Module org.apache.jena.core
Package org.apache.jena.reasoner.rulesys

Class LPBackwardRuleInfGraph

java.lang.Object
org.apache.jena.graph.impl.GraphBase
org.apache.jena.reasoner.BaseInfGraph
org.apache.jena.reasoner.rulesys.LPBackwardRuleInfGraph
All Implemented Interfaces:
Graph, GraphWithPerform, InfGraph, BackwardRuleInfGraphI, SilentAddI
public class LPBackwardRuleInfGraph extends BaseInfGraph implements BackwardRuleInfGraphI
Inference graph for accessing the LP version of the backward chaining rule engine.

  • Constructor Details

    • LPBackwardRuleInfGraph

      public LPBackwardRuleInfGraph(Reasoner reasoner, LPRuleStore ruleStore, Graph data, Graph schema)
      Constructor. Create a new backward inference graph to process the given data. The parent reasoner supplies the ruleset and any additional schema graph.
      Parameters:
      reasoner - the parent reasoner
      ruleStore - the indexed set of rules to use
      data - the data graph to be processed
      schema - optional precached schema (use null if not required)

  • Method Details

    • getSchemaGraph

      public Graph getSchemaGraph()
      Return the schema graph, if any, bound into this inference graph.
      Specified by:
      getSchemaGraph in class BaseInfGraph

    • 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 preparation is done.
      Specified by:
      prepare in interface InfGraph
      Overrides:
      prepare in class BaseInfGraph

    • 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
      Overrides:
      rebind in class BaseInfGraph
      Parameters:
      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
      Overrides:
      rebind in class BaseInfGraph

    • reset

      public void reset()
      Flush out all cached results. Future queries have to start from scratch.
      Specified by:
      reset in interface InfGraph
      Overrides:
      reset in class BaseInfGraph

    • findWithContinuation

      public 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.
      Specified by:
      findWithContinuation in class BaseInfGraph
      Parameters:
      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.

    • graphBaseFind

      public ExtendedIterator<Triple> graphBaseFind(Node subject, Node property, Node object)
      Returns an iterator over Triples. This implementation assumes that the underlying findWithContinuation will have also consulted the raw data.

    • 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.
      Overrides:
      find in class BaseInfGraph
      Parameters:
      pattern - a TriplePattern to be matched against the data
      Returns:
      a ExtendedIterator over all Triples in the data set that match the pattern

    • 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
      Overrides:
      performAdd in class BaseInfGraph

    • 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
      Overrides:
      performDelete in class BaseInfGraph

    • setTabled

      public void setTabled(Node predicate)
      Set a predicate to be tabled/memoized by the LP engine.

    • setDerivationLogging

      public void setDerivationLogging(boolean recordDerivations)
      Set to true to enable derivation caching
      Specified by:
      setDerivationLogging in interface InfGraph
      Overrides:
      setDerivationLogging in class BaseInfGraph

    • getDerivation

      public Iterator<Derivation> getDerivation(Triple t)
      Return the derivation of at triple. The derivation is a List of DerivationRecords
      Specified by:
      getDerivation in interface InfGraph
      Overrides:
      getDerivation in class BaseInfGraph
      Returns:
      an iterator over Derivation records or null if there is no derivation information available for this triple.

    • setTraceOn

      public void setTraceOn(boolean state)
      Set the state of the trace flag. If set to true then rule firings are logged out to the Log at "INFO" level.

    • isTraceOn

      public boolean isTraceOn()
      Return true if tracing is switched on

    • logDerivation

      public void logDerivation(Triple t, Derivation derivation)
      Log a derivation record against the given triple.
      Specified by:
      logDerivation in interface BackwardRuleInfGraphI

    • findDataMatches

      public ExtendedIterator<Triple> findDataMatches(TriplePattern pattern)
      Match a pattern just against the stored data (raw data, schema, axioms) but no derivation.
      Specified by:
      findDataMatches in interface BackwardRuleInfGraphI

    • processBuiltin

      public boolean processBuiltin(ClauseEntry clause, Rule rule, BindingEnvironment env)
      Process a call to a builtin predicate
      Specified by:
      processBuiltin in interface BackwardRuleInfGraphI
      Parameters:
      clause - the Functor representing the call
      env - the BindingEnvironment for this call
      rule - the rule which is invoking this call
      Returns:
      true if the predicate succeeds

    • silentAdd

      public void silentAdd(Triple t)
      Assert a new triple in the deduction graph, bypassing any processing machinery.
      Specified by:
      silentAdd in interface SilentAddI

    • getTemp

      public Node getTemp(Node instance, Node prop, Node pclass)
      Retrieve or create a bNode representing an inferred property value.
      Specified by:
      getTemp in interface BackwardRuleInfGraphI
      Parameters:
      instance - the base instance node to which the property applies
      prop - the property node whose value is being inferred
      pclass - the (optional, can be null) class for the inferred value.
      Returns:
      the bNode representing the property value