| /* |
| * 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.BaseOperator; |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.InputPortFieldAnnotation; |
| import com.datatorrent.api.annotation.OutputPortFieldAnnotation; |
| |
| /** |
| * 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); |
| } |