use std::borrow::Cow;
use std::fmt::{self, Debug, Display};
use std::str::FromStr;
use crate::Error;
/// A header name.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct HeaderName(Cow<'static, str>);
impl HeaderName {
/// Create a new `HeaderName` from a Vec of ASCII bytes.
///
/// # Error
///
/// This function will error if the bytes is not valid ASCII.
pub fn from_bytes(mut bytes: Vec<u8>) -> Result<Self, Error> {
crate::ensure!(bytes.is_ascii(), "Bytes should be valid ASCII");
bytes.make_ascii_lowercase();
// This is permitted because ASCII is valid UTF-8, and we just checked that.
let string = unsafe { String::from_utf8_unchecked(bytes.to_vec()) };
Ok(HeaderName(Cow::Owned(string)))
}
/// Create a new `HeaderName` from an ASCII string.
///
/// # Error
///
/// This function will error if the string is not valid ASCII.
pub fn from_string(s: String) -> Result<Self, Error> {
Self::from_bytes(s.into_bytes())
}
/// Returns the header name as a `&str`.
pub fn as_str(&self) -> &'_ str {
&self.0
}
/// Converts a vector of bytes to a `HeaderName` without checking that the string contains
/// valid ASCII.
///
/// # Safety
///
/// This function is unsafe because it does not check that the bytes passed to it are valid
/// ASCII. If this constraint is violated, it may cause memory
/// unsafety issues with future users of the HeaderName, as the rest of the library assumes
/// that Strings are valid ASCII.
pub unsafe fn from_bytes_unchecked(mut bytes: Vec<u8>) -> Self {
bytes.make_ascii_lowercase();
let string = String::from_utf8_unchecked(bytes);
HeaderName(Cow::Owned(string))
}
/// Converts a string assumed to lowercase into a `HeaderName`
pub(crate) const fn from_lowercase_str(str: &'static str) -> Self {
HeaderName(Cow::Borrowed(str))
}
}
impl Debug for HeaderName {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self.0)
}
}
impl Display for HeaderName {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.0)
}
}
impl FromStr for HeaderName {
type Err = Error;
/// Create a new `HeaderName`.
///
/// This checks it's valid ASCII, and lowercases it.
fn from_str(s: &str) -> Result<Self, Self::Err> {
crate::ensure!(s.is_ascii(), "String slice should be valid ASCII");
Ok(HeaderName(Cow::Owned(s.to_ascii_lowercase())))
}
}
impl From<&HeaderName> for HeaderName {
fn from(value: &HeaderName) -> HeaderName {
value.clone()
}
}
impl<'a> From<&'a str> for HeaderName {
fn from(value: &'a str) -> Self {
Self::from_str(value).expect("String slice should be valid ASCII")
}
}
impl PartialEq<str> for HeaderName {
fn eq(&self, other: &str) -> bool {
match HeaderName::from_str(other) {
Err(_) => false,
Ok(other) => self == &other,
}
}
}
impl<'a> PartialEq<&'a str> for HeaderName {
fn eq(&self, other: &&'a str) -> bool {
match HeaderName::from_str(other) {
Err(_) => false,
Ok(other) => self == &other,
}
}
}
impl PartialEq<String> for HeaderName {
fn eq(&self, other: &String) -> bool {
match HeaderName::from_str(other) {
Err(_) => false,
Ok(other) => self == &other,
}
}
}
impl<'a> PartialEq<&String> for HeaderName {
fn eq(&self, other: &&String) -> bool {
match HeaderName::from_str(other) {
Err(_) => false,
Ok(other) => self == &other,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
#[allow(clippy::eq_op)]
fn test_header_name_static_non_static() {
let static_header = HeaderName::from_lowercase_str("hello");
let non_static_header = HeaderName::from_str("hello").unwrap();
assert_eq!(&static_header, &non_static_header);
assert_eq!(&static_header, &static_header);
assert_eq!(&non_static_header, &non_static_header);
assert_eq!(static_header, non_static_header);
assert_eq!(static_header, static_header);
assert_eq!(non_static_header, non_static_header);
}
#[test]
fn equality() {
let static_header = HeaderName::from_lowercase_str("hello");
assert_eq!(static_header, "hello");
assert_eq!(&static_header, "hello");
assert_eq!(static_header, String::from("hello"));
assert_eq!(static_header, &String::from("hello"));
// Must validate regardless of casing.
assert_eq!(static_header, &String::from("Hello"));
}
#[test]
fn pass_name_by_ref() {
let mut res = crate::Response::new(200);
res.insert_header(&crate::headers::HOST, "127.0.0.1");
}
#[test]
fn test_debug() {
let header_name = HeaderName::from_str("hello").unwrap();
assert_eq!(format!("{:?}", header_name), "\"hello\"");
}
}