| /* |
| * 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.step.map; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.ByModulating; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalRing; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| |
| import java.util.Arrays; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class ProjectStep<S, E> extends MapStep<S, Map<String, E>> implements TraversalParent, ByModulating { |
| |
| private final List<String> projectKeys; |
| private TraversalRing<S, E> traversalRing; |
| |
| public ProjectStep(final Traversal.Admin traversal, final String... projectKeys) { |
| super(traversal); |
| this.projectKeys = Arrays.asList(projectKeys); |
| this.traversalRing = new TraversalRing<>(); |
| } |
| |
| @Override |
| protected Map<String, E> map(final Traverser.Admin<S> traverser) { |
| final Map<String, E> end = new LinkedHashMap<>(this.projectKeys.size(), 1.0f); |
| for (final String projectKey : this.projectKeys) { |
| end.put(projectKey, TraversalUtil.applyNullable(traverser, this.traversalRing.next())); |
| } |
| this.traversalRing.reset(); |
| return end; |
| } |
| |
| @Override |
| public void reset() { |
| super.reset(); |
| this.traversalRing.reset(); |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this, this.projectKeys, this.traversalRing); |
| } |
| |
| @Override |
| public ProjectStep<S, E> clone() { |
| final ProjectStep<S, E> clone = (ProjectStep<S, E>) super.clone(); |
| clone.traversalRing = this.traversalRing.clone(); |
| return clone; |
| } |
| |
| @Override |
| public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) { |
| super.setTraversal(parentTraversal); |
| this.traversalRing.getTraversals().forEach(this::integrateChild); |
| } |
| |
| @Override |
| public int hashCode() { |
| return super.hashCode() ^ this.traversalRing.hashCode() ^ this.projectKeys.hashCode(); |
| } |
| |
| @Override |
| public List<Traversal.Admin<S, E>> getLocalChildren() { |
| return this.traversalRing.getTraversals(); |
| } |
| |
| @Override |
| public void modulateBy(final Traversal.Admin<?, ?> selectTraversal) { |
| this.traversalRing.addTraversal(this.integrateChild(selectTraversal)); |
| } |
| |
| public List<String> getProjectKeys() { |
| return this.projectKeys; |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return this.getSelfAndChildRequirements(); |
| } |
| } |