arrow_data/transform/
list.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use super::{
19    _MutableArrayData, Extend,
20    utils::{extend_offsets, get_last_offset},
21};
22use crate::ArrayData;
23use arrow_buffer::ArrowNativeType;
24use num_integer::Integer;
25use num_traits::CheckedAdd;
26
27pub(super) fn build_extend<T: ArrowNativeType + Integer + CheckedAdd>(
28    array: &ArrayData,
29) -> Extend<'_> {
30    let offsets = array.buffer::<T>(0);
31    Box::new(
32        move |mutable: &mut _MutableArrayData, index: usize, start: usize, len: usize| {
33            let offset_buffer = &mut mutable.buffer1;
34
35            // this is safe due to how offset is built. See details on `get_last_offset`
36            let last_offset: T = unsafe { get_last_offset(offset_buffer) };
37
38            // offsets
39            extend_offsets::<T>(offset_buffer, last_offset, &offsets[start..start + len + 1]);
40
41            mutable.child_data[0].extend(
42                index,
43                offsets[start].as_usize(),
44                offsets[start + len].as_usize(),
45            )
46        },
47    )
48}
49
50pub(super) fn extend_nulls<T: ArrowNativeType>(mutable: &mut _MutableArrayData, len: usize) {
51    let offset_buffer = &mut mutable.buffer1;
52
53    // this is safe due to how offset is built. See details on `get_last_offset`
54    let last_offset: T = unsafe { get_last_offset(offset_buffer) };
55
56    (0..len).for_each(|_| offset_buffer.push(last_offset))
57}