MergeDataSource Class Reference

A DataSource that presents an RDF merge of multiple other data sources. More...

Inheritance diagram for MergeDataSource:

Collaboration diagram for MergeDataSource:

Public Member Functions
	MergeDataSource (DataSource... sources)
	MergeDataSource (Collection< DataSource > sources)
	MergeDataSource (Collection< DataSource > sources, PrefixMapping mustHavePrefixes)
boolean	canDescribe (String absoluteIRI)
	Indicates whether this data source may have some information about a given IRI. More...
Model	describeResource (String iri, String language)
	Returns a subgraph of the data source describing one resource. More...
Model	describeResource (String iri)
	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)
	Returns a subgraph of the data source. 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 Collection< DataSource >	sources

Static Public Attributes
static final int	MAX_INDEX_SIZE = 1000000

Package Functions
private< K > Map< K, Integer >	addIntegerMaps (Map< K, Integer > map1, Map< K, Integer > map2)

Private Attributes
final PrefixMapping	mustHavePrefixes

Detailed Description

A DataSource that presents an RDF merge of multiple other data sources.

Can also be initialized with a prefix mapping that will be guaranteed to be defined on all result models.

Constructor & Destructor Documentation

MergeDataSource() [1/3]

MergeDataSource

(

DataSource...

sources

)

                                                      {
                this(Arrays.asList(sources));
        }

References MergeDataSource.sources.

MergeDataSource() [2/3]

MergeDataSource

(

Collection< DataSource >

sources

)

                                                               {
                this(sources, new PrefixMappingImpl());
        }

References MergeDataSource.sources.

MergeDataSource() [3/3]

MergeDataSource	(	Collection< DataSource >	sources,
		PrefixMapping	mustHavePrefixes
	)

                                                                                               {
                this.sources = sources;
                this.mustHavePrefixes = mustHavePrefixes;
        }

References MergeDataSource.mustHavePrefixes, and MergeDataSource.sources.

Member Function Documentation

addIntegerMaps()

private<K> Map<K, Integer> addIntegerMaps ( Map< K, Integer >  map1, Map< K, Integer >  map2  )

package

                                                                                               {
                if (map1 == null) return map2;
                if (map2 == null) return map1;
                for (K key: map2.keySet()) {
                        int value = map2.get(key);
                        if (value == 0) continue;
                        map1.put(key, map1.containsKey(key) ? map1.get(key) + value : value);
                }
                return map1;
        }

Referenced by MergeDataSource.getHighIndegreeProperties(), and MergeDataSource.getHighOutdegreeProperties().

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.

                                                       {
                for (DataSource source: sources) {
                        if (source.canDescribe(absoluteIRI)) return true;
                }
                return false;
        }

References MergeDataSource.sources.

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.

                                                  {
                Model result = ModelFactory.createDefaultModel();
                for (DataSource source: sources) {
                        if (!source.canDescribe(iri)) continue;
                        ModelUtil.mergeModels(result, source.describeResource(iri));
                }
                // Remove any other prefixes that may already be defined for the must-have namespaces
                for (String prefix: mustHavePrefixes.getNsPrefixMap().keySet()) {
                        String ns = mustHavePrefixes.getNsPrefixURI(prefix);
                        while (result.getNsURIPrefix(ns) != null) {
                                result.removeNsPrefix(result.getNsURIPrefix(ns));
                        }
                }
                // Set all the must-have prefix/namespace pairs
                ModelUtil.mergePrefixes(result, mustHavePrefixes);
                return result;
        }

References ModelUtil.mergeModels(), ModelUtil.mergePrefixes(), MergeDataSource.mustHavePrefixes, and MergeDataSource.sources.

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.

                                                                  {
                Model result = ModelFactory.createDefaultModel();
                for (DataSource source: sources) {
                        if (!source.canDescribe(iri)) continue;
                        ModelUtil.mergeModels(result, source.describeResource(iri,language));
                }
                // Remove any other prefixes that may already be defined for the must-have namespaces
                for (String prefix: mustHavePrefixes.getNsPrefixMap().keySet()) {
                        String ns = mustHavePrefixes.getNsPrefixURI(prefix);
                        while (result.getNsURIPrefix(ns) != null) {
                                result.removeNsPrefix(result.getNsURIPrefix(ns));
                        }
                }
                // Set all the must-have prefix/namespace pairs
                ModelUtil.mergePrefixes(result, mustHavePrefixes);
                return result;
        }

References ModelUtil.mergeModels(), ModelUtil.mergePrefixes(), MergeDataSource.mustHavePrefixes, and MergeDataSource.sources.

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.

                                                                                    {
                Map<Property, Integer> result = new HashMap<Property, Integer>();
                for (DataSource source: sources) {
                        result = addIntegerMaps(result, 
                                        source.getHighIndegreeProperties(resourceIRI));
                }
                return result;
        }

References MergeDataSource.addIntegerMaps(), and MergeDataSource.sources.

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.

                                                                                     {
                Map<Property, Integer> result = new HashMap<Property, Integer>();
                for (DataSource source: sources) {
                        result = addIntegerMaps(result, 
                                        source.getHighOutdegreeProperties(resourceIRI));
                }
                return result;
        }

References MergeDataSource.addIntegerMaps(), and MergeDataSource.sources.

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.

                                         {
                List<Resource> result = new ArrayList<Resource>();
                for (DataSource source: sources) {
                        System.out.println(source);
                        result.addAll(source.getIndex());
                }
                return result;
        }

References MergeDataSource.sources.

getLabelIndex()

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

(

)

Implements DataSource.

                                                                                              {
                System.out.println("MergeDataSource: GetLabelIndex()");
                for(DataSource ds:sources) {
                        ds.getLabelIndex();
                }
                return SearchIndexInstance.getInstance();
        }

References SearchIndexInstance.getInstance(), and MergeDataSource.sources.

listPropertyValues()

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

Returns a subgraph of the data source.

It lists the values of a particular property of a particular resource. Where values are blank nodes, a complete description of these anonymous resources must be included.

Parameters

resourceIRI	The resource to be examined
property	The property we're interested in
isInverse	Are we interested in outgoing arcs (false) or incoming (true)?

Returns

A subgraph of the data source.

Implements DataSource.

                                           {
                Model result = ModelFactory.createDefaultModel();
                for (DataSource source: sources) {
                        ModelUtil.mergeModels(result, 
                                        source.listPropertyValues(resourceIRI, property, isInverse));
                }
                ModelUtil.mergePrefixes(result, mustHavePrefixes);
                return result;
        }

References ModelUtil.mergeModels(), ModelUtil.mergePrefixes(), MergeDataSource.mustHavePrefixes, and MergeDataSource.sources.

Member Data Documentation

MAX_INDEX_SIZE

final int MAX_INDEX_SIZE = 1000000

staticinherited

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

mustHavePrefixes

final PrefixMapping mustHavePrefixes

private

Referenced by MergeDataSource.describeResource(), MergeDataSource.listPropertyValues(), and MergeDataSource.MergeDataSource().

sources

final Collection<DataSource> sources

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