Revision control
Copy as Markdown
Other Tools
use super::ETag;
use util::EntityTagRange;
use HeaderValue;
/// `If-None-Match` header, defined in
///
/// The `If-None-Match` header field makes the request method conditional
/// on a recipient cache or origin server either not having any current
/// representation of the target resource, when the field-value is "*",
/// or having a selected representation with an entity-tag that does not
/// match any of those listed in the field-value.
///
/// A recipient MUST use the weak comparison function when comparing
/// entity-tags for If-None-Match (Section 2.3.2), since weak entity-tags
/// can be used for cache validation even if there have been changes to
/// the representation data.
///
/// # ABNF
///
/// ```text
/// If-None-Match = "*" / 1#entity-tag
/// ```
///
/// # Example values
///
/// * `"xyzzy"`
/// * `W/"xyzzy"`
/// * `"xyzzy", "r2d2xxxx", "c3piozzzz"`
/// * `W/"xyzzy", W/"r2d2xxxx", W/"c3piozzzz"`
/// * `*`
///
/// # Examples
///
/// ```
/// # extern crate headers;
/// use headers::IfNoneMatch;
///
/// let if_none_match = IfNoneMatch::any();
/// ```
#[derive(Clone, Debug, PartialEq)]
pub struct IfNoneMatch(EntityTagRange);
derive_header! {
IfNoneMatch(_),
name: IF_NONE_MATCH
}
impl IfNoneMatch {
/// Create a new `If-None-Match: *` header.
pub fn any() -> IfNoneMatch {
IfNoneMatch(EntityTagRange::Any)
}
/// Checks whether the ETag passes this precondition.
pub fn precondition_passes(&self, etag: &ETag) -> bool {
!self.0.matches_weak(&etag.0)
}
}
impl From<ETag> for IfNoneMatch {
fn from(etag: ETag) -> IfNoneMatch {
IfNoneMatch(EntityTagRange::Tags(HeaderValue::from(etag.0).into()))
}
}
/*
test_if_none_match {
test_header!(test1, vec![b"\"xyzzy\""]);
test_header!(test2, vec![b"W/\"xyzzy\""]);
test_header!(test3, vec![b"\"xyzzy\", \"r2d2xxxx\", \"c3piozzzz\""]);
test_header!(test4, vec![b"W/\"xyzzy\", W/\"r2d2xxxx\", W/\"c3piozzzz\""]);
test_header!(test5, vec![b"*"]);
}
*/
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn precondition_fails() {
let foo = ETag::from_static("\"foo\"");
let weak_foo = ETag::from_static("W/\"foo\"");
let if_none = IfNoneMatch::from(foo.clone());
assert!(!if_none.precondition_passes(&foo));
assert!(!if_none.precondition_passes(&weak_foo));
}
#[test]
fn precondition_passes() {
let if_none = IfNoneMatch::from(ETag::from_static("\"foo\""));
let bar = ETag::from_static("\"bar\"");
let weak_bar = ETag::from_static("W/\"bar\"");
assert!(if_none.precondition_passes(&bar));
assert!(if_none.precondition_passes(&weak_bar));
}
#[test]
fn precondition_any() {
let foo = ETag::from_static("\"foo\"");
let if_none = IfNoneMatch::any();
assert!(!if_none.precondition_passes(&foo));
}
}