vortex_layout/scan/
arrow.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::sync::Arc;
5
6use arrow_array::RecordBatch;
7use arrow_array::RecordBatchReader;
8use arrow_array::cast::AsArray;
9use arrow_schema::ArrowError;
10use arrow_schema::DataType;
11use arrow_schema::SchemaRef;
12use futures::Stream;
13use futures::TryStreamExt;
14use vortex_array::ArrayRef;
15use vortex_array::ExecutionCtx;
16use vortex_array::VortexSessionExecute;
17use vortex_array::arrow::ArrowArrayExecutor;
18use vortex_error::VortexResult;
19use vortex_io::runtime::BlockingRuntime;
20
21use crate::scan::scan_builder::ScanBuilder;
22
23impl ScanBuilder<ArrayRef> {
24    /// Creates a new `RecordBatchReader` from the scan builder.
25    ///
26    /// The `schema` parameter is used to define the schema of the resulting record batches. In
27    /// general, it is not possible to exactly infer an Arrow schema from a Vortex
28    /// [`vortex_array::dtype::DType`], therefore it is required to be provided explicitly.
29    pub fn into_record_batch_reader<B: BlockingRuntime>(
30        self,
31        schema: SchemaRef,
32        runtime: &B,
33    ) -> VortexResult<impl RecordBatchReader + 'static> {
34        let data_type = DataType::Struct(schema.fields().clone());
35        let session = self.session().clone();
36
37        let iter = self
38            .map(move |chunk| {
39                let mut ctx = session.create_execution_ctx();
40                to_record_batch(chunk, &data_type, &mut ctx)
41            })
42            .into_iter(runtime)?
43            .map(|result| result.map_err(|e| ArrowError::ExternalError(Box::new(e))));
44
45        Ok(RecordBatchIteratorAdapter { iter, schema })
46    }
47
48    pub fn into_record_batch_stream(
49        self,
50        schema: SchemaRef,
51    ) -> VortexResult<impl Stream<Item = Result<RecordBatch, ArrowError>> + Send + 'static> {
52        let data_type = DataType::Struct(schema.fields().clone());
53        let session = self.session().clone();
54
55        let stream = self
56            .map(move |chunk| {
57                let mut ctx = session.create_execution_ctx();
58                to_record_batch(chunk, &data_type, &mut ctx)
59            })
60            .into_stream()?
61            .map_err(|e| ArrowError::ExternalError(Box::new(e)));
62
63        Ok(stream)
64    }
65}
66
67fn to_record_batch(
68    chunk: ArrayRef,
69    data_type: &DataType,
70    ctx: &mut ExecutionCtx,
71) -> VortexResult<RecordBatch> {
72    let arrow = chunk.execute_arrow(Some(data_type), ctx)?;
73    Ok(RecordBatch::from(arrow.as_struct().clone()))
74}
75
76/// We create an adapter for record batch iterators that supports clone.
77/// This allows us to create thread-safe [`arrow_array::RecordBatchIterator`].
78#[derive(Clone)]
79pub struct RecordBatchIteratorAdapter<I> {
80    iter: I,
81    schema: SchemaRef,
82}
83
84impl<I> RecordBatchIteratorAdapter<I> {
85    /// Creates a new `RecordBatchIteratorAdapter`.
86    pub fn new(iter: I, schema: SchemaRef) -> Self {
87        Self { iter, schema }
88    }
89}
90
91impl<I> Iterator for RecordBatchIteratorAdapter<I>
92where
93    I: Iterator<Item = Result<RecordBatch, ArrowError>>,
94{
95    type Item = Result<RecordBatch, ArrowError>;
96
97    #[inline]
98    fn next(&mut self) -> Option<Self::Item> {
99        self.iter.next()
100    }
101}
102
103impl<I> RecordBatchReader for RecordBatchIteratorAdapter<I>
104where
105    I: Iterator<Item = Result<RecordBatch, ArrowError>>,
106{
107    #[inline]
108    fn schema(&self) -> SchemaRef {
109        Arc::clone(&self.schema)
110    }
111}
112
113#[cfg(test)]
114mod tests {
115    use std::sync::Arc;
116
117    use arrow_array::Array;
118    use arrow_array::ArrayRef as ArrowArrayRef;
119    use arrow_array::Int32Array;
120    use arrow_array::RecordBatch;
121    use arrow_array::StringArray;
122    use arrow_array::StructArray;
123    use arrow_array::cast::AsArray;
124    use arrow_schema::ArrowError;
125    use arrow_schema::DataType;
126    use arrow_schema::Field;
127    use arrow_schema::Schema;
128    use vortex_array::ArrayRef;
129    use vortex_array::arrow::FromArrowArray;
130    use vortex_error::VortexResult;
131
132    use super::*;
133    use crate::scan::test::SCAN_SESSION;
134
135    fn create_test_struct_array() -> VortexResult<ArrayRef> {
136        // Create Arrow arrays
137        let id_array = Int32Array::from(vec![Some(1), Some(2), None, Some(4)]);
138        let name_array = StringArray::from(vec![Some("Alice"), Some("Bob"), Some("Charlie"), None]);
139
140        // Create Arrow struct array
141        let schema = Arc::new(Schema::new(vec![
142            Field::new("id", DataType::Int32, true),
143            Field::new("name", DataType::Utf8, true),
144        ]));
145
