| /** |
| * 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.apex.malhar.lib.window.accumulation; |
| |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.apex.malhar.lib.window.MergeAccumulation; |
| |
| /** |
| * Combine Join Accumulation, inner-joins tuples with same type from different streams. |
| * |
| * @since 3.6.0 |
| */ |
| public class InnerJoin<T> implements MergeAccumulation<T, T, List<Set<T>>, List<List<T>>> |
| { |
| |
| public InnerJoin() |
| { |
| //for kryo |
| } |
| |
| @Override |
| public List<Set<T>> accumulate(List<Set<T>> accumulatedValue, T input) |
| { |
| return accumulateWithIndex(0, accumulatedValue, input); |
| } |
| |
| @Override |
| public List<Set<T>> accumulate2(List<Set<T>> accumulatedValue, T input) |
| { |
| return accumulateWithIndex(1, accumulatedValue, input); |
| } |
| |
| |
| public List<Set<T>> accumulateWithIndex(int index, List<Set<T>> accumulatedValue, T input) |
| { |
| Set<T> accuSet = accumulatedValue.get(index); |
| accuSet.add(input); |
| accumulatedValue.set(index, accuSet); |
| return accumulatedValue; |
| } |
| |
| @Override |
| public List<Set<T>> defaultAccumulatedValue() |
| { |
| ArrayList<Set<T>> accu = new ArrayList<>(); |
| for (int i = 0; i < 2; i++) { |
| accu.add(new HashSet<T>()); |
| } |
| return accu; |
| } |
| |
| @Override |
| public List<Set<T>> merge(List<Set<T>> accumulatedValue1, List<Set<T>> accumulatedValue2) |
| { |
| for (int i = 0; i < 2; i++) { |
| Set<T> accuSet1 = accumulatedValue1.get(i); |
| Set<T> accuSet2 = accumulatedValue2.get(i); |
| accuSet1.addAll(accuSet2); |
| accumulatedValue1.set(i, accuSet1); |
| } |
| return accumulatedValue1; |
| } |
| |
| @Override |
| public List<List<T>> getOutput(List<Set<T>> accumulatedValue) |
| { |
| List<List<T>> result = new ArrayList<>(); |
| |
| // TODO: May need to revisit (use state manager). |
| result = getAllCombo(accumulatedValue, result, new ArrayList<T>()); |
| |
| return result; |
| } |
| |
| |
| public List<List<T>> getAllCombo(List<Set<T>> accu, List<List<T>> result, List<T> curList) |
| { |
| if (curList.size() == 2) { |
| result.add(curList); |
| return result; |
| } else { |
| for (T item : accu.get(curList.size())) { |
| List<T> tempList = new ArrayList<>(curList); |
| tempList.add(item); |
| result = getAllCombo(accu, result, tempList); |
| } |
| return result; |
| } |
| } |
| |
| |
| @Override |
| public List<List<T>> getRetraction(List<List<T>> value) |
| { |
| return new ArrayList<>(); |
| } |
| } |