xuyangzhong commented on code in PR #24068: URL: https://github.com/apache/flink/pull/24068#discussion_r1456822860
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/operators/window/MergeCallback.java: ########## @@ -0,0 +1,43 @@ +/* + * 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; + +import javax.annotation.Nullable; + +/** + * Callback to be used in when merging slices or windows for specifying which slices or windows + * should be merged. + * + * @param <W> The type {@link Window} for windows or the type {@link Long} for slices that this + * callback used to merge. + * @param <R> The result type like {@link java.util.Collection} or {@link Iterable} to specify which + * slices or windows should be merged. TODO use {@link java.util.Collection} uniformly. + */ +public interface MergeCallback<W, R> { + + /** + * Specifies that states of the given windows or slices should be merged into the result window + * or slice. + * + * @param mergeResult The resulting merged window or slice, {@code null} if it represents a + * non-state namespace. + * @param toBeMerged Windows or slices that should be merged into one window or slice. + */ + void merge(@Nullable W mergeResult, R toBeMerged) throws Exception; Review Comment: Agree with you. I create an extra JIRA for this. https://issues.apache.org/jira/browse/FLINK-34138 -- 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. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