146        let struct_array = StructArray::new(
147            schema.fields().clone(),
148            vec![
149                Arc::new(id_array) as ArrowArrayRef,
150                Arc::new(name_array) as ArrowArrayRef,
151            ],
152            None,
153        );
154
155        // Convert to Vortex
156        ArrayRef::from_arrow(&struct_array, true)
157    }
158
159    fn create_arrow_schema() -> Arc<Schema> {
160        Arc::new(Schema::new(vec![
161            Field::new("id", DataType::Int32, true),
162            Field::new("name", DataType::Utf8, true),
163        ]))
164    }
165
166    #[test]
167    fn test_record_batch_conversion() -> VortexResult<()> {
168        let vortex_array = create_test_struct_array()?;
169        let schema = create_arrow_schema();
170        let data_type = DataType::Struct(schema.fields().clone());
171        let mut ctx = SCAN_SESSION.create_execution_ctx();
172
173        let batch = to_record_batch(vortex_array, &data_type, &mut ctx)?;
174        assert_eq!(batch.num_columns(), 2);
175        assert_eq!(batch.num_rows(), 4);
176
177        // Check id column
178        let id_col = batch
179            .column(0)
180            .as_primitive::<arrow_array::types::Int32Type>();
181        assert_eq!(id_col.value(0), 1);
182        assert_eq!(id_col.value(1), 2);
183        assert!(id_col.is_null(2));
184        assert_eq!(id_col.value(3), 4);
185
186        // Check name column
187        let name_col = batch.column(1).as_string::<i32>();
188        assert_eq!(name_col.value(0), "Alice");
189        assert_eq!(name_col.value(1), "Bob");
190        assert_eq!(name_col.value(2), "Charlie");
191        assert!(name_col.is_null(3));
192
193        Ok(())
194    }
195
196    #[test]
197    fn test_record_batch_iterator_adapter() -> VortexResult<()> {
198        let schema = create_arrow_schema();
199        let batch1 = RecordBatch::try_new(
200            Arc::clone(&schema),
201            vec![
202                Arc::new(Int32Array::from(vec![Some(1), Some(2)])) as ArrowArrayRef,
203                Arc::new(StringArray::from(vec![Some("Alice"), Some("Bob")])) as ArrowArrayRef,
204            ],
205        )?;
206        let batch2 = RecordBatch::try_new(
207            Arc::clone(&schema),
208            vec![
209                Arc::new(Int32Array::from(vec![None, Some(4)])) as ArrowArrayRef,
210                Arc::new(StringArray::from(vec![Some("Charlie"), None])) as ArrowArrayRef,
211            ],
212        )?;
213
214        let iter = vec![Ok(batch1), Ok(batch2)].into_iter();
215        let mut adapter = RecordBatchIteratorAdapter {
216            iter,
217            schema: Arc::clone(&schema),
218        };
219
220        // Test RecordBatchReader trait
221        assert_eq!(adapter.schema(), schema);
222
223        // Test Iterator trait
224        let first = adapter.next().unwrap()?;
225        assert_eq!(first.num_rows(), 2);
226
227        let second = adapter.next().unwrap()?;
228        assert_eq!(second.num_rows(), 2);
229
230        assert!(adapter.next().is_none());
231
232        Ok(())
233    }
234
235    #[test]
236    fn test_error_in_iterator() {
237        let schema = create_arrow_schema();
238        let error = ArrowError::ComputeError("test error".to_string());
239
240        let iter = vec![Err(error)].into_iter();
241        let mut adapter = RecordBatchIteratorAdapter {
242            iter,
243            schema: Arc::clone(&schema),
244        };
245
246        // Test that error is propagated
247        assert_eq!(adapter.schema(), schema);
248        let result = adapter.next().unwrap();
249        assert!(result.is_err());
250    }
251
252    #[test]
253    fn test_mixed_success_and_error() {
254        let schema = create_arrow_schema();
255        let batch = RecordBatch::try_new(
256            Arc::clone(&schema),
257            vec![
258                Arc::new(Int32Array::from(vec![Some(1)])) as ArrowArrayRef,
259                Arc::new(StringArray::from(vec![Some("Test")])) as ArrowArrayRef,
260            ],
261        )
262        .unwrap();
263
264        let error = ArrowError::ComputeError("test error".to_string());
265
266        let iter = vec![Ok(batch.clone()), Err(error), Ok(batch)].into_iter();
267        let mut adapter = RecordBatchIteratorAdapter { iter, schema };
268
269        // First batch succeeds
270        let first = adapter.next().unwrap();
271        assert!(first.is_ok());
272
273        // Second batch errors
274        let second = adapter.next().unwrap();
275        assert!(second.is_err());
276
277        // Third batch succeeds
278        let third = adapter.next().unwrap();
279        assert!(third.is_ok());
280    }
281}
vortex_layout/scan/arrow.rs

vortex_layout/scan/
arrow.rs
