1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

use lazy_static::lazy_static;
use std::collections::BTreeMap;
use std::ops::Add;

#[derive(Debug, PartialEq, Clone, Ord, Eq, PartialOrd)]
pub enum Header {
    Null,
    Host,
    Connection,
    CacheControl,
    UpgradeInsecureRequests,
    UserAgent,
    Accept,
    SecFetchSite,
    SecFetchMode,
    SecFetchDest,
    AcceptEncoding,
    AcceptLanguage,
}

#[derive(Debug, PartialEq)]
pub struct HeaderChar {
    char_code: u8,
    next_char: Vec<HeaderChar>,
    header: Header,
}

fn add_header(header_chars: &mut Vec<HeaderChar>, header_enum_value: &[u8], header_enum: Header) {
    let mut ptr = header_chars;
    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 {
                header_enum.clone()
            } else {
                Header::Null
            };
            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 header_chars = Vec::<HeaderChar>::new();
        add_header(
            &mut header_chars,
            b"Host".to_ascii_lowercase().as_slice(),
            Header::Host,
        );
        add_header(
            &mut header_chars,
            b"Connection".to_ascii_lowercase().as_slice(),
            Header::Connection,
        );
        add_header(
            &mut header_chars,
            b"Cache-Control".to_ascii_lowercase().as_slice(),
            Header::CacheControl,
        );
        add_header(
            &mut header_chars,
            b"Upgrade-Insecure-Requests".to_ascii_lowercase().as_slice(),
            Header::UpgradeInsecureRequests,
        );
        add_header(
            &mut header_chars,
            b"User-Agent".to_ascii_lowercase().as_slice(),
            Header::UserAgent,
        );
        add_header(
            &mut header_chars,
            b"Accept".to_ascii_lowercase().as_slice(),
            Header::Accept,
        );
        add_header(
            &mut header_chars,
            b"Sec-Fetch-Site".to_ascii_lowercase().as_slice(),
            Header::SecFetchSite,
        );
        add_header(
            &mut header_chars,
            b"Sec-Fetch-Mode".to_ascii_lowercase().as_slice(),
            Header::SecFetchMode,
        );
        add_header(
            &mut header_chars,
            b"Sec-Fetch-Dest".to_ascii_lowercase().as_slice(),
            Header::SecFetchDest,
        );
        add_header(
            &mut header_chars,
            b"Accept-Encoding".to_ascii_lowercase().as_slice(),
            Header::AcceptEncoding,
        );
        add_header(
            &mut header_chars,
            b"Accept-Language".to_ascii_lowercase().as_slice(),
            Header::AcceptLanguage,
        );
        header_chars
    };
}

pub fn get_header_enum(value: &[u8]) -> Header {
    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));
        if search_result.is_err() {
            return Header::Null;
        }
        let index = search_result.unwrap();
        if idx == end_idx {
            return ptr[index].header.clone();
        }
        ptr = &ptr[index].next_char;
    }
    Header::Null
}

#[derive(Debug)]
pub struct Headers {
    map: BTreeMap<Header, Vec<u8>>,
}

impl Headers {
    pub fn new() -> Self {
        Headers {
            map: BTreeMap::new(),
        }
    }

    pub fn add(&mut self, key: Header, value: Vec<u8>) {
        self.map.insert(key, value);
    }

    pub fn get(&self, key: Header) -> Option<&Vec<u8>> {
        self.map.get(&key)
    }

    pub fn del(&mut self, key: Header) {
        self.map.remove(&key);
    }
}

impl Add<Headers> for Headers {
    type Output = Headers;
    fn add(self, mut other: Headers) -> Headers {
        let mut map = self.map;
        map.append(&mut other.map);
        Headers { map }
    }
}