Package org.eclipse.rdf4j.repository.evaluation

Class RepositoryTripleSource

java.lang.Object

org.eclipse.rdf4j.repository.evaluation.RepositoryTripleSource

All Implemented Interfaces:

AvailableStatementOrder, TripleSource

public class RepositoryTripleSource
extends Object
implements TripleSource

Field Summary

Fields inherited from interface org.eclipse.rdf4j.query.algebra.evaluation.TripleSource

EMPTY_ITERATION

Constructor Summary

Constructors

Constructor	Description
RepositoryTripleSource(RepositoryConnection repo)
RepositoryTripleSource(RepositoryConnection repo, boolean includeInferred)

Method Summary

Modifier and Type	Method	Description
Comparator<Value>	getComparator()	Different underlying datastructures may have different ways of ordering statements.
CloseableIteration<? extends Statement>	getStatements(Resource subj, IRI pred, Value obj, Resource... contexts)	Gets all statements that have a specific subject, predicate and/or object.
ValueFactory	getValueFactory()	Gets a ValueFactory object that can be used to create IRI-, blank node- and literal objects.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.eclipse.rdf4j.query.algebra.evaluation.TripleSource

getStatements, getSupportedOrders

Constructor Details

RepositoryTripleSource

public RepositoryTripleSource(RepositoryConnection repo)

RepositoryTripleSource

public RepositoryTripleSource(RepositoryConnection repo,
 boolean includeInferred)

Method Details

getStatements

public CloseableIteration<? extends Statement> getStatements(Resource subj,
 IRI pred,
 Value obj,
 Resource... contexts)
                                                      throws QueryEvaluationException

Description copied from interface: TripleSource

Gets all statements that have a specific subject, predicate and/or object. All three parameters may be null to indicate wildcards. Optionally a (set of) context(s) may be specified in which case the result will be restricted to statements matching one or more of the specified contexts.

Specified by:

getStatements in interface TripleSource

Parameters:

subj - A Resource specifying the subject, or null for a wildcard.

pred - A IRI specifying the predicate, or null for a wildcard.

obj - A Value specifying the object, or null for a wildcard.

contexts - The context(s) to get the statements from. Note that this parameter is a vararg and as such is optional. If no contexts are supplied the method operates on the entire repository.

Returns:

An iterator over the relevant statements.

Throws:

QueryEvaluationException - If the triple source failed to get the statements.

getValueFactory

public ValueFactory getValueFactory()

Description copied from interface: TripleSource

Gets a ValueFactory object that can be used to create IRI-, blank node- and literal objects.

Specified by:

getValueFactory in interface TripleSource

Returns:

a ValueFactory object for this TripleSource.

getComparator

public Comparator<Value> getComparator()

Description copied from interface: TripleSource

Different underlying datastructures may have different ways of ordering statements. On-disk stores typically use a long to represent a value and only stores the actual value in a dictionary, in this case the order would be the order that values where inserted into the dictionary. Stores that instead store values in SPARQL-order can return an instance of ValueComparator which may allow for further optimizations.

Note that this method is experimental and may be changed or removed without notice.

Specified by:

getComparator in interface TripleSource

Returns:

a comparator that matches the order of values in the store