1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.giraph.examples;
20
21 import org.apache.giraph.graph.BasicComputation;
22 import org.apache.hadoop.io.LongWritable;
23 import org.apache.hadoop.io.DoubleWritable;
24 import org.apache.giraph.graph.Vertex;
25
26 import java.io.IOException;
27
28 /**
29 * Simple function to return the out degree for each vertex.
30 */
31 @Algorithm(
32 name = "Outdegree Count"
33 )
34 public class SimpleOutDegreeCountComputation extends BasicComputation<
35 LongWritable, LongWritable, DoubleWritable, DoubleWritable> {
36
37 @Override
38 public void compute(
39 Vertex<LongWritable, LongWritable, DoubleWritable> vertex,
40 Iterable<DoubleWritable> messages) throws IOException {
41 LongWritable vertexValue = vertex.getValue();
42 vertexValue.set(vertex.getNumEdges());
43 vertex.setValue(vertexValue);
44 vertex.voteToHalt();
45 }
46 }