storm-client/src/jvm/org/apache/storm/topology/IWindowedBolt.java

/**
 * 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.topology;

import java.util.Map;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.windowing.TimestampExtractor;
import org.apache.storm.windowing.TupleWindow;

/**
 * A bolt abstraction for supporting time and count based sliding & tumbling windows.
 */
public interface IWindowedBolt extends IComponent {
    /**
     * This is similar to the {@link org.apache.storm.task.IBolt#prepare(Map, TopologyContext, OutputCollector)} except that while emitting,
     * the tuples are automatically anchored to the tuples in the inputWindow.
     */
    void prepare(Map<String, Object> topoConf, TopologyContext context, OutputCollector collector);

    /**
     * Process the tuple window and optionally emit new tuples based on the tuples in the input window.
     */
    void execute(TupleWindow inputWindow);

    void cleanup();

    /**
     * Return a {@link TimestampExtractor} for extracting timestamps from a tuple for event time based processing, or null for processing
     * time.
     *
     * @return the timestamp extractor
     */
    TimestampExtractor getTimestampExtractor();
}