| /* |
| * 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.rya.indexing.entity; |
| |
| import static java.util.Objects.requireNonNull; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| |
| import org.apache.rya.api.domain.RyaURI; |
| import org.apache.rya.indexing.entity.model.Entity; |
| import org.apache.rya.indexing.entity.model.Type; |
| import org.apache.rya.indexing.entity.query.EntityQueryNode; |
| import org.apache.rya.indexing.entity.storage.EntityStorage; |
| import org.apache.rya.indexing.entity.storage.TypeStorage; |
| import org.apache.rya.indexing.entity.storage.TypeStorage.TypeStorageException; |
| import org.apache.rya.indexing.external.matching.ExternalSetProvider; |
| import org.apache.rya.indexing.external.matching.QuerySegment; |
| import org.eclipse.rdf4j.model.ValueFactory; |
| import org.eclipse.rdf4j.model.impl.SimpleValueFactory; |
| import org.eclipse.rdf4j.model.vocabulary.RDF; |
| import org.eclipse.rdf4j.query.algebra.QueryModelNode; |
| import org.eclipse.rdf4j.query.algebra.StatementPattern; |
| import org.eclipse.rdf4j.query.algebra.Var; |
| |
| import com.google.common.collect.HashMultimap; |
| import com.google.common.collect.Multimap; |
| |
| /** |
| * Provides {@link EntityQueryNodes}s. |
| */ |
| public class EntityIndexSetProvider implements ExternalSetProvider<EntityQueryNode> { |
| private static final ValueFactory VF = SimpleValueFactory.getInstance(); |
| private Multimap<Type, StatementPattern> typeMap; |
| private Map<String, Type> subjectTypeMap; |
| private final TypeStorage typeStorage; |
| private final EntityStorage entityStorage; |
| |
| /** |
| * Creates a new {@link EntityIndexSetProvider}. |
| * @param typeStorage - The mechanism for access the various {@link Type}s. (not null) |
| * @param entityStorage - The mechanism for access to the various {@link Entity}s. (not null) |
| */ |
| public EntityIndexSetProvider(final TypeStorage typeStorage, final EntityStorage entityStorage) { |
| this.typeStorage = requireNonNull(typeStorage); |
| this.entityStorage = requireNonNull(entityStorage); |
| } |
| |
| private Var getTypeSubject(final Type type) { |
| //we just need the first pattern since all the patterns in this type map are the same subject |
| final StatementPattern pattern = typeMap.get(type).iterator().next(); |
| return pattern.getSubjectVar(); |
| } |
| |
| private RyaURI getPredURI(final StatementPattern pattern) { |
| final Var pred = pattern.getPredicateVar(); |
| return new RyaURI(pred.getValue().stringValue()); |
| } |
| |
| @Override |
| public List<EntityQueryNode> getExternalSets(final QuerySegment<EntityQueryNode> node) { |
| typeMap = HashMultimap.create(); |
| subjectTypeMap = new HashMap<>(); |
| |
| //discover entities |
| final List<StatementPattern> unused = new ArrayList<>(); |
| for (final QueryModelNode pattern : node.getOrderedNodes()) { |
| if(pattern instanceof StatementPattern) { |
| discoverEntities((StatementPattern) pattern, unused); |
| } |
| } |
| |
| final List<EntityQueryNode> nodes = new ArrayList<>(); |
| for(final Type type : typeMap.keySet()) { |
| //replace all nodes in the tupleExpr of the collection of statement patterns with this node. |
| final EntityQueryNode entity = new EntityQueryNode(type, typeMap.get(type), entityStorage); |
| nodes.add(entity); |
| } |
| return nodes; |
| } |
| |
| private void discoverEntities(final StatementPattern pattern, final List<StatementPattern> unmatched) { |
| final Var subj = pattern.getSubjectVar(); |
| final String subjStr = subj.getName(); |
| final RyaURI predURI = getPredURI(pattern); |
| //check to see if current node is type |
| if(VF.createIRI(predURI.getData()).equals(RDF.TYPE)) { |
| final Var obj = pattern.getObjectVar(); |
| final RyaURI objURI = new RyaURI(obj.getValue().stringValue()); |
| try { |
| final Optional<Type> optType = typeStorage.get(objURI); |
| //if is type, fetch type add to subject -> type map |
| if(optType.isPresent()) { |
| final Type type = optType.get(); |
| typeMap.put(type, pattern); |
| subjectTypeMap.put(subjStr, type); |
| //check unmatched properties, add matches |
| for(final StatementPattern propertyPattern : unmatched) { |
| //store sps into the type -> property map |
| final RyaURI property = getPredURI(propertyPattern); |
| final Var typeSubVar = getTypeSubject(type); |
| final Var patternSubVar = propertyPattern.getSubjectVar(); |
| if (type.getPropertyNames().contains(property) && typeSubVar.equals(patternSubVar)) { |
| typeMap.put(type, propertyPattern); |
| } |
| } |
| } |
| } catch (final TypeStorageException e) { |
| e.printStackTrace(); |
| } |
| } else { |
| //if not type, check to see if subject is in type map |
| if(subjectTypeMap.containsKey(subjStr)) { |
| //if is, check to see if pred is a property of type |
| final Type type = subjectTypeMap.get(subjStr); |
| if(type.getPropertyNames().contains(predURI)) { |
| //if is, add sp to type -> sp map |
| if(!typeMap.containsKey(type)) { |
| //each variable can only contain 1 type for now @see:Rya-235? |
| typeMap.put(type, pattern); |
| } |
| } else { |
| //if not, add to unmatched type |
| unmatched.add(pattern); |
| } |
| } else { |
| //if not, add to unmatched |
| unmatched.add(pattern); |
| } |
| } |
| } |
| |
| @Override |
| public Iterator<List<EntityQueryNode>> getExternalSetCombos(final QuerySegment<EntityQueryNode> segment) { |
| final List<List<EntityQueryNode>> comboList = new ArrayList<>(); |
| comboList.add(getExternalSets(segment)); |
| return comboList.iterator(); |
| } |
| } |