fluent-uri

A full-featured URI reference handling library compliant with RFC 3986. It is:

• Fast: Zero-copy parsing. Benchmarked to be highly performant.¹
• Easy: Carefully designed and documented APIs. Handy percent-encoding utilities.
• Correct: Forbids unsafe code. Extensively fuzz-tested against other implementations.

Documentation | Discussions

Terminology

A URI reference is either a URI or a relative reference. If it starts with a scheme (like http, ftp, mailto, etc.) followed by a colon (:), it is a URI. For example, http://example.com/ and mailto:user@example.com are URIs. Otherwise, it is a relative reference. For example, //example.org/, /index.html, ../, foo, ?bar, and #baz are relative references.

Examples

• Parse and extract components zero-copy from a URI reference:

  const SCHEME_FOO: &Scheme = Scheme::new_or_panic("foo");
  
  let uri_ref = UriRef::parse("foo://user@example.com:8042/over/there?name=ferret#nose")?;
  
  assert_eq!(uri_ref.scheme().unwrap(), SCHEME_FOO);
  
  let auth = uri_ref.authority().unwrap();
  assert_eq!(auth.as_str(), "user@example.com:8042");
  assert_eq!(auth.userinfo().unwrap(), "user");
  assert_eq!(auth.host(), "example.com");
  assert!(matches!(auth.host_parsed(), Host::RegName(name) if name == "example.com"));
  assert_eq!(auth.port().unwrap(), "8042");
  assert_eq!(auth.port_to_u16(), Ok(Some(8042)));
  
  assert_eq!(uri_ref.path(), "/over/there");
  assert_eq!(uri_ref.query().unwrap(), "name=ferret");
  assert_eq!(uri_ref.fragment().unwrap(), "nose");

• Build a URI reference using the builder pattern:

  const SCHEME_FOO: &Scheme = Scheme::new_or_panic("foo");
  
  let uri_ref = UriRef::builder()
      .scheme(SCHEME_FOO)
      .authority_with(|b| {
          b.userinfo(EStr::new_or_panic("user"))
              .host(EStr::new_or_panic("example.com"))
              .port(8042)
      })
      .path(EStr::new_or_panic("/over/there"))
      .query(EStr::new_or_panic("name=ferret"))
      .fragment(EStr::new_or_panic("nose"))
      .build()
      .unwrap();
  
  assert_eq!(
      uri_ref.as_str(),
      "foo://user@example.com:8042/over/there?name=ferret#nose"
  );

• Resolve a URI reference against a base URI:

  let base = UriRef::parse("http://example.com/foo/bar")?;
  
  let uri_ref = UriRef::parse("baz")?;
  assert_eq!(uri_ref.resolve_against(&base).unwrap(), "http://example.com/foo/baz");
  let uri_ref = UriRef::parse("../baz")?;
  assert_eq!(uri_ref.resolve_against(&base).unwrap(), "http://example.com/baz");
  let uri_ref = UriRef::parse("?baz")?;
  assert_eq!(uri_ref.resolve_against(&base).unwrap(), "http://example.com/foo/bar?baz");

• Normalize a URI reference:

  let uri_ref = UriRef::parse("eXAMPLE://a/./b/../b/%63/%7bfoo%7d")?;
  assert_eq!(uri_ref.normalize(), "example://a/b/c/%7Bfoo%7D");

• EStr (Percent-encoded string slices):

  All components in a URI that may be percent-encoded are parsed as EStrs, which allows easy splitting and decoding:

  let s = "?name=%E5%BC%A0%E4%B8%89&speech=%C2%A1Ol%C3%A9%21";
  let query = UriRef::parse(s).unwrap().query().unwrap();
  let map: HashMap<_, _> = query
      .split('&')
      .map(|s| s.split_once('=').unwrap_or((s, EStr::EMPTY)))
      .map(|(k, v)| (k.decode().into_string_lossy(), v.decode().into_string_lossy()))
      .collect();
  assert_eq!(map["name"], "张三");
  assert_eq!(map["speech"], "¡Olé!");

• EString (A percent-encoded, growable string):

  You can encode key-value pairs to a query string and use it to build a UriRef:

  let pairs = [("name", "张三"), ("speech", "¡Olé!")];
  let mut buf = EString::<Query>::new();
  for (k, v) in pairs {
      if !buf.is_empty() {
          buf.push_byte(b'&');
      }
      buf.encode::<Data>(k);
      buf.push_byte(b'=');
      buf.encode::<Data>(v);
  }
  
  assert_eq!(buf, "name=%E5%BC%A0%E4%B8%89&speech=%C2%A1Ol%C3%A9%21");
  
  let uri_ref = UriRef::builder()
      .path(EStr::EMPTY)
      .query(&buf)
      .build()
      .unwrap();
  assert_eq!(uri_ref.as_str(), "?name=%E5%BC%A0%E4%B8%89&speech=%C2%A1Ol%C3%A9%21");

Footnotes

1. In a benchmark on an Intel Core i5-11300H processor, fluent-uri parsed a URI in 49ns compared to 89ns for iref and 135ns for iri-string. ↩