| /** |
| * 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.apex.malhar.lib.window; |
| |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import com.datatorrent.api.Component; |
| |
| /** |
| * Interface for generators for implicit watermarks. |
| * An operator which does not want to rely on explicit watermarks (generated from upstream), |
| * can use implementations of this interface to get implicit watermarks. |
| * |
| * @since 3.7.0 |
| */ |
| @InterfaceStability.Evolving |
| public interface ImplicitWatermarkGenerator extends Component |
| { |
| /** |
| * Called on arrival of every tuple. |
| * Implementations would update the state of the watermark generator in order to keep their state updated |
| * @param t the incoming windowed tuple |
| * @param currentProcessingTime the current notion of processing time |
| * (usually the system time generated based on the window id) |
| */ |
| void processTupleForWatermark(Tuple.WindowedTuple t, long currentProcessingTime); |
| |
| /** |
| * Returns the current watermark tuple as per the generator's state |
| * @param currentProcessingTime the current notion of processing time |
| * (usually the system time generated based on the window id) |
| * @return the latest watermark tuple created based on the implementation |
| */ |
| ControlTuple.Watermark getWatermarkTuple(long currentProcessingTime); |
| } |