| /** |
| * 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.storm.streams.processors; |
| |
| import java.io.Serializable; |
| import org.apache.storm.annotation.InterfaceStability; |
| |
| /** |
| * A processor processes a stream of elements and produces some result. |
| * |
| * @param <T> the type of the input that is processed |
| */ |
| @InterfaceStability.Unstable |
| public interface Processor<T> extends Serializable { |
| /** |
| * Initializes the processor. This is typically invoked from the underlying storm bolt's prepare method. |
| * |
| * @param context the processor context |
| */ |
| void init(ProcessorContext context); |
| |
| /** |
| * Executes some operations on the input and possibly emits some results. |
| * |
| * @param input the input to be processed |
| * @param streamId the source stream id from where the input is received |
| */ |
| void execute(T input, String streamId); |
| |
| /** |
| * Punctuation marks end of a batch which can be used to compute and pass the results of one stage in the pipeline to the next. For e.g. |
| * emit the results of an aggregation. |
| * |
| * @param stream the stream id on which the punctuation arrived |
| */ |
| void punctuate(String stream); |
| } |