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.block_app.framework.piece.global_comm; 19 20 import org.apache.giraph.block_app.framework.api.BlockMasterApi; 21 import org.apache.giraph.master.MasterGlobalCommUsage; 22 23 /** 24 * Handle to a reducer. 25 * 26 * @param <S> Single value type 27 * @param <R> Reduced value type 28 */ 29 public interface ReducerHandle<S, R> { 30 /** Reduce single value */ 31 void reduce(S valueToReduce); 32 /** Get reduced value */ 33 R getReducedValue(MasterGlobalCommUsage master); 34 35 /** 36 * Broadcast reduced value from master 37 * 38 * @return Handle to the broadcasted value. 39 */ 40 BroadcastHandle<R> broadcastValue(BlockMasterApi master); 41 }