/**
* 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 backtype.storm.windowing;
/**
* An event is a wrapper object that gets stored in the window.
*
* @param <T> the type of the object thats wrapped. E.g Tuple
*/
interface Event<T> {
/**
* The event timestamp in millis. This could be the time
* when the source generated the tuple or the time
* when the tuple was received by a bolt.
*
* @return the event timestamp in milliseconds.
*/
long getTimestamp();
/**
* Returns the wrapped object, E.g. a tuple
*
* @return the wrapped object.
*/
T get();
/**
* If this is a watermark event or not. Watermark events are used
* for tracking time while processing event based ts.
*
* @return true if this is a watermark event
*/
boolean isWatermark();
}