| /* |
| * 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.strategy.optimization; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Step; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Barrier; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.PathProcessor; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.filter.HasStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.filter.NoneStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.FlatMapStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.GraphStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.NoOpBarrierStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.sideEffect.ProfileSideEffectStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.EmptyStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.ProfileStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversalStrategy; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper; |
| |
| import java.util.Arrays; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class LazyBarrierStrategy extends AbstractTraversalStrategy<TraversalStrategy.OptimizationStrategy> implements TraversalStrategy.OptimizationStrategy { |
| |
| private final boolean IS_TESTING = Boolean.valueOf(System.getProperty("is.testing", "false")); |
| private static final LazyBarrierStrategy INSTANCE = new LazyBarrierStrategy(); |
| private static final Set<Class<? extends OptimizationStrategy>> PRIORS = new HashSet<>(Arrays.asList( |
| CountStrategy.class, |
| PathRetractionStrategy.class, |
| IncidentToAdjacentStrategy.class, |
| AdjacentToIncidentStrategy.class, |
| FilterRankingStrategy.class, |
| InlineFilterStrategy.class, |
| MatchPredicateStrategy.class, |
| EarlyLimitStrategy.class)); |
| |
| private static final int BIG_START_SIZE = 5; |
| protected static final int MAX_BARRIER_SIZE = 2500; |
| |
| private LazyBarrierStrategy() { |
| } |
| |
| @Override |
| public void apply(final Traversal.Admin<?, ?> traversal) { |
| if (TraversalHelper.onGraphComputer(traversal) || |
| traversal.getTraverserRequirements().contains(TraverserRequirement.PATH) || |
| (IS_TESTING && ((TraversalHelper.hasStepOfAssignableClass(ProfileStep.class, TraversalHelper.getRootTraversal(traversal)) || |
| TraversalHelper.hasStepOfAssignableClass(ProfileSideEffectStep.class, TraversalHelper.getRootTraversal(traversal)))))) // necessary cause ProfileTest analyzes counts |
| return; |
| |
| boolean foundFlatMap = false; |
| boolean labeledPath = false; |
| for (int i = 0; i < traversal.getSteps().size(); i++) { |
| final Step<?, ?> step = traversal.getSteps().get(i); |
| |
| if (step instanceof PathProcessor) { |
| final Set<String> keepLabels = ((PathProcessor) step).getKeepLabels(); |
| if (null != keepLabels && keepLabels.isEmpty()) // if no more path data, then start barrier'ing again |
| labeledPath = false; |
| } |
| if (step instanceof FlatMapStep && |
| !(step instanceof VertexStep && ((VertexStep) step).returnsEdge()) || |
| (step instanceof GraphStep && |
| (i > 0 || ((GraphStep) step).getIds().length >= BIG_START_SIZE || |
| (((GraphStep) step).getIds().length == 0 && !(step.getNextStep() instanceof HasStep))))) { |
| if (foundFlatMap && !labeledPath && |
| !(step.getNextStep() instanceof Barrier) && |
| !(step.getNextStep() instanceof NoneStep) && |
| !(step.getNextStep() instanceof EmptyStep)) { |
| final Step noOpBarrierStep = new NoOpBarrierStep<>(traversal, MAX_BARRIER_SIZE); |
| TraversalHelper.copyLabels(step, noOpBarrierStep, true); |
| TraversalHelper.insertAfterStep(noOpBarrierStep, step, traversal); |
| } else |
| foundFlatMap = true; |
| } |
| if (!step.getLabels().isEmpty()) |
| labeledPath = true; |
| |
| } |
| } |
| |
| |
| @Override |
| public Set<Class<? extends OptimizationStrategy>> applyPrior() { |
| return PRIORS; |
| } |
| |
| public static LazyBarrierStrategy instance() { |
| return INSTANCE; |
| } |
| } |