arrow_data/equal/
byte_view.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 crate::{ArrayData, ByteView};
19
20pub(super) fn byte_view_equal(
21    lhs: &ArrayData,
22    rhs: &ArrayData,
23    lhs_start: usize,
24    rhs_start: usize,
25    len: usize,
26) -> bool {
27    let lhs_views = &lhs.buffer::<u128>(0)[lhs_start..lhs_start + len];
28    let lhs_buffers = &lhs.buffers()[1..];
29    let rhs_views = &rhs.buffer::<u128>(0)[rhs_start..rhs_start + len];
30    let rhs_buffers = &rhs.buffers()[1..];
31
32    for (idx, (l, r)) in lhs_views.iter().zip(rhs_views).enumerate() {
33        // Only checking one null mask here because by the time the control flow reaches
34        // this point, the equality of the two masks would have already been verified.
35        // `idx` counts from `lhs_start`, so offset it to index the null mask.
36        if lhs.is_null(lhs_start + idx) {
37            continue;
38        }
39
40        let l_len_prefix = *l as u64;
41        let r_len_prefix = *r as u64;
42        // short-circuit, check length and prefix
43        if l_len_prefix != r_len_prefix {
44            return false;
45        }
46
47        let len = l_len_prefix as u32;
48        // for inline storage, only need check view
49        if len <= 12 {
50            if l != r {
51                return false;
52            }
53            continue;
54        }
55
56        // check buffers
57        let l_view = ByteView::from(*l);
58        let r_view = ByteView::from(*r);
59
60        let l_buffer = &lhs_buffers[l_view.buffer_index as usize];
61        let r_buffer = &rhs_buffers[r_view.buffer_index as usize];
62
63        // prefixes are already known to be equal; skip checking them
64        let len = len as usize - 4;
65        let l_offset = l_view.offset as usize + 4;
66        let r_offset = r_view.offset as usize + 4;
67        if l_buffer[l_offset..l_offset + len] != r_buffer[r_offset..r_offset + len] {
68            return false;
69        }
70    }
71    true
72}
arrow_data/equal/byte_view.rs

arrow_data/equal/
byte_view.rs
