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 }