| package org.apache.rya.indexing.external.matching; |
| /* |
| * 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. |
| */ |
| |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.rya.indexing.external.matching.QueryNodesToTupleExpr.TupleExprAndNodes; |
| import org.apache.rya.indexing.pcj.matching.PCJOptimizerUtilities; |
| import org.eclipse.rdf4j.query.BindingSet; |
| import org.eclipse.rdf4j.query.Dataset; |
| import org.eclipse.rdf4j.query.algebra.BinaryTupleOperator; |
| import org.eclipse.rdf4j.query.algebra.Filter; |
| import org.eclipse.rdf4j.query.algebra.Join; |
| import org.eclipse.rdf4j.query.algebra.LeftJoin; |
| import org.eclipse.rdf4j.query.algebra.QueryModelNode; |
| import org.eclipse.rdf4j.query.algebra.TupleExpr; |
| import org.eclipse.rdf4j.query.algebra.UnaryTupleOperator; |
| import org.eclipse.rdf4j.query.algebra.evaluation.QueryOptimizer; |
| import org.eclipse.rdf4j.query.algebra.evaluation.impl.ExternalSet; |
| import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor; |
| |
| import com.google.common.base.Optional; |
| |
| /** |
| * Abstract base class meant to be extended by any QueryOptimizer that matches ExternalSets |
| * to QueryModelNodes within the parsed query plan. |
| * |
| * @param <T> - ExternalSet parameter |
| */ |
| public abstract class AbstractExternalSetOptimizer<T extends ExternalSet> implements QueryOptimizer { |
| |
| protected boolean useOptimal = false; |
| |
| @Override |
| public void optimize(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings) { |
| QuerySegmentMatchVisitor visitor = new QuerySegmentMatchVisitor(); |
| tupleExpr.visit(visitor); |
| } |
| |
| /** |
| * This visitor navigates query until it reaches either a Join, Filter, or |
| * LeftJoin. Once it reaches this node, it creates the appropriate |
| * ExternalSetMatcher and uses this to match each of the {@link ExternalSet} |
| * s to the {@link QuerySegment} starting with the Join, Filter, or |
| * LeftJoin. Once each ExternalSet has been compared for matching, the |
| * portion of the query starting with the Join, Filter, or LeftJoin is |
| * replaced by the {@link TupleExpr} returned by |
| * {@link ExternalSetMatcher#getQuery()}. This visitor then visits each of |
| * the nodes returned by {@link ExternalSetMatcher#getUnmatchedArgs()}. |
| * |
| */ |
| protected class QuerySegmentMatchVisitor extends AbstractQueryModelVisitor<RuntimeException> { |
| |
| private final QuerySegmentFactory<T> factory = new QuerySegmentFactory<T>(); |
| |
| @Override |
| public void meetNode(QueryModelNode node) { |
| |
| if (checkNode(node)) { |
| QuerySegment<T> segment = factory.getQuerySegment(node); |
| ExternalSetProvider<T> provider = getProvider(); |
| ExternalSetMatcher<T> matcher = getMatcher(segment); |
| QuerySegment<T> tempSeg = null; |
| if(useOptimal) { |
| tempSeg = matcher.match(provider.getExternalSetCombos(segment), getNodeListRater(segment)); |
| } else { |
| tempSeg = matcher.match(provider.getExternalSets(segment)); |
| } |
| |
| TupleExprAndNodes tups = tempSeg.getQuery(); |
| node.replaceWith(tups.getTupleExpr()); |
| Set<TupleExpr> unmatched = getUnMatchedArgNodes(tups.getNodes()); |
| PCJOptimizerUtilities.relocateFilters(tups.getFilters()); |
| |
| for (final TupleExpr tupleExpr : unmatched) { |
| tupleExpr.visit(this); |
| } |
| } else { |
| super.meetNode(node); |
| } |
| } |
| } |
| |
| private Set<TupleExpr> getUnMatchedArgNodes(List<QueryModelNode> nodes) { |
| Set<TupleExpr> unmatched = new HashSet<>(); |
| for (final QueryModelNode q : nodes) { |
| if (q instanceof UnaryTupleOperator || q instanceof BinaryTupleOperator) { |
| unmatched.add((TupleExpr) q); |
| } else if (q instanceof FlattenedOptional) { |
| FlattenedOptional opt = (FlattenedOptional) q; |
| TupleExpr rightArg = opt.getRightArg(); |
| if (rightArg instanceof UnaryTupleOperator || rightArg instanceof BinaryTupleOperator) { |
| unmatched.add(rightArg); |
| } |
| } |
| } |
| return unmatched; |
| } |
| |
| |
| private static boolean checkNode(QueryModelNode node) { |
| return (node instanceof Join || node instanceof Filter || node instanceof LeftJoin); |
| } |
| |
| /** |
| * Get Matcher used to match ExternalSets to query |
| * |
| * @param segment |
| * @return |
| */ |
| protected abstract ExternalSetMatcher<T> getMatcher(QuerySegment<T> segment); |
| |
| /** |
| * Get ExternalSetProvider for source of ExternalSets to match to query |
| * |
| * @return |
| */ |
| protected abstract ExternalSetProvider<T> getProvider(); |
| |
| /** |
| * Get QueryNodeListRater to find optimal QueryNodeList after matching ExternalSets |
| * |
| * @return |
| */ |
| protected abstract Optional<QueryNodeListRater> getNodeListRater(QuerySegment<T> segment); |
| |
| } |