| /** |
| * 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.heron.streamlet.impl.groupings; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.heron.api.grouping.CustomStreamGrouping; |
| import org.apache.heron.api.topology.TopologyContext; |
| import org.apache.heron.api.utils.Utils; |
| import org.apache.heron.streamlet.SerializableBiFunction; |
| |
| /** |
| * RemapCustomGrouping is the class that routes the incoming tuples |
| * into the ReMapBolt. It takes in a user defined remapFn as input. |
| * The remapFn defines how tuples should be redirected. |
| */ |
| public class RemapCustomGrouping<R> implements CustomStreamGrouping { |
| private static final long serialVersionUID = 8118844912340601079L; |
| private List<Integer> taskIds; |
| private SerializableBiFunction<? super R, Integer, List<Integer>> remapFn; |
| |
| public RemapCustomGrouping(SerializableBiFunction<? super R, Integer, List<Integer>> remapFn) { |
| this.remapFn = remapFn; |
| } |
| |
| @Override |
| public void prepare(TopologyContext context, String component, |
| String streamId, List<Integer> targetTasks) { |
| this.taskIds = targetTasks; |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public List<Integer> chooseTasks(List<Object> values) { |
| List<Integer> ret = new ArrayList<>(); |
| R obj = (R) values.get(0); |
| List<Integer> targets = remapFn.apply(obj, taskIds.size()); |
| for (Integer target : targets) { |
| ret.add(Utils.assignKeyToTask(target, taskIds)); |
| } |
| return ret; |
| } |
| } |