oxrdf/graph.rs
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//! [In-memory implementation](Graph) of [RDF graphs](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-graph).
//!
//! Usage example:
//! ```
//! use oxrdf::*;
//!
//! let mut graph = Graph::default();
//!
//! // insertion
//! let ex = NamedNodeRef::new("http://example.com")?;
//! let triple = TripleRef::new(ex, ex, ex);
//! graph.insert(triple);
//!
//! // simple filter
//! let results: Vec<_> = graph.triples_for_subject(ex).collect();
//! assert_eq!(vec![triple], results);
//!
//! // Print
//! assert_eq!(
//! graph.to_string(),
//! "<http://example.com> <http://example.com> <http://example.com> .\n"
//! );
//! # Result::<_, Box<dyn std::error::Error>>::Ok(())
//! ```
//!
//! See also [`Dataset`] if you want to get support of multiple RDF graphs at the same time.
pub use crate::dataset::CanonicalizationAlgorithm;
use crate::dataset::*;
use crate::*;
use std::fmt;
/// An in-memory [RDF graph](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-graph).
///
/// It can accommodate a fairly large number of triples (in the few millions).
///
/// <div class="warning">It interns the string and does not do any garbage collection yet:
/// if you insert and remove a lot of different terms, memory will grow without any reduction.</div>
///
/// Usage example:
/// ```
/// use oxrdf::*;
///
/// let mut graph = Graph::default();
///
/// // insertion
/// let ex = NamedNodeRef::new("http://example.com")?;
/// let triple = TripleRef::new(ex, ex, ex);
/// graph.insert(triple);
///
/// // simple filter
/// let results: Vec<_> = graph.triples_for_subject(ex).collect();
/// assert_eq!(vec![triple], results);
/// # Result::<_, Box<dyn std::error::Error>>::Ok(())
/// ```
#[derive(Debug, Default, Clone)]
pub struct Graph {
dataset: Dataset,
}
impl Graph {
/// Creates a new graph.
pub fn new() -> Self {
Self::default()
}
fn graph(&self) -> GraphView<'_> {
self.dataset.graph(GraphNameRef::DefaultGraph)
}
fn graph_mut(&mut self) -> GraphViewMut<'_> {
self.dataset.graph_mut(GraphNameRef::DefaultGraph)
}
/// Returns all the triples contained by the graph.
pub fn iter(&self) -> Iter<'_> {
Iter {
inner: self.graph().iter(),
}
}
pub fn triples_for_subject<'a, 'b>(
&'a self,
subject: impl Into<SubjectRef<'b>>,
) -> impl Iterator<Item = TripleRef<'a>> + 'a {
self.graph()
.triples_for_interned_subject(self.dataset.encoded_subject(subject))
}
pub fn objects_for_subject_predicate<'a, 'b>(
&'a self,
subject: impl Into<SubjectRef<'b>>,
predicate: impl Into<NamedNodeRef<'b>>,
) -> impl Iterator<Item = TermRef<'a>> + 'a {
self.graph().objects_for_interned_subject_predicate(
self.dataset.encoded_subject(subject),
self.dataset.encoded_named_node(predicate),
)
}
pub fn object_for_subject_predicate<'a, 'b>(
&'a self,
subject: impl Into<SubjectRef<'b>>,
predicate: impl Into<NamedNodeRef<'b>>,
) -> Option<TermRef<'a>> {
self.graph()
.objects_for_subject_predicate(subject, predicate)
.next()
}
pub fn predicates_for_subject_object<'a, 'b>(
&'a self,
subject: impl Into<SubjectRef<'b>>,
object: impl Into<TermRef<'b>>,
) -> impl Iterator<Item = NamedNodeRef<'a>> + 'a {
self.graph().predicates_for_interned_subject_object(
self.dataset.encoded_subject(subject),
self.dataset.encoded_term(object),
)
}
pub fn triples_for_predicate<'a, 'b>(
&'a self,
predicate: impl Into<NamedNodeRef<'b>>,
) -> impl Iterator<Item = TripleRef<'a>> + 'a {
self.graph()
.triples_for_interned_predicate(self.dataset.encoded_named_node(predicate))
}
pub fn subjects_for_predicate_object<'a, 'b>(
&'a self,
predicate: impl Into<NamedNodeRef<'b>>,
object: impl Into<TermRef<'b>>,
) -> impl Iterator<Item = SubjectRef<'a>> + 'a {
self.graph().subjects_for_interned_predicate_object(
self.dataset.encoded_named_node(predicate),
self.dataset.encoded_term(object),
)
}
pub fn subject_for_predicate_object<'a, 'b>(
&'a self,
predicate: impl Into<NamedNodeRef<'b>>,
object: impl Into<TermRef<'b>>,
) -> Option<SubjectRef<'a>> {
self.graph().subject_for_predicate_object(predicate, object)
}
pub fn triples_for_object<'a, 'b>(
&'a self,
object: impl Into<TermRef<'b>>,
) -> impl Iterator<Item = TripleRef<'a>> + 'a {
self.graph()
.triples_for_interned_object(self.dataset.encoded_term(object))
}
/// Checks if the graph contains the given triple.
