KurtYoung commented on a change in pull request #8109: [FLINK-12017][table-planner-blink] Support translation from Rank/Deduplicate to StreamTransformation URL: https://github.com/apache/flink/pull/8109#discussion_r274851278
########## File path: flink-table/flink-table-runtime-blink/src/main/java/org/apache/flink/table/runtime/deduplicate/DeduplicateFunctionHelper.java ########## @@ -0,0 +1,68 @@ +/* + * 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.deduplicate; + +import org.apache.flink.api.common.state.ValueState; +import org.apache.flink.table.dataformat.BaseRow; +import org.apache.flink.table.dataformat.util.BaseRowUtil; +import org.apache.flink.table.generated.RecordEqualiser; +import org.apache.flink.util.Collector; +import org.apache.flink.util.Preconditions; + +/** + * Utility for deduplicate function. + */ +class DeduplicateFunctionHelper { + + static void processLastRow(BaseRow preRow, BaseRow currentRow, boolean generateRetraction, + boolean stateCleaningEnabled, ValueState<BaseRow> pkRow, RecordEqualiser equaliser, + Collector<BaseRow> out) throws Exception { + // should be accumulate msg. + Preconditions.checkArgument(BaseRowUtil.isAccumulateMsg(currentRow)); + if (!stateCleaningEnabled && preRow != null && + equaliser.equalsWithoutHeader(preRow, currentRow)) { + // If state cleaning is not enabled, don't emit retraction and acc message. But if state cleaning is + // enabled, we have to emit message to prevent too early state eviction of downstream operators. + return; + } + pkRow.update(currentRow); + if (preRow != null && generateRetraction) { + preRow.setHeader(BaseRowUtil.RETRACT_MSG); + out.collect(preRow); + } + out.collect(currentRow); + } + + static void processFirstRow(BaseRow preRow, BaseRow currentRow, ValueState<BaseRow> pkRow, Review comment: add some comments to explain what are these rows ---------------------------------------------------------------- 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: [email protected] With regards, Apache Git Services
