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 package org.apache.giraph.worker; 19 20 import java.util.ArrayList; 21 import java.util.List; 22 23 import com.google.common.base.Preconditions; 24 25 import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap; 26 27 /** 28 * Information about all workers, their WorkerInfo values, and indices. 29 */ 30 public class AllWorkersInfo { 31 /** List of workers in current superstep, sorted by task id */ 32 private final List<WorkerInfo> workerInfos; 33 /** My worker index */ 34 private final int myWorkerIndex; 35 /** Map of taskId to worker index */ 36 private final Int2IntOpenHashMap taskIdToIndex; 37 38 /** 39 * Constructor 40 * @param workers Ordered list of workers 41 * @param myWorker My worker 42 */ 43 public AllWorkersInfo(List<WorkerInfo> workers, WorkerInfo myWorker) { 44 workerInfos = new ArrayList<>(workers); 45 46 taskIdToIndex = new Int2IntOpenHashMap(workerInfos.size()); 47 taskIdToIndex.defaultReturnValue(-1); 48 for (int i = 0; i < workerInfos.size(); i++) { 49 int task = workerInfos.get(i).getTaskId(); 50 if (i > 0) { 51 Preconditions.checkState( 52 task > workerInfos.get(i - 1).getTaskId(), "Tasks not ordered"); 53 } 54 Preconditions.checkState(task >= 0, "Task not specified, %d", task); 55 int old = taskIdToIndex.put(task, i); 56 Preconditions.checkState(old == -1, 57 "Task with %d id found twice (positions %d and %d)", 58 task, i, old); 59 } 60 61 myWorkerIndex = getWorkerIndex(myWorker); 62 } 63 64 /** 65 * List of WorkerInfos 66 * 67 * @return List of WorkerInfos 68 */ 69 public List<WorkerInfo> getWorkerList() { 70 return workerInfos; 71 } 72 73 /** 74 * Get number of workers 75 * 76 * @return Number of workers 77 */ 78 public int getWorkerCount() { 79 return workerInfos.size(); 80 } 81 82 /** 83 * Get index for this worker 84 * 85 * @return Index of this worker 86 */ 87 public int getMyWorkerIndex() { 88 return myWorkerIndex; 89 } 90 91 /** 92 * For every worker this method returns unique number 93 * between 0 and N, where N is the total number of workers. 94 * This number stays the same throughout the computation. 95 * TaskID may be different from this number and task ID 96 * is not necessarily continuous 97 * @param workerInfo worker info object 98 * @return worker number 99 */ 100 public int getWorkerIndex(WorkerInfo workerInfo) { 101 return taskIdToIndex.get(workerInfo.getTaskId()); 102 } 103 }