| /* |
| * Copyright (c) 2013 DataTorrent, Inc. ALL Rights Reserved. |
| * |
| * Licensed 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 com.datatorrent.lib.util; |
| |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.Context.OperatorContext; |
| import com.datatorrent.api.Operator.Unifier; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * This unifier consumes hash maps whose keys are objects and whose values are numbers. |
| * The values for each key are summed and emitted in a hash map at the end of each application window. |
| * <p> |
| * This unifier uses round robin partitioning. |
| * </p> |
| * @displayName Unifier Hash Map Sum Keys |
| * @category Algorithmic |
| * @tags numeric, key value |
| * @since 0.3.2 |
| */ |
| public class UnifierHashMapSumKeys<K, V extends Number> extends BaseNumberKeyValueOperator<K,V> implements Unifier<HashMap<K, V>> |
| { |
| public HashMap<K, Double> mergedTuple = new HashMap<K, Double>(); |
| /** |
| * This is the output port which emits key value pairs which map keys to sums. |
| */ |
| public final transient DefaultOutputPort<HashMap<K, V>> mergedport = new DefaultOutputPort<HashMap<K, V>>(); |
| |
| @Override |
| public void process(HashMap<K, V> tuple) |
| { |
| for (Map.Entry<K, V> e: tuple.entrySet()) { |
| Double val = mergedTuple.get(e.getKey()); |
| if (val == null) { |
| mergedTuple.put(e.getKey(), e.getValue().doubleValue()); |
| } |
| else { |
| val += e.getValue().doubleValue(); |
| mergedTuple.put(e.getKey(), val); |
| } |
| } |
| } |
| |
| /** |
| * emits mergedTuple on mergedport if it is not empty |
| */ |
| @Override |
| public void endWindow() |
| { |
| if (!mergedTuple.isEmpty()) { |
| HashMap<K, V> stuples = new HashMap<K, V>(); |
| for (Map.Entry<K, Double> e: mergedTuple.entrySet()) { |
| stuples.put(e.getKey(), getValue(e.getValue())); |
| } |
| mergedport.emit(stuples); |
| mergedTuple = new HashMap<K, Double>(); |
| } |
| } |
| |
| /** |
| * a no-op |
| * @param context |
| */ |
| @Override |
| public void setup(OperatorContext context) |
| { |
| } |
| |
| /** |
| * a noop |
| */ |
| @Override |
| public void teardown() |
| { |
| } |
| } |