| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| VertexReader |
|
| 1.0;1 |
| 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.graph; | |
| 20 | ||
| 21 | import org.apache.hadoop.io.Writable; | |
| 22 | import org.apache.hadoop.io.WritableComparable; | |
| 23 | import org.apache.hadoop.mapreduce.InputSplit; | |
| 24 | import org.apache.hadoop.mapreduce.TaskAttemptContext; | |
| 25 | ||
| 26 | import java.io.IOException; | |
| 27 | ||
| 28 | /** | |
| 29 | * Analogous to {@link RecordReader} for vertices. Will read the vertices | |
| 30 | * from an input split. | |
| 31 | * | |
| 32 | * @param <I> Vertex id | |
| 33 | * @param <V> Vertex data | |
| 34 | * @param <E> Edge data | |
| 35 | * @param <M> Message data | |
| 36 | */ | |
| 37 | @SuppressWarnings("rawtypes") | |
| 38 | public interface VertexReader<I extends WritableComparable, | |
| 39 | V extends Writable, E extends Writable, M extends Writable> { | |
| 40 | /** | |
| 41 | * Use the input split and context to setup reading the vertices. | |
| 42 | * Guaranteed to be called prior to any other function. | |
| 43 | * | |
| 44 | * @param inputSplit Input split to be used for reading vertices. | |
| 45 | * @param context Context from the task. | |
| 46 | * @throws IOException | |
| 47 | * @throws InterruptedException | |
| 48 | */ | |
| 49 | void initialize(InputSplit inputSplit, TaskAttemptContext context) | |
| 50 | throws IOException, InterruptedException; | |
| 51 | ||
| 52 | /** | |
| 53 | * | |
| 54 | * @return false iff there are no more vertices | |
| 55 | * @throws IOException | |
| 56 | * @throws InterruptedException | |
| 57 | */ | |
| 58 | boolean nextVertex() throws IOException, InterruptedException; | |
| 59 | ||
| 60 | /** | |
| 61 | * Get the current vertex. | |
| 62 | * | |
| 63 | * @return the current vertex which has been read. | |
| 64 | * nextVertex() should be called first. | |
| 65 | * @throws IOException | |
| 66 | * @throws InterruptedException | |
| 67 | */ | |
| 68 | Vertex<I, V, E, M> getCurrentVertex() | |
| 69 | throws IOException, InterruptedException; | |
| 70 | ||
| 71 | /** | |
| 72 | * Close this {@link VertexReader} to future operations. | |
| 73 | * | |
| 74 | * @throws IOException | |
| 75 | */ | |
| 76 | void close() throws IOException; | |
| 77 | ||
| 78 | /** | |
| 79 | * How much of the input has the {@link VertexReader} consumed i.e. | |
| 80 | * has been processed by? | |
| 81 | * | |
| 82 | * @return Progress from <code>0.0</code> to <code>1.0</code>. | |
| 83 | * @throws IOException | |
| 84 | * @throws InterruptedException | |
| 85 | */ | |
| 86 | float getProgress() throws IOException, InterruptedException; | |
| 87 | } |