| /* |
| * 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.spark.process.computer; |
| |
| import org.apache.tinkerpop.gremlin.process.computer.MessageScope; |
| import org.apache.tinkerpop.gremlin.process.computer.Messenger; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStep; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper; |
| import org.apache.tinkerpop.gremlin.structure.Direction; |
| import org.apache.tinkerpop.gremlin.structure.Edge; |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| import org.apache.tinkerpop.gremlin.structure.util.star.StarGraph; |
| import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils; |
| import scala.Tuple2; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class SparkMessenger<M> implements Messenger<M> { |
| |
| private Vertex vertex; |
| private Iterable<M> incomingMessages; |
| private List<Tuple2<Object, M>> outgoingMessages = new ArrayList<>(); |
| |
| public void setVertexAndIncomingMessages(final Vertex vertex, final Iterable<M> incomingMessages) { |
| this.vertex = vertex; |
| this.incomingMessages = incomingMessages; |
| this.outgoingMessages = new ArrayList<>(); |
| } |
| |
| public List<Tuple2<Object, M>> getOutgoingMessages() { |
| return this.outgoingMessages; |
| } |
| |
| @Override |
| public Iterator<M> receiveMessages() { |
| return IteratorUtils.removeOnNext(this.incomingMessages.iterator()); |
| } |
| |
| @Override |
| public void sendMessage(final MessageScope messageScope, final M message) { |
| if (messageScope instanceof MessageScope.Local) { |
| final MessageScope.Local<M> localMessageScope = (MessageScope.Local) messageScope; |
| final Traversal.Admin<Vertex, Edge> incidentTraversal = SparkMessenger.setVertexStart(localMessageScope.getIncidentTraversal().get().asAdmin(), this.vertex); |
| final Direction direction = SparkMessenger.getOppositeDirection(incidentTraversal); |
| |
| // handle processing for BOTH given TINKERPOP-1862 where the target of the message is the one opposite |
| // the current vertex |
| incidentTraversal.forEachRemaining(edge -> { |
| if (direction.equals(Direction.IN) || direction.equals(Direction.OUT)) |
| this.outgoingMessages.add(new Tuple2<>(edge.vertices(direction).next().id(), localMessageScope.getEdgeFunction().apply(message, edge))); |
| else |
| this.outgoingMessages.add(new Tuple2<>(edge instanceof StarGraph.StarOutEdge ? edge.inVertex().id() : edge.outVertex().id(), localMessageScope.getEdgeFunction().apply(message, edge))); |
| |
| }); |
| } else { |
| ((MessageScope.Global) messageScope).vertices().forEach(v -> this.outgoingMessages.add(new Tuple2<>(v.id(), message))); |
| } |
| } |
| |
| /////////// |
| |
| private static <T extends Traversal.Admin<Vertex, Edge>> T setVertexStart(final Traversal.Admin<Vertex, Edge> incidentTraversal, final Vertex vertex) { |
| incidentTraversal.asAdmin().addStart(incidentTraversal.getTraverserGenerator().generate(vertex, incidentTraversal.asAdmin().getStartStep(), 1l)); |
| return (T) incidentTraversal; |
| } |
| |
| private static Direction getOppositeDirection(final Traversal.Admin<Vertex, Edge> incidentTraversal) { |
| final VertexStep step = TraversalHelper.getLastStepOfAssignableClass(VertexStep.class, incidentTraversal).get(); |
| return step.getDirection().opposite(); |
| } |
| } |