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melib/headers: add proper Display impl for HeaderName

master
Manos Pitsidianakis 2023-05-31 18:22:17 +03:00
parent 954329d848
commit d332e4578d
Signed by: Manos Pitsidianakis
GPG Key ID: 7729C7707F7E09D0
1 changed files with 145 additions and 4 deletions

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@ -24,6 +24,7 @@
use std::{
borrow::{Borrow, Cow},
cmp::Ordering,
convert::TryFrom,
error::Error,
hash::{Hash, Hasher},
@ -52,12 +53,27 @@ pub struct HeaderName {
inner: Repr<Custom>,
}
impl Custom {
fn as_str(&self) -> &str {
unsafe { std::str::from_utf8_unchecked(&*self.0) }
}
}
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
enum Repr<T> {
Standard(StandardHeader),
Custom(T),
}
impl<T: std::fmt::Display> std::fmt::Display for Repr<T> {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Self::Standard(inner) => write!(fmt, "{}", inner.as_str()),
Self::Custom(inner) => inner.fmt(fmt),
}
}
}
// Used to hijack the Hash impl
#[derive(Debug, Clone, Eq, PartialEq)]
struct Custom(SmallVec<[u8; 32]>);
@ -527,18 +543,20 @@ const HEADER_CHARS: [u8; 128] = [
impl HeaderName {
/// Returns a `str` representation of the header.
///
/// The returned string will always be lower case.
/// The returned string will always be lower case. Use `Display` for a
/// properly formatted representation.
#[inline]
pub fn as_str(&self) -> &str {
match self.inner {
Repr::Standard(v) => v.as_str(),
Repr::Custom(ref v) => unsafe { std::str::from_utf8_unchecked(&*v.0) },
Repr::Custom(ref v) => v.as_str(),
}
}
/// Returns a `&[u8]` representation of the header.
///
/// The returned slice will always be lower case.
/// The returned string will always be lower case. Use `Display` for a
/// properly formatted representation.
#[inline]
pub fn as_bytes(&self) -> &[u8] {
match self.inner {
@ -606,7 +624,7 @@ impl Borrow<str> for HeaderName {
impl std::fmt::Display for HeaderName {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(fmt, "{}", self.as_str())
write!(fmt, "{}", &self.inner)
}
}
@ -807,3 +825,126 @@ impl Hash for Custom {
}
}
}
const UPPERCASE_TOKENS: &[&str] = &[
"ARC", "DKIM", "DL", "EDIINT", "ID", "IPMS", "MD5", "MIME", "MT", "MTS", "NNTP", "PICS", "RSS",
"SIO", "SPF", "TLS", "VBR",
];
impl std::fmt::Display for Custom {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let as_str = self.as_str();
let len = as_str.len();
let mut bytes_count = 0;
for chunk in as_str.split('-') {
if let Ok(tok) = UPPERCASE_TOKENS.binary_search_by(|probe| {
if probe.eq_ignore_ascii_case(chunk) {
Ordering::Equal
} else {
let mut iter = AsciiIgnoreCaseCmp {
ord: Ordering::Equal,
a: probe.as_bytes(),
b: chunk.as_bytes(),
};
let _cnt: usize = iter.by_ref().fuse().count();
debug_assert!(_cnt < probe.len());
debug_assert!(_cnt < chunk.len());
iter.ord
}
}) {
write!(fmt, "{}", UPPERCASE_TOKENS[tok])?;
} else {
if let Some(first) = chunk.chars().next() {
write!(fmt, "{}", first.to_ascii_uppercase())?;
}
for ch in chunk.chars().skip(1) {
write!(fmt, "{}", ch.to_ascii_lowercase())?
}
}
bytes_count += chunk.len();
if bytes_count != len {
bytes_count += 1;
write!(fmt, "-")?;
}
}
Ok(())
}
}
// an iterator which alternates between Some and None
struct AsciiIgnoreCaseCmp<'a, 'b> {
ord: Ordering,
a: &'a [u8],
b: &'b [u8],
}
impl<'a, 'b> Iterator for AsciiIgnoreCaseCmp<'a, 'b> {
type Item = ();
fn next(&mut self) -> Option<()> {
match (self.a.get(0), self.b.get(0)) {
(Some(a_char), Some(b_char)) => {
self.ord = a_char
.to_ascii_lowercase()
.cmp(&b_char.to_ascii_lowercase());
self.a = &self.a[1..];
self.b = &self.b[1..];
if self.ord == Ordering::Equal {
Some(())
} else {
None
}
}
(Some(_), None) => {
self.ord = Ordering::Greater;
None
}
(None, Some(_)) => {
self.ord = Ordering::Less;
None
}
(None, None) => None,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_headername_display() {
assert_eq!(&HeaderName::SUBJECT.to_string(), "Subject");
assert_eq!(&HeaderName::CC.to_string(), "Cc");
assert_eq!(&HeaderName::IN_REPLY_TO.to_string(), "In-Reply-To");
assert_eq!(
&HeaderName::ORIGINAL_MESSAGE_ID.to_string(),
"Original-Message-ID"
);
assert_eq!(
&HeaderName::try_from("x-user-agent").unwrap().to_string(),
"X-User-Agent"
);
assert_eq!(
&HeaderName::try_from("arc-foobar").unwrap().to_string(),
"ARC-Foobar"
);
assert_eq!(
&HeaderName::try_from("x-rss-feed").unwrap().to_string(),
"X-RSS-Feed"
);
assert_eq!(
&HeaderName::try_from("With-regards-to").unwrap().to_string(),
"With-Regards-To"
);
assert_eq!(
&HeaderName::try_from("in-response-to-id")
.unwrap()
.to_string(),
"In-Response-To-ID"
);
assert_eq!(
&HeaderName::try_from("something-dKim").unwrap().to_string(),
"Something-DKIM"
);
}
}