| /* |
| * 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.computer.traversal.step.map; |
| |
| import org.apache.tinkerpop.gremlin.process.computer.ComputerResult; |
| import org.apache.tinkerpop.gremlin.process.computer.traversal.TraversalVertexProgram; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet; |
| import org.apache.tinkerpop.gremlin.structure.Element; |
| import org.apache.tinkerpop.gremlin.structure.Graph; |
| import org.apache.tinkerpop.gremlin.structure.Property; |
| import org.apache.tinkerpop.gremlin.structure.util.Attachable; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| import org.apache.tinkerpop.gremlin.util.iterator.EmptyIterator; |
| import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils; |
| |
| import java.util.EnumSet; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class ComputerResultStep<S> extends AbstractStep<ComputerResult, S> { |
| |
| private final boolean attachElements = Boolean.valueOf(System.getProperty("is.testing", "false")); |
| private Iterator<Traverser.Admin<S>> currentIterator = EmptyIterator.instance(); |
| |
| public ComputerResultStep(final Traversal.Admin traversal) { |
| super(traversal); |
| } |
| |
| public Iterator<Traverser.Admin<S>> attach(final Iterator<Traverser.Admin<S>> iterator, final Graph graph) { |
| return IteratorUtils.map(iterator, traverser -> { |
| traverser.setSideEffects(this.getTraversal().getSideEffects()); // necessary to ensure no NPE |
| if (this.attachElements && (traverser.get() instanceof Attachable) && !(traverser.get() instanceof Property)) |
| traverser.set((S) ((Attachable<Element>) traverser.get()).attach(Attachable.Method.get(graph))); |
| return traverser; |
| }); |
| } |
| |
| @Override |
| protected Traverser.Admin<S> processNextStart() throws NoSuchElementException { |
| while (true) { |
| if (this.currentIterator.hasNext()) |
| return this.currentIterator.next(); |
| else { |
| final ComputerResult result = this.starts.next().get(); |
| this.currentIterator = attach(result.memory().exists(TraversalVertexProgram.HALTED_TRAVERSERS) |
| ? result.memory().<TraverserSet<S>>get(TraversalVertexProgram.HALTED_TRAVERSERS).iterator() |
| : EmptyIterator.instance(), result.graph()); |
| } |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this); |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return EnumSet.of(TraverserRequirement.OBJECT); |
| } |
| |
| @Override |
| public ComputerResultStep<S> clone() { |
| final ComputerResultStep<S> clone = (ComputerResultStep<S>) super.clone(); |
| clone.currentIterator = EmptyIterator.instance(); |
| return clone; |
| } |
| } |