http_types/content/
content_length.rs

1use crate::headers::{HeaderName, HeaderValue, Headers, CONTENT_LENGTH};
2use crate::Status;
3
4/// The size of the entity-body, in bytes, sent to the recipient.
5///
6/// # Specifications
7///
8/// - [RFC 7230, section 3.3.2: Content-Length](https://tools.ietf.org/html/rfc7230#section-3.3.2)
9///
10/// # Examples
11///
12/// ```
13/// # fn main() -> http_types::Result<()> {
14/// #
15/// use http_types::Response;
16/// use http_types::content::{ContentLength};
17///
18/// let content_len = ContentLength::new(12);
19///
20/// let mut res = Response::new(200);
21/// content_len.apply(&mut res);
22///
23/// let content_len = ContentLength::from_headers(res)?.unwrap();
24/// assert_eq!(content_len.len(), 12);
25/// #
26/// # Ok(()) }
27/// ```
28#[derive(Debug)]
29pub struct ContentLength {
30    length: u64,
31}
32
33#[allow(clippy::len_without_is_empty)]
34impl ContentLength {
35    /// Create a new instance.
36    pub fn new(length: u64) -> Self {
37        Self { length }
38    }
39
40    /// Create a new instance from headers.
41    pub fn from_headers(headers: impl AsRef<Headers>) -> crate::Result<Option<Self>> {
42        let headers = match headers.as_ref().get(CONTENT_LENGTH) {
43            Some(headers) => headers,
44            None => return Ok(None),
45        };
46
47        // If we successfully parsed the header then there's always at least one
48        // entry. We want the last entry.
49        let value = headers.iter().last().unwrap();
50        let length = value.as_str().trim().parse().status(400)?;
51        Ok(Some(Self { length }))
52    }
53
54    /// Sets the header.
55    pub fn apply(&self, mut headers: impl AsMut<Headers>) {
56        headers.as_mut().insert(self.name(), self.value());
57    }
58
59    /// Get the `HeaderName`.
60    pub fn name(&self) -> HeaderName {
61        CONTENT_LENGTH
62    }
63
64    /// Get the `HeaderValue`.
65    pub fn value(&self) -> HeaderValue {
66        let output = format!("{}", self.length);
67
68        // SAFETY: the internal string is validated to be ASCII.
69        unsafe { HeaderValue::from_bytes_unchecked(output.into()) }
70    }
71
72    /// Get the content length.
73    pub fn len(&self) -> u64 {
74        self.length
75    }
76
77    /// Set the content length.
78    pub fn set_len(&mut self, len: u64) {
79        self.length = len;
80    }
81}
82
83#[cfg(test)]
84mod test {
85    use super::*;
86    use crate::headers::Headers;
87
88    #[test]
89    fn smoke() -> crate::Result<()> {
90        let content_len = ContentLength::new(12);
91
92        let mut headers = Headers::new();
93        content_len.apply(&mut headers);
94
95        let content_len = ContentLength::from_headers(headers)?.unwrap();
96        assert_eq!(content_len.len(), 12);
97        Ok(())
98    }
99
100    #[test]
101    fn bad_request_on_parse_error() {
102        let mut headers = Headers::new();
103        headers.insert(CONTENT_LENGTH, "<nori ate the tag. yum.>");
104        let err = ContentLength::from_headers(headers).unwrap_err();
105        assert_eq!(err.status(), 400);
106    }
107}
http_types/content/content_length.rs

http_types/content/
content_length.rs
