| /* |
| * 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.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.ByModulating; |
| 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.map.GroupStep; |
| 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.TraversalUtil; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| import org.apache.tinkerpop.gremlin.util.function.HashMapSupplier; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class GroupSideEffectStep<S, K, V> extends SideEffectStep<S> implements SideEffectCapable<Map<K, ?>, Map<K, V>>, TraversalParent, ByModulating { |
| |
| private char state = 'k'; |
| private Traversal.Admin<S, K> keyTraversal = null; |
| private Traversal.Admin<S, ?> preTraversal = null; |
| private Traversal.Admin<S, V> valueTraversal = this.integrateChild(__.fold().asAdmin()); |
| /// |
| private String sideEffectKey; |
| |
| public GroupSideEffectStep(final Traversal.Admin traversal, final String sideEffectKey) { |
| super(traversal); |
| this.sideEffectKey = sideEffectKey; |
| this.valueTraversal = this.integrateChild(__.fold().asAdmin()); |
| this.preTraversal = this.integrateChild(GroupStep.generatePreTraversal(this.valueTraversal)); |
| this.getTraversal().getSideEffects().registerIfAbsent(this.sideEffectKey, HashMapSupplier.instance(), new GroupStep.GroupBiOperator<>(this.valueTraversal)); |
| } |
| |
| @Override |
| public void modulateBy(final Traversal.Admin<?, ?> kvTraversal) { |
| if ('k' == this.state) { |
| this.keyTraversal = this.integrateChild(kvTraversal); |
| this.state = 'v'; |
| } else if ('v' == this.state) { |
| this.valueTraversal = this.integrateChild(GroupStep.convertValueTraversal(kvTraversal)); |
| this.preTraversal = this.integrateChild(GroupStep.generatePreTraversal(this.valueTraversal)); |
| this.getTraversal().getSideEffects().register(this.sideEffectKey, null, new GroupStep.GroupBiOperator<>(this.valueTraversal)); |
| this.state = 'x'; |
| } else { |
| throw new IllegalStateException("The key and value traversals for group()-step have already been set: " + this); |
| } |
| } |
| |
| @Override |
| protected void sideEffect(final Traverser.Admin<S> traverser) { |
| final Map<K, V> map = new HashMap<>(1); |
| if (null == this.preTraversal) { |
| map.put(TraversalUtil.applyNullable(traverser, this.keyTraversal), (V) traverser.split()); |
| } else { |
| final TraverserSet traverserSet = new TraverserSet<>(); |
| this.preTraversal.reset(); |
| this.preTraversal.addStart(traverser.split()); |
| this.preTraversal.getEndStep().forEachRemaining(traverserSet::add); |
| map.put(TraversalUtil.applyNullable(traverser, this.keyTraversal), (V) traverserSet); |
| } |
| this.getTraversal().getSideEffects().add(this.sideEffectKey, map); |
| } |
| |
| @Override |
| public String getSideEffectKey() { |
| return this.sideEffectKey; |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this, this.sideEffectKey, this.keyTraversal, this.valueTraversal); |
| } |
| |
| @Override |
| public List<Traversal.Admin<?, ?>> getLocalChildren() { |
| final List<Traversal.Admin<?, ?>> children = new ArrayList<>(2); |
| if (null != this.keyTraversal) |
| children.add((Traversal.Admin) this.keyTraversal); |
| children.add(this.valueTraversal); |
| return children; |
| } |
| |
| @Override |
| public Set<TraverserRequirement> getRequirements() { |
| return this.getSelfAndChildRequirements(TraverserRequirement.OBJECT, TraverserRequirement.BULK, TraverserRequirement.SIDE_EFFECTS); |
| } |
| |
| @Override |
| public GroupSideEffectStep<S, K, V> clone() { |
| final GroupSideEffectStep<S, K, V> clone = (GroupSideEffectStep<S, K, V>) super.clone(); |
| if (null != this.keyTraversal) |
| clone.keyTraversal = this.keyTraversal.clone(); |
| clone.valueTraversal = this.valueTraversal.clone(); |
| clone.preTraversal = this.integrateChild(GroupStep.generatePreTraversal(clone.valueTraversal)); |
| return clone; |
| } |
| |
| @Override |
| public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) { |
| super.setTraversal(parentTraversal); |
| this.integrateChild(this.keyTraversal); |
| this.integrateChild(this.valueTraversal); |
| this.integrateChild(this.preTraversal); |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = super.hashCode() ^ this.sideEffectKey.hashCode(); |
| if (this.keyTraversal != null) result ^= this.keyTraversal.hashCode(); |
| result ^= this.valueTraversal.hashCode(); |
| return result; |
| } |
| |
| @Override |
| public Map<K, V> generateFinalResult(final Map<K, ?> object) { |
| return GroupStep.doFinalReduction((Map<K, Object>) object, this.valueTraversal); |
| } |
| } |