parthchandra commented on code in PR #1169: URL: https://github.com/apache/datafusion-comet/pull/1169#discussion_r1887185774
########## native/spark-expr/src/schema_adapter.rs: ########## @@ -0,0 +1,376 @@ +// 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. + +//! Custom schema adapter that uses Spark-compatible casts + +use crate::cast::cast_supported; +use crate::{spark_cast, SparkCastOptions}; +use arrow_array::{new_null_array, Array, RecordBatch, RecordBatchOptions}; +use arrow_schema::{Schema, SchemaRef}; +use datafusion::datasource::schema_adapter::{SchemaAdapter, SchemaAdapterFactory, SchemaMapper}; +use datafusion_common::plan_err; +use datafusion_expr::ColumnarValue; +use std::sync::Arc; + +/// An implementation of DataFusion's `SchemaAdapterFactory` that uses a Spark-compatible +/// `cast` implementation. +#[derive(Clone, Debug)] +pub struct SparkSchemaAdapterFactory { + /// Spark cast options + cast_options: SparkCastOptions, +} + +impl SparkSchemaAdapterFactory { + pub fn new(options: SparkCastOptions) -> Self { + Self { + cast_options: options, + } + } +} + +impl SchemaAdapterFactory for SparkSchemaAdapterFactory { + /// Create a new factory for mapping batches from a file schema to a table + /// schema. + /// + /// This is a convenience for [`DefaultSchemaAdapterFactory::create`] with + /// the same schema for both the projected table schema and the table + /// schema. + fn create( + &self, + required_schema: SchemaRef, + table_schema: SchemaRef, + ) -> Box<dyn SchemaAdapter> { + Box::new(SparkSchemaAdapter { + required_schema, + table_schema, + cast_options: self.cast_options.clone(), + }) + } +} + +/// This SchemaAdapter requires both the table schema and the projected table +/// schema. See [`SchemaMapping`] for more details +#[derive(Clone, Debug)] +pub struct SparkSchemaAdapter { + /// The schema for the table, projected to include only the fields being output (projected) by the + /// associated ParquetExec + required_schema: SchemaRef, + /// The entire table schema for the table we're using this to adapt. + /// + /// This is used to evaluate any filters pushed down into the scan + /// which may refer to columns that are not referred to anywhere + /// else in the plan. + table_schema: SchemaRef, + /// Spark cast options + cast_options: SparkCastOptions, +} + +impl SchemaAdapter for SparkSchemaAdapter { + /// Map a column index in the table schema to a column index in a particular + /// file schema + /// + /// Panics if index is not in range for the table schema + fn map_column_index(&self, index: usize, file_schema: &Schema) -> Option<usize> { + let field = self.required_schema.field(index); Review Comment: IIRC, the name `required_schema` was to match the parameter of the same name in `NativeScanExec`. -- 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]
