| /* |
| * 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.sideEffect; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Operator; |
| 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.LocalBarrier; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.SideEffectCapable; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.BulkSet; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.TraverserRequirement; |
| import org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.FastNoSuchElementException; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| import org.apache.tinkerpop.gremlin.util.function.BulkSetSupplier; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| import java.util.function.Supplier; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class AggregateStep<S> extends AbstractStep<S, S> implements SideEffectCapable<Collection, Collection>, TraversalParent, ByModulating, LocalBarrier<S> { |
| |
| private Traversal.Admin<S, Object> aggregateTraversal = null; |
| private String sideEffectKey; |
| private TraverserSet<S> barrier = new TraverserSet<>(); |
| |
| public AggregateStep(final Traversal.Admin traversal, final String sideEffectKey) { |
| super(traversal); |
| this.sideEffectKey = sideEffectKey; |
| this.getTraversal().getSideEffects().registerIfAbsent(this.sideEffectKey, (Supplier) BulkSetSupplier.instance(), Operator.addAll); |
| } |
| |
| @Override |
| public String getSideEffectKey() { |
| return this.sideEffectKey; |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this, this.sideEffectKey, this.aggregateTraversal); |
| } |
| |
| @Override |
| public void modulateBy(final Traversal.Admin<?, ?> aggregateTraversal) { |
| this.aggregateTraversal = this.integrateChild(aggregateTraversal); |
| } |
| |
| @Override |
| public List<Traversal.Admin<S, Object>> getLocalChildren() { |
| return null == this.aggregateTraversal ? Collections.emptyList() : Collections.singletonList(this.aggregateTraversal); |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return this.getSelfAndChildRequirements(TraverserRequirement.BULK, TraverserRequirement.SIDE_EFFECTS); |
| } |
| |
| @Override |
| public AggregateStep<S> clone() { |
| final AggregateStep<S> clone = (AggregateStep<S>) super.clone(); |
| clone.barrier = new TraverserSet<>(); |
| if (null != this.aggregateTraversal) |
| clone.aggregateTraversal = this.aggregateTraversal.clone(); |
| return clone; |
| } |
| |
| @Override |
| public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) { |
| super.setTraversal(parentTraversal); |
| this.integrateChild(this.aggregateTraversal); |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = super.hashCode() ^ this.sideEffectKey.hashCode(); |
| if (this.aggregateTraversal != null) |
| result ^= this.aggregateTraversal.hashCode(); |
| return result; |
| } |
| |
| @Override |
| protected Traverser.Admin<S> processNextStart() { |
| this.processAllStarts(); |
| return this.barrier.remove(); |
| } |
| |
| @Override |
| public void processAllStarts() { |
| if (this.starts.hasNext()) { |
| final BulkSet<Object> bulkSet = new BulkSet<>(); |
| while (this.starts.hasNext()) { |
| final Traverser.Admin<S> traverser = this.starts.next(); |
| bulkSet.add(TraversalUtil.applyNullable(traverser, this.aggregateTraversal), traverser.bulk()); |
| traverser.setStepId(this.getNextStep().getId()); // when barrier is reloaded, the traversers should be at the next step |
| this.barrier.add(traverser); |
| } |
| this.getTraversal().getSideEffects().add(this.sideEffectKey, bulkSet); |
| } |
| } |
| |
| @Override |
| public boolean hasNextBarrier() { |
| this.processAllStarts(); |
| return !this.barrier.isEmpty(); |
| } |
| |
| @Override |
| public TraverserSet<S> nextBarrier() throws NoSuchElementException { |
| this.processAllStarts(); |
| if (this.barrier.isEmpty()) |
| throw FastNoSuchElementException.instance(); |
| else { |
| final TraverserSet<S> temp = this.barrier; |
| this.barrier = new TraverserSet<>(); |
| return temp; |
| } |
| } |
| |
| @Override |
| public void addBarrier(final TraverserSet<S> barrier) { |
| this.barrier.addAll(barrier); |
| } |
| |
| @Override |
| public void reset() { |
| super.reset(); |
| this.barrier.clear(); |
| } |
| } |