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;
20
21 import java.io.IOException;
22 import org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable;
23 import org.apache.hadoop.io.Writable;
24 import org.apache.hadoop.io.WritableComparable;
25 import org.apache.hadoop.mapreduce.TaskAttemptContext;
26
27 /**
28 * Implement to output a vertex range of the graph after the computation
29 *
30 * @param <I> Vertex id
31 * @param <V> Vertex value
32 * @param <E> Edge value
33 */
34 @SuppressWarnings("rawtypes")
35 public abstract class VertexWriter<I extends WritableComparable,
36 V extends Writable, E extends Writable>
37 extends DefaultImmutableClassesGiraphConfigurable<I, V, E>
38 implements SimpleVertexWriter<I, V, E> {
39 /**
40 * Use the context to setup writing the vertices.
41 * Guaranteed to be called prior to any other function.
42 *
43 * @param context Context used to write the vertices.
44 * @throws IOException
45 * @throws InterruptedException
46 */
47 public abstract void initialize(TaskAttemptContext context)
48 throws IOException, InterruptedException;
49
50 /**
51 * Close this {@link VertexWriter} to future operations.
52 *
53 * @param context the context of the task
54 * @throws IOException
55 * @throws InterruptedException
56 */
57 public abstract void close(TaskAttemptContext context)
58 throws IOException, InterruptedException;
59 }