| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package storm.trident.state; |
| |
| import java.util.List; |
| import storm.trident.operation.ReducerAggregator; |
| import storm.trident.tuple.TridentTuple; |
| |
| public class ReducerValueUpdater implements ValueUpdater<Object> { |
| List<TridentTuple> tuples; |
| ReducerAggregator agg; |
| |
| public ReducerValueUpdater(ReducerAggregator agg, List<TridentTuple> tuples) { |
| this.agg = agg; |
| this.tuples = tuples; |
| } |
| |
| @Override |
| public Object update(Object stored) { |
| Object ret = (stored == null) ? this.agg.init() : stored; |
| for (TridentTuple t : tuples) { |
| ret = this.agg.reduce(ret, t); |
| } |
| return ret; |
| } |
| } |