vortex_alp/alp_rd/
ops.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use vortex_array::ArrayView;
5use vortex_array::ExecutionCtx;
6use vortex_array::dtype::PType;
7use vortex_array::scalar::Scalar;
8use vortex_array::vtable::OperationsVTable;
9use vortex_error::VortexExpect;
10use vortex_error::VortexResult;
11
12use crate::ALPRD;
13use crate::ALPRDArrayExt;
14use crate::ALPRDArraySlotsExt;
15
16impl OperationsVTable<ALPRD> for ALPRD {
17    fn scalar_at(
18        array: ArrayView<'_, ALPRD>,
19        index: usize,
20        ctx: &mut ExecutionCtx,
21    ) -> VortexResult<Scalar> {
22        // The left value can either be a direct value, or an exception.
23        // The exceptions array represents exception positions with non-null values.
24        let maybe_patched_value = match array.left_parts_patches() {
25            Some(patches) => patches.get_patched(index)?,
26            None => None,
27        };
28        let left = match maybe_patched_value {
29            Some(patched_value) => patched_value
30                .as_primitive()
31                .as_::<u16>()
32                .vortex_expect("patched values must be non-null"),
33            _ => {
34                let left_code: u16 = array
35                    .left_parts()
36                    .execute_scalar(index, ctx)?
37                    .as_primitive()
38                    .as_::<u16>()
39                    .vortex_expect("left_code must be non-null");
40                array.left_parts_dictionary()[left_code as usize]
41            }
42        };
43
44        // combine left and right values
45        Ok(if array.dtype().as_ptype() == PType::F32 {
46            let right: u32 = array
47                .right_parts()
48                .execute_scalar(index, ctx)?
49                .as_primitive()
50                .as_::<u32>()
51                .vortex_expect("non-null");
52            let packed = f32::from_bits((left as u32) << array.right_bit_width() | right);
53            Scalar::primitive(packed, array.dtype().nullability())
54        } else {
55            let right: u64 = array
56                .right_parts()
57                .execute_scalar(index, ctx)?
58                .as_primitive()
59                .as_::<u64>()
60                .vortex_expect("non-null");
61            let packed = f64::from_bits(((left as u64) << array.right_bit_width()) | right);
62            Scalar::primitive(packed, array.dtype().nullability())
63        })
64    }
65}
66
67#[cfg(test)]
68mod test {
69    use std::sync::LazyLock;
70
71    use rstest::rstest;
72    use vortex_array::VortexSessionExecute;
73    use vortex_array::arrays::PrimitiveArray;
74    use vortex_array::assert_arrays_eq;
75    use vortex_array::scalar::Scalar;
76    use vortex_session::VortexSession;
77
78    use crate::ALPRDArrayExt;
79    use crate::ALPRDFloat;
80    use crate::RDEncoder;
81
82    static SESSION: LazyLock<VortexSession> = LazyLock::new(|| {
83        let session = vortex_array::array_session();
84        crate::initialize(&session);
85        session
86    });
87
88    #[rstest]
89    #[case(0.1f32, 0.2f32, 3e25f32)]
90    #[case(0.1f64, 0.2f64, 3e100f64)]
91    fn test_slice<T: ALPRDFloat>(#[case] a: T, #[case] b: T, #[case] outlier: T) {
92        let mut ctx = SESSION.create_execution_ctx();
93        let array = PrimitiveArray::from_iter([a, b, outlier]);
94        let encoded = RDEncoder::new(&[a, b]).encode(array.as_view());
95
96        assert!(encoded.left_parts_patches().is_some());
97        assert_arrays_eq!(encoded, array, &mut ctx);
98    }
99
100    #[rstest]
101    #[case(0.1f32, 0.2f32, 3e25f32)]
102    #[case(0.1f64, 0.2f64, 3e100f64)]
103    fn test_scalar_at<T: ALPRDFloat + Into<Scalar>>(
104        #[case] a: T,
105        #[case] b: T,
106        #[case] outlier: T,
107    ) {
108        let mut ctx = SESSION.create_execution_ctx();
109        let array = PrimitiveArray::from_iter([a, b, outlier]);
110        let encoded = RDEncoder::new(&[a, b]).encode(array.as_view());
111        assert!(encoded.left_parts_patches().is_some());
112        assert_arrays_eq!(encoded, array, &mut ctx);
113    }
114
115    #[test]
116    fn nullable_scalar_at() {
117        let mut ctx = SESSION.create_execution_ctx();
118        let a = 0.1f64;
119        let b = 0.2f64;
120        let outlier = 3e100f64;
121        let array = PrimitiveArray::from_option_iter([Some(a), Some(b), Some(outlier)]);
122        let encoded = RDEncoder::new(&[a, b]).encode(array.as_view());
123        assert!(encoded.left_parts_patches().is_some());
124        assert_arrays_eq!(
125            encoded,
126            PrimitiveArray::from_option_iter([Some(a), Some(b), Some(outlier)]),
127            &mut ctx
128        );
129    }
130}
vortex_alp/alp_rd/ops.rs

vortex_alp/alp_rd/
ops.rs
