kosiew commented on code in PR #16148: URL: https://github.com/apache/datafusion/pull/16148#discussion_r2106439691
########## datafusion/core/tests/test_adapter_updated.rs: ########## @@ -0,0 +1,201 @@ +// 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::datatypes::{DataType, Field, Schema, SchemaRef}; +use arrow::record_batch::RecordBatch; +use datafusion_common::{ColumnStatistics, DataFusionError, Result, Statistics}; +use datafusion_datasource::file::FileSource; +use datafusion_datasource::file_scan_config::FileScanConfig; +use datafusion_datasource::file_stream::FileOpener; +use datafusion_datasource::schema_adapter::{ + SchemaAdapter, SchemaAdapterFactory, SchemaMapper, +}; +use datafusion_physical_plan::metrics::ExecutionPlanMetricsSet; +use object_store::ObjectStore; +use std::any::Any; +use std::fmt::Debug; +use std::sync::Arc; + +/// A test source for testing schema adapters +#[derive(Debug, Clone)] +struct TestSource { + schema_adapter_factory: Option<Arc<dyn SchemaAdapterFactory>>, +} + +impl TestSource { + fn new() -> Self { + Self { + schema_adapter_factory: None, + } + } +} + +impl FileSource for TestSource { + fn file_type(&self) -> &str { + "test" + } + + fn as_any(&self) -> &dyn Any { + self + } + + fn create_file_opener( + &self, + _store: Arc<dyn ObjectStore>, + _conf: &FileScanConfig, + _index: usize, + ) -> Arc<dyn FileOpener> { + unimplemented!("Not needed for this test") + } + + fn with_batch_size(&self, _batch_size: usize) -> Arc<dyn FileSource> { + Arc::new(self.clone()) + } + + fn with_schema(&self, _schema: SchemaRef) -> Arc<dyn FileSource> { + Arc::new(self.clone()) + } + + fn with_projection(&self, _projection: &FileScanConfig) -> Arc<dyn FileSource> { + Arc::new(self.clone()) + } + + fn with_statistics(&self, _statistics: Statistics) -> Arc<dyn FileSource> { + Arc::new(self.clone()) + } + + fn metrics(&self) -> &ExecutionPlanMetricsSet { + unimplemented!("Not needed for this test") + } + + fn statistics(&self) -> Result<Statistics, DataFusionError> { + Ok(Statistics::default()) + } + + fn with_schema_adapter_factory( + &self, + schema_adapter_factory: Arc<dyn SchemaAdapterFactory>, + ) -> Arc<dyn FileSource> { + Arc::new(Self { + schema_adapter_factory: Some(schema_adapter_factory), + }) + } + + fn schema_adapter_factory(&self) -> Option<Arc<dyn SchemaAdapterFactory>> { + self.schema_adapter_factory.clone() + } +} + +/// A test schema adapter factory +#[derive(Debug)] +struct TestSchemaAdapterFactory {} + +impl SchemaAdapterFactory for TestSchemaAdapterFactory { + fn create( + &self, + projected_table_schema: SchemaRef, + _table_schema: SchemaRef, + ) -> Box<dyn SchemaAdapter> { + Box::new(TestSchemaAdapter { + table_schema: projected_table_schema, + }) + } +} + +/// A test schema adapter implementation +#[derive(Debug)] +struct TestSchemaAdapter { + table_schema: SchemaRef, +} + +impl SchemaAdapter for TestSchemaAdapter { + fn map_column_index(&self, index: usize, file_schema: &Schema) -> Option<usize> { + let field = self.table_schema.field(index); + file_schema.fields.find(field.name()).map(|(i, _)| i) + } + + fn map_schema( + &self, + file_schema: &Schema, + ) -> Result<(Arc<dyn SchemaMapper>, Vec<usize>)> { + let mut projection = Vec::with_capacity(file_schema.fields().len()); + for (file_idx, file_field) in file_schema.fields().iter().enumerate() { + if self.table_schema.fields().find(file_field.name()).is_some() { + projection.push(file_idx); + } + } + + Ok((Arc::new(TestSchemaMapping {}), projection)) + } +} + +/// A test schema mapper implementation +#[derive(Debug)] +struct TestSchemaMapping {} + +impl SchemaMapper for TestSchemaMapping { + fn map_batch(&self, batch: RecordBatch) -> Result<RecordBatch> { + // For testing, just return the original batch + Ok(batch) + } + + fn map_column_statistics( + &self, + stats: &[ColumnStatistics], + ) -> Result<Vec<ColumnStatistics>> { + // For testing, just return the input statistics + Ok(stats.to_vec()) + } +} + +#[test] +fn test_schema_adapter() { + // Create a test schema + let table_schema = Arc::new(Schema::new(vec![ + Field::new("id", DataType::Int32, false), + Field::new("name", DataType::Utf8, true), + ])); + + // Create a file schema + let file_schema = Schema::new(vec![ + Field::new("id", DataType::Int32, false), + Field::new("name", DataType::Utf8, true), + Field::new("extra", DataType::Int64, true), + ]); + + // Create a TestSource Review Comment: test_schema_adapter validates that: 1. Creating and attaching a schema adapter factory to a file source 2. Creating a schema adapter using the factory 3. The schema adapter's ability to map column indices between a table schema and a file schema 4. The schema adapter's ability to create a projection that selects only the columns from the file schema that are present in the table schema -- 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...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
