cloud-fan commented on code in PR #40308: URL: https://github.com/apache/spark/pull/40308#discussion_r1132482968
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/AssignmentUtils.scala: ########## @@ -0,0 +1,275 @@ +/* + * 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.spark.sql.catalyst.analysis + +import scala.collection.mutable + +import org.apache.spark.sql.AnalysisException +import org.apache.spark.sql.catalyst.SQLConfHelper +import org.apache.spark.sql.catalyst.expressions.{Alias, Attribute, AttributeReference, CreateNamedStruct, Expression, ExtractValue, GetStructField, Literal, NamedExpression} +import org.apache.spark.sql.catalyst.plans.logical.Assignment +import org.apache.spark.sql.catalyst.util.CharVarcharUtils +import org.apache.spark.sql.connector.catalog.CatalogV2Implicits._ +import org.apache.spark.sql.errors.QueryCompilationErrors +import org.apache.spark.sql.internal.SQLConf.StoreAssignmentPolicy +import org.apache.spark.sql.types.{ArrayType, DataType, MapType, StructType} + +object AssignmentUtils extends SQLConfHelper with CastSupport { + + private case class ColumnUpdate(ref: Seq[String], expr: Expression) + + /** + * Aligns assignments to match table columns. + * <p> + * This method processes and reorders given assignments so that each target column gets + * an expression it should be set to. If a column does not have a matching assignment, + * it will be set to its current value. For example, if one passes table attributes c1, c2 + * and an assignment c2 = 1, this method will return c1 = c1, c2 = 1. + * <p> + * This method also handles updates to nested columns. If there is an assignment to a particular + * nested field, this method will construct a new struct with one field updated preserving other + * fields that have not been modified. For example, if one passes table attributes c1, c2 + * where c2 is a struct with fields n1 and n2 and an assignment c2.n2 = 1, this method will + * return c1 = c1, c2 = struct(c2.n1, 1). + * + * @param attrs table attributes + * @param assignments assignments to align + * @return aligned assignments that match table columns + */ + def alignAssignments( + attrs: Seq[Attribute], + assignments: Seq[Assignment]): Seq[Assignment] = { + + val errors = new mutable.ArrayBuffer[String]() + + val output = applyUpdates( + updates = assignments.map(toColumnUpdate), + cols = attrs.map(restoreActualType), + colExprs = attrs, + addError = err => errors += err) + + if (errors.nonEmpty) { + throw QueryCompilationErrors.invalidRowLevelOperationAssignments(assignments, errors.toSeq) + } + + attrs.zip(output).map { case (attr, expr) => Assignment(attr, expr) } + } + + private def toColumnUpdate(assignment: Assignment): ColumnUpdate = { + ColumnUpdate(toRef(assignment.key), assignment.value) + } + + private def restoreActualType(attr: Attribute): Attribute = { + attr.withDataType(CharVarcharUtils.getRawType(attr.metadata).getOrElse(attr.dataType)) + } + + private def applyUpdates( + updates: Seq[ColumnUpdate], + cols: Seq[Attribute], + colExprs: Seq[Expression], + addError: String => Unit, + colPath: Seq[String] = Nil): Seq[Expression] = { + + // iterate through columns at the current level and find matching updates + cols.zip(colExprs).map { case (col, colExpr) => + // find matches for this column or any of its children + val prefixMatchedUpdates = updates.filter(update => conf.resolver(update.ref.head, col.name)) + prefixMatchedUpdates match { + // if there is no exact match and no match for children, return the column expr as is + case matchedUpdates if matchedUpdates.isEmpty => + colExpr + + // if there is only one update and it is an exact match, return the assigned expression + case Seq(matchedUpdate) if isExactMatch(matchedUpdate, col) => + applyUpdate(matchedUpdate.expr, col, addError, colPath :+ col.name) + + // if there are matches only for children + case matchedUpdates if !hasExactMatch(matchedUpdates, col) => + val newColPath = colPath :+ col.name + col.dataType match { + case colType: StructType => + // build field expressions + val fieldExprs = colType.fields.zipWithIndex.map { case (field, ordinal) => + GetStructField(col, ordinal, Some(field.name)) + } + + // recursively apply this method to nested fields + val updatedFieldExprs = applyUpdates( + matchedUpdates.map(update => update.copy(ref = update.ref.tail)), + colType.toAttributes, + fieldExprs, + addError, + newColPath) + + // construct a new struct with updated field expressions + toNamedStruct(colType, updatedFieldExprs) + + case otherType => + addError( + "Updating nested fields is only supported for StructType but " + + s"${newColPath.quoted} is of type $otherType") + col + } + + // if there are conflicting updates, throw an exception + // there are