hyper/
headers.rs

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1#[cfg(feature = "http1")]
2use bytes::BytesMut;
3use http::header::CONTENT_LENGTH;
4use http::header::{HeaderValue, ValueIter};
5use http::HeaderMap;
6#[cfg(all(feature = "http2", feature = "client"))]
7use http::Method;
8
9#[cfg(feature = "http1")]
10pub(super) fn connection_keep_alive(value: &HeaderValue) -> bool {
11    connection_has(value, "keep-alive")
12}
13
14#[cfg(feature = "http1")]
15pub(super) fn connection_close(value: &HeaderValue) -> bool {
16    connection_has(value, "close")
17}
18
19#[cfg(feature = "http1")]
20fn connection_has(value: &HeaderValue, needle: &str) -> bool {
21    if let Ok(s) = value.to_str() {
22        for val in s.split(',') {
23            if val.trim().eq_ignore_ascii_case(needle) {
24                return true;
25            }
26        }
27    }
28    false
29}
30
31#[cfg(all(feature = "http1", feature = "server"))]
32pub(super) fn content_length_parse(value: &HeaderValue) -> Option<u64> {
33    from_digits(value.as_bytes())
34}
35
36pub(super) fn content_length_parse_all(headers: &HeaderMap) -> Option<u64> {
37    content_length_parse_all_values(headers.get_all(CONTENT_LENGTH).into_iter())
38}
39
40pub(super) fn content_length_parse_all_values(values: ValueIter<'_, HeaderValue>) -> Option<u64> {
41    // If multiple Content-Length headers were sent, everything can still
42    // be alright if they all contain the same value, and all parse
43    // correctly. If not, then it's an error.
44
45    let mut content_length: Option<u64> = None;
46    for h in values {
47        if let Ok(line) = h.to_str() {
48            for v in line.split(',') {
49                if let Some(n) = from_digits(v.trim().as_bytes()) {
50                    if content_length.is_none() {
51                        content_length = Some(n)
52                    } else if content_length != Some(n) {
53                        return None;
54                    }
55                } else {
56                    return None
57                }
58            }
59        } else {
60            return None
61        }
62    }
63
64    return content_length
65}
66
67fn from_digits(bytes: &[u8]) -> Option<u64> {
68    // cannot use FromStr for u64, since it allows a signed prefix
69    let mut result = 0u64;
70    const RADIX: u64 = 10;
71
72    if bytes.is_empty() {
73        return None;
74    }
75
76    for &b in bytes {
77        // can't use char::to_digit, since we haven't verified these bytes
78        // are utf-8.
79        match b {
80            b'0'..=b'9' => {
81                result = result.checked_mul(RADIX)?;
82                result = result.checked_add((b - b'0') as u64)?;
83            },
84            _ => {
85                // not a DIGIT, get outta here!
86                return None;
87            }
88        }
89    }
90
91    Some(result)
92}
93
94#[cfg(all(feature = "http2", feature = "client"))]
95pub(super) fn method_has_defined_payload_semantics(method: &Method) -> bool {
96    match *method {
97        Method::GET | Method::HEAD | Method::DELETE | Method::CONNECT => false,
98        _ => true,
99    }
100}
101
102#[cfg(feature = "http2")]
103pub(super) fn set_content_length_if_missing(headers: &mut HeaderMap, len: u64) {
104    headers
105        .entry(CONTENT_LENGTH)
106        .or_insert_with(|| HeaderValue::from(len));
107}
108
109#[cfg(feature = "http1")]
110pub(super) fn transfer_encoding_is_chunked(headers: &HeaderMap) -> bool {
111    is_chunked(headers.get_all(http::header::TRANSFER_ENCODING).into_iter())
112}
113
114#[cfg(feature = "http1")]
115pub(super) fn is_chunked(mut encodings: ValueIter<'_, HeaderValue>) -> bool {
116    // chunked must always be the last encoding, according to spec
117    if let Some(line) = encodings.next_back() {
118        return is_chunked_(line);
119    }
120
121    false
122}
123
124#[cfg(feature = "http1")]
125pub(super) fn is_chunked_(value: &HeaderValue) -> bool {
126    // chunked must always be the last encoding, according to spec
127    if let Ok(s) = value.to_str() {
128        if let Some(encoding) = s.rsplit(',').next() {
129            return encoding.trim().eq_ignore_ascii_case("chunked");
130        }
131    }
132
133    false
134}
135
136#[cfg(feature = "http1")]
137pub(super) fn add_chunked(mut entry: http::header::OccupiedEntry<'_, HeaderValue>) {
138    const CHUNKED: &str = "chunked";
139
140    if let Some(line) = entry.iter_mut().next_back() {
141        // + 2 for ", "
142        let new_cap = line.as_bytes().len() + CHUNKED.len() + 2;
143        let mut buf = BytesMut::with_capacity(new_cap);
144        buf.extend_from_slice(line.as_bytes());
145        buf.extend_from_slice(b", ");
146        buf.extend_from_slice(CHUNKED.as_bytes());
147
148        *line = HeaderValue::from_maybe_shared(buf.freeze())
149            .expect("original header value plus ascii is valid");
150        return;
151    }
152
153    entry.insert(HeaderValue::from_static(CHUNKED));
154}
hyper/headers.rs

hyper/
headers.rs
