| /* |
| * 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.util; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Barrier; |
| 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.util.StringFactory; |
| |
| import java.util.Collections; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public abstract class CollectingBarrierStep<S> extends AbstractStep<S, S> implements Barrier { |
| private TraverserSet<S> traverserSet = new TraverserSet<>(); |
| |
| private int maxBarrierSize; |
| |
| public CollectingBarrierStep(final Traversal.Admin traversal) { |
| this(traversal, Integer.MAX_VALUE); |
| } |
| |
| public CollectingBarrierStep(final Traversal.Admin traversal, final int maxBarrierSize) { |
| super(traversal); |
| this.maxBarrierSize = maxBarrierSize; |
| } |
| |
| public abstract void barrierConsumer(final TraverserSet<S> traverserSet); |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return Collections.singleton(TraverserRequirement.BULK); |
| } |
| |
| @Override |
| public void processAllStarts() { |
| if (this.starts.hasNext()) { |
| if (Integer.MAX_VALUE == this.maxBarrierSize) { |
| this.starts.forEachRemaining(this.traverserSet::add); |
| this.barrierConsumer(this.traverserSet); |
| } else { |
| while (this.starts.hasNext() && this.traverserSet.size() < this.maxBarrierSize) { |
| this.traverserSet.add(this.starts.next()); |
| } |
| this.barrierConsumer(this.traverserSet); |
| } |
| } |
| } |
| |
| @Override |
| public Traverser<S> processNextStart() { |
| if (!this.traverserSet.isEmpty()) { |
| return this.traverserSet.remove(); |
| } else if (this.starts.hasNext()) { |
| this.processAllStarts(); |
| } |
| return this.traverserSet.remove(); |
| } |
| |
| @Override |
| public CollectingBarrierStep<S> clone() { |
| final CollectingBarrierStep<S> clone = (CollectingBarrierStep<S>) super.clone(); |
| clone.traverserSet = new TraverserSet<>(); |
| return clone; |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this, this.maxBarrierSize == Integer.MAX_VALUE ? null : this.maxBarrierSize); |
| } |
| |
| @Override |
| public int hashCode() { |
| return super.hashCode() ^ this.maxBarrierSize; |
| } |
| |
| @Override |
| public void reset() { |
| super.reset(); |
| this.traverserSet.clear(); |
| } |
| } |