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.utils; 20 21 import org.apache.hadoop.io.WritableComparable; 22 23 /** 24 * Special iterator that reuses vertex ids and data objects so that the 25 * lifetime of the object is only until next() is called. 26 * 27 * Vertex id ownership can be released if desired through 28 * releaseCurrentVertexId(). This optimization allows us to cut down 29 * on the number of objects instantiated and garbage collected. 30 * 31 * @param <I> vertexId type parameter 32 * @param <T> vertexData type parameter 33 */ 34 public interface VertexIdDataIterator<I extends WritableComparable, T> 35 extends VertexIdIterator<I> { 36 /** 37 * Get the current data. 38 * 39 * @return Current data 40 */ 41 T getCurrentData(); 42 43 /** 44 * Get serialized size of current data 45 * 46 * @return serialized size of data 47 */ 48 int getCurrentDataSize(); 49 50 /** 51 * Release the current data object. 52 * 53 * @return Released data object 54 */ 55 T releaseCurrentData(); 56 }