/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.reasoner.rulesys;
import java.util.*;
import org.apache.jena.graph.* ;
import org.apache.jena.reasoner.* ;
import org.apache.jena.reasoner.rulesys.impl.OWLRuleTranslationHook ;
import org.apache.jena.shared.impl.JenaParameters ;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A hybrid forward/backward implementation of the OWL closure rules.
*/
public class OWLFBRuleReasoner extends FBRuleReasoner {
/** The location of the OWL rule definitions on the class path */
protected static final String RULE_FILE = "etc/owl-fb.rules";
/** The parsed rules */
protected static List<Rule> ruleSet;
/** The precomputed axiom closure and compiled rule set */
protected static FBRuleInfGraph staticPreload;
protected static Logger logger = LoggerFactory.getLogger(OWLFBRuleReasoner.class);
/**
* Constructor
*/
public OWLFBRuleReasoner(ReasonerFactory factory) {
super(loadRules(), factory);
}
/**
* Internal constructor, used to generated a partial binding of a schema
* to a rule reasoner instance.
*/
private OWLFBRuleReasoner(OWLFBRuleReasoner parent, InfGraph schemaGraph) {
super(parent.rules, schemaGraph, parent.factory);
}
/**
* Return the rule set, loading it in if necessary
*/
public static List<Rule> loadRules() {
if (ruleSet == null) ruleSet = loadRules( RULE_FILE );
return ruleSet;
}
/**
* Precompute the implications of a schema graph. The statements in the graph
* will be combined with the data when the final InfGraph is created.
*/
@Override
public Reasoner bindSchema(Graph tbox) throws ReasonerException {
checkArgGraph(tbox);
if (schemaGraph != null) {
throw new ReasonerException("Can only bind one schema at a time to an OWLRuleReasoner");
}
FBRuleInfGraph graph = new FBRuleInfGraph(this, rules, getPreload(), tbox);
graph.addPreprocessingHook(new OWLRuleTranslationHook());
graph.prepare();
return new OWLFBRuleReasoner(this, graph);
}
/**
* Attach the reasoner to a set of RDF data to process.
* The reasoner may already have been bound to specific rules or ontology
* axioms (encoded in RDF) through earlier bindRuleset calls.
*
* @param data the RDF data to be processed, some reasoners may restrict
* the range of RDF which is legal here (e.g. syntactic restrictions in OWL).
* @return an inference graph through which the data+reasoner can be queried.
* @throws ReasonerException if the data is ill-formed according to the
* constraints imposed by this reasoner.
*/
@Override
public InfGraph bind(Graph data) throws ReasonerException {
checkArgGraph(data);
FBRuleInfGraph graph = null;
InfGraph schemaArg = schemaGraph == null ? getPreload() : (FBRuleInfGraph)schemaGraph;
List<Rule> baseRules = ((FBRuleInfGraph)schemaArg).getRules();
graph = new FBRuleInfGraph(this, baseRules, schemaArg);
graph.addPreprocessingHook(new OWLRuleTranslationHook());
graph.setDerivationLogging(recordDerivations);
graph.setTraceOn(traceOn);
graph.rebind(data);
graph.setDatatypeRangeValidation(true);
return graph;
}
/**
* Get the single static precomputed rule closure.
*/
@Override
public synchronized InfGraph getPreload() {
// Method synchronized - synchronize with other FBRulereasoer sync methods
// synchronized block - sync on static
synchronized (OWLFBRuleReasoner.class) {
if (staticPreload == null) {
boolean prior = JenaParameters.enableFilteringOfHiddenInfNodes;
try {
JenaParameters.enableFilteringOfHiddenInfNodes = true;
staticPreload = new FBRuleInfGraph(this, rules, null);
staticPreload.prepare();
} finally {
JenaParameters.enableFilteringOfHiddenInfNodes = prior;
}
}
return staticPreload;
}
}
/**
* Check an argument graph to make sure it is not an OWL rule graph
* already and if so log a warning message.
*/
private void checkArgGraph(Graph g) {
if (JenaParameters.enableOWLRuleOverOWLRuleWarnings) {
if (g instanceof InfGraph) {
if (((InfGraph)g).getReasoner() instanceof OWLFBRuleReasoner) {
logger.warn("Creating OWL rule reasoner working over another OWL rule reasoner");
}
}
}
}
}