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ASF GitHub Bot commented on FLINK-7491: --------------------------------------- Github user fhueske commented on a diff in the pull request: https://github.com/apache/flink/pull/4585#discussion_r140022994 --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/aggfunctions/CollectAggFunction.scala --- @@ -0,0 +1,121 @@ +/* + * 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.functions.aggfunctions + +import java.lang.{Iterable => JIterable} +import java.util +import java.util.function.BiFunction + +import org.apache.flink.api.common.typeinfo.TypeInformation +import org.apache.flink.api.java.tuple.{Tuple1 => JTuple1} +import org.apache.flink.api.java.typeutils.{GenericTypeInfo, TupleTypeInfo} +import org.apache.flink.table.functions.AggregateFunction + +import scala.collection.JavaConverters._ + +/** The initial accumulator for Collect aggregate function */ +class CollectAccumulator[E] extends JTuple1[util.Map[E, Integer]] + +abstract class CollectAggFunction[E] + extends AggregateFunction[util.Map[E, Integer], CollectAccumulator[E]] { + + @transient + private lazy val addFunction = new BiFunction[Integer, Integer, Integer] { + override def apply(t: Integer, u: Integer): Integer = t + u + } + + override def createAccumulator(): CollectAccumulator[E] = { + val acc = new CollectAccumulator[E]() + acc.f0 = new util.HashMap[E, Integer]() + acc + } + + def accumulate(accumulator: CollectAccumulator[E], value: E): Unit = { + if (value != null) { + if (accumulator.f0.containsKey(value)) { + val add = (x: Integer, y: Integer) => x + y --- End diff -- `add` is not used, right? > Support COLLECT Aggregate function in Flink SQL > ----------------------------------------------- > > Key: FLINK-7491 > URL: https://issues.apache.org/jira/browse/FLINK-7491 > Project: Flink > Issue Type: New Feature > Components: Table API & SQL > Reporter: Shuyi Chen > Assignee: Shuyi Chen > -- This message was sent by Atlassian JIRA (v6.4.14#64029)