vortex_array/arrays/slice/
vtable.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::fmt::Debug;
5use std::fmt::Formatter;
6use std::hash::Hash;
7use std::hash::Hasher;
8use std::ops::Range;
9
10use vortex_dtype::DType;
11use vortex_error::VortexExpect;
12use vortex_error::VortexResult;
13use vortex_error::vortex_bail;
14use vortex_error::vortex_ensure;
15use vortex_session::VortexSession;
16
17use crate::AnyCanonical;
18use crate::Array;
19use crate::ArrayBufferVisitor;
20use crate::ArrayChildVisitor;
21use crate::ArrayEq;
22use crate::ArrayHash;
23use crate::ArrayRef;
24use crate::Canonical;
25use crate::Precision;
26use crate::arrays::slice::array::SliceArray;
27use crate::arrays::slice::rules::PARENT_RULES;
28use crate::buffer::BufferHandle;
29use crate::executor::ExecutionCtx;
30use crate::scalar::Scalar;
31use crate::serde::ArrayChildren;
32use crate::stats::StatsSetRef;
33use crate::validity::Validity;
34use crate::vtable;
35use crate::vtable::ArrayId;
36use crate::vtable::BaseArrayVTable;
37use crate::vtable::OperationsVTable;
38use crate::vtable::VTable;
39use crate::vtable::ValidityVTable;
40use crate::vtable::VisitorVTable;
41
42vtable!(Slice);
43
44#[derive(Debug)]
45pub struct SliceVTable;
46
47impl SliceVTable {
48    pub const ID: ArrayId = ArrayId::new_ref("vortex.slice");
49}
50
51impl VTable for SliceVTable {
52    type Array = SliceArray;
53    type Metadata = SliceMetadata;
54    type ArrayVTable = Self;
55    type OperationsVTable = Self;
56    type ValidityVTable = Self;
57    type VisitorVTable = Self;
58
59    fn id(_array: &Self::Array) -> ArrayId {
60        SliceVTable::ID
61    }
62
63    fn metadata(array: &Self::Array) -> VortexResult<Self::Metadata> {
64        Ok(SliceMetadata(array.range.clone()))
65    }
66
67    fn serialize(_metadata: Self::Metadata) -> VortexResult<Option<Vec<u8>>> {
68        // TODO(joe): make this configurable
69        vortex_bail!("Slice array is not serializable")
70    }
71
72    fn deserialize(
73        _bytes: &[u8],
74        _dtype: &DType,
75        _len: usize,
76        _buffers: &[BufferHandle],
77        _session: &VortexSession,
78    ) -> VortexResult<Self::Metadata> {
79        vortex_bail!("Slice array is not serializable")
80    }
81
82    fn build(
83        dtype: &DType,
84        len: usize,
85        metadata: &SliceMetadata,
86        _buffers: &[BufferHandle],
87        children: &dyn ArrayChildren,
88    ) -> VortexResult<Self::Array> {
89        assert_eq!(len, metadata.0.len());
90        let child = children.get(0, dtype, metadata.0.end)?;
91        Ok(SliceArray {
92            child,
93            range: metadata.0.clone(),
94            stats: Default::default(),
95        })
96    }
97
98    fn with_children(array: &mut Self::Array, children: Vec<ArrayRef>) -> VortexResult<()> {
99        vortex_ensure!(
100            children.len() == 1,
101            "SliceArray expects exactly 1 child, got {}",
102            children.len()
103        );
104        array.child = children
105            .into_iter()
106            .next()
107            .vortex_expect("children length already validated");
108        Ok(())
109    }
110
111    fn execute(array: &Self::Array, ctx: &mut ExecutionCtx) -> VortexResult<ArrayRef> {
112        // Execute the child to get canonical form, then slice it
113        let Some(canonical) = array.child.as_opt::<AnyCanonical>() else {
114            // If the child is not canonical, recurse.
115            return array
116                .child
117                .clone()
118                .execute::<ArrayRef>(ctx)?
119                .slice(array.slice_range().clone());
120        };
121
122        // TODO(ngates): we should inline canonical slice logic here.
123        Canonical::from(canonical)
124            .as_ref()
125            .slice(array.range.clone())
126    }
127
128    fn reduce_parent(
129        array: &Self::Array,
130        parent: &ArrayRef,
131        child_idx: usize,
132    ) -> VortexResult<Option<ArrayRef>> {
133        PARENT_RULES.evaluate(array, parent, child_idx)
134    }
135}
136
137impl BaseArrayVTable<SliceVTable> for SliceVTable {
138    fn len(array: &SliceArray) -> usize {
139        array.range.len()
140    }
141
142    fn dtype(array: &SliceArray) -> &DType {
143        array.child.dtype()
144    }
145
146    fn stats(array: &SliceArray) -> StatsSetRef<'_> {
147        array.stats.to_ref(array.as_ref())
148    }
149
150    fn array_hash<H: Hasher>(array: &SliceArray, state: &mut H, precision: Precision) {
151        array.child.array_hash(state, precision);
152        array.range.start.hash(state);
153        array.range.end.hash(state);
154    }
155
156    fn array_eq(array: &SliceArray, other: &SliceArray, precision: Precision) -> bool {
157        array.child.array_eq(&other.child, precision) && array.range == other.range
158    }
159}
160
161impl OperationsVTable<SliceVTable> for SliceVTable {
162    fn scalar_at(array: &SliceArray, index: usize) -> VortexResult<Scalar> {
163        array.child.scalar_at(array.range.start + index)
164    }
165}
166
167impl ValidityVTable<SliceVTable> for SliceVTable {
168    fn validity(array: &SliceArray) -> VortexResult<Validity> {
169        array.child.validity()?.slice(array.range.clone())
170    }
171}
172
173impl VisitorVTable<SliceVTable> for SliceVTable {
174    fn visit_buffers(_array: &SliceArray, _visitor: &mut dyn ArrayBufferVisitor) {}
175
176    fn visit_children(array: &SliceArray, visitor: &mut dyn ArrayChildVisitor) {
177        visitor.visit_child("child", &array.child);
178    }
179
180    fn nchildren(_array: &SliceArray) -> usize {
181        1
182    }
183
184    fn nth_child(array: &SliceArray, idx: usize) -> Option<ArrayRef> {
185        match idx {
186            0 => Some(array.child.clone()),
187            _ => None,
188        }
189    }
190}
191
192pub struct SliceMetadata(pub(super) Range<usize>);
193
194impl Debug for SliceMetadata {
195    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
196        write!(f, "{}..{}", self.0.start, self.0.end)
197    }
198}
199
200#[cfg(test)]
201mod tests {
202    use vortex_error::VortexResult;
203
204    use crate::Array;
205    use crate::IntoArray;
206    use crate::arrays::PrimitiveArray;
207    use crate::arrays::SliceArray;
208    use crate::assert_arrays_eq;
209
210    #[test]
211    fn test_slice_slice() -> VortexResult<()> {
212        // Slice(1..4, Slice(2..8, base)) combines to Slice(3..6, base)
213        let arr = PrimitiveArray::from_iter(0i32..10).into_array();
214        let inner_slice = SliceArray::new(arr, 2..8).into_array();
215        let slice = inner_slice.slice(1..4)?;
216
217        assert_arrays_eq!(slice, PrimitiveArray::from_iter([3i32, 4, 5]));
218
219        Ok(())
220    }
221}
vortex_array/arrays/slice/vtable.rs

vortex_array/arrays/slice/
vtable.rs
