linrrzqqq commented on code in PR #66968: URL: https://github.com/apache/doris/pull/66968#discussion_r3868327088
########## fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/MapLambdaFunctionUtils.java: ########## @@ -0,0 +1,129 @@ +// 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.doris.nereids.trees.expressions.functions.scalar; + +import org.apache.doris.nereids.exceptions.AnalysisException; +import org.apache.doris.nereids.trees.expressions.ArrayItemReference; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.Slot; +import org.apache.doris.nereids.trees.expressions.literal.IntegerLiteral; +import org.apache.doris.nereids.types.ArrayType; +import org.apache.doris.nereids.types.DataType; +import org.apache.doris.nereids.types.MapType; +import org.apache.doris.nereids.types.StructField; +import org.apache.doris.nereids.types.StructType; + +import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; + +import java.util.List; + +/** Utilities for building Map Lambda functions from one bound Map-entry array driver. */ +final class MapLambdaFunctionUtils { + + private MapLambdaFunctionUtils() { + } + + /** Build the function-specific body around a bound Map-entry Lambda. */ + static RewrittenMapLambda rewrite(Lambda lambda, EntryBodyBuilder bodyBuilder) { + Expression mapExpression = extractMapExpression(lambda); + List<ArrayItemReference> arguments = lambda.getLambdaArguments(); + ArrayItemReference entryArgument = arguments.get(0); + Slot entrySlot = entryArgument.toSlot(); + Expression key = new ElementAt(entrySlot, new IntegerLiteral(1)); + Expression value = new ElementAt(entrySlot, new IntegerLiteral(2)); + + Expression rewrittenBody = bodyBuilder.build(lambda.getLambdaFunction(), key, value, entrySlot); + Lambda rewrittenLambda = new Lambda( + ImmutableList.of(entryArgument.getName()), rewrittenBody, ImmutableList.of(entryArgument)); + return new RewrittenMapLambda(mapExpression, rewrittenLambda); + } + + /** Require a bound Lambda argument. */ + static Lambda requireLambda(String functionName, Expression expression) { + if (!(expression instanceof Lambda)) { + throw new AnalysisException(String.format( + "The 1st arg of %s must be lambda but is %s", functionName, expression)); + } + return (Lambda) expression; + } + + /** Fill only NULL_TYPE positions from the corresponding input Map field type. */ + static DataType mergeNestedNullTypes(DataType outputType, DataType inputType) { + if (outputType.isNullType()) { + return inputType; + } else if (outputType instanceof ArrayType && inputType instanceof ArrayType) { + return ArrayType.of(mergeNestedNullTypes( + ((ArrayType) outputType).getItemType(), ((ArrayType) inputType).getItemType())); + } else if (outputType instanceof MapType && inputType instanceof MapType) { + return MapType.of( + mergeNestedNullTypes( + ((MapType) outputType).getKeyType(), ((MapType) inputType).getKeyType()), + mergeNestedNullTypes( + ((MapType) outputType).getValueType(), ((MapType) inputType).getValueType())); + } else if (outputType instanceof StructType && inputType instanceof StructType) { + List<StructField> outputFields = ((StructType) outputType).getFields(); + List<StructField> inputFields = ((StructType) inputType).getFields(); + if (outputFields.size() != inputFields.size()) { + return outputType; + } + ImmutableList.Builder<StructField> fields + = ImmutableList.builderWithExpectedSize(outputFields.size()); + for (int i = 0; i < outputFields.size(); i++) { + fields.add(outputFields.get(i).withDataType(mergeNestedNullTypes( + outputFields.get(i).getDataType(), inputFields.get(i).getDataType()))); + } + return new StructType(fields.build()); + } + return outputType; + } + + private static Expression extractMapExpression(Lambda lambda) { + List<ArrayItemReference> arguments = lambda.getLambdaArguments(); + Preconditions.checkArgument(arguments.size() == 1, + "A bound Map Lambda must have one entry argument"); + Expression entries = arguments.get(0).getArrayExpression(); + Preconditions.checkArgument(entries instanceof MapEntries, + "A bound Map Lambda must use a map_entries argument"); + return entries.child(0); + } + + @FunctionalInterface + interface EntryBodyBuilder { + Expression build(Expression body, Expression key, Expression value, Slot entry); + } + + /** One original Map and its one-driver entry Lambda. */ + static final class RewrittenMapLambda { + private final Expression mapExpression; + private final Lambda lambda; + + private RewrittenMapLambda(Expression mapExpression, Lambda lambda) { + this.mapExpression = mapExpression; + this.lambda = lambda; + } + + Expression getMapExpression() { + return mapExpression; + } + + ArrayMap toArrayMap() { + return new ArrayMap(lambda); Review Comment: array map 原本的执行不处理 null 的问题,无关 -- This is an automated message from the Apache Git Service. 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