1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166

use std::fmt;
use std::str::FromStr;
use header::{Header, HeaderFormat};
use header::parsing::{from_one_comma_delimited, fmt_comma_delimited};

/// The Cache-Control header.
#[derive(PartialEq, Clone, Debug)]
pub struct CacheControl(pub Vec<CacheDirective>);

deref!(CacheControl => Vec<CacheDirective>);

impl Header for CacheControl {
    fn header_name() -> &'static str {
        "Cache-Control"
    }

    fn parse_header(raw: &[Vec<u8>]) -> Option<CacheControl> {
        let directives = raw.iter()
            .filter_map(|line| from_one_comma_delimited(&line[..]))
            .collect::<Vec<Vec<CacheDirective>>>()
            .concat();
        if directives.len() > 0 {
            Some(CacheControl(directives))
        } else {
            None
        }
    }
}

impl HeaderFormat for CacheControl {
    fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt_comma_delimited(fmt, &self[..])
    }
}

/// CacheControl contains a list of these directives.
#[derive(PartialEq, Clone, Debug)]
pub enum CacheDirective {
    /// "no-cache"
    NoCache,
    /// "no-store"
    NoStore,
    /// "no-transform"
    NoTransform,
    /// "only-if-cached"
    OnlyIfCached,

    // request directives
    /// "max-age=delta"
    MaxAge(u32),
    /// "max-stale=delta"
    MaxStale(u32),
    /// "min-fresh=delta"
    MinFresh(u32),

    // response directives
    /// "must-revalidate"
    MustRevalidate,
    /// "public"
    Public,
    /// "private"
    Private,
    /// "proxy-revalidate"
    ProxyRevalidate,
    /// "s-maxage=delta"
    SMaxAge(u32),

    /// Extension directives. Optionally include an argument.
    Extension(String, Option<String>)
}

impl fmt::Display for CacheDirective {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        use self::CacheDirective::*;
        fmt::Display::fmt(match *self {
            NoCache => "no-cache",
            NoStore => "no-store",
            NoTransform => "no-transform",
            OnlyIfCached => "only-if-cached",

            MaxAge(secs) => return write!(f, "max-age={}", secs),
            MaxStale(secs) => return write!(f, "max-stale={}", secs),
            MinFresh(secs) => return write!(f, "min-fresh={}", secs),

            MustRevalidate => "must-revalidate",
            Public => "public",
            Private => "private",
            ProxyRevalidate => "proxy-revalidate",
            SMaxAge(secs) => return write!(f, "s-maxage={}", secs),

            Extension(ref name, None) => &name[..],
            Extension(ref name, Some(ref arg)) => return write!(f, "{}={}", name, arg),

        }, f)
    }
}

impl FromStr for CacheDirective {
    type Err = Option<<u32 as FromStr>::Err>;
    fn from_str(s: &str) -> Result<CacheDirective, Option<<u32 as FromStr>::Err>> {
        use self::CacheDirective::*;
        match s {
            "no-cache" => Ok(NoCache),
            "no-store" => Ok(NoStore),
            "no-transform" => Ok(NoTransform),
            "only-if-cached" => Ok(OnlyIfCached),
            "must-revalidate" => Ok(MustRevalidate),
            "public" => Ok(Public),
            "private" => Ok(Private),
            "proxy-revalidate" => Ok(ProxyRevalidate),
            "" => Err(None),
            _ => match s.find('=') {
                Some(idx) if idx+1 < s.len() => match (&s[..idx], &s[idx+1..].trim_matches('"')) {
                    ("max-age" , secs) => secs.parse().map(MaxAge).map_err(|x| Some(x)),
                    ("max-stale", secs) => secs.parse().map(MaxStale).map_err(|x| Some(x)),
                    ("min-fresh", secs) => secs.parse().map(MinFresh).map_err(|x| Some(x)),
                    ("s-maxage", secs) => secs.parse().map(SMaxAge).map_err(|x| Some(x)),
                    (left, right) => Ok(Extension(left.to_string(), Some(right.to_string())))
                },
                Some(_) => Err(None),
                None => Ok(Extension(s.to_string(), None))
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use header::Header;
    use super::*;

    #[test]
    fn test_parse_multiple_headers() {
        let cache = Header::parse_header(&[b"no-cache".to_vec(), b"private".to_vec()]);
        assert_eq!(cache, Some(CacheControl(vec![CacheDirective::NoCache,
                                                 CacheDirective::Private])))
    }

    #[test]
    fn test_parse_argument() {
        let cache = Header::parse_header(&[b"max-age=100, private".to_vec()]);
        assert_eq!(cache, Some(CacheControl(vec![CacheDirective::MaxAge(100),
                                                 CacheDirective::Private])))
    }

    #[test]
    fn test_parse_quote_form() {
        let cache = Header::parse_header(&[b"max-age=\"200\"".to_vec()]);
        assert_eq!(cache, Some(CacheControl(vec![CacheDirective::MaxAge(200)])))
    }

    #[test]
    fn test_parse_extension() {
        let cache = Header::parse_header(&[b"foo, bar=baz".to_vec()]);
        assert_eq!(cache, Some(CacheControl(vec![CacheDirective::Extension("foo".to_string(), None),
                                                 CacheDirective::Extension("bar".to_string(), Some("baz".to_string()))])))
    }

    #[test]
    fn test_parse_bad_syntax() {
        let cache: Option<CacheControl> = Header::parse_header(&[b"foo=".to_vec()]);
        assert_eq!(cache, None)
    }
}

bench_header!(normal, CacheControl, { vec![b"no-cache, private".to_vec(), b"max-age=100".to_vec()] });