dawidwys commented on code in PR #23173: URL: https://github.com/apache/flink/pull/23173#discussion_r1510988286
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/functions/scalar/ArrayExceptFunction.java: ########## @@ -0,0 +1,102 @@ +/* + * 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.functions.scalar; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.data.ArrayData; +import org.apache.flink.table.data.GenericArrayData; +import org.apache.flink.table.functions.BuiltInFunctionDefinitions; +import org.apache.flink.table.functions.FunctionContext; +import org.apache.flink.table.functions.SpecializedFunction; +import org.apache.flink.table.runtime.util.EqualityAndHashcodeProvider; +import org.apache.flink.table.runtime.util.ObjectContainer; +import org.apache.flink.table.types.CollectionDataType; +import org.apache.flink.table.types.DataType; +import org.apache.flink.util.FlinkRuntimeException; + +import javax.annotation.Nullable; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** Implementation of {@link BuiltInFunctionDefinitions#ARRAY_EXCEPT}. */ +@Internal +public class ArrayExceptFunction extends BuiltInScalarFunction { + private final ArrayData.ElementGetter elementGetter; + private final EqualityAndHashcodeProvider equalityAndHashcodeProvider; + + public ArrayExceptFunction(SpecializedFunction.SpecializedContext context) { + super(BuiltInFunctionDefinitions.ARRAY_EXCEPT, context); + final DataType dataType = + ((CollectionDataType) context.getCallContext().getArgumentDataTypes().get(0)) + .getElementDataType() + .toInternal(); + elementGetter = ArrayData.createElementGetter(dataType.toInternal().getLogicalType()); + this.equalityAndHashcodeProvider = new EqualityAndHashcodeProvider(context, dataType); + } + + @Override + public void open(FunctionContext context) throws Exception { + equalityAndHashcodeProvider.open(context); + } + + public @Nullable ArrayData eval(ArrayData arrayOne, ArrayData arrayTwo) { + try { + if (arrayOne == null || arrayTwo == null) { + return null; + } + + List<Object> list = new ArrayList<>(); + Map<ObjectContainer, Integer> map = new HashMap<>(); + for (int pos = 0; pos < arrayTwo.size(); pos++) { + final Object element = elementGetter.getElementOrNull(arrayTwo, pos); + if (element == null) { + map.merge(null, 1, (k, v) -> v + 1); + } else { + ObjectContainer objectContainer = new ObjectContainer(element); + map.merge(objectContainer, 1, (k, v) -> v + 1); + } + } + for (int pos = 0; pos < arrayOne.size(); pos++) { + final Object element = elementGetter.getElementOrNull(arrayOne, pos); + final ObjectContainer objectContainer = + element == null ? null : new ObjectContainer(element); + if (map.containsKey(objectContainer)) { + if (map.get(objectContainer) > 1) { + map.put(objectContainer, map.get(objectContainer) - 1); + } else { + map.remove(objectContainer); + } Review Comment: Let's be consistent. If you do here: ``` final ObjectContainer objectContainer = element == null ? null : new ObjectContainer(element); ``` do it also few lines above: ``` if (element == null) { map.merge(null, 1, (k, v) -> v + 1); } else { ObjectContainer objectContainer = new ObjectContainer(element); map.merge(objectContainer, 1, (k, v) -> v + 1); } ``` Don't mix and match different approaches, because it only confuses the reader. Code is read more often than written and we should optimise for reading. Doing the same thing in two different ways forces the reader to analyze the code twice spending twice as much time reviewing it. -- 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
