| /* |
| * 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.map; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Step; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraverserGenerator; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.FromToModulating; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Mutating; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.Scoping; |
| 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.Parameters; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.event.CallbackRegistry; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.event.Event; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.util.event.ListCallbackRegistry; |
| import org.apache.tinkerpop.gremlin.process.traversal.strategy.decoration.EventStrategy; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.FastNoSuchElementException; |
| import org.apache.tinkerpop.gremlin.structure.Edge; |
| import org.apache.tinkerpop.gremlin.structure.Graph; |
| import org.apache.tinkerpop.gremlin.structure.T; |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| import org.apache.tinkerpop.gremlin.structure.util.Attachable; |
| import org.apache.tinkerpop.gremlin.structure.util.StringFactory; |
| import org.apache.tinkerpop.gremlin.structure.util.detached.DetachedFactory; |
| import org.apache.tinkerpop.gremlin.structure.util.empty.EmptyGraph; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public class AddEdgeStartStep extends AbstractStep<Edge, Edge> |
| implements Mutating<Event.EdgeAddedEvent>, TraversalParent, Scoping, FromToModulating { |
| |
| private static final String FROM = Graph.Hidden.hide("from"); |
| private static final String TO = Graph.Hidden.hide("to"); |
| |
| private boolean first = true; |
| private Parameters parameters = new Parameters(); |
| private CallbackRegistry<Event.EdgeAddedEvent> callbackRegistry; |
| |
| public AddEdgeStartStep(final Traversal.Admin traversal, final String edgeLabel) { |
| super(traversal); |
| this.parameters.set(this, T.label, edgeLabel); |
| } |
| |
| public AddEdgeStartStep(final Traversal.Admin traversal, final Traversal<?, String> edgeLabelTraversal) { |
| super(traversal); |
| this.parameters.set(this, T.label, edgeLabelTraversal); |
| } |
| |
| @Override |
| public <S, E> List<Traversal.Admin<S, E>> getLocalChildren() { |
| return this.parameters.getTraversals(); |
| } |
| |
| @Override |
| public Parameters getParameters() { |
| return this.parameters; |
| } |
| |
| @Override |
| public Set<String> getScopeKeys() { |
| return this.parameters.getReferencedLabels(); |
| } |
| |
| @Override |
| public void configure(final Object... keyValues) { |
| this.parameters.set(this, keyValues); |
| } |
| |
| @Override |
| public void addTo(final Traversal.Admin<?, ?> toObject) { |
| this.parameters.set(this, TO, toObject); |
| } |
| |
| @Override |
| public void addFrom(final Traversal.Admin<?, ?> fromObject) { |
| this.parameters.set(this, FROM, fromObject); |
| } |
| |
| @Override |
| protected Traverser.Admin<Edge> processNextStart() { |
| if (this.first) { |
| this.first = false; |
| final TraverserGenerator generator = this.getTraversal().getTraverserGenerator(); |
| final Traverser.Admin traverser = generator.generate(1, (Step) this, 1); // a dead traverser to trigger the traversal |
| Vertex toVertex = (Vertex) this.parameters.get(traverser, TO, Collections::emptyList).get(0); |
| Vertex fromVertex = (Vertex) this.parameters.get(traverser, FROM, Collections::emptyList).get(0); |
| if (toVertex instanceof Attachable) |
| toVertex = ((Attachable<Vertex>) toVertex) |
| .attach(Attachable.Method.get(this.getTraversal().getGraph().orElse(EmptyGraph.instance()))); |
| if (fromVertex instanceof Attachable) |
| fromVertex = ((Attachable<Vertex>) fromVertex) |
| .attach(Attachable.Method.get(this.getTraversal().getGraph().orElse(EmptyGraph.instance()))); |
| final String edgeLabel = (String) this.parameters.get(traverser, T.label, () -> Edge.DEFAULT_LABEL).get(0); |
| final Edge edge = fromVertex.addEdge(edgeLabel, toVertex, this.parameters.getKeyValues(traverser, TO, FROM, T.label)); |
| if (callbackRegistry != null) { |
| final EventStrategy eventStrategy = getTraversal().getStrategies().getStrategy(EventStrategy.class).get(); |
| final Event.EdgeAddedEvent vae = new Event.EdgeAddedEvent(eventStrategy.detach(edge)); |
| callbackRegistry.getCallbacks().forEach(c -> c.accept(vae)); |
| } |
| return generator.generate(edge, this, 1L); |
| } else |
| throw FastNoSuchElementException.instance(); |
| |
| |
| } |
| |
| @Override |
| public CallbackRegistry<Event.EdgeAddedEvent> getMutatingCallbackRegistry() { |
| if (null == this.callbackRegistry) this.callbackRegistry = new ListCallbackRegistry<>(); |
| return this.callbackRegistry; |
| } |
| |
| @Override |
| public int hashCode() { |
| return super.hashCode() ^ this.parameters.hashCode(); |
| } |
| |
| @Override |
| public String toString() { |
| return StringFactory.stepString(this, this.parameters.toString()); |
| } |
| |
| @Override |
| public void setTraversal(final Traversal.Admin<?, ?> parentTraversal) { |
| super.setTraversal(parentTraversal); |
| this.parameters.getTraversals().forEach(this::integrateChild); |
| } |
| |
| @Override |
| public AddEdgeStartStep clone() { |
| final AddEdgeStartStep clone = (AddEdgeStartStep) super.clone(); |
| clone.parameters = this.parameters.clone(); |
| return clone; |
| } |
| |
| } |