vortex_array/arrays/varbinview/compute/
is_constant.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use vortex_error::VortexExpect;
5use vortex_error::VortexResult;
6use vortex_vector::binaryview::Ref;
7
8use crate::arrays::VarBinViewArray;
9use crate::arrays::VarBinViewVTable;
10use crate::compute::IsConstantKernel;
11use crate::compute::IsConstantKernelAdapter;
12use crate::compute::IsConstantOpts;
13use crate::register_kernel;
14
15impl IsConstantKernel for VarBinViewVTable {
16    fn is_constant(
17        &self,
18        array: &VarBinViewArray,
19        _opts: &IsConstantOpts,
20    ) -> VortexResult<Option<bool>> {
21        let mut views_iter = array.views().iter();
22        let first_value = views_iter
23            .next()
24            .vortex_expect("Must have at least one value");
25
26        // For the array to be constant, all views must be of the same type
27        if first_value.is_inlined() {
28            let first_value = first_value.as_inlined();
29
30            for view in views_iter {
31                // Short circuit if the view is of the wrong type, then if both are inlined they must be equal.
32                if !view.is_inlined() || view.as_inlined() != first_value {
33                    return Ok(Some(false));
34                }
35            }
36        } else {
37            // Directly fetch the values for a `Ref`
38            let ref_bytes = |view_ref: &Ref| {
39                &array.buffer(view_ref.buffer_index as usize).as_slice()[view_ref.as_range()]
40            };
41
42            let first_view_ref = first_value.as_view();
43            let first_value_bytes = ref_bytes(first_view_ref);
44
45            for view in views_iter {
46                // Short circuit if the view is of the wrong type
47                if view.is_inlined() || view.len() != first_value.len() {
48                    return Ok(Some(false));
49                }
50
51                let view_ref = view.as_view();
52                let value = ref_bytes(view_ref);
53                if value != first_value_bytes {
54                    return Ok(Some(false));
55                }
56            }
57        }
58
59        Ok(Some(true))
60    }
61}
62
63register_kernel!(IsConstantKernelAdapter(VarBinViewVTable).lift());
vortex_array/arrays/varbinview/compute/is_constant.rs

vortex_array/arrays/varbinview/compute/
is_constant.rs
