| /* |
| * 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.finalization; |
| |
| 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.HasContainerHolder; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.filter.FilterStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.EdgeVertexStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.GraphStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.CollectingBarrierStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.LambdaCollectingBarrierStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.SupplyingBarrierStep; |
| 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.HashSet; |
| import java.util.Set; |
| import java.util.function.Consumer; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class LazyBarrierStrategy extends AbstractTraversalStrategy<TraversalStrategy.FinalizationStrategy> implements TraversalStrategy.FinalizationStrategy { |
| |
| private static final LazyBarrierStrategy INSTANCE = new LazyBarrierStrategy(); |
| private static final Set<Class<? extends FinalizationStrategy>> PRIORS = new HashSet<>(); |
| private static final Set<Class<? extends FinalizationStrategy>> POSTS = new HashSet<>(); |
| |
| private static final int REQUIRED_DEPTH = 2; |
| private static final int BIG_START_SIZE = 5; |
| protected static final int MAX_BARRIER_SIZE = 10000; |
| |
| static { |
| POSTS.add(ProfileStrategy.class); |
| } |
| |
| |
| private LazyBarrierStrategy() { |
| } |
| |
| @Override |
| public void apply(final Traversal.Admin<?, ?> traversal) { |
| if (traversal.getEngine().isComputer()) |
| return; |
| |
| if (traversal.getTraverserRequirements().contains(TraverserRequirement.PATH)) |
| return; |
| |
| int depth = 0; |
| for (final Step<?, ?> step : traversal.getSteps()) { |
| if (step instanceof VertexStep) |
| depth++; |
| } |
| |
| if (depth > REQUIRED_DEPTH) { |
| boolean bigStart = false; |
| char foundVertexStep = 'x'; |
| for (int i = 0; i < traversal.getSteps().size() - 1; i++) { |
| final Step<?, ?> step = traversal.getSteps().get(i); |
| if (i == 0) |
| bigStart = step instanceof GraphStep && (((GraphStep) step).getIds().length >= BIG_START_SIZE || (((GraphStep) step).getIds().length == 0 && step instanceof HasContainerHolder && ((HasContainerHolder) step).getHasContainers().isEmpty())); |
| else if ('v' == foundVertexStep || bigStart) { |
| if (!(step instanceof FilterStep) && |
| !(step instanceof CollectingBarrierStep) && |
| !(step instanceof SupplyingBarrierStep) && |
| !(step instanceof ReducingBarrierStep) && |
| !(step instanceof VertexStep && ((VertexStep) step).returnsEdge())) { |
| TraversalHelper.insertAfterStep(new LambdaCollectingBarrierStep<>(traversal, (Consumer) LambdaCollectingBarrierStep.Consumers.noOp, MAX_BARRIER_SIZE), step, traversal); |
| } |
| } |
| |
| if ('x' == foundVertexStep && step instanceof VertexStep) |
| foundVertexStep = ((VertexStep) step).returnsVertex() ? 'v' : 'e'; |
| else if ('e' == foundVertexStep && step instanceof EdgeVertexStep) |
| foundVertexStep = 'v'; |
| } |
| } |
| } |
| |
| |
| @Override |
| public Set<Class<? extends FinalizationStrategy>> applyPrior() { |
| return PRIORS; |
| } |
| |
| @Override |
| public Set<Class<? extends FinalizationStrategy>> applyPost() { |
| return POSTS; |
| } |
| |
| public static LazyBarrierStrategy instance() { |
| return INSTANCE; |
| } |
| } |