headers/common/
retry_after.rs

1use std::time::{Duration, SystemTime};
2
3use util::{HttpDate, Seconds, TryFromValues};
4use HeaderValue;
5
6/// The `Retry-After` header.
7///
8/// The `Retry-After` response-header field can be used with a 503 (Service
9/// Unavailable) response to indicate how long the service is expected to be
10/// unavailable to the requesting client. This field MAY also be used with any
11/// 3xx (Redirection) response to indicate the minimum time the user-agent is
12/// asked wait before issuing the redirected request. The value of this field
13/// can be either an HTTP-date or an integer number of seconds (in decimal)
14/// after the time of the response.
15///
16/// # Examples
17/// ```
18/// # extern crate headers;
19/// use std::time::{Duration, SystemTime};
20/// use headers::RetryAfter;
21///
22/// let delay = RetryAfter::delay(Duration::from_secs(300));
23/// let date = RetryAfter::date(SystemTime::now());
24/// ```
25
26/// Retry-After header, defined in [RFC7231](http://tools.ietf.org/html/rfc7231#section-7.1.3)
27#[derive(Debug, Clone, PartialEq, Eq)]
28pub struct RetryAfter(After);
29
30derive_header! {
31    RetryAfter(_),
32    name: RETRY_AFTER
33}
34
35#[derive(Debug, Clone, PartialEq, Eq)]
36enum After {
37    /// Retry after the given DateTime
38    DateTime(HttpDate),
39    /// Retry after this duration has elapsed
40    Delay(Seconds),
41}
42
43impl RetryAfter {
44    /// Create an `RetryAfter` header with a date value.
45    pub fn date(time: SystemTime) -> RetryAfter {
46        RetryAfter(After::DateTime(time.into()))
47    }
48
49    /// Create an `RetryAfter` header with a date value.
50    pub fn delay(dur: Duration) -> RetryAfter {
51        RetryAfter(After::Delay(dur.into()))
52    }
53}
54
55impl TryFromValues for After {
56    fn try_from_values<'i, I>(values: &mut I) -> Result<Self, ::Error>
57    where
58        I: Iterator<Item = &'i HeaderValue>,
59    {
60        values
61            .next()
62            .and_then(|val| {
63                if let Some(delay) = Seconds::from_val(val) {
64                    return Some(After::Delay(delay));
65                }
66
67                let date = HttpDate::from_val(val)?;
68                Some(After::DateTime(date))
69            })
70            .ok_or_else(::Error::invalid)
71    }
72}
73
74impl<'a> From<&'a After> for HeaderValue {
75    fn from(after: &'a After) -> HeaderValue {
76        match *after {
77            After::Delay(ref delay) => delay.into(),
78            After::DateTime(ref date) => date.into(),
79        }
80    }
81}
82
83#[cfg(test)]
84mod tests {
85    use super::super::test_decode;
86    use super::RetryAfter;
87    use std::time::Duration;
88    use util::HttpDate;
89
90    #[test]
91    fn delay_decode() {
92        let r: RetryAfter = test_decode(&["1234"]).unwrap();
93        assert_eq!(r, RetryAfter::delay(Duration::from_secs(1234)),);
94    }
95
96    macro_rules! test_retry_after_datetime {
97        ($name:ident, $s:expr) => {
98            #[test]
99            fn $name() {
100                let r: RetryAfter = test_decode(&[$s]).unwrap();
101                let dt = "Sun, 06 Nov 1994 08:49:37 GMT".parse::<HttpDate>().unwrap();
102
103                assert_eq!(r, RetryAfter(super::After::DateTime(dt)));
104            }
105        };
106    }
107
108    test_retry_after_datetime!(date_decode_rfc1123, "Sun, 06 Nov 1994 08:49:37 GMT");
109    test_retry_after_datetime!(date_decode_rfc850, "Sunday, 06-Nov-94 08:49:37 GMT");
110    test_retry_after_datetime!(date_decode_asctime, "Sun Nov  6 08:49:37 1994");
111}
headers/common/retry_after.rs

headers/common/
retry_after.rs
