| /** |
| * 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.util; |
| |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.InputPortFieldAnnotation; |
| import com.datatorrent.api.annotation.OutputPortFieldAnnotation; |
| import com.datatorrent.common.util.BaseOperator; |
| |
| /** |
| * This is the base implementation of an operator, which consumes tuples. |
| * If the tuples satisfy a specified filtering function, then they are emitted. |
| * Subclasses should implement the filtering method. |
| * <p></p> |
| * @displayName Filter |
| * @category Algorithmic |
| * @tags filter |
| * @since 0.3.4 |
| */ |
| public abstract class FilterOperator extends BaseOperator |
| { |
| /** |
| * This is the input port on which tuples are received. |
| */ |
| @InputPortFieldAnnotation(optional = false) |
| public final transient DefaultInputPort<Object> in = new DefaultInputPort<Object>() |
| { |
| @Override |
| public void process(Object tuple) |
| { |
| if (satisfiesFilter(tuple)) { |
| out.emit(tuple); |
| } |
| } |
| |
| }; |
| |
| /** |
| * This is the output port, which emits tuples that satisfy the filter. |
| */ |
| @OutputPortFieldAnnotation(optional = false) |
| public final transient DefaultOutputPort<Object> out = new DefaultOutputPort<Object>(); |
| |
| public abstract boolean satisfiesFilter(Object tuple); |
| } |