| /* |
| * 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 org.apache.storm.metric.api; |
| |
| public class MeanReducer implements IReducer<MeanReducerState> { |
| @Override |
| public MeanReducerState init() { |
| return new MeanReducerState(); |
| } |
| |
| @Override |
| public MeanReducerState reduce(MeanReducerState acc, Object input) { |
| acc.count++; |
| if (input instanceof Double) { |
| acc.sum += (Double) input; |
| } else if (input instanceof Long) { |
| acc.sum += ((Long) input).doubleValue(); |
| } else if (input instanceof Integer) { |
| acc.sum += ((Integer) input).doubleValue(); |
| } else { |
| throw new RuntimeException( |
| "MeanReducer::reduce called with unsupported input type `" + input.getClass() |
| + "`. Supported types are Double, Long, Integer."); |
| } |
| return acc; |
| } |
| |
| @Override |
| public Object extractResult(MeanReducerState acc) { |
| if (acc.count > 0) { |
| return acc.sum / (double) acc.count; |
| } else { |
| return null; |
| } |
| } |
| } |