IndexDataSource Class Reference

A DataSource that wraps another data source and adds an index of the resources in that data source. More...

Inheritance diagram for IndexDataSource:

Collaboration diagram for IndexDataSource:

Public Member Functions
	IndexDataSource (String indexIRI, DataSource wrapped)
boolean	canDescribe (String absoluteIRI)
	Indicates whether this data source may have some information about a given IRI. More...
Model	describeResource (String iri)
	Returns a subgraph of the data source describing one resource. More...
Model	describeResource (String iri, String language)
	Returns a subgraph of the data source describing one resource. More...
Map< Property, Integer >	getHighIndegreeProperties (String resourceIRI)
	If describeResource(String) omits properties of high indegree, then those properties must be returned here with the count of arcs. More...
Map< Property, Integer >	getHighOutdegreeProperties (String resourceIRI)
	If describeResource(String) omits properties of high outdegree, then those properties must be returned here with the count of arcs. More...
Model	listPropertyValues (String resourceIRI, Property property, boolean isInverse)
	Describe the index resource, and extract all the statements that have our property and the right subject/object. More...
List< Resource >	getIndex ()
	A list of IRI resources described in this data source. More...
de.fuberlin.wiwiss.pubby.util.AutocompleteEngine< SearchRecord >	getLabelIndex ()

Public Attributes
final DataSource	wrapped

Static Public Attributes
static final int	MAX_INDEX_SIZE = 1000000

Private Attributes
final String	indexIRI

Static Private Attributes
static final String	SIOC_NS = "http://rdfs.org/sioc/ns#"
static final Property	siocContainerOf

Detailed Description

A DataSource that wraps another data source and adds an index of the resources in that data source.

Constructor & Destructor Documentation

IndexDataSource()

IndexDataSource	(	String	indexIRI,
		DataSource	wrapped
	)

                                                                    {
                this.indexIRI = indexIRI;
                this.wrapped = wrapped;
        }

References IndexDataSource.indexIRI, and IndexDataSource.wrapped.

Member Function Documentation

canDescribe()

boolean canDescribe

(

String

absoluteIRI

)

Indicates whether this data source may have some information about a given IRI.

If this is false, a client should not bother to call describeResource(String). This method is to allow for optimizations and should respond very fast.

It is also used by the UI to decide whether a click on a resource should go to a Pubby page (if true) or out to the Web (if false).

Parameters

absoluteIRI

The IRI of a resource to be described

Returns

true if this data source might have something about it

Implements DataSource.

                                                       {
                return indexIRI.equals(absoluteIRI) || wrapped.canDescribe(absoluteIRI);
        }

References DataSource.canDescribe(), IndexDataSource.indexIRI, and IndexDataSource.wrapped.

describeResource() [1/2]

Model describeResource

(

String

absoluteIRI

)

Returns a subgraph of the data source describing one resource.

This should include both incoming and outgoing triples. However, it should exclude outgoing arcs where the property is a high-outdegree property, and it should exclude incoming arcs where the property is a high-indegree property. If labels for other resources are included in the result, then they will be used.

Parameters

absoluteIRI

The IRI of the resource to be described

Returns

A subgraph of the data source describing the resource.

Implements DataSource.

                                                  {
                if (!indexIRI.equals(iri)) return wrapped.describeResource(iri);
                Model result = ModelFactory.createDefaultModel();
                result.setNsPrefix("sioc", SIOC_NS);
                result.setNsPrefix("rdfs", RDFS.getURI());
                Resource index = result.createResource(indexIRI);
                // TODO: Get label from the vocabulary store, and make it i18nable
                index.addProperty(RDFS.label, "Index of Resources", "en");
                for (Resource r: wrapped.getIndex()) {
                        index.addProperty(siocContainerOf, r);
                }
                return result;
        }

References DataSource.describeResource(), DataSource.getIndex(), IndexDataSource.indexIRI, IndexDataSource.SIOC_NS, IndexDataSource.siocContainerOf, and IndexDataSource.wrapped.

Referenced by IndexDataSource.listPropertyValues().

describeResource() [2/2]

Model describeResource	(	String	absoluteIRI,
		String	language
	)

Returns a subgraph of the data source describing one resource.

This should include both incoming and outgoing triples. However, it should exclude outgoing arcs where the property is a high-outdegree property, and it should exclude incoming arcs where the property is a high-indegree property. If labels for other resources are included in the result, then they will be used.

Parameters

absoluteIRI

The IRI of the resource to be described

Returns

A subgraph of the data source describing the resource.

Implements DataSource.

