Class BaseInfGraph

All Implemented Interfaces:
Graph, GraphWithPerform, InfGraph
Direct Known Subclasses:
BasicForwardRuleInfGraph, LPBackwardRuleInfGraph, TransitiveInfGraph

public abstract class BaseInfGraph extends GraphBase implements InfGraph
A base level implementation of the InfGraph interface.
  • Field Details

    • reasonerInfCapabilities

      public static Capabilities reasonerInfCapabilities
      Capabilities that a reason must conform to. A base graph may also provide handling literal datatypes.
  • Constructor Details

    • BaseInfGraph

      public BaseInfGraph(Graph data, Reasoner reasoner)
      data - the raw data file to be augmented with entailments
      reasoner - the engine, with associated tbox data, whose find interface can be used to extract all entailments from the data.
  • Method Details

    • getPrefixMapping

      public PrefixMapping getPrefixMapping()
      Inference graphs share the prefix-mapping of their underlying raw graph.
      Specified by:
      getPrefixMapping in interface Graph
      getPrefixMapping in class GraphBase
      See Also:
    • getCapabilities

      public Capabilities getCapabilities()
      Answer the InfCapabilities of this InfGraph.
      Specified by:
      getCapabilities in interface Graph
      getCapabilities in class GraphBase
    • remove

      public void remove(Node s, Node p, Node o)
      Description copied from class: GraphBase
      Remove all triples that match by find(s, p, o)
      Specified by:
      remove in interface Graph
      remove in class GraphBase
    • clear

      public void clear()
      Description copied from class: GraphBase
      Remove all the statements from this graph.
      Specified by:
      clear in interface Graph
      clear in class GraphBase
    • getTransactionHandler

      public TransactionHandler getTransactionHandler()
      Description copied from class: GraphBase
      Answer a transaction handler bound to this graph. The default is SimpleTransactionHandler, which handles no transactions.
      Specified by:
      getTransactionHandler in interface Graph
      getTransactionHandler in class GraphBase
    • getRawGraph

      public Graph getRawGraph()
      Return the raw RDF data Graph being processed (i.e. the argument to the Reasonder.bind call that created this InfGraph).
      Specified by:
      getRawGraph in interface InfGraph
    • getReasoner

      public Reasoner getReasoner()
      Return the Reasoner which is being used to answer queries to this graph.
      Specified by:
      getReasoner in interface InfGraph
    • rebind

      public void rebind(Graph data)
      Replace the underlying data graph for this inference graph and start any inferences over again. This is primarily using in setting up ontology imports processing to allow an imports multiunion graph to be inserted between the inference graph and the raw data, before processing.
      Specified by:
      rebind in interface InfGraph
      data - the new raw data graph
    • rebind

      public void rebind()
      Cause the inference graph to reconsult the underlying graph to take into account changes. Normally changes are made through the InfGraph's add and remove calls are will be handled appropriately. However, in some cases changes are made "behind the InfGraph's back" and this forces a full reconsult of the changed data.
      Specified by:
      rebind in interface InfGraph
    • reset

      public void reset()
      Reset any internal caches. Some systems, such as the tabled backchainer, retain information after each query. A reset will wipe this information preventing unbounded memory use at the expense of more expensive future queries. A reset does not cause the raw data to be reconsulted and so is less expensive than a rebind.
      Specified by:
      reset in interface InfGraph
    • prepare

      public void prepare()
      Perform any initial processing and caching. This call is optional. Most engines either have negligable set up work or will perform an implicit "prepare" if necessary. The call is provided for those occasions where substantial preparation work is possible (e.g. running a forward chaining rule system) and where an application might wish greater control over when this prepration is done.
      Specified by:
      prepare in interface InfGraph
    • getDeductionsGraph

      public Graph getDeductionsGraph()
      Returns a derivations graph. The rule reasoners typically create a graph containing those triples added to the base graph due to rule firings. In some applications it can useful to be able to access those deductions directly, without seeing the raw data which triggered them. In particular, this allows the forward rules to be used as if they were rewrite transformation rules.
      Specified by:
      getDeductionsGraph in interface InfGraph
      the deductions graph, if relevant for this class of inference engine or null if not.
    • getGlobalProperty