two illegal scenarios: + // - multiple updates to the same column + // - updates to a top-level struct and its nested fields (like a.b and a.b.c) + case matchedUpdates if hasExactMatch(matchedUpdates, col) => + val conflictingColNames = matchedUpdates.map(update => (colPath ++ update.ref).quoted) + addError("Update conflicts for columns: " + conflictingColNames.distinct.mkString(", ")) + col + } + } + } + + private def toNamedStruct(structType: StructType, fieldExprs: Seq[Expression]): Expression = { + val namedStructExprs = structType.fields.zip(fieldExprs).flatMap { case (field, expr) => + Seq(Literal(field.name), expr) + } + CreateNamedStruct(namedStructExprs) + } + + private def hasExactMatch(updates: Seq[ColumnUpdate], col: NamedExpression): Boolean = { + updates.exists(isExactMatch(_, col)) + } + + private def isExactMatch(update: ColumnUpdate, col: NamedExpression): Boolean = { + update.ref match { + case Seq(namePart) if conf.resolver(namePart, col.name) => true + case _ => false + } + } + + private def applyUpdate( + value: Expression, + col: Attribute, + addError: String => Unit, + colPath: Seq[String]): Expression = { + + (value.dataType, col.dataType) match { + // no need to reorder inner fields or cast if types are equal ignoring nullability + case (valueType, colType) if valueType.sameType(colType) => + TableOutputResolver.checkNullability(value, col, conf, addError, colPath) + validateAssignment(valueType, colType, addError, colPath) + value + + case (valueType: StructType, colType: StructType) => + TableOutputResolver.checkNullability(value, col, conf, addError, colPath) + val resolvedValue = TableOutputResolver.resolveStructType( + value, valueType, colType, + conf, addError, colPath) + resolvedValue.getOrElse(col) + + case (valueType: ArrayType, colType: ArrayType) => + TableOutputResolver.checkNullability(value, col, conf, addError, colPath) + val resolvedValue = TableOutputResolver.resolveArrayType( + value, valueType, colType, + conf, addError, colPath) + resolvedValue.getOrElse(col) + + case (valueType: MapType, colType: MapType) => + TableOutputResolver.checkNullability(value, col, conf, addError, colPath) + val resolvedValue = TableOutputResolver.resolveMapType( + value, valueType, colType, + conf, addError, colPath) + resolvedValue.getOrElse(col) + + case (valueType, colType) => + TableOutputResolver.checkNullability(value, col, conf, addError, colPath) + + val colTypeHasCharVarchar = CharVarcharUtils.hasCharVarchar(colType) + val colTypeWithoutCharVarchar = if (colTypeHasCharVarchar) { + CharVarcharUtils.replaceCharVarcharWithString(colType) + } else { + colType + } + + validateAssignment(valueType, colTypeWithoutCharVarchar, addError, colPath) + + val casted = TableOutputResolver.cast( + value, colTypeWithoutCharVarchar, + conf, colPath.quoted) + + if (conf.charVarcharAsString || !colTypeHasCharVarchar) { + casted + } else { + CharVarcharUtils.stringLengthCheck(casted, colType) + } + } + } + + private def validateAssignment( + valueType: DataType, + expectedType: DataType, + addError: String => Unit, + colPath: Seq[String]): Unit = { + + conf.storeAssignmentPolicy match { + case StoreAssignmentPolicy.STRICT | StoreAssignmentPolicy.ANSI => + DataType.canWrite( + valueType, expectedType, byName = true, conf.resolver, colPath.quoted, + conf.storeAssignmentPolicy, addError) + + case _ => // OK + } + } + + /** + * Checks whether assignments are aligned and are compatible with table columns. + * + * @param attrs table attributes + * @param assignments assignments to check + * @return true if the assignments are aligned + */ + def aligned(attrs: Seq[Attribute], assignments: Seq[Assignment]): Boolean = { + if (attrs.size != assignments.size) { + return false + } + + attrs.zip(assignments).forall { case (attr, assignment) => + val key = assignment.key + val value = assignment.value + + val attrType = CharVarcharUtils.getRawType(attr.metadata).getOrElse(attr.dataType) + + sameRef(toRef(key), toRef(attr)) && + DataType.equalsIgnoreCompatibleNullability(value.dataType, attrType) && + (attr.nullable || !value.nullable) + } + } + + private def sameRef(ref: Seq[String], otherRef: Seq[String]): Boolean = { + ref.size == otherRef.size && ref.zip(otherRef).forall { case (namePart, otherNamePart) => + conf.resolver(namePart, otherNamePart) + } + } + + private def toRef(expr: Expression): Seq[String] = expr match { + case attr: AttributeReference => + Seq(attr.name) + case Alias(child, _) => + toRef(child) + case GetStructField(child, _, Some(name)) => + toRef(child) :+ name + case other: ExtractValue => Review Comment: how about `GetArrayStructField`? -- This is an automated message from the Apache Git Service. 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