common_meta/
util.rs

1// Copyright 2023 Greptime Team
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use api::v1::meta::ResponseHeader;
16
17use crate::error::{IllegalServerStateSnafu, Result};
18
19/// Get prefix end key of `key`.
20pub fn get_prefix_end_key(key: &[u8]) -> Vec<u8> {
21    for (i, v) in key.iter().enumerate().rev() {
22        if *v < 0xFF {
23            let mut end = Vec::from(&key[..=i]);
24            end[i] = *v + 1;
25            return end;
26        }
27    }
28
29    // next prefix does not exist (e.g., 0xffff);
30    vec![0]
31}
32
33pub fn check_response_header(header: Option<&ResponseHeader>) -> Result<()> {
34    if let Some(header) = header {
35        if let Some(error) = &header.error {
36            let code = error.code;
37            let err_msg = &error.err_msg;
38            return IllegalServerStateSnafu { code, err_msg }.fail();
39        }
40    }
41
42    Ok(())
43}
44
45/// Get next prefix key of `key`.
46pub fn get_next_prefix_key(key: &[u8]) -> Vec<u8> {
47    let mut next = Vec::with_capacity(key.len() + 1);
48    next.extend_from_slice(key);
49    next.push(0);
50
51    next
52}
53
54#[cfg(test)]
55mod tests {
56
57    use super::*;
58
59    #[test]
60    fn test_get_next_prefix() {
61        let key = b"testa";
62        let mut expected = b"testa".to_vec();
63        expected.push(0);
64        assert_eq!(expected, get_next_prefix_key(key));
65    }
66
67    #[test]
68    fn test_get_prefix() {
69        let key = b"testa";
70        assert_eq!(b"testb".to_vec(), get_prefix_end_key(key));
71
72        let key = vec![0, 0, 26];
73        assert_eq!(vec![0, 0, 27], get_prefix_end_key(&key));
74
75        let key = vec![0, 0, 255];
76        assert_eq!(vec![0, 1], get_prefix_end_key(&key));
77
78        let key = vec![0, 255, 255];
79        assert_eq!(vec![1], get_prefix_end_key(&key));
80    }
81}
common_meta/util.rs

common_meta/
util.rs
