headers/common/
etag.rs

1use std::str::FromStr;
2
3use crate::util::EntityTag;
4
5/// `ETag` header, defined in [RFC7232](https://datatracker.ietf.org/doc/html/rfc7232#section-2.3)
6///
7/// The `ETag` header field in a response provides the current entity-tag
8/// for the selected representation, as determined at the conclusion of
9/// handling the request.  An entity-tag is an opaque validator for
10/// differentiating between multiple representations of the same
11/// resource, regardless of whether those multiple representations are
12/// due to resource state changes over time, content negotiation
13/// resulting in multiple representations being valid at the same time,
14/// or both.  An entity-tag consists of an opaque quoted string, possibly
15/// prefixed by a weakness indicator.
16///
17/// # ABNF
18///
19/// ```text
20/// ETag       = entity-tag
21/// ```
22///
23/// # Example values
24///
25/// * `"xyzzy"`
26/// * `W/"xyzzy"`
27/// * `""`
28///
29/// # Examples
30///
31/// ```
32/// let etag = "\"xyzzy\"".parse::<headers::ETag>().unwrap();
33/// ```
34#[derive(Clone, Debug, PartialEq, Eq)]
35pub struct ETag(pub(super) EntityTag);
36
37derive_header! {
38    ETag(_),
39    name: ETAG
40}
41
42impl ETag {
43    #[cfg(test)]
44    pub(crate) fn from_static(src: &'static str) -> ETag {
45        ETag(EntityTag::from_static(src))
46    }
47
48    /// Returns `true` if the etag is [weak](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/ETag#directives).
49    pub fn is_weak(&self) -> bool {
50        self.0.is_weak()
51    }
52}
53
54error_type!(InvalidETag);
55
56impl FromStr for ETag {
57    type Err = InvalidETag;
58    fn from_str(src: &str) -> Result<Self, Self::Err> {
59        let val = src.parse().map_err(|_| InvalidETag { _inner: () })?;
60
61        EntityTag::from_owned(val)
62            .map(ETag)
63            .ok_or(InvalidETag { _inner: () })
64    }
65}
66
67/*
68test_etag {
69    // From the RFC
70    test_header!(test1,
71        vec![b"\"xyzzy\""],
72        Some(ETag(EntityTag::new(false, "xyzzy".to_owned()))));
73    test_header!(test2,
74        vec![b"W/\"xyzzy\""],
75        Some(ETag(EntityTag::new(true, "xyzzy".to_owned()))));
76    test_header!(test3,
77        vec![b"\"\""],
78        Some(ETag(EntityTag::new(false, "".to_owned()))));
79    // Own tests
80    test_header!(test4,
81        vec![b"\"foobar\""],
82        Some(ETag(EntityTag::new(false, "foobar".to_owned()))));
83    test_header!(test5,
84        vec![b"\"\""],
85        Some(ETag(EntityTag::new(false, "".to_owned()))));
86    test_header!(test6,
87        vec![b"W/\"weak-etag\""],
88        Some(ETag(EntityTag::new(true, "weak-etag".to_owned()))));
89    test_header!(test7,
90        vec![b"W/\"\x65\x62\""],
91        Some(ETag(EntityTag::new(true, "\u{0065}\u{0062}".to_owned()))));
92    test_header!(test8,
93        vec![b"W/\"\""],
94        Some(ETag(EntityTag::new(true, "".to_owned()))));
95    test_header!(test9,
96        vec![b"no-dquotes"],
97        None::<ETag>);
98    test_header!(test10,
99        vec![b"w/\"the-first-w-is-case-sensitive\""],
100        None::<ETag>);
101    test_header!(test11,
102        vec![b""],
103        None::<ETag>);
104    test_header!(test12,
105        vec![b"\"unmatched-dquotes1"],
106        None::<ETag>);
107    test_header!(test13,
108        vec![b"unmatched-dquotes2\""],
109        None::<ETag>);
110    test_header!(test14,
111        vec![b"matched-\"dquotes\""],
112        None::<ETag>);
113    test_header!(test15,
114        vec![b"\""],
115        None::<ETag>);
116}
117*/
headers/common/etag.rs

headers/common/
etag.rs
