| /* |
| * 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.samza.task; |
| |
| /** |
| * Add-on interface to {@link org.apache.samza.task.StreamTask} implementations to add code which will be run on |
| * a specified time interval (via configuration). This can be used to implement direct time-based windowing or, |
| * with a frequent window interval, windowing based on some other condition which is checked during the call to |
| * window. The window method will be called even if no messages are received for a particular StreamTask. |
| */ |
| public interface WindowableTask { |
| /** |
| * Called by TaskRunner for each implementing task at the end of every specified window. |
| * @param collector Contains the means of sending message envelopes to the output stream. The collector must only |
| * be used during the current call to the window method; you should not reuse the collector between invocations |
| * of this method. |
| * |
| * @param coordinator Manages execution of tasks. |
| * @throws Exception Any exception types encountered during the execution of the processing task. |
| */ |
| void window(MessageCollector collector, TaskCoordinator coordinator) throws Exception; |
| } |
