risingwave_expr_impl/scalar/
length.rs

1// Copyright 2025 RisingWave Labs
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 risingwave_expr::function;
16
17#[function("length(varchar) -> int4")]
18#[function("char_length(varchar) -> int4")]
19pub fn char_length(s: &str) -> i32 {
20    s.chars().count() as i32
21}
22
23#[function("octet_length(varchar) -> int4")]
24#[function("length(bytea) -> int4")]
25#[function("octet_length(bytea) -> int4")]
26pub fn octet_length(s: impl AsRef<[u8]>) -> i32 {
27    s.as_ref().len() as i32
28}
29
30#[function("bit_length(varchar) -> int4")]
31#[function("bit_length(bytea) -> int4")]
32pub fn bit_length(s: impl AsRef<[u8]>) -> i32 {
33    octet_length(s) * 8
34}
35
36#[cfg(test)]
37mod tests {
38
39    use super::*;
40
41    #[test]
42    fn test_length() {
43        let cases = [("hello world", 11), ("hello rust", 10)];
44
45        for (s, expected) in cases {
46            assert_eq!(char_length(s), expected);
47        }
48    }
49
50    #[test]
51    fn test_octet_length() {
52        let cases = [("hello world", 11), ("你好", 6), ("😇哈哈hhh", 13)];
53
54        for (s, expected) in cases {
55            assert_eq!(octet_length(s), expected);
56        }
57    }
58
59    #[test]
60    fn test_bit_length() {
61        let cases = [
62            ("hello world", 11 * 8),
63            ("你好", 6 * 8),
64            ("😇哈哈hhh", 13 * 8),
65        ];
66
67        for (s, expected) in cases {
68            assert_eq!(bit_length(s), expected);
69        }
70    }
71}
risingwave_expr_impl/scalar/length.rs

risingwave_expr_impl/scalar/
length.rs
