vladimirg-db commented on code in PR #49029: URL: https://github.com/apache/spark/pull/49029#discussion_r1878028442
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/resolver/TimezoneAwareExpressionResolver.scala: ########## @@ -0,0 +1,75 @@ +/* + * 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.resolver + +import org.apache.spark.sql.catalyst.SQLConfHelper +import org.apache.spark.sql.catalyst.expressions.{Expression, TimeZoneAwareExpression} + +/** + * Resolves [[TimeZoneAwareExpressions]] by applying the session's local timezone. + * + * This class is responsible for resolving [[TimeZoneAwareExpression]]s by first resolving their + * children and then applying the session's local timezone. Additionally, ensures that any tags from + * the original expression are preserved during the resolution process. + * + * @constructor Creates a new TimezoneAwareExpressionResolver with the given expression resolver. + * @param expressionResolver The [[ExpressionResolver]] used to resolve child expressions. + */ +class TimezoneAwareExpressionResolver(expressionResolver: ExpressionResolverBase[Expression]) + extends ExpressionResolverBase[TimeZoneAwareExpression] + with ResolvesExpressionChildren + with SQLConfHelper { + + /** + * Resolves a [[TimeZoneAwareExpression]] by resolving its children and applying a timezone. + * + * @param unresolvedTimezoneExpression The [[TimeZoneAwareExpression]] to resolve. + * @return A resolved [[Expression]] with the session's local timezone applied. + */ + override def resolve(unresolvedTimezoneExpression: TimeZoneAwareExpression): Expression = { + val expressionWithResolvedChildren = + withResolvedChildren(unresolvedTimezoneExpression, expressionResolver.resolve) + withResolvedTimezoneCopyTags(expressionWithResolvedChildren, conf.sessionLocalTimeZone) + } + + /** + * Applies a timezone to a [[TimeZoneAwareExpression]] while preserving original tags. + * + * This method is particularly useful for cases like resolving [[Cast]] expressions where tags + * such as [[USER_SPECIFIED_CAST]] need to be preserved. + * + * @param expression The [[TimeZoneAwareExpression]] to apply the timezone to. + * @param timeZoneId The timezone ID to apply. + * @return A new [[TimeZoneAwareExpression]] with the specified timezone and original tags. + */ + def withResolvedTimezoneCopyTags(expression: Expression, timeZoneId: String): Expression = { + val withTimeZone = withResolvedTimezone(expression, timeZoneId) + withTimeZone.copyTagsFrom(expression) + withTimeZone + } + + /** + * Apply timezone to [[TimeZoneAwareExpression]] expressions. + */ + def withResolvedTimezone(expression: Expression, timeZoneId: String): Expression = + expression match { + case timezoneExpression: TimeZoneAwareExpression if timezoneExpression.timeZoneId.isEmpty => + timezoneExpression.withTimeZone(timeZoneId) Review Comment: @mihailotim-db can provide more context here. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
