| // Copyright 2017 Twitter. All rights reserved. |
| // |
| // Licensed 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.twitter.heron.api.windowing; |
| |
| import java.util.List; |
| |
| /** |
| * A callback for expiry, activation of events tracked by the {@link WindowManager} |
| * |
| * @param <T> The type of Event in the window (e.g. Tuple). |
| */ |
| public interface WindowLifecycleListener<T> { |
| /** |
| * Called on expiry of events from the window due to {@link EvictionPolicy} |
| * |
| * @param events the expired events |
| */ |
| void onExpiry(List<T> events); |
| |
| /** |
| * Called on activation of the window due to the {@link TriggerPolicy} |
| * |
| * @param events the list of current events in the window. |
| * @param newEvents the newly added events since last activation. |
| * @param expired the expired events since last activation. |
| * @param referenceTime the reference (event or processing) time that resulted in activation |
| */ |
| default void onActivation(List<T> events, List<T> newEvents, List<T> expired, Long |
| referenceTime) { |
| throw new UnsupportedOperationException("Not implemented"); |
| } |
| } |