iroh_base/
relay_url.rs

1use std::{fmt, ops::Deref, str::FromStr, sync::Arc};
2
3use serde::{Deserialize, Serialize};
4use url::Url;
5
6/// A URL identifying a relay server.
7///
8/// It is cheaply clonable, as the underlying type is wrapped into an `Arc`.
9/// The main type under the hood though is [`Url`], with a few custom tweaks:
10///
11/// - A relay URL is never a relative URL, so an implicit `.` is added at the end of the
12///   domain name if missing.
13///
14/// - [`fmt::Debug`] is implemented so it prints the URL rather than the URL struct fields.
15///   Useful when logging e.g. `Option<RelayUrl>`.
16///
17/// To create a [`RelayUrl`] use the `From<Url>` implementation.
18#[derive(
19    Clone, derive_more::Display, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize,
20)]
21pub struct RelayUrl(Arc<Url>);
22
23impl From<Url> for RelayUrl {
24    fn from(mut url: Url) -> Self {
25        if let Some(domain) = url.domain() {
26            if !domain.ends_with('.') {
27                let domain = String::from(domain) + ".";
28
29                // This can fail, though it is unlikely the resulting URL is usable as a
30                // relay URL, probably it has the wrong scheme or is not a base URL or the
31                // like.  We don't do full URL validation however, so just silently leave
32                // this bad URL in place.  Something will fail later.
33                url.set_host(Some(&domain)).ok();
34            }
35        }
36        Self(Arc::new(url))
37    }
38}
39
40/// Can occur when parsing a string into a [`RelayUrl`].
41#[derive(Debug, thiserror::Error)]
42#[error("Failed to parse: {0}")]
43pub struct RelayUrlParseError(#[from] url::ParseError);
44
45/// Support for parsing strings directly.
46///
47/// If you need more control over the error first create a [`Url`] and use [`RelayUrl::from`]
48/// instead.
49impl FromStr for RelayUrl {
50    type Err = RelayUrlParseError;
51
52    fn from_str(s: &str) -> Result<Self, Self::Err> {
53        let inner = Url::from_str(s)?;
54        Ok(RelayUrl::from(inner))
55    }
56}
57
58impl From<RelayUrl> for Url {
59    fn from(value: RelayUrl) -> Self {
60        Arc::unwrap_or_clone(value.0)
61    }
62}
63
64/// Dereferences to the wrapped [`Url`].
65///
66/// Note that [`DerefMut`] is not implemented on purpose, so this type has more flexibility
67/// to change the inner later.
68///
69/// [`DerefMut`]: std::ops::DerefMut
70impl Deref for RelayUrl {
71    type Target = Url;
72
73    fn deref(&self) -> &Self::Target {
74        &self.0
75    }
76}
77
78impl fmt::Debug for RelayUrl {
79    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
80        f.debug_tuple("RelayUrl")
81            .field(&DbgStr(self.0.as_str()))
82            .finish()
83    }
84}
85
86/// Helper struct to format a &str without allocating a String.
87///
88/// Maybe this is entirely unneeded and the compiler would be smart enough to never allocate
89/// the String anyway.  Who knows.  Writing this was faster than checking the assembler
90/// output.
91struct DbgStr<'a>(&'a str);
92
93impl fmt::Debug for DbgStr<'_> {
94    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
95        write!(f, r#""{}""#, self.0)
96    }
97}
98
99#[cfg(test)]
100mod tests {
101    use super::*;
102
103    #[test]
104    fn test_relay_url_debug_display() {
105        let url = RelayUrl::from(Url::parse("https://example.com").unwrap());
106
107        assert_eq!(format!("{url:?}"), r#"RelayUrl("https://example.com./")"#);
108
109        assert_eq!(format!("{url}"), "https://example.com./");
110    }
111
112    #[test]
113    fn test_relay_url_absolute() {
114        let url = RelayUrl::from(Url::parse("https://example.com").unwrap());
115
116        assert_eq!(url.domain(), Some("example.com."));
117
118        let url1 = RelayUrl::from(Url::parse("https://example.com.").unwrap());
119        assert_eq!(url, url1);
120
121        let url2 = RelayUrl::from(Url::parse("https://example.com./").unwrap());
122        assert_eq!(url, url2);
123
124        let url3 = RelayUrl::from(Url::parse("https://example.com/").unwrap());
125        assert_eq!(url, url3);
126    }
127}
iroh_base/relay_url.rs

iroh_base/
relay_url.rs
