| /* |
| 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.edgent.oplet.core; |
| |
| /** |
| * Oplet that allows a peek at each tuple and always forwards a tuple onto |
| * its single output port. |
| * |
| * {@link #peek(Object)} is called before the tuple is forwarded |
| * and it is intended that the peek be a low cost operation |
| * such as increasing a metric. |
| * |
| * @param <T> |
| * Type of the tuple. |
| */ |
| public abstract class Peek<T> extends Pipe<T, T> { |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public final void accept(T tuple) { |
| peek(tuple); |
| submit(tuple); |
| } |
| |
| protected abstract void peek(T tuple); |
| } |