      public Node getGlobalProperty(Node property)
      Test a global boolean property of the graph. This might included properties like consistency, OWLSyntacticValidity etc. It remains to be seen what level of generality is needed here. We could replace this by a small number of specific tests for common concepts.
      Specified by:
      getGlobalProperty in interface InfGraph
      property - the URI of the property to be tested
      a Node giving the value of the global property, this may be a boolean literal, some other literal value (e.g. a size).
    • testGlobalProperty

      public boolean testGlobalProperty(Node property)
      A convenience version of getGlobalProperty which can only return a boolean result.
      Specified by:
      testGlobalProperty in interface InfGraph
    • validate

      public ValidityReport validate()
      Test the consistency of the bound data. This normally tests the validity of the bound instance data against the bound schema data.
      Specified by:
      validate in interface InfGraph
      a ValidityReport structure
    • find

      public ExtendedIterator<Triple> find(Node subject, Node property, Node object, Graph param)
      An extension of the Graph.find interface which allows the caller to encode complex expressions in RDF and then refer to those expressions within the query triple. For example, one might encode a class expression and then ask if there are any instances of this class expression in the InfGraph.
      Specified by:
      find in interface InfGraph
      subject - the subject Node of the query triple, may be a Node in the graph or a node in the parameter micro-graph or null
      property - the property to be retrieved or null
      object - the object Node of the query triple, may be a Node in the graph or a node in the parameter micro-graph.
      param - a small graph encoding an expression which the subject and/or object nodes refer.
    • findWithContinuation

      public abstract ExtendedIterator<Triple> findWithContinuation(TriplePattern pattern, Finder continuation)
      Extended find interface used in situations where the implementator may or may not be able to answer the complete query. It will attempt to answer the pattern but if its answers are not known to be complete then it will also pass the request on to the nested Finder to append more results.
      pattern - a TriplePattern to be matched against the data
      continuation - either a Finder or a normal Graph which will be asked for additional match results if the implementor may not have completely satisfied the query.
    • find

      public ExtendedIterator<Triple> find(TriplePattern pattern)
      Basic pattern lookup interface. This implementation assumes that the underlying findWithContinuation will have also consulted the raw data.
      pattern - a TriplePattern to be matched against the data
      a ExtendedIterator over all Triples in the data set that match the pattern
    • setDerivationLogging

      public void setDerivationLogging(boolean logOn)
      Switch on/off drivation logging
      Specified by:
      setDerivationLogging in interface InfGraph
    • getDerivation

      public Iterator<Derivation> getDerivation(Triple triple)
      Return the derivation of the given triple (which is the result of some previous find operation). Not all reasoneers will support derivations.
      Specified by:
      getDerivation in interface InfGraph
      an iterator over Derivation records or null if there is no derivation information available for this triple.
    • graphBaseSize

      public int graphBaseSize()
      Return the number of triples in the just the base graph
    • isEmpty

      public boolean isEmpty()
      Answer true iff this graph is empty. [Used to be in QueryHandler, but moved in here because it's a more primitive operation.]
      Specified by:
      isEmpty in interface Graph
      isEmpty in class GraphBase
    • close

      public void close()
      Free all resources, any further use of this Graph is an error.
      Specified by:
      close in interface Graph
      close in class GraphBase
    • getVersion

      public int getVersion()
      Return a version stamp for this graph which can be used to fast-fail concurrent modification exceptions.
    • performAdd

      public void performAdd(Triple t)
      Add one triple to the data graph, run any rules triggered by the new data item, recursively adding any generated triples.
      Specified by:
      performAdd in interface GraphWithPerform
      performAdd in class GraphBase
    • performDelete

      public void performDelete(Triple t)
      Removes the triple t (if possible) from the set belonging to this graph.
      Specified by:
      performDelete in interface GraphWithPerform
      performDelete in class GraphBase
    • getSchemaGraph

      public abstract Graph getSchemaGraph()
      Return the schema graph, if any, bound into this inference graph.
    • cloneWithPremises

      public InfGraph cloneWithPremises(Graph premises)
      Return a new inference graph which is a clone of the current graph together with an additional set of data premises. The default implementation loses ALL partial deductions so far. Some subclasses may be able to a more efficient job.
    • isPrepared

      public boolean isPrepared()
      Answer true iff this graph has been through the prepare() step. For testing purposes.
      Whether the graph is prepared