headers/util/
http_date.rs

1use std::fmt;
2use std::str::FromStr;
3use std::time::SystemTime;
4
5use bytes::Bytes;
6use http::header::HeaderValue;
7
8use super::IterExt;
9
10/// A timestamp with HTTP formatting and parsing
11//   Prior to 1995, there were three different formats commonly used by
12//   servers to communicate timestamps.  For compatibility with old
13//   implementations, all three are defined here.  The preferred format is
14//   a fixed-length and single-zone subset of the date and time
15//   specification used by the Internet Message Format [RFC5322].
16//
17//     HTTP-date    = IMF-fixdate / obs-date
18//
19//   An example of the preferred format is
20//
21//     Sun, 06 Nov 1994 08:49:37 GMT    ; IMF-fixdate
22//
23//   Examples of the two obsolete formats are
24//
25//     Sunday, 06-Nov-94 08:49:37 GMT   ; obsolete RFC 850 format
26//     Sun Nov  6 08:49:37 1994         ; ANSI C's asctime() format
27//
28//   A recipient that parses a timestamp value in an HTTP header field
29//   MUST accept all three HTTP-date formats.  When a sender generates a
30//   header field that contains one or more timestamps defined as
31//   HTTP-date, the sender MUST generate those timestamps in the
32//   IMF-fixdate format.
33#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
34pub(crate) struct HttpDate(httpdate::HttpDate);
35
36impl HttpDate {
37    pub(crate) fn from_val(val: &HeaderValue) -> Option<Self> {
38        val.to_str().ok()?.parse().ok()
39    }
40}
41
42// TODO: remove this and FromStr?
43#[derive(Debug)]
44pub struct Error(());
45
46impl super::TryFromValues for HttpDate {
47    fn try_from_values<'i, I>(values: &mut I) -> Result<Self, crate::Error>
48    where
49        I: Iterator<Item = &'i HeaderValue>,
50    {
51        values
52            .just_one()
53            .and_then(HttpDate::from_val)
54            .ok_or_else(crate::Error::invalid)
55    }
56}
57
58impl From<HttpDate> for HeaderValue {
59    fn from(date: HttpDate) -> HeaderValue {
60        (&date).into()
61    }
62}
63
64impl<'a> From<&'a HttpDate> for HeaderValue {
65    fn from(date: &'a HttpDate) -> HeaderValue {
66        // TODO: could be just BytesMut instead of String
67        let s = date.to_string();
68        let bytes = Bytes::from(s);
69        HeaderValue::from_maybe_shared(bytes).expect("HttpDate always is a valid value")
70    }
71}
72
73impl FromStr for HttpDate {
74    type Err = Error;
75    fn from_str(s: &str) -> Result<HttpDate, Error> {
76        Ok(HttpDate(s.parse().map_err(|_| Error(()))?))
77    }
78}
79
80impl fmt::Debug for HttpDate {
81    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
82        fmt::Display::fmt(&self.0, f)
83    }
84}
85
86impl fmt::Display for HttpDate {
87    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
88        fmt::Display::fmt(&self.0, f)
89    }
90}
91
92impl From<SystemTime> for HttpDate {
93    fn from(sys: SystemTime) -> HttpDate {
94        HttpDate(sys.into())
95    }
96}
97
98impl From<HttpDate> for SystemTime {
99    fn from(date: HttpDate) -> SystemTime {
100        SystemTime::from(date.0)
101    }
102}
103
104#[cfg(test)]
105mod tests {
106    use super::HttpDate;
107
108    use std::time::{Duration, UNIX_EPOCH};
109
110    // The old tests had Sunday, but 1994-11-07 is a Monday.
111    // See https://github.com/pyfisch/httpdate/pull/6#issuecomment-846881001
112    fn nov_07() -> HttpDate {
113        HttpDate((UNIX_EPOCH + Duration::new(784198117, 0)).into())
114    }
115
116    #[test]
117    fn test_display_is_imf_fixdate() {
118        assert_eq!("Mon, 07 Nov 1994 08:48:37 GMT", &nov_07().to_string());
119    }
120
121    #[test]
122    fn test_imf_fixdate() {
123        assert_eq!(
124            "Mon, 07 Nov 1994 08:48:37 GMT".parse::<HttpDate>().unwrap(),
125            nov_07()
126        );
127    }
128
129    #[test]
130    fn test_rfc_850() {
131        assert_eq!(
132            "Monday, 07-Nov-94 08:48:37 GMT"
133                .parse::<HttpDate>()
134                .unwrap(),
135            nov_07()
136        );
137    }
138
139    #[test]
140    fn test_asctime() {
141        assert_eq!(
142            "Mon Nov  7 08:48:37 1994".parse::<HttpDate>().unwrap(),
143            nov_07()
144        );
145    }
146
147    #[test]
148    fn test_no_date() {
149        assert!("this-is-no-date".parse::<HttpDate>().is_err());
150    }
151}
headers/util/http_date.rs

headers/util/
http_date.rs