                                                                  {
                if (!indexIRI.equals(iri)) return wrapped.describeResource(iri);
                Model result = ModelFactory.createDefaultModel();
                result.setNsPrefix("sioc", SIOC_NS);
                result.setNsPrefix("rdfs", RDFS.getURI());
                Resource index = result.createResource(indexIRI);
                // TODO: Get label from the vocabulary store, and make it i18nable
                index.addProperty(RDFS.label, "Index of Resources", language);
                for (Resource r: wrapped.getIndex()) {
                        index.addProperty(siocContainerOf, r);
                }
                return result;
        }

References DataSource.describeResource(), DataSource.getIndex(), IndexDataSource.indexIRI, IndexDataSource.SIOC_NS, IndexDataSource.siocContainerOf, and IndexDataSource.wrapped.

getHighIndegreeProperties()

Map<Property, Integer> getHighIndegreeProperties

(

String

resourceIRI

)

If describeResource(String) omits properties of high indegree, then those properties must be returned here with the count of arcs.

If high-indegree properties are not omitted, or the resource doesn't have any, then an empty map or null may be returned. Entries with value 0 will be ignored.

Parameters

resourceIRI

The IRI of the resource to be described

Returns

A map containing high-indegree properties with number of arcs for the resource

Implements DataSource.

                                                                                    {
                return wrapped.getHighIndegreeProperties(resourceIRI);
        }

References DataSource.getHighIndegreeProperties(), and IndexDataSource.wrapped.

getHighOutdegreeProperties()

Map<Property, Integer> getHighOutdegreeProperties

(

String

resourceIRI

)

If describeResource(String) omits properties of high outdegree, then those properties must be returned here with the count of arcs.

If high-outdegree properties are not omitted, or the resource doesn't have any, then an empty map or null may be returned. Entries with value 0 will be ignored.

Parameters

resourceIRI

The IRI of the resource to be described

Returns

A map containing high-outdegree properties with number of arcs for the resource

Implements DataSource.

                                                                                     {
                return wrapped.getHighOutdegreeProperties(resourceIRI);
        }

References DataSource.getHighOutdegreeProperties(), and IndexDataSource.wrapped.

getIndex()

List<Resource> getIndex

(

)

A list of IRI resources described in this data source.

Ordering is implementation-defined. Usually a reasonable limit should be applied to the number of resources returned.

Implements DataSource.

                                         {
                // We could add the indexIRI as an additional resource here, but we
                // don't want it to show up in the list of resources generated in
                // describeResource(), and we don't want it turn an otherwise
                // empty dataset into a non-empty one. 
                return wrapped.getIndex();
        }

References DataSource.getIndex(), and IndexDataSource.wrapped.

getLabelIndex()

de.fuberlin.wiwiss.pubby.util.AutocompleteEngine<SearchRecord> getLabelIndex

(

)

Implements DataSource.

                                                                                              {
                System.out.println("IndexDataSource: GetLabelIndex()");
                return wrapped.getLabelIndex();
        }

References DataSource.getLabelIndex(), and IndexDataSource.wrapped.

listPropertyValues()

Model listPropertyValues	(	String	resourceIRI,
		Property	property,
		boolean	isInverse
	)

Describe the index resource, and extract all the statements that have our property and the right subject/object.

Implements DataSource.

                                                              {
                if (!indexIRI.equals(resourceIRI)) {
                        return wrapped.listPropertyValues(resourceIRI, property, isInverse);
                }
                Model all = describeResource(resourceIRI);
                Resource r = all.getResource(resourceIRI);
                StmtIterator it = isInverse
                                ? all.listStatements(null, property, r)
                                : all.listStatements(r, property, (RDFNode) null);
                Model result = ModelFactory.createDefaultModel();
                while (it.hasNext()) {
                        result.add(it.next());
                }
                return result;
        }

References IndexDataSource.describeResource(), IndexDataSource.indexIRI, DataSource.listPropertyValues(), and IndexDataSource.wrapped.

Member Data Documentation

indexIRI

final String indexIRI

private

Referenced by IndexDataSource.canDescribe(), IndexDataSource.describeResource(), IndexDataSource.IndexDataSource(), and IndexDataSource.listPropertyValues().

MAX_INDEX_SIZE

final int MAX_INDEX_SIZE = 1000000

staticinherited

Referenced by ModelDataSource.getIndex(), RemoteSPARQLDataSource.getIndex(), ModelDataSource.getLabelIndex(), and RemoteSPARQLDataSource.getLabelIndex().

SIOC_NS

final String SIOC_NS = "http://rdfs.org/sioc/ns#"

staticprivate

Referenced by IndexDataSource.describeResource().

siocContainerOf

final Property siocContainerOf

staticprivate

Initial value:

= 
                        ResourceFactory.createProperty(SIOC_NS + "container_of")

Referenced by IndexDataSource.describeResource().

wrapped

final DataSource wrapped

Referenced by IndexDataSource.canDescribe(), IndexDataSource.describeResource(), IndexDataSource.getHighIndegreeProperties(), IndexDataSource.getHighOutdegreeProperties(), IndexDataSource.getIndex(), IndexDataSource.getLabelIndex(), IndexDataSource.IndexDataSource(), and IndexDataSource.listPropertyValues().