Package org.eclipse.rdf4j.sail.memory.model

Class MemValueFactory

java.lang.Object
org.eclipse.rdf4j.model.base.AbstractValueFactory
org.eclipse.rdf4j.sail.memory.model.MemValueFactory
All Implemented Interfaces:
ValueFactory
public class MemValueFactory extends AbstractValueFactory
A factory for MemValue objects that keeps track of created objects to prevent the creation of duplicate objects, minimizing memory usage as a result.
Author:
Arjohn Kampman, David Huynh

  • Constructor Details

    • MemValueFactory

      public MemValueFactory()
      A cache of the most common IRIs to improve lookup performance when users use our vocabularies (eg. RDF.TYPE).

  • Method Details

    • clear

      public void clear()

    • getMemValue

      public MemValue getMemValue(Value value)
      Returns a previously created MemValue that is equal to the supplied value, or null if the supplied value is a new value or is equal to null.
      Parameters:
      value - The MemValue equivalent of the supplied value, or null.
      Returns:
      A previously created MemValue that is equal to value, or null if no such value exists or if value is equal to null.

    • getMemResource

      public MemResource getMemResource(Resource resource)
      See getMemValue() for description.

    • getMemURI

      public MemIRI getMemURI(IRI uri)
      See getMemValue() for description.

    • getMemBNode

      public MemBNode getMemBNode(BNode bnode)
      See getMemValue() for description.

    • getMemLiteral

      public MemLiteral getMemLiteral(Literal literal)
      See getMemValue() for description.

    • getMemIRIsIterator

      public WeakObjectRegistry.AutoCloseableIterator<MemIRI> getMemIRIsIterator()
      Gets all URIs that are managed by this value factory.
      Returns:
      An autocloseable iterator.

    • getMemBNodesIterator

      public WeakObjectRegistry.AutoCloseableIterator<MemBNode> getMemBNodesIterator()
      Gets all bnodes that are managed by this value factory.
      Returns:
      An autocloseable iterator.

    • getMemLiteralsIterator

      public WeakObjectRegistry.AutoCloseableIterator<MemLiteral> getMemLiteralsIterator()
      Gets all literals that are managed by this value factory.
      Returns:
      An autocloseable iterator.

    • getOrCreateMemValue

      public MemValue getOrCreateMemValue(Value value)
      Gets or creates a MemValue for the supplied Value. If the factory already contains a MemValue object that is equivalent to the supplied value then this equivalent value will be returned. Otherwise a new MemValue will be created, stored for future calls and then returned.
      Parameters:
      value - A Resource or Literal.
      Returns:
      The existing or created MemValue.

    • getOrCreateMemResource

      public MemResource getOrCreateMemResource(Resource resource)
      See getOrCreateMemValue(Value) for description.

    • getOrCreateMemURI

      public MemIRI getOrCreateMemURI(IRI uri)
      See getOrCreateMemValue(Value) for description.

    • getOrCreateMemBNode

      public MemBNode getOrCreateMemBNode(BNode bnode)
      See getOrCreateMemValue(Value) for description.

    • getOrCreateMemLiteral

      public MemLiteral getOrCreateMemLiteral(Literal literal)
      See getOrCreateMemValue(Value) for description.

    • createIRI

      public IRI createIRI(String uri)
      Description copied from interface: ValueFactory
      Creates a new IRI from the supplied string-representation.
      Specified by:
      createIRI in interface ValueFactory
      Overrides:
      createIRI in class AbstractValueFactory
      Parameters:
      uri - A string-representation of a IRI.
      Returns:
      An object representing the IRI.

    • createIRI

      public IRI createIRI(String namespace, String localName)
      Description copied from interface: ValueFactory
      Creates a new IRI from the supplied namespace and local name. Calling this method is funtionally equivalent to calling createIRI(namespace+localName), but allows the ValueFactory to reuse supplied namespace and local name strings whenever possible. Note that the values returned by IRI.getNamespace() and IRI.getLocalName() are not necessarily the same as the values that are supplied to this method.
      Specified by:
      createIRI in interface ValueFactory
      Overrides:
      createIRI in class AbstractValueFactory
      Parameters:
      namespace - The IRI's namespace.
      localName - The IRI's local name.

    • createBNode

      public BNode createBNode(String nodeID)
      Description copied from interface: ValueFactory
      Creates a new blank node with the given node identifier.
      Specified by:
      createBNode in interface ValueFactory
      Overrides:
      createBNode in class AbstractValueFactory
      Parameters:
      nodeID - The blank node identifier.
      Returns:
      An object representing the blank node.

    • createLiteral

      public Literal createLiteral(String value)
      Description copied from interface: ValueFactory
      Creates a new literal with the supplied label. The return value of Literal.getDatatype() for the returned object must be xsd:string.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      value - The literal's label, must not be null.
      Returns:
      A literal for the specified value.

    • createLiteral

      public Literal createLiteral(String value, String language)
      Description copied from interface: ValueFactory
      Creates a new literal with the supplied label and language attribute. The return value of Literal.getDatatype() for the returned object must be rdf:langString.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      value - The literal's label, must not be null.
      language - The literal's language attribute, must not be null.
      Returns:
      A literal for the specified value and language attribute.

    • createLiteral

      public Literal createLiteral(String value, IRI datatype)
      Description copied from interface: ValueFactory
      Creates a new literal with the supplied label and datatype.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      value - The literal's label, must not be null.
      datatype - The literal's datatype. If it is null, the datatype xsd:string will be assigned to this literal.
      Returns:
      A literal for the specified value and type.

    • createLiteral

      public Literal createLiteral(String value, CoreDatatype datatype)
      Description copied from interface: ValueFactory
      Creates a new literal with the supplied label and datatype.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      value - The literal's label, must not be null.
      datatype - The literal's datatype. It may not be null.

    • createLiteral

      public Literal createLiteral(boolean value)
      Description copied from interface: ValueFactory
      Creates a new xsd:boolean-typed literal representing the specified value.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      value - The value for the literal.
      Returns:
      An xsd:boolean-typed literal for the specified value.

    • createLiteral

      public Literal createLiteral(XMLGregorianCalendar calendar)
      Description copied from interface: ValueFactory
      Creates a new literal representing the specified calendar that is typed using the appropriate XML Schema date/time datatype.
      Specified by:
      createLiteral in interface ValueFactory
      Overrides:
      createLiteral in class AbstractValueFactory
      Parameters:
      calendar - The value for the literal.
      Returns:
      A typed literal for the specified calendar.