| /* |
| * 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.tinkerpop.gremlin.process.traversal.util; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategies; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy; |
| import org.javatuples.Pair; |
| import org.javatuples.Triplet; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| import java.util.stream.Stream; |
| |
| /** |
| * A TraversalExplanation takes a {@link Traversal} and, for each registered {@link TraversalStrategy}, it creates a |
| * mapping reflecting how each strategy alters the traversal. This is useful for understanding how each traversal |
| * strategy mutates the traversal. This is useful in debugging and analysis of traversal compilation. The |
| * {@link TraversalExplanation#toString()} has a pretty-print representation that is useful in the Gremlin Console. |
| * |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public class TraversalExplanation extends AbstractExplanation implements Serializable { |
| |
| private Traversal.Admin<?, ?> traversal; |
| private List<Pair<TraversalStrategy, Traversal.Admin<?, ?>>> strategyTraversals = new ArrayList<>(); |
| |
| protected TraversalExplanation() { |
| // no arg constructor for serialization |
| } |
| |
| public TraversalExplanation(final Traversal.Admin<?, ?> traversal) { |
| this.traversal = traversal.clone(); |
| TraversalStrategies mutatingStrategies = new DefaultTraversalStrategies(); |
| for (final TraversalStrategy strategy : this.traversal.getStrategies().toList()) { |
| final Traversal.Admin<?, ?> mutatingTraversal = this.traversal.clone(); |
| mutatingStrategies.addStrategies(strategy); |
| mutatingTraversal.setStrategies(mutatingStrategies); |
| mutatingTraversal.applyStrategies(); |
| this.strategyTraversals.add(Pair.with(strategy, mutatingTraversal)); |
| } |
| } |
| |
| /** |
| * Get the list of {@link TraversalStrategy} applications. For strategy, the resultant mutated {@link Traversal} is provided. |
| * |
| * @return the list of strategy/traversal pairs |
| */ |
| public List<Pair<TraversalStrategy, Traversal.Admin<?, ?>>> getStrategyTraversals() { |
| return Collections.unmodifiableList(this.strategyTraversals); |
| } |
| |
| /** |
| * Get the original {@link Traversal} used to create this explanation. |
| * |
| * @return the original traversal |
| */ |
| public Traversal.Admin<?, ?> getOriginalTraversal() { |
| return this.traversal; |
| } |
| |
| public ImmutableExplanation asImmutable() { |
| return new ImmutableExplanation(getOriginalTraversalAsString(), |
| this.getIntermediates().collect(Collectors.toList())); |
| } |
| |
| @Override |
| protected Stream<String> getStrategyTraversalsAsString() { |
| return this.strategyTraversals.stream() |
| .map(Pair::getValue0) |
| .map(Object::toString); |
| } |
| |
| @Override |
| protected String getOriginalTraversalAsString() { |
| return getOriginalTraversal().toString(); |
| } |
| |
| @Override |
| protected Stream<Triplet<String, String, String>> getIntermediates() { |
| return this.strategyTraversals.stream().map( p -> Triplet.with(p.getValue0().toString(), |
| p.getValue0().getTraversalCategory().getSimpleName(), p.getValue1().toString())); |
| } |
| } |