ruma_common/identifiers/
session_id.rs

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1//! Matrix session ID.
2
3use ruma_macros::IdZst;
4
5use super::IdParseError;
6
7/// A session ID.
8///
9/// Session IDs in Matrix are opaque character sequences of `[0-9a-zA-Z.=_-]`. Their length must
10/// must not exceed 255 characters.
11#[repr(transparent)]
12#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, IdZst)]
13#[ruma_id(validate = validate_session_id)]
14pub struct SessionId(str);
15
16impl SessionId {
17    #[doc(hidden)]
18    pub const fn _priv_const_new(s: &str) -> Result<&Self, &'static str> {
19        match validate_session_id(s) {
20            Ok(()) => Ok(Self::from_borrowed(s)),
21            Err(IdParseError::MaximumLengthExceeded) => {
22                Err("Invalid Session ID: exceeds 255 bytes")
23            }
24            Err(IdParseError::InvalidCharacters) => {
25                Err("Invalid Session ID: contains invalid characters")
26            }
27            Err(IdParseError::Empty) => Err("Invalid Session ID: empty"),
28            Err(_) => unreachable!(),
29        }
30    }
31}
32
33const fn validate_session_id(s: &str) -> Result<(), IdParseError> {
34    if s.len() > 255 {
35        return Err(IdParseError::MaximumLengthExceeded);
36    } else if contains_invalid_byte(s.as_bytes()) {
37        return Err(IdParseError::InvalidCharacters);
38    } else if s.is_empty() {
39        return Err(IdParseError::Empty);
40    }
41
42    Ok(())
43}
44
45const fn contains_invalid_byte(mut bytes: &[u8]) -> bool {
46    // non-const form:
47    //
48    // bytes.iter().all(|b| b.is_ascii_alphanumeric() || b".=_-".contains(&b))
49    loop {
50        if let Some((byte, rest)) = bytes.split_first() {
51            if byte.is_ascii_alphanumeric() || matches!(byte, b'.' | b'=' | b'_' | b'-') {
52                bytes = rest;
53            } else {
54                break true;
55            }
56        } else {
57            break false;
58        }
59    }
60}
ruma_common/identifiers/session_id.rs

ruma_common/identifiers/
session_id.rs
