rluvaton commented on code in PR #18183: URL: https://github.com/apache/datafusion/pull/18183#discussion_r2586279348
########## datafusion/physical-expr/src/expressions/case/literal_lookup_table/boolean_lookup_table.rs: ########## @@ -0,0 +1,122 @@ +// 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 crate::expressions::case::literal_lookup_table::WhenLiteralIndexMap; +use arrow::array::{Array, ArrayRef, AsArray, BooleanArray}; +use arrow::datatypes::DataType; +use datafusion_common::{internal_err, ScalarValue}; + +#[derive(Clone, Debug)] +pub(super) struct BooleanIndexMap { + true_index: Option<u32>, + false_index: Option<u32>, +} + +impl BooleanIndexMap { + /// Try creating a new lookup table from the given literals and else index + /// The index of each literal in the vector is used as the mapped value in the lookup table. + /// + /// `literals` are guaranteed to be unique and non-nullable + pub(super) fn try_new( + unique_non_null_literals: Vec<ScalarValue>, + ) -> datafusion_common::Result<Self> { + let mut true_index: Option<u32> = None; + let mut false_index: Option<u32> = None; + + for (index, literal) in unique_non_null_literals.into_iter().enumerate() { + match literal { + ScalarValue::Boolean(Some(true)) => { + if true_index.is_some() { + return internal_err!( + "Duplicate true literal found in literals for BooleanIndexMap" + ); + } + true_index = Some(index as u32); + } + ScalarValue::Boolean(Some(false)) => { + if false_index.is_some() { + return internal_err!( + "Duplicate false literal found in literals for BooleanIndexMap" + ); + } + false_index = Some(index as u32); + } + ScalarValue::Boolean(None) => { + return internal_err!( + "Null literal found in non-null literals for BooleanIndexMap" + ) + } + _ => { + return internal_err!( + "Non-boolean literal found in literals for BooleanIndexMap" + ) + } + } + } + + Ok(Self { + true_index, + false_index, + }) + } + + fn map_boolean_array_to_when_indices( + &self, + array: &BooleanArray, + else_index: u32, + ) -> datafusion_common::Result<Vec<u32>> { + let true_index = self.true_index.unwrap_or(else_index); + let false_index = self.false_index.unwrap_or(else_index); + + Ok(array + .into_iter() + .map(|value| match value { + Some(true) => true_index, + Some(false) => false_index, + None => else_index, + }) + .collect::<Vec<u32>>()) + } +} + +impl WhenLiteralIndexMap for BooleanIndexMap { + fn map_to_when_indices( + &self, + array: &ArrayRef, + else_index: u32, + ) -> datafusion_common::Result<Vec<u32>> { + match array.data_type() { + DataType::Boolean => { + self.map_boolean_array_to_when_indices(array.as_boolean(), else_index) + } + // We support dictionary boolean array as we create the lookup table in `CaseWhen` expression + // creation when we don't know the schema, so we may receive dictionary encoded boolean arrays at execution time. + DataType::Dictionary(_, value_type) + if value_type.as_ref() == &DataType::Boolean => + { + // Since it is not common to have dictionary encoded boolean arrays + // at all than it is ok to do the cast here to simplify the implementation. + let converted = arrow::compute::cast(array.as_ref(), &DataType::Boolean)?; Review Comment: yes -- 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]
