vortex_scan/
arrow.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use arrow_array::RecordBatch;
5use arrow_array::RecordBatchReader;
6use arrow_array::cast::AsArray;
7use arrow_schema::ArrowError;
8use arrow_schema::DataType;
9use arrow_schema::SchemaRef;
10use futures::Stream;
11use futures::TryStreamExt;
12use vortex_array::ArrayRef;
13use vortex_array::ExecutionCtx;
14use vortex_array::VortexSessionExecute;
15use vortex_array::arrow::ArrowArrayExecutor;
16use vortex_error::VortexResult;
17use vortex_io::runtime::BlockingRuntime;
18
19use crate::ScanBuilder;
20
21impl ScanBuilder<ArrayRef> {
22    /// Creates a new `RecordBatchReader` from the scan builder.
23    ///
24    /// The `schema` parameter is used to define the schema of the resulting record batches. In
25    /// general, it is not possible to exactly infer an Arrow schema from a Vortex
26    /// [`vortex_dtype::DType`], therefore it is required to be provided explicitly.
27    pub fn into_record_batch_reader<B: BlockingRuntime>(
28        self,
29        schema: SchemaRef,
30        runtime: &B,
31    ) -> VortexResult<impl RecordBatchReader + 'static> {
32        let data_type = DataType::Struct(schema.fields().clone());
33        let session = self.session().clone();
34
35        let iter = self
36            .map(move |chunk| {
37                let mut ctx = session.create_execution_ctx();
38                to_record_batch(chunk, &data_type, &mut ctx)
39            })
40            .into_iter(runtime)?
41            .map(|result| result.map_err(|e| ArrowError::ExternalError(Box::new(e))));
42
43        Ok(RecordBatchIteratorAdapter { iter, schema })
44    }
45
46    pub fn into_record_batch_stream(
47        self,
48        schema: SchemaRef,
49    ) -> VortexResult<impl Stream<Item = Result<RecordBatch, ArrowError>> + Send + 'static> {
50        let data_type = DataType::Struct(schema.fields().clone());
51        let session = self.session().clone();
52
53        let stream = self
54            .map(move |chunk| {
55                let mut ctx = session.create_execution_ctx();
56                to_record_batch(chunk, &data_type, &mut ctx)
57            })
58            .into_stream()?
59            .map_err(|e| ArrowError::ExternalError(Box::new(e)));
60
61        Ok(stream)
62    }
63}
64
65fn to_record_batch(
66    chunk: ArrayRef,
67    data_type: &DataType,
68    ctx: &mut ExecutionCtx,
69) -> VortexResult<RecordBatch> {
70    let arrow = chunk.execute_arrow(Some(data_type), ctx)?;
71    Ok(RecordBatch::from(arrow.as_struct().clone()))
72}
73
74/// We create an adapter for record batch iterators that supports clone.
75/// This allows us to create thread-safe [`arrow_array::RecordBatchIterator`].
76#[derive(Clone)]
77pub struct RecordBatchIteratorAdapter<I> {
78    iter: I,
79    schema: SchemaRef,
80}
81
82impl<I> RecordBatchIteratorAdapter<I> {
83    /// Creates a new `RecordBatchIteratorAdapter`.
84    pub fn new(iter: I, schema: SchemaRef) -> Self {
85        Self { iter, schema }
86    }
87}
88
89impl<I> Iterator for RecordBatchIteratorAdapter<I>
90where
91    I: Iterator<Item = Result<RecordBatch, ArrowError>>,
92{
93    type Item = Result<RecordBatch, ArrowError>;
94
95    #[inline]
96    fn next(&mut self) -> Option<Self::Item> {
97        self.iter.next()
98    }
99}
100
101impl<I> RecordBatchReader for RecordBatchIteratorAdapter<I>
102where
103    I: Iterator<Item = Result<RecordBatch, ArrowError>>,
104{
105    #[inline]
106    fn schema(&self) -> SchemaRef {
107        self.schema.clone()
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use std::sync::Arc;
114
115    use arrow_array::Array;
116    use arrow_array::ArrayRef as ArrowArrayRef;
117    use arrow_array::Int32Array;
118    use arrow_array::RecordBatch;
119    use arrow_array::StringArray;
120    use arrow_array::StructArray;
121    use arrow_array::cast::AsArray;
122    use arrow_schema::ArrowError;
123    use arrow_schema::DataType;
124    use arrow_schema::Field;
125    use arrow_schema::Schema;
126    use vortex_array::ArrayRef;
127    use vortex_array::arrow::FromArrowArray;
128    use vortex_error::VortexResult;
129
130    use super::*;
131    use crate::test::SCAN_SESSION;
132
133    fn create_test_struct_array() -> VortexResult<ArrayRef> {
134        // Create Arrow arrays
135        let id_array = Int32Array::from(vec![Some(1), Some(2), None, Some(4)]);
136        let name_array = StringArray::from(vec![Some("Alice"), Some("Bob"), Some("Charlie"), None]);
137
138        // Create Arrow struct array
139        let schema = Arc::new(Schema::new(vec![
140            Field::new("id", DataType::Int32, true),
141            Field::new("name", DataType::Utf8, true),
142        ]));
143
