/* * 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.flink.graph.drivers; import org.apache.flink.api.common.typeinfo.TypeInformation; import org.apache.flink.api.java.DataSet; import org.apache.flink.api.java.tuple.Tuple3; import org.apache.flink.api.java.typeutils.TupleTypeInfo; import org.apache.flink.api.java.typeutils.ValueTypeInfo; import org.apache.flink.graph.Edge; import org.apache.flink.graph.Graph; import org.apache.flink.graph.utils.EdgeToTuple2Map; import org.apache.flink.types.NullValue; /** * Convert a {@link Graph} to the {@link DataSet} of {@link Edge}. * * @param <K> graph ID type * @param <VV> vertex value type * @param <EV> edge value type */ public class EdgeList<K, VV, EV> extends DriverBase<K, VV, EV> { @Override public String getShortDescription() { return "the edge list"; } @Override public String getLongDescription() { return "Pass-through of the graph's edge list."; } @Override public DataSet plan(Graph<K, VV, EV> graph) throws Exception { DataSet<Edge<K, EV>> edges = graph.getEdges(); if (hasNullValueEdges(edges)) { return edges .map(new EdgeToTuple2Map<>()) .name("Edge to Tuple2") .setParallelism(parallelism.getValue().intValue()); } else { return edges; } } /** * Check whether the edge type of the {@link DataSet} is {@link NullValue}. * * @param edges data set for introspection * @param <T> graph ID type * @param <ET> edge value type * @return whether the edge type of the {@link DataSet} is {@link NullValue} */ private static <T, ET> boolean hasNullValueEdges(DataSet<Edge<T, ET>> edges) { TypeInformation<?> genericTypeInfo = edges.getType(); @SuppressWarnings("unchecked") TupleTypeInfo<Tuple3<T, T, ET>> tupleTypeInfo = (TupleTypeInfo<Tuple3<T, T, ET>>) genericTypeInfo; return tupleTypeInfo.getTypeAt(2).equals(ValueTypeInfo.NULL_VALUE_TYPE_INFO); } }