dawidwys commented on code in PR #23173: URL: https://github.com/apache/flink/pull/23173#discussion_r1492239042
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/functions/scalar/ArrayExceptFunction.java: ########## @@ -0,0 +1,161 @@ +/* + * 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.api.DataTypes; +import org.apache.flink.table.api.Expressions; +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.types.CollectionDataType; +import org.apache.flink.table.types.DataType; +import org.apache.flink.util.FlinkRuntimeException; + +import javax.annotation.Nullable; + +import java.lang.invoke.MethodHandle; +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Set; + +import static org.apache.flink.table.api.Expressions.$; + +/** Implementation of {@link BuiltInFunctionDefinitions#ARRAY_EXCEPT}. */ +@Internal +public class ArrayExceptFunction extends BuiltInScalarFunction { + private final ArrayData.ElementGetter elementGetter; + private final SpecializedFunction.ExpressionEvaluator hashcodeEvaluator; + private final SpecializedFunction.ExpressionEvaluator equalityEvaluator; + private transient MethodHandle hashcodeHandle; + + private transient MethodHandle equalityHandle; + + public ArrayExceptFunction(SpecializedFunction.SpecializedContext context) { + super(BuiltInFunctionDefinitions.ARRAY_EXCEPT, context); + final DataType dataType = + ((CollectionDataType) context.getCallContext().getArgumentDataTypes().get(0)) + .getElementDataType() + .toInternal(); + elementGetter = ArrayData.createElementGetter(dataType.toInternal().getLogicalType()); + hashcodeEvaluator = + context.createEvaluator( + Expressions.call("$HASHCODE$1", $("element1")), + DataTypes.INT(), + DataTypes.FIELD("element1", dataType.notNull().toInternal())); + equalityEvaluator = + context.createEvaluator( + $("element1").isEqual($("element2")), + DataTypes.BOOLEAN(), + DataTypes.FIELD("element1", dataType.notNull().toInternal()), + DataTypes.FIELD("element2", dataType.notNull().toInternal())); + } + + @Override + public void open(FunctionContext context) throws Exception { + hashcodeHandle = hashcodeEvaluator.open(context); + equalityHandle = equalityEvaluator.open(context); + } + + public @Nullable ArrayData eval(ArrayData arrayOne, ArrayData arrayTwo) { + try { + if (arrayOne == null) { + return null; + } + + List<Object> list = new ArrayList<>(); + Set<ObjectContainer> seen = new HashSet<>(); + + boolean isNullPresentInArrayTwo = false; + if (arrayTwo != null) { + for (int pos = 0; pos < arrayTwo.size(); pos++) { + final Object element = elementGetter.getElementOrNull(arrayTwo, pos); + if (element == null) { + isNullPresentInArrayTwo = true; + } else { + ObjectContainer objectContainer = new ObjectContainer(element); + seen.add(objectContainer); + } + } + } + boolean isNullPresentInArrayOne = false; + for (int pos = 0; pos < arrayOne.size(); pos++) { + final Object element = elementGetter.getElementOrNull(arrayOne, pos); + if (element == null) { + isNullPresentInArrayOne = true; + } else { + ObjectContainer objectContainer = new ObjectContainer(element); + if (!seen.contains(objectContainer)) { + seen.add(objectContainer); + list.add(element); + } + } + } + if (!isNullPresentInArrayTwo && isNullPresentInArrayOne) { + list.add(null); + } Review Comment: Is this what we want? Have you checked this is what other DBs do? If that's the case can we add this behaviour to the docs? Personally, I find it really surprising. -- 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
