vortex_alp/alp_rd/compute/
cast.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use vortex_array::ArrayRef;
5use vortex_array::ArrayView;
6use vortex_array::IntoArray;
7use vortex_array::builtins::ArrayBuiltins;
8use vortex_array::dtype::DType;
9use vortex_array::scalar_fn::fns::cast::CastReduce;
10use vortex_error::VortexResult;
11
12use crate::ALPRDArrayExt;
13use crate::alp_rd::ALPRD;
14
15impl CastReduce for ALPRD {
16    fn cast(array: ArrayView<'_, Self>, dtype: &DType) -> VortexResult<Option<ArrayRef>> {
17        // Check if this is just a nullability change
18        if !array.dtype().eq_ignore_nullability(dtype) {
19            return Ok(None);
20        }
21
22        // For nullability-only changes, we need to cast the left_parts array
23        // since it carries the validity information
24        let new_left_parts = array.left_parts().cast(
25            array
26                .left_parts()
27                .dtype()
28                .with_nullability(dtype.nullability()),
29        )?;
30
31        Ok(Some(
32            unsafe {
33                ALPRD::new_unchecked(
34                    dtype.clone(),
35                    new_left_parts,
36                    array.left_parts_dictionary().clone(),
37                    array.right_parts().clone(),
38                    array.right_bit_width(),
39                    array.left_parts_patches(),
40                )
41            }
42            .into_array(),
43        ))
44    }
45}
46
47#[cfg(test)]
48mod tests {
49    use rstest::rstest;
50    use vortex_array::IntoArray;
51    use vortex_array::VortexSessionExecute;
52    use vortex_array::array_session;
53    use vortex_array::arrays::PrimitiveArray;
54    use vortex_array::builtins::ArrayBuiltins;
55    use vortex_array::compute::conformance::cast::test_cast_conformance;
56    use vortex_array::dtype::DType;
57    use vortex_array::dtype::Nullability;
58    use vortex_array::dtype::PType;
59
60    use crate::RDEncoder;
61
62    #[test]
63    fn test_cast_alprd_f32_to_f64() {
64        let mut ctx = array_session().create_execution_ctx();
65        let values = vec![1.0f32, 1.1, 1.2, 1.3, 1.4];
66        let arr = PrimitiveArray::from_iter(values.clone());
67        let encoder = RDEncoder::new(&values);
68        let alprd = encoder.encode(arr.as_view());
69
70        let casted = alprd
71            .into_array()
72            .cast(DType::Primitive(PType::F64, Nullability::NonNullable))
73            .unwrap();
74        assert_eq!(
75            casted.dtype(),
76            &DType::Primitive(PType::F64, Nullability::NonNullable)
77        );
78
79        let decoded = casted.execute::<PrimitiveArray>(&mut ctx).unwrap();
80        let f64_values = decoded.as_slice::<f64>();
81        assert_eq!(f64_values.len(), 5);
82        assert!((f64_values[0] - 1.0).abs() < f64::EPSILON);
83        assert!((f64_values[1] - 1.1).abs() < 1e-6); // Use larger epsilon for f32->f64 conversion
84    }
85
86    #[test]
87    fn test_cast_alprd_nullable() {
88        let mut ctx = array_session().create_execution_ctx();
89        let arr =
90            PrimitiveArray::from_option_iter([Some(10.0f64), None, Some(10.1), Some(10.2), None]);
91        let values = vec![10.0f64, 10.1, 10.2];
92        let encoder = RDEncoder::new(&values);
93        let alprd = encoder.encode(arr.as_view());
94
95        // Cast to NonNullable should fail since we have nulls. The failure surfaces during
96        // execution since the reduce path defers when the validity stat is not cached.
97        let result = alprd
98            .clone()
99            .into_array()
100            .cast(DType::Primitive(PType::F64, Nullability::NonNullable))
101            .and_then(|a| {
102                a.execute::<PrimitiveArray>(&mut ctx)
103                    .map(|p| p.into_array())
104            });
105        assert!(result.is_err(), "Expected error, got: {result:?}");
106
107        // Cast to same type with Nullable should succeed
108        let casted = alprd
109            .into_array()
110            .cast(DType::Primitive(PType::F64, Nullability::Nullable))
111            .unwrap();
112        assert_eq!(
113            casted.dtype(),
114            &DType::Primitive(PType::F64, Nullability::Nullable)
115        );
116    }
117
118    #[rstest]
119    #[case::f32({
120        let values = vec![1.23f32, 4.56, 7.89, 10.11, 12.13];
121        let arr = PrimitiveArray::from_iter(values.clone());
122        let encoder = RDEncoder::new(&values);
123        encoder.encode(arr.as_view())
124    })]
125    #[case::f64({
126        let values = vec![100.1f64, 200.2, 300.3, 400.4, 500.5];
127        let arr = PrimitiveArray::from_iter(values.clone());
128        let encoder = RDEncoder::new(&values);
129        encoder.encode(arr.as_view())
130    })]
131    #[case::single({
132        let values = vec![42.42f64];
133        let arr = PrimitiveArray::from_iter(values.clone());
134        let encoder = RDEncoder::new(&values);
135        encoder.encode(arr.as_view())
136    })]
137    #[case::negative({
138        let values = vec![0.0f32, -1.5, 2.5, -3.5, 4.5];
139        let arr = PrimitiveArray::from_iter(values.clone());
140        let encoder = RDEncoder::new(&values);
141        encoder.encode(arr.as_view())
142    })]
143    #[case::nullable({
144        let arr = PrimitiveArray::from_option_iter([Some(1.1f32), None, Some(2.2), Some(3.3), None]);
145        let values = vec![1.1f32, 2.2, 3.3];
146        let encoder = RDEncoder::new(&values);
147        encoder.encode(arr.as_view())
148    })]
149    fn test_cast_alprd_conformance(#[case] alprd: crate::alp_rd::ALPRDArray) {
150        test_cast_conformance(
151            &alprd.into_array(),
152            &mut array_session().create_execution_ctx(),
153        );
154    }
155}
vortex_alp/alp_rd/compute/cast.rs

vortex_alp/alp_rd/compute/
cast.rs
