use std::array;
use http::header::{self, HeaderName, HeaderValue};
use super::preflight_request_headers;
#[derive(Clone, Debug)]
pub struct Vary(Vec<HeaderValue>);
impl Vary {
pub fn list<I>(headers: I) -> Self
where
I: IntoIterator<Item = HeaderName>,
{
Self(headers.into_iter().map(Into::into).collect())
}
pub(super) fn to_header(&self) -> Option<(HeaderName, HeaderValue)> {
let values = &self.0;
let mut res = values.first()?.as_bytes().to_owned();
for val in &values[1..] {
res.extend_from_slice(b", ");
res.extend_from_slice(val.as_bytes());
}
let header_val = HeaderValue::from_bytes(&res)
.expect("comma-separated list of HeaderValues is always a valid HeaderValue");
Some((header::VARY, header_val))
}
}
impl Default for Vary {
fn default() -> Self {
Self::list(preflight_request_headers())
}
}
impl<const N: usize> From<[HeaderName; N]> for Vary {
fn from(arr: [HeaderName; N]) -> Self {
#[allow(deprecated)] Self::list(array::IntoIter::new(arr))
}
}
impl From<Vec<HeaderName>> for Vary {
fn from(vec: Vec<HeaderName>) -> Self {
Self::list(vec)
}
}