/*
* 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.generator;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.graph.Graph;
import org.apache.flink.types.LongValue;
import org.apache.flink.types.NullValue;
import org.apache.flink.util.Preconditions;
/**
* @see <a href="http://mathworld.wolfram.com/CycleGraph.html">Cycle Graph at Wolfram MathWorld</a>
*/
public class CycleGraph
extends AbstractGraphGenerator<LongValue, NullValue, NullValue> {
public static final int MINIMUM_VERTEX_COUNT = 2;
// Required to create the DataSource
private final ExecutionEnvironment env;
// Required configuration
private long vertexCount;
/**
* An undirected {@link Graph} with {@code n} vertices where each vertex
* v<sub>i</sub> is connected to adjacent vertices v<sub>(i+1)%n</sub> and
* v<sub>(i-1)%n</sub>.
*
* @param env the Flink execution environment
* @param vertexCount number of vertices
*/
public CycleGraph(ExecutionEnvironment env, long vertexCount) {
Preconditions.checkArgument(vertexCount >= MINIMUM_VERTEX_COUNT,
"Vertex count must be at least " + MINIMUM_VERTEX_COUNT);
this.env = env;
this.vertexCount = vertexCount;
}
@Override
public Graph<LongValue, NullValue, NullValue> generate() {
return new GridGraph(env)
.addDimension(vertexCount, true)
.setParallelism(parallelism)
.generate();
}
}