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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  package org.apache.giraph.factories;
19  
20  import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;
21  import org.apache.giraph.utils.WritableUtils;
22  import org.apache.hadoop.io.Writable;
23  
24  import com.google.common.base.Objects;
25  
26  /**
27   * Factory class to create default message values.
28   *
29   * @param <M> Message Value
30   */
31  public class DefaultMessageValueFactory<M extends Writable>
32      implements MessageValueFactory<M> {
33    /** Message value class */
34    private final Class<M> messageValueClass;
35    /** Configuration */
36    private final ImmutableClassesGiraphConfiguration conf;
37  
38    /**
39     * Constructor
40     * @param messageValueClass message value class
41     * @param conf configuration
42     */
43    public DefaultMessageValueFactory(Class<M> messageValueClass,
44        ImmutableClassesGiraphConfiguration conf) {
45      this.messageValueClass = messageValueClass;
46      this.conf = conf;
47    }
48  
49    @Override public M newInstance() {
50      return WritableUtils.createWritable(messageValueClass, conf);
51    }
52  
53    @Override public String toString() {
54      return Objects.toStringHelper(this)
55          .add("messageValueClass", messageValueClass)
56          .toString();
57    }
58  }