs(&self) -> impl Iterator<Item = &GraphName>

Returns an iterator over the names of all named graphs (excluding default)

pub fn graph_count(&self) -> usize

Returns the number of named graphs (excluding the default graph)

pub fn total_graph_count(&self) -> usize

Returns the total number of graphs including the default graph

pub fn insert_triple( &mut self, graph: &GraphName, triple: Triple, ) -> Result<bool>

Insert a triple into the specified graph

If the graph does not exist it is created automatically. Returns true if the triple was newly inserted.

pub fn remove_triple( &mut self, graph: &GraphName, triple: &Triple, ) -> Result<bool>

Remove a triple from the specified graph

Returns true if the triple was present and removed. Returns an error if the graph does not exist.

pub fn contains_triple(&self, graph: &GraphName, triple: &Triple) -> bool

Returns true if the specified graph contains the given triple

pub fn triples_in_graph(&self, graph: &GraphName) -> Vec<Triple>

Returns an owned Vec of all triples in the specified graph

Returns an empty vector if the graph does not exist.

pub fn triple_count_in(&self, graph: &GraphName) -> usize

Returns the number of triples in the specified graph

pub fn triple_count(&self) -> usize

Returns the total number of triples across all graphs (named + default)

pub fn clear_graph(&mut self, graph: &GraphName) -> Result<usize>

Remove all triples from the specified graph (graph itself remains)

Returns the number of triples removed.

pub fn drop_graph(&mut self, graph: &GraphName) -> bool

Remove all triples from the specified graph and delete the graph entry

Returns true if the graph existed. For the default graph this clears its contents but does not destroy the graph slot.

pub fn union_graph(&self) -> Graph

Build the union graph: all triples from all named graphs merged together

The returned Graph is a fresh copy; modifications do not affect the original graphs.

pub fn union_of_named_graphs(&self) -> Graph

Merge all named graphs (but NOT the default graph) into a union graph

Useful when implementing the SPARQL UNION DEFAULT GRAPH feature.

pub fn insert_quad(&mut self, quad: Quad) -> Result<bool>

Insert a Quad (routing it to the appropriate named graph)

pub fn iter_quads(&self) -> impl Iterator<Item = Quad> + '_

Returns an iterator over all quads in the dataset

pub fn statistics(&self) -> GraphStatistics

Compute statistics for this dataset

pub fn bulk_insert<I>(&mut self, graph: &GraphName, triples: I) -> usize

where I: IntoIterator<Item = Triple>,

Load all triples from an iterator into the given named graph

Returns the number of triples inserted (deduplicated).

pub fn copy_graph( &mut self, source: &GraphName, destination: &GraphName, ) -> Result<usize>

Copy all triples from source graph into destination graph

Returns the number of triples copied (may be fewer if destination already contains some of them).

pub fn move_graph( &mut self, source: &GraphName, destination: &GraphName, ) -> Result<usize>

Move all triples from source graph into destination graph

The source graph is emptied (but kept) after the operation. Returns the number of triples moved.

Trait Implementations

impl Clone for NamedGraphManager

fn clone(&self) -> NamedGraphManager

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NamedGraphManager

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

Formats the value using the given formatter.

impl Default for NamedGraphManager

fn default() -> Self

Returns the “default value” for a type.

impl GraphStore for NamedGraphManager

In-memory implementation of GraphStore backed by NamedGraphManager

fn add_triple(&mut self, graph: &GraphName, triple: Triple) -> Result<bool>

Add a triple to the given graph

fn remove_triple(&mut self, graph: &GraphName, triple: &Triple) -> Result<bool>

Remove a triple from the given graph

fn contains_triple(&self, graph: &GraphName, triple: &Triple) -> Result<bool>

Returns true if the graph contains the triple

fn triples_in_graph(&self, graph: &GraphName) -> Result<Vec<Triple>>

Returns an owned list of all triples in the graph

fn clear_graph(&mut self, graph: &GraphName) -> Result<usize>

Remove all triples from the graph (graph entry is kept)

fn drop_graph(&mut self, graph: &GraphName) -> Result<bool>

Delete the graph and all its triples