144        let struct_array = StructArray::new(
145            schema.fields().clone(),
146            vec![
147                Arc::new(id_array) as ArrowArrayRef,
148                Arc::new(name_array) as ArrowArrayRef,
149            ],
150            None,
151        );
152
153        // Convert to Vortex
154        ArrayRef::from_arrow(&struct_array, true)
155    }
156
157    fn create_arrow_schema() -> Arc<Schema> {
158        Arc::new(Schema::new(vec![
159            Field::new("id", DataType::Int32, true),
160            Field::new("name", DataType::Utf8, true),
161        ]))
162    }
163
164    #[test]
165    fn test_record_batch_conversion() -> VortexResult<()> {
166        let vortex_array = create_test_struct_array()?;
167        let schema = create_arrow_schema();
168        let data_type = DataType::Struct(schema.fields().clone());
169        let mut ctx = SCAN_SESSION.create_execution_ctx();
170
171        let batch = to_record_batch(vortex_array, &data_type, &mut ctx)?;
172        assert_eq!(batch.num_columns(), 2);
173        assert_eq!(batch.num_rows(), 4);
174
175        // Check id column
176        let id_col = batch
177            .column(0)
178            .as_primitive::<arrow_array::types::Int32Type>();
179        assert_eq!(id_col.value(0), 1);
180        assert_eq!(id_col.value(1), 2);
181        assert!(id_col.is_null(2));
182        assert_eq!(id_col.value(3), 4);
183
184        // Check name column
185        let name_col = batch.column(1).as_string::<i32>();
186        assert_eq!(name_col.value(0), "Alice");
187        assert_eq!(name_col.value(1), "Bob");
188        assert_eq!(name_col.value(2), "Charlie");
189        assert!(name_col.is_null(3));
190
191        Ok(())
192    }
193
194    #[test]
195    fn test_record_batch_iterator_adapter() -> VortexResult<()> {
196        let schema = create_arrow_schema();
197        let batch1 = RecordBatch::try_new(
198            schema.clone(),
199            vec![
200                Arc::new(Int32Array::from(vec![Some(1), Some(2)])) as ArrowArrayRef,
201                Arc::new(StringArray::from(vec![Some("Alice"), Some("Bob")])) as ArrowArrayRef,
202            ],
203        )?;
204        let batch2 = RecordBatch::try_new(
205            schema.clone(),
206            vec![
207                Arc::new(Int32Array::from(vec![None, Some(4)])) as ArrowArrayRef,
208                Arc::new(StringArray::from(vec![Some("Charlie"), None])) as ArrowArrayRef,
209            ],
210        )?;
211
212        let iter = vec![Ok(batch1), Ok(batch2)].into_iter();
213        let mut adapter = RecordBatchIteratorAdapter {
214            iter,
215            schema: schema.clone(),
216        };
217
218        // Test RecordBatchReader trait
219        assert_eq!(adapter.schema(), schema);
220
221        // Test Iterator trait
222        let first = adapter.next().unwrap()?;
223        assert_eq!(first.num_rows(), 2);
224
225        let second = adapter.next().unwrap()?;
226        assert_eq!(second.num_rows(), 2);
227
228        assert!(adapter.next().is_none());
229
230        Ok(())
231    }
232
233    #[test]
234    fn test_error_in_iterator() {
235        let schema = create_arrow_schema();
236        let error = ArrowError::ComputeError("test error".to_string());
237
238        let iter = vec![Err(error)].into_iter();
239        let mut adapter = RecordBatchIteratorAdapter {
240            iter,
241            schema: schema.clone(),
242        };
243
244        // Test that error is propagated
245        assert_eq!(adapter.schema(), schema);
246        let result = adapter.next().unwrap();
247        assert!(result.is_err());
248    }
249
250    #[test]
251    fn test_mixed_success_and_error() {
252        let schema = create_arrow_schema();
253        let batch = RecordBatch::try_new(
254            schema.clone(),
255            vec![
256                Arc::new(Int32Array::from(vec![Some(1)])) as ArrowArrayRef,
257                Arc::new(StringArray::from(vec![Some("Test")])) as ArrowArrayRef,
258            ],
259        )
260        .unwrap();
261
262        let error = ArrowError::ComputeError("test error".to_string());
263
264        let iter = vec![Ok(batch.clone()), Err(error), Ok(batch)].into_iter();
265        let mut adapter = RecordBatchIteratorAdapter { iter, schema };
266
267        // First batch succeeds
268        let first = adapter.next().unwrap();
269        assert!(first.is_ok());
270
271        // Second batch errors
272        let second = adapter.next().unwrap();
273        assert!(second.is_err());
274
275        // Third batch succeeds
276        let third = adapter.next().unwrap();
277        assert!(third.is_ok());
278    }
279}
vortex_scan/arrow.rs

vortex_scan/
arrow.rs
