neon/types_impl/
utf8.rs

1use std::borrow::Cow;
2
3const SMALL_MAX: usize = i32::MAX as usize;
4
5/// V8 APIs that take UTF-8 strings take their length in the form of 32-bit
6/// signed integers. This type represents a UTF-8 string that contains no
7/// more than `i32::MAX` bytes of code units.
8pub struct SmallUtf8<'a> {
9    contents: Cow<'a, str>,
10}
11
12impl<'a> SmallUtf8<'a> {
13    pub fn lower(&self) -> (*const u8, i32) {
14        (self.contents.as_ptr(), self.contents.len() as i32)
15    }
16}
17
18/// A UTF-8 string that can be lowered to a representation usable for V8
19/// APIs.
20pub struct Utf8<'a> {
21    contents: Cow<'a, str>,
22}
23
24impl<'a> From<&'a str> for Utf8<'a> {
25    fn from(s: &'a str) -> Self {
26        Utf8 {
27            contents: Cow::from(s),
28        }
29    }
30}
31
32impl<'a> Utf8<'a> {
33    pub fn size(&self) -> usize {
34        self.contents.len()
35    }
36
37    pub fn into_small(self) -> Option<SmallUtf8<'a>> {
38        if self.size() < SMALL_MAX {
39            Some(SmallUtf8 {
40                contents: self.contents,
41            })
42        } else {
43            None
44        }
45    }
46
47    pub fn into_small_unwrap(self) -> SmallUtf8<'a> {
48        let size = self.size();
49        self.into_small().unwrap_or_else(|| {
50            panic!("{size} >= i32::MAX");
51        })
52    }
53
54    pub fn truncate(self) -> SmallUtf8<'a> {
55        let size = self.size();
56        let mut contents = self.contents;
57
58        if size >= SMALL_MAX {
59            let s: &mut String = contents.to_mut();
60            s.truncate(SMALL_MAX - 3);
61            s.push_str("...");
62        }
63
64        SmallUtf8 { contents }
65    }
66}
neon/types_impl/utf8.rs

neon/types_impl/
utf8.rs
