bowenli86 commented on a change in pull request #8700: [FLINK-12657][hive] Integrate Flink with Hive UDF URL: https://github.com/apache/flink/pull/8700#discussion_r293094641
########## File path: flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/table/functions/hive/HiveScalarFunction.java ########## @@ -0,0 +1,107 @@ +/* + * 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.hive; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.table.functions.FunctionContext; +import org.apache.flink.table.functions.ScalarFunction; +import org.apache.flink.table.types.CollectionDataType; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.utils.LegacyTypeInfoDataTypeConverter; + +import org.apache.hadoop.hive.ql.exec.UDF; +import org.apache.hadoop.hive.ql.udf.generic.GenericUDF; +import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; + + +/** + * Abstract class to provide more information for Hive {@link UDF} and {@link GenericUDF} functions. + */ +@Internal +public abstract class HiveScalarFunction<UDFType> extends ScalarFunction implements HiveFunction { + + protected final HiveFunctionWrapper<UDFType> hiveFunctionWrapper; + + protected Object[] constantArguments; + protected DataType[] argTypes; + + protected transient UDFType function; Review comment: @xuefuz sorry that I accidentally deleted your comment here. So your question is what's the difference between this function instance and the one in `HiveFunctionWrapper`. The one in `HiveFunctionWrapper` acts as a cache for GenericUDF, GenericUDTA, and UDAFResolver, but not `UDF` (I'm still not sure why not `UDF`, that logic is borrowed from Spark). So this function instance in `HiveScalarFunction` is actually the one gonna be invoked to process data. ---------------------------------------------------------------- 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 With regards, Apache Git Services
