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

Class BasicForwardRuleInfGraph

java.lang.Object
org.apache.jena.graph.impl.GraphBase
org.apache.jena.reasoner.BaseInfGraph
org.apache.jena.reasoner.rulesys.BasicForwardRuleInfGraph
All Implemented Interfaces:
Graph, GraphWithPerform, InfGraph, ForwardRuleInfGraphI, SilentAddI
Direct Known Subclasses:
FBRuleInfGraph, RETERuleInfGraph
public class BasicForwardRuleInfGraph extends BaseInfGraph implements ForwardRuleInfGraphI
An inference graph interface that runs a set of forward chaining rules to conclusion on each added triple and stores the entire result set.

This implementation has a horribly inefficient rule chainer built in. Once we have this working generalize this to an interface than can call out to a rule engine and build a real rule engine (e.g. Rete style).

  • Field Details

    • filterFunctors

      public boolean filterFunctors
      Flag, if true then find results will be filtered to remove functors and illegal RDF

  • Constructor Details

    • BasicForwardRuleInfGraph

      public BasicForwardRuleInfGraph(Reasoner reasoner, Graph schema)
      Constructor. Creates a new inference graph to which a (compiled) rule set and a data graph can be attached. This separation of binding is useful to allow any configuration parameters (such as logging) to be set before the data is added. Note that until the data is added using rebind then any operations like add, remove, find will result in errors.
      Parameters:
      reasoner - the parent reasoner
      schema - the (optional) schema data which is being processed

    • BasicForwardRuleInfGraph

      public BasicForwardRuleInfGraph(Reasoner reasoner, List<Rule> rules, Graph schema)
      Constructor. Creates a new inference graph based on the given rule set. No data graph is attached at this stage. This is to allow any configuration parameters (such as logging) to be set before the data is added. Note that until the data is added using rebind then any operations like add, remove, find will result in errors.
      Parameters:
      reasoner - the parent reasoner
      rules - the list of rules to use this time
      schema - the (optional) schema or preload data which is being processed

    • BasicForwardRuleInfGraph

      public BasicForwardRuleInfGraph(Reasoner reasoner, List<Rule> rules, Graph schema, Graph data)
      Constructor. Creates a new inference graph based on the given rule set then processes the initial data graph. No precomputed deductions are loaded.
      Parameters:
      reasoner - the parent reasoner
      rules - the list of rules to use this time
      schema - the (optional) schema or preload data which is being processed
      data - the data graph to be processed

  • Method Details

    • setRuleStore

      public void setRuleStore(Object ruleStore)
      Attach a compiled rule set to this inference graph.
      Parameters:
      ruleStore - a compiled set of rules (i.e. the result of an FRuleEngine.compile).

    • 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

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

    • addDeduction

      public void addDeduction(Triple t)
      Add a new deduction to the deductions graph.
      Specified by:
      addDeduction in interface ForwardRuleInfGraphI

    • setFunctorFiltering

      public void setFunctorFiltering(boolean param)
      Set to true to cause functor-valued literals to be dropped from rule output. Default is true.
      Specified by:
      setFunctorFiltering in interface ForwardRuleInfGraphI

    • 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.

    • 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

    • graphBaseSize

      public int graphBaseSize()
      Return the number of triples in the inferred graph
      Overrides:
      graphBaseSize 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

    • close

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

    • addBRule

      public void addBRule(Rule brule)
      Adds a new Backward rule as a rules of a forward rule process. Only some infgraphs support this.
      Specified by:
      addBRule in interface ForwardRuleInfGraphI

    • deleteBRule

      public void deleteBRule(Rule brule)
      Deletes a new Backward rule as a rules of a forward rule process. Only some infgraphs support this.
      Specified by:
      deleteBRule in interface ForwardRuleInfGraphI

    • getDeductionsGraph

      public Graph getDeductionsGraph()
      Return the Graph containing all the static deductions available so far. Will force a prepare.
      Specified by:
      getDeductionsGraph in interface ForwardRuleInfGraphI
      Specified by:
      getDeductionsGraph in interface InfGraph
      Overrides:
      getDeductionsGraph in class BaseInfGraph
      Returns:
      the deductions graph, if relevant for this class of inference engine or null if not.

    • getCurrentDeductionsGraph

      public Graph getCurrentDeductionsGraph()
      Return the Graph containing all the static deductions available so far. Does not trigger a prepare action. Returns a SafeWrapper and so can be used for update (thus triggering listeners) but not for access to generalized triples
      Specified by:
      getCurrentDeductionsGraph in interface ForwardRuleInfGraphI

    • findDataMatches

      public ExtendedIterator<Triple> findDataMatches(Node subject, Node predicate, Node object)
      Search the combination of data and deductions graphs for the given triple pattern. This may different from the normal find operation in the base of hybrid reasoners where we are side-stepping the backward deduction step.
      Specified by:
      findDataMatches in interface ForwardRuleInfGraphI

    • logDerivation

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

    • silentAdd

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

    • setDerivationLogging

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

    • shouldLogDerivations

      public boolean shouldLogDerivations()
      Return true if derivation logging is enabled.
      Specified by:
      shouldLogDerivations in interface ForwardRuleInfGraphI

    • 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.

    • shouldTrace

      public boolean shouldTrace()
      Return true if tracing should be acted on - i.e. if traceOn is true and we are past the bootstrap phase.
      Specified by:
      shouldTrace in interface ForwardRuleInfGraphI

    • getNRulesFired

      public long getNRulesFired()
      Return the number of rules fired since this rule engine instance was created and initialized