cashmand commented on code in PR #7921: URL: https://github.com/apache/arrow-rs/pull/7921#discussion_r2205302590
########## parquet-variant-compute/src/shredding.rs: ########## @@ -0,0 +1,364 @@ +// 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. + +use arrow_schema::{ArrowError, DataType, Fields}; + +// Keywords defined by the shredding spec +pub const METADATA: &str = "metadata"; +pub const VALUE: &str = "value"; +pub const TYPED_VALUE: &str = "typed_value"; + +pub fn validate_value_and_typed_value( + fields: &Fields, + allow_both_null: bool, +) -> Result<(), ArrowError> { + let value_field_res = fields.iter().find(|f| f.name() == VALUE); + let typed_value_field_res = fields.iter().find(|f| f.name() == TYPED_VALUE); + + if !allow_both_null { + if let (None, None) = (value_field_res, typed_value_field_res) { + return Err(ArrowError::InvalidArgumentError( + "Invalid VariantArray: StructArray must contain either `value` or `typed_value` fields or both.".to_string() + )); + } + } + + if let Some(value_field) = value_field_res { + // if !value_field.is_nullable() { + // return Err(ArrowError::InvalidArgumentError( + // "Expected value field to be nullable".to_string(), + // )); + // } Review Comment: The relevant paragraph from the [spec](https://github.com/apache/parquet-format/blob/master/VariantShredding.md#objects) for my second comment: ``` Each shredded field in the typed_value group is represented as a required group that contains optional value and typed_value fields. The value field stores the value as Variant-encoded binary when the typed_value cannot represent the field. This layout enables readers to skip data based on the field statistics for value and typed_value. The typed_value field may be omitted when not shredding fields as a specific type. ``` -- 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: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
