Package org.eclipse.rdf4j.sail.evaluation

Class SailTripleSource

java.lang.Object

org.eclipse.rdf4j.sail.evaluation.SailTripleSource

All Implemented Interfaces:

AvailableStatementOrder, TripleSource

public class SailTripleSource
extends Object
implements TripleSource

Field Summary

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

EMPTY_ITERATION

Constructor Summary

Constructors

Constructor	Description
SailTripleSource(SailConnection conn, boolean includeInferred, ValueFactory valueFactory)

Method Summary

Modifier and Type	Method	Description
Comparator<Value>	getComparator()	Different underlying datastructures may have different ways of ordering statements.
CloseableIteration<? extends Statement>	getStatements(StatementOrder order, Resource subj, IRI pred, Value obj, Resource... contexts)	Gets all statements that have a specific subject, predicate and/or object.
CloseableIteration<? extends Statement>	getStatements(Resource subj, IRI pred, Value obj, Resource... contexts)	Gets all statements that have a specific subject, predicate and/or object.
Set<StatementOrder>	getSupportedOrders(Resource subj, IRI pred, Value obj, Resource... contexts)	The underlying store may support some, but not all, statement orders based on the statement pattern.
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

Constructor Details

SailTripleSource

public SailTripleSource(SailConnection conn,
 boolean includeInferred,
 ValueFactory valueFactory)

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.

getStatements

public CloseableIteration<? extends Statement> getStatements(StatementOrder order,
 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.

Statements are returned in the order specified by the statementOrder parameter. Use TripleSource.getSupportedOrders(Resource, IRI, Value, Resource...) to first retrieve the statement orders supported by this store for this statement pattern.

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

Specified by:

getStatements in interface TripleSource

Parameters:

order - The order in which the statements should be returned.

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 ordered iterator over the relevant statements.

Throws:

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

getSupportedOrders

public Set<StatementOrder> getSupportedOrders(Resource subj,
 IRI pred,
 Value obj,
 Resource... contexts)

Description copied from interface: TripleSource

The underlying store may support some, but not all, statement orders based on the statement pattern. This method can be used to determine which orders are supported for a given statement pattern. The supported orders can be used to retrieve statements in a specific order using TripleSource.getStatements(StatementOrder, Resource, IRI, Value, Resource...) .

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

Specified by:

getSupportedOrders in interface AvailableStatementOrder

Specified by:

getSupportedOrders 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 data from. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Returns:

a set of supported statement orders

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