wuchong commented on a change in pull request #14708: URL: https://github.com/apache/flink/pull/14708#discussion_r563305734
########## File path: flink-table/flink-table-runtime-blink/src/main/java/org/apache/flink/table/runtime/operators/window/slicing/SliceSharedAssigner.java ########## @@ -0,0 +1,81 @@ +/* + * 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.flink.table.runtime.operators.window.slicing; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.runtime.operators.aggregate.window.processors.SliceSharedWindowAggProcessor; + +import javax.annotation.Nullable; + +import java.util.Optional; +import java.util.function.Supplier; + +/** + * A {@link SliceAssigner} which shares slices for windows, which means a window is divided into + * multiple slices and need to merge the slices into windows when emitting windows. + * + * <p>Classical window of {@link SliceSharedAssigner} is hopping window. + */ +@Internal +public interface SliceSharedAssigner extends SliceAssigner { + + /** + * Determines which slices (if any) should be merged. + * + * @param sliceEnd the triggered slice, identified by end timestamp + * @param callback a callback that can be invoked to signal which slices should be merged. + */ + void mergeSlices(long sliceEnd, MergeCallback callback) throws Exception; + + /** + * Returns the optional end timestamp of next window which should be triggered. Empty if no + * following window to trigger for now. + * + * <p>The purpose of this method is avoid register too many timers for each hopping and + * cumulative slice, e.g. HOP(1day, 10s) needs register 4300 timers for every slice. In order to Review comment: Should be 8640? Why -1 ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
