use crate::header::{Header, HeaderError};
use lazy_static::lazy_static;
#[derive(Debug, PartialEq)]
pub struct HeaderChar {
char_code: u8,
next_char: Vec<HeaderChar>,
header: Option<Header>,
}
fn add_header(header_chars: &mut Vec<HeaderChar>, header: &[u8], header_enum: Header) {
let mut ptr = header_chars;
let header_enum_value = header.to_ascii_lowercase();
let end_idx = header_enum_value.len() - 1;
for (idx, char_code) in header_enum_value.iter().enumerate() {
let mut search_result =
ptr.binary_search_by(|header_char| (header_char.char_code).cmp(char_code));
if search_result.is_err() {
let header = if idx == end_idx {
Some(header_enum.clone())
} else {
None
};
ptr.push(HeaderChar {
char_code: *char_code,
next_char: Vec::new(),
header,
});
ptr.sort_unstable_by(|a, b| a.char_code.cmp(&b.char_code));
search_result =
ptr.binary_search_by(|header_char| (header_char.char_code).cmp(char_code));
}
let index = search_result.unwrap();
ptr = &mut ptr[index].next_char;
}
}
lazy_static! {
pub static ref HEADER_CHARS: Vec<HeaderChar> = {
let mut h = Vec::<HeaderChar>::new();
add_header(&mut h, b"Referer", Header::Referer);
add_header(&mut h, b"Pragma", Header::Pragma);
add_header(&mut h, b"Upgrade", Header::Upgrade);
add_header(&mut h, b"Content-Type", Header::ContentType);
add_header(&mut h, b"Content-Length", Header::ContentLength);
add_header(&mut h, b"Content-Encoding", Header::ContentEncoding);
add_header(&mut h, b"Authorization", Header::Authorization);
add_header(&mut h, b"Accept", Header::Accept);
add_header(&mut h, b"Accept-Encoding", Header::AcceptEncoding);
add_header(&mut h, b"Accept-Language", Header::AcceptLanguage);
add_header(&mut h, b"Sec-Fetch-Dest", Header::SecFetchDest);
add_header(&mut h, b"Sec-Fetch-User", Header::SecFetchUser);
add_header(&mut h, b"Sec-Fetch-Site", Header::SecFetchSite);
add_header(&mut h, b"Sec-Fetch-Mode", Header::SecFetchMode);
add_header(&mut h, b"Host", Header::Host);
add_header(&mut h, b"Cache-Control", Header::CacheControl);
add_header(&mut h, b"Connection", Header::Connection);
add_header(&mut h, b"User-Agent", Header::UserAgent);
add_header(
&mut h,
b"Upgrade-Insecure-Requests",
Header::UpgradeInsecureRequests,
);
h
};
}
pub fn get_header(value: &[u8]) -> Result<Header, HeaderError> {
let lowercase_value = value.to_ascii_lowercase();
let mut ptr = &*HEADER_CHARS;
let end_idx = lowercase_value.len() - 1;
for (idx, char_code) in lowercase_value.iter().enumerate() {
let search_result =
ptr.binary_search_by(|header_char| (header_char.char_code).cmp(&char_code));
let index = search_result.map_err(|_| HeaderError::InvalidHeader)?;
if idx == end_idx {
return ptr[index].header.clone().ok_or(HeaderError::InvalidHeader);
}
ptr = &ptr[index].next_char;
}
Err(HeaderError::InvalidHeader)
}
pub fn check_header_value(v: &[u8]) -> Result<(), HeaderError> {
for e in v.iter() {
if *e < 32 || *e > 126 {
return Err(HeaderError::InvalidHeaderValue);
}
}
Ok(())
}