pub fn contains<'a>(&self, triple: impl Into<TripleRef<'a>>) -> bool {
self.graph().contains(triple)
}
/// Returns the number of triples in this graph.
pub fn len(&self) -> usize {
self.dataset.len()
}
/// Checks if this graph contains a triple.
pub fn is_empty(&self) -> bool {
self.dataset.is_empty()
}
/// Adds a triple to the graph.
pub fn insert<'a>(&mut self, triple: impl Into<TripleRef<'a>>) -> bool {
self.graph_mut().insert(triple)
}
/// Removes a concrete triple from the graph.
pub fn remove<'a>(&mut self, triple: impl Into<TripleRef<'a>>) -> bool {
self.graph_mut().remove(triple)
}
/// Clears the graph.
pub fn clear(&mut self) {
self.dataset.clear()
}
/// Canonicalizes the dataset by renaming blank nodes.
///
/// Usage example ([Graph isomorphism](https://www.w3.org/TR/rdf11-concepts/#dfn-graph-isomorphism)):
/// ```
/// use oxrdf::graph::CanonicalizationAlgorithm;
/// use oxrdf::*;
///
/// let iri = NamedNodeRef::new("http://example.com")?;
///
/// let mut graph1 = Graph::new();
/// let bnode1 = BlankNode::default();
/// graph1.insert(TripleRef::new(iri, iri, &bnode1));
/// graph1.insert(TripleRef::new(&bnode1, iri, iri));
///
/// let mut graph2 = Graph::new();
/// let bnode2 = BlankNode::default();
/// graph2.insert(TripleRef::new(iri, iri, &bnode2));
/// graph2.insert(TripleRef::new(&bnode2, iri, iri));
///
/// assert_ne!(graph1, graph2);
/// graph1.canonicalize(CanonicalizationAlgorithm::Unstable);
/// graph2.canonicalize(CanonicalizationAlgorithm::Unstable);
/// assert_eq!(graph1, graph2);
/// # Result::<_, Box<dyn std::error::Error>>::Ok(())
/// ```
///
/// <div class="warning">Blank node ids depends on the current shape of the graph. Adding a new quad might change the ids of a lot of blank nodes.
/// Hence, this canonization might not be suitable for diffs.</div>
///
/// <div class="warning">This implementation worst-case complexity is in *O(b!)* with *b* the number of blank nodes in the input dataset.</div>
pub fn canonicalize(&mut self, algorithm: CanonicalizationAlgorithm) {
self.dataset.canonicalize(algorithm)
}
}
impl PartialEq for Graph {
fn eq(&self, other: &Self) -> bool {
self.dataset == other.dataset
}
}
impl Eq for Graph {}
impl<'a> IntoIterator for &'a Graph {
type Item = TripleRef<'a>;
type IntoIter = Iter<'a>;
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
impl FromIterator<Triple> for Graph {
fn from_iter<I: IntoIterator<Item = Triple>>(iter: I) -> Self {
let mut g = Self::new();
g.extend(iter);
g
}
}
impl<'a, T: Into<TripleRef<'a>>> FromIterator<T> for Graph {
fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
let mut g = Self::new();
g.extend(iter);
g
}
}
impl Extend<Triple> for Graph {
fn extend<I: IntoIterator<Item = Triple>>(&mut self, iter: I) {
self.graph_mut().extend(iter)
}
}
impl<'a, T: Into<TripleRef<'a>>> Extend<T> for Graph {
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
self.graph_mut().extend(iter)
}
}
impl fmt::Display for Graph {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.graph().fmt(f)
}
}
/// Iterator returned by [`Graph::iter`].
pub struct Iter<'a> {
inner: GraphViewIter<'a>,
}
impl<'a> Iterator for Iter<'a> {
type Item = TripleRef<'a>;
fn next(&mut self) -> Option<Self::Item> {
self.inner.next()
}
}