This project has retired. For details please refer to its Attic page.
IntNullNullTextInputFormat xref
View Javadoc

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  package org.apache.giraph.io.formats;
19  
20  import com.google.common.collect.ImmutableList;
21  import org.apache.giraph.edge.Edge;
22  import org.apache.hadoop.io.IntWritable;
23  import org.apache.hadoop.io.NullWritable;
24  import org.apache.hadoop.io.Text;
25  import org.apache.hadoop.mapreduce.InputSplit;
26  import org.apache.hadoop.mapreduce.TaskAttemptContext;
27  
28  import java.io.IOException;
29  
30  /**
31   * Simple text-based {@link org.apache.giraph.io.VertexInputFormat} for
32   * unweighted graphs without edges or values, just vertices with ids.
33   *
34   * Each line is just simply the vertex id.
35   */
36  public class IntNullNullTextInputFormat extends TextVertexInputFormat<
37      IntWritable, NullWritable, NullWritable> {
38    @Override
39    public TextVertexReader createVertexReader(
40        InputSplit split, TaskAttemptContext context) throws IOException {
41      return new IntNullNullNullVertexReader();
42    }
43  
44    /**
45     * Reader for this InputFormat.
46     */
47    public class IntNullNullNullVertexReader extends
48        TextVertexReaderFromEachLineProcessed<String> {
49      /** Cached vertex id */
50      private IntWritable id;
51  
52      @Override
53      protected String preprocessLine(Text line) throws IOException {
54        id = new IntWritable(Integer.parseInt(line.toString()));
55        return line.toString();
56      }
57  
58      @Override
59      protected IntWritable getId(String line) throws IOException {
60        return id;
61      }
62  
63      @Override
64      protected NullWritable getValue(String line) throws IOException {
65        return NullWritable.get();
66      }
67  
68      @Override
69      protected Iterable<Edge<IntWritable, NullWritable>> getEdges(String line)
70        throws IOException {
71        return ImmutableList.of();
72      }
73    }
74  }