| /* |
| * 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.server.util; |
| |
| import org.apache.tinkerpop.gremlin.process.remote.traversal.DefaultRemoteTraverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.strategy.decoration.HaltedTraverserStrategy; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet; |
| |
| import java.util.Iterator; |
| |
| /** |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public class TraverserIterator implements Iterator<Object> { |
| |
| private final Traversal.Admin traversal; |
| private final HaltedTraverserStrategy haltedTraverserStrategy; |
| private final TraverserSet bulker = new TraverserSet(); |
| private final int barrierSize; |
| |
| public TraverserIterator(final Traversal.Admin traversal) { |
| this.traversal = traversal; |
| this.barrierSize = traversal.getTraverserRequirements().contains(TraverserRequirement.ONE_BULK) ? 1 : 1000; |
| this.haltedTraverserStrategy = traversal.getStrategies().getStrategy(HaltedTraverserStrategy.class).orElse( |
| Boolean.valueOf(System.getProperty("is.testing", "false")) ? |
| HaltedTraverserStrategy.detached() : |
| HaltedTraverserStrategy.reference()); |
| } |
| |
| public Traversal.Admin getTraversal() { |
| return this.traversal; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (this.bulker.isEmpty()) |
| this.fillBulker(); |
| return !this.bulker.isEmpty(); |
| } |
| |
| @Override |
| public Object next() { |
| if (this.bulker.isEmpty()) |
| this.fillBulker(); |
| final Traverser.Admin t = this.haltedTraverserStrategy.halt(this.bulker.remove()); |
| return new DefaultRemoteTraverser<>(t.get(), t.bulk()); |
| } |
| |
| private final void fillBulker() { |
| while (this.traversal.hasNext() && this.bulker.size() < this.barrierSize) { |
| this.bulker.add(this.traversal.nextTraverser()); |
| } |
| } |
| } |