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.superstep_output; 20 21 import org.apache.giraph.io.SimpleVertexWriter; 22 import org.apache.hadoop.io.Writable; 23 import org.apache.hadoop.io.WritableComparable; 24 25 import java.io.IOException; 26 27 /** 28 * Interface for outputing data during the computation. 29 * 30 * @param <I> Vertex id 31 * @param <V> Vertex value 32 * @param <E> Edge value 33 */ 34 public interface SuperstepOutput<I extends WritableComparable, 35 V extends Writable, E extends Writable> { 36 37 /** 38 * Get the Writer. You have to return it after usage in order for it to be 39 * properly closed. 40 * 41 * @return SimpleVertexWriter 42 */ 43 SimpleVertexWriter<I, V, E> getVertexWriter(); 44 45 /** 46 * Return the Writer after usage, which you got by calling 47 * {@link #getVertexWriter()} 48 * 49 * @param vertexWriter SimpleVertexWriter which you are returning 50 */ 51 void returnVertexWriter(SimpleVertexWriter<I, V, E> vertexWriter); 52 53 /** 54 * Finalize this output in the end of the application 55 */ 56 void postApplication() throws IOException, InterruptedException; 57 }