AMashenkov commented on a change in pull request #9081: URL: https://github.com/apache/ignite/pull/9081#discussion_r645139164
########## File path: modules/core/src/main/java/org/apache/ignite/internal/processors/cache/query/DistributedCacheQueryReducer.java ########## @@ -0,0 +1,58 @@ +/* + * 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.ignite.internal.processors.cache.query; + +import java.util.UUID; +import org.apache.ignite.internal.IgniteInterruptedCheckedException; +import org.jetbrains.annotations.Nullable; + +/** + * Reducer for distributed cache query. + */ +public interface DistributedCacheQueryReducer<T> extends CacheQueryReducer<T> { + /** + * Callback that invoked after getting a page from remote node. Checks whether it is the last page for query or not. + * + * @param nodeId Node ID of remote page. + * @param last Whether page is last for specified node. + * @return Whether page is last for a query. Review comment: It looks like the method is called when we got a new page and notify the Reducer. What the purpose to get a flag to the caller back? Why reducer can't apply additional logic by itself or call a listener (like in true OOP) instead of return magic value. What the purpose of the `last` parameter? What does `false` value mean and what is the impact to return value? -- 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
