/**
* 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.alibaba.jstorm.window;
import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.IComponent;
import backtype.storm.tuple.Tuple;
import java.util.Map;
/**
* A bolt abstraction for supporting time and count based sliding & tumbling windows.
*/
interface IWindowedBolt<T extends Tuple> extends IComponent {
void prepare(Map stormConf, TopologyContext context, OutputCollector collector);
void cleanup();
/**
* Init window state. This will be called before calling execute method.
*
* @return user-defined window state
*/
Object initWindowState(TimeWindow window);
/**
* Execute a tuple within a window. If a tuple belongs to multiple windows,
* all windows will be iterated and this method will be called on each window.
*
* @param tuple the tuple arrived
* @param state user-defined window state, note that currently only reference objects are supported, primitive
* type states are not supported. you are supposed to operate directly on state and the framework
* will update the state automatically.
* @param window the window to which the tuple belongs
*/
void execute(T tuple, Object state, TimeWindow window);
/**
* Purge the window. Called after the window is computed. Users may emit the whole state or a part of it.
*
* @param state user-defined window state,
* @param window the window to be purged.
*/
void purgeWindow(Object state, TimeWindow window);
}