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

Class FRuleEngine

java.lang.Object
org.apache.jena.reasoner.rulesys.impl.FRuleEngine
All Implemented Interfaces:
FRuleEngineI
public class FRuleEngine extends Object implements FRuleEngineI
The processing engine for forward production rules. It needs to reference an enclosing ForwardInfGraphI which holds the raw data and deductions.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    FRuleEngine.RuleStore
    Structure used to wrap up processed rule indexes.

  • Constructor Summary

    Constructors
    Constructor
    Description
    FRuleEngine(ForwardRuleInfGraphI parent)
    Constructor.
    FRuleEngine(ForwardRuleInfGraphI parent, List<Rule> rules)
    Constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(Triple t)
    Add one triple to the data graph, run any rules triggered by the new data item, recursively adding any generated triples.
    void
    addSet(BFRuleContext context)
    Add a set of new triple to the data graph, run any rules triggered by the new data item, recursively adding any generated triples.
    void
    compile(List<Rule> rules, boolean ignoreBrules)
    Compile a list of rules into the internal rule store representation.
    boolean
    delete(Triple t)
    Remove one triple to the data graph.
    void
    fastInit(Finder inserts)
    Process all available data.
    long
    getNRulesFired()
    Return the number of rules fired since this rule engine instance was created and initialized
    Object
    getRuleStore()
    Access the precomputed internal rule form.
    void
    init(boolean ignoreBrules, Finder inserts)
    Process all available data.
    static boolean
    match(Node pattern, Node node, BindingStack env)
    Test if a pattern Node matches a Triple Node in the given binding environment.
    static boolean
    match(TriplePattern pattern, Triple triple, BindingStack env)
    Test if a TriplePattern matches a Triple in the given binding environment.
    static int
    scoreNodeBoundness(Node n, BindingEnvironment env)
    Score a Node in terms of groundedness - heuristic.
    void
    setDerivationLogging(boolean recordDerivations)
    Set to true to enable derivation caching
    void
    setRuleStore(Object ruleStore)
    Set the internal rule from a precomputed state.
    boolean
    shouldTrace()
    Return true if the internal engine state means that tracing is worthwhile.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • FRuleEngine

      public FRuleEngine(ForwardRuleInfGraphI parent, List<Rule> rules)
      Constructor.
      Parameters:
      parent - the F or FB infGraph that it using this engine, the parent graph holds the deductions graph and source data.
      rules - the rule set to be processed

    • FRuleEngine

      public FRuleEngine(ForwardRuleInfGraphI parent)
      Constructor. Build an empty engine to which rules must be added using setRuleStore().
      Parameters:
      parent - the F or FB infGraph that it using this engine, the parent graph holds the deductions graph and source data.

  • Method Details

    • init

      public void init(boolean ignoreBrules, Finder inserts)
      Process all available data. This should be called once a deductions graph has be prepared and loaded with any precomputed deductions. It will process the rule axioms and all relevant existing exiting data entries.
      Specified by:
      init in interface FRuleEngineI
      Parameters:
      ignoreBrules - set to true if rules written in backward notation should be ignored
      inserts - the set of triples to be processed, normally this is the raw data graph but may include additional deductions made by preprocessing hooks

    • fastInit

      public void fastInit(Finder inserts)
      Process all available data. This version expects that all the axioms have already be preprocessed and the clause index already exists.
      Specified by:
      fastInit in interface FRuleEngineI
      Parameters:
      inserts - the set of triples to be processed, normally this is the raw data graph but may include additional deductions made by preprocessing hooks

    • add

      public void add(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:
      add in interface FRuleEngineI

    • delete

      public boolean delete(Triple t)
      Remove one triple to the data graph.
      Specified by:
      delete in interface FRuleEngineI
      Returns:
      true if the effects could be correctly propagated or false if not (in which case the entire engine should be restarted).

    • getNRulesFired

      public long getNRulesFired()
      Return the number of rules fired since this rule engine instance was created and initialized
      Specified by:
      getNRulesFired in interface FRuleEngineI

    • shouldTrace

      public boolean shouldTrace()
      Return true if the internal engine state means that tracing is worthwhile. It will return false during the axiom bootstrap phase.
      Specified by:
      shouldTrace in interface FRuleEngineI

    • setDerivationLogging

      public void setDerivationLogging(boolean recordDerivations)
      Set to true to enable derivation caching
      Specified by:
      setDerivationLogging in interface FRuleEngineI

    • getRuleStore

      public Object getRuleStore()
      Access the precomputed internal rule form. Used when precomputing the internal axiom closures.
      Specified by:
      getRuleStore in interface FRuleEngineI

    • setRuleStore

      public void setRuleStore(Object ruleStore)
      Set the internal rule from a precomputed state.
      Specified by:
      setRuleStore in interface FRuleEngineI

    • addSet

      public void addSet(BFRuleContext context)
      Add a set of new triple to the data graph, run any rules triggered by the new data item, recursively adding any generated triples. Technically the triples having been physically added to either the base or deduction graphs and the job of this function is just to process the stack of additions firing any relevant rules.
      Parameters:
      context - a context containing a set of new triples to be added

    • compile

      public void compile(List<Rule> rules, boolean ignoreBrules)
      Compile a list of rules into the internal rule store representation.
      Parameters:
      rules - the list of Rule objects
      ignoreBrules - set to true if rules written in backward notation should be ignored

    • scoreNodeBoundness

      public static int scoreNodeBoundness(Node n, BindingEnvironment env)
      Score a Node in terms of groundedness - heuristic. Treats a variable as better than a wildcard because it constrains later clauses. Treats rdf:type as worse than any other ground node because that tends to link to lots of expensive rules.

    • match

      public static boolean match(TriplePattern pattern, Triple triple, BindingStack env)
      Test if a TriplePattern matches a Triple in the given binding environment. If it does then the binding environment is modified the reflect any additional bindings.
      Returns:
      true if the pattern matches the triple

    • match

      public static boolean match(Node pattern, Node node, BindingStack env)
      Test if a pattern Node matches a Triple Node in the given binding environment. If it does then the binding environment is modified the reflect any additional bindings.
      Returns:
      true if the pattern matches the node