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WrappedMappingInputFormat xref
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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.io.internal;
20  
21  import org.apache.giraph.io.MappingInputFormat;
22  import org.apache.giraph.io.MappingReader;
23  import org.apache.giraph.job.HadoopUtils;
24  import org.apache.hadoop.conf.Configuration;
25  import org.apache.hadoop.io.Writable;
26  import org.apache.hadoop.io.WritableComparable;
27  import org.apache.hadoop.mapreduce.InputSplit;
28  import org.apache.hadoop.mapreduce.JobContext;
29  import org.apache.hadoop.mapreduce.TaskAttemptContext;
30  
31  import java.io.DataInput;
32  import java.io.DataOutput;
33  import java.io.IOException;
34  import java.util.List;
35  
36  /**
37   * For internal use only.
38   *
39   * Wraps user set {@link org.apache.giraph.io.VertexInputFormat} to make
40   * sure proper configuration parameters are passed around, that user can set
41   * parameters in configuration and they will be available in other methods
42   * related to this format.
43   *
44   * @param <I> vertexId type
45   * @param <V> vertexValue type
46   * @param <E> edgeValue type
47   * @param <B> mappingTarget type
48   */
49  public class WrappedMappingInputFormat<I extends WritableComparable,
50    V extends Writable, E extends Writable, B extends Writable>
51    extends MappingInputFormat<I, V, E, B> {
52    /** originalInputFormat to wrap over */
53    private MappingInputFormat<I, V, E, B> originalInputFormat;
54  
55    /**
56     * Constructor
57     *
58     * @param mappingInputFormat original mappingInputFormat
59     */
60    public WrappedMappingInputFormat(
61        MappingInputFormat<I, V, E, B> mappingInputFormat) {
62      originalInputFormat = mappingInputFormat;
63    }
64  
65    @Override
66    public void checkInputSpecs(Configuration conf) {
67      originalInputFormat.checkInputSpecs(conf);
68    }
69  
70    @Override
71    public List<InputSplit> getSplits(JobContext context, int minSplitCountHint)
72      throws IOException, InterruptedException {
73      return originalInputFormat.getSplits(
74          HadoopUtils.makeJobContext(getConf(), context),
75          minSplitCountHint);
76    }
77  
78    @Override
79    public MappingReader<I, V, E, B> createMappingReader(InputSplit split,
80      TaskAttemptContext context) throws IOException {
81      final MappingReader<I, V, E, B> mappingReader = originalInputFormat
82          .createMappingReader(split,
83              HadoopUtils.makeTaskAttemptContext(getConf(), context));
84      return new WrappedMappingReader<>(mappingReader, getConf());
85    }
86  
87  
88    @Override
89    public void writeInputSplit(InputSplit inputSplit,
90      DataOutput dataOutput) throws IOException {
91      originalInputFormat.writeInputSplit(inputSplit, dataOutput);
92    }
93  
94    @Override
95    public InputSplit readInputSplit(
96      DataInput dataInput) throws IOException, ClassNotFoundException {
97      return originalInputFormat.readInputSplit(dataInput);
98    }
99  }