| /** |
| * 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 com.datatorrent.lib.math; |
| |
| import java.util.Collection; |
| |
| import com.datatorrent.api.DefaultInputPort; |
| |
| /** |
| * Aggregates input tuples that are collections of longs and double and emits result on four ports. |
| * <p> |
| * Invokes two abstract functions aggregateLongs(Collection<T> collection), and |
| * aggregateDoubles(Collection<T> collection) on input tuple and emits the |
| * result on four ports, namely \"doubleResult\", \"floatResult\", |
| * \"integerResult\", \"longResult\". Input tuple object has to be an |
| * implementation of the interface Collection<T>. Tuples are emitted on |
| * the output ports only if they are connected. This is done to avoid the cost |
| * of calling the functions when some ports are not connected. integerResult and |
| * floatResult get rounded results respectively. |
| * <br> |
| * This is a pass through operator<br> |
| * <b>Ports</b>:<br> |
| * <b>data</b>: expects Collection<T extends Number><br> |
| * <b>doubleResult</b>: emits Double<br> |
| * <b>floatResult</b>: emits Float<br> |
| * <b>integerResult</b>: emits Integer<br> |
| * <b>longResult</b>: emits Long<br> |
| * <br> |
| * |
| * @displayName Abstract Aggregate Calculator |
| * @category Math |
| * @tags aggregate, collection |
| * @since 0.3.3 |
| */ |
| public abstract class AbstractAggregateCalc<T extends Number> extends |
| AbstractOutput |
| { |
| /** |
| * Input port, accepts collection of values of type 'T'. |
| */ |
| public final transient DefaultInputPort<Collection<T>> input = new DefaultInputPort<Collection<T>>() |
| { |
| /** |
| * Aggregate calculation result is only emitted on output port if it is connected. |
| */ |
| @Override |
| public void process(Collection<T> collection) |
| { |
| Double dResult = null; |
| if (doubleResult.isConnected()) { |
| doubleResult.emit(dResult = aggregateDoubles(collection)); |
| } |
| |
| if (floatResult.isConnected()) { |
| floatResult.emit(dResult == null ? (float)(aggregateDoubles(collection)) : dResult.floatValue()); |
| } |
| |
| Long lResult = null; |
| if (longResult.isConnected()) { |
| longResult.emit(lResult = aggregateLongs(collection)); |
| } |
| |
| if (integerResult.isConnected()) { |
| integerResult.emit(lResult == null ? (int)aggregateLongs(collection) |
| : lResult.intValue()); |
| } |
| } |
| |
| }; |
| |
| /** |
| * Abstract function to be implemented by sub class, custom calculation on input aggregate. |
| * @param collection Aggregate of values |
| * @return calculated value. |
| */ |
| public abstract long aggregateLongs(Collection<T> collection); |
| |
| /** |
| * Abstract function to be implemented by sub class, custom calculation on input aggregate. |
| * @param collection Aggregate of values |
| * @return calculated value. |
| */ |
| public abstract double aggregateDoubles(Collection<T> collection); |
| } |