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.master; 20 21 import org.apache.giraph.aggregators.Aggregator; 22 import org.apache.giraph.aggregators.AggregatorUsage; 23 import org.apache.hadoop.io.Writable; 24 25 /** 26 * Master compute can access and change aggregators through this interface 27 */ 28 public interface MasterAggregatorUsage extends AggregatorUsage { 29 /** 30 * Register an aggregator in preSuperstep() and/or preApplication(). This 31 * aggregator will have its value reset at the end of each super step. 32 * 33 * @param name of aggregator 34 * @param aggregatorClass Class type of the aggregator 35 * @param <A> Aggregator type 36 * @return True iff aggregator wasn't already registered 37 * @throws InstantiationException 38 * @throws IllegalAccessException 39 */ 40 <A extends Writable> boolean registerAggregator(String name, 41 Class<? extends Aggregator<A>> aggregatorClass) throws 42 InstantiationException, IllegalAccessException; 43 44 /** 45 * Register persistent aggregator in preSuperstep() and/or 46 * preApplication(). This aggregator will not reset value at the end of 47 * super step. 48 * 49 * @param name of aggregator 50 * @param aggregatorClass Class type of the aggregator 51 * @param <A> Aggregator type 52 * @return True iff aggregator wasn't already registered 53 * @throws InstantiationException 54 * @throws IllegalAccessException 55 */ 56 <A extends Writable> boolean registerPersistentAggregator(String name, 57 Class<? extends Aggregator<A>> aggregatorClass) throws 58 InstantiationException, IllegalAccessException; 59 60 /** 61 * Sets value of an aggregator. 62 * 63 * @param name Name of aggregator 64 * @param value Value to set 65 * @param <A> Aggregated value 66 */ 67 <A extends Writable> void setAggregatedValue(String name, A value); 68 }