Struct Headers

Source

pub struct Headers(pub HeaderMap);

Expand description

Headers extractor

Provides access to all request headers as a typed map.

§Example

use rustapi_core::extract::Headers;

async fn handler(headers: Headers) -> impl IntoResponse {
    if let Some(content_type) = headers.get("content-type") {
        format!("Content-Type: {:?}", content_type)
    } else {
        "No Content-Type header".to_string()
    }
}

Tuple Fields§

§0: HeaderMap

Implementations§

Source §

impl Headers

Source

pub fn get(&self, name: &str) -> Option<&HeaderValue>

Get a header value by name

Source

pub fn contains(&self, name: &str) -> bool

Check if a header exists

Source

pub fn len(&self) -> usize

Get the number of headers

Source

pub fn is_empty(&self) -> bool

Check if headers are empty

Source

pub fn iter(&self) -> Iter<'_, HeaderValue>

Iterate over all headers

Methods from Deref<Target = HeaderMap>§

Source

pub fn len(&self) -> usize

Returns the number of headers stored in the map.

This number represents the total number of values stored in the map. This number can be greater than or equal to the number of keys stored given that a single key may have more than one associated value.

§Examples

let mut map = HeaderMap::new();

assert_eq!(0, map.len());

map.insert(ACCEPT, "text/plain".parse().unwrap());
map.insert(HOST, "localhost".parse().unwrap());

assert_eq!(2, map.len());

map.append(ACCEPT, "text/html".parse().unwrap());

assert_eq!(3, map.len());

Source

pub fn keys_len(&self) -> usize

Returns the number of keys stored in the map.

This number will be less than or equal to len() as each key may have more than one associated value.

§Examples

let mut map = HeaderMap::new();

assert_eq!(0, map.keys_len());

map.insert(ACCEPT, "text/plain".parse().unwrap());
map.insert(HOST, "localhost".parse().unwrap());

assert_eq!(2, map.keys_len());

map.insert(ACCEPT, "text/html".parse().unwrap());

assert_eq!(2, map.keys_len());

Source

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

§Examples

let mut map = HeaderMap::new();

assert!(map.is_empty());

map.insert(HOST, "hello.world".parse().unwrap());

assert!(!map.is_empty());

Source

pub fn capacity(&self) -> usize

Returns the number of headers the map can hold without reallocating.

This number is an approximation as certain usage patterns could cause additional allocations before the returned capacity is filled.

§Examples

let mut map = HeaderMap::new();

assert_eq!(0, map.capacity());

map.insert(HOST, "hello.world".parse().unwrap());
assert_eq!(6, map.capacity());

Source

pub fn get<K>(&self, key: K) -> Option<&T>
where K: AsHeaderName,

Returns a reference to the value associated with the key.

If there are multiple values associated with the key, then the first one is returned. Use get_all to get all values associated with a given key. Returns None if there are no values associated with the key.

§Examples

let mut map = HeaderMap::new();
assert!(map.get("host").is_none());

map.insert(HOST, "hello".parse().unwrap());
assert_eq!(map.get(HOST).unwrap(), &"hello");
assert_eq!(map.get("host").unwrap(), &"hello");

map.append(HOST, "world".parse().unwrap());
assert_eq!(map.get("host").unwrap(), &"hello");

Source

pub fn get_all<K>(&self, key: K) -> GetAll<'_, T>
where K: AsHeaderName,

Returns a view of all values associated with a key.

The returned view does not incur any allocations and allows iterating the values associated with the key. See GetAll for more details. Returns None if there are no values associated with the key.

§Examples

let mut map = HeaderMap::new();

map.insert(HOST, "hello".parse().unwrap());
map.append(HOST, "goodbye".parse().unwrap());

let view = map.get_all("host");

let mut iter = view.iter();
assert_eq!(&"hello", iter.next().unwrap());
assert_eq!(&"goodbye", iter.next().unwrap());
assert!(iter.next().is_none());

Source

pub fn contains_key<K>(&self, key: K) -> bool
where K: AsHeaderName,

Returns true if the map contains a value for the specified key.

§Examples

let mut map = HeaderMap::new();
assert!(!map.contains_key(HOST));

map.insert(HOST, "world".parse().unwrap());
assert!(map.contains_key("host"));

Source

pub fn iter(&self) -> Iter<'_, T>

An iterator visiting all key-value pairs.

The iteration order is arbitrary, but consistent across platforms for the same crate version. Each key will be yielded once per associated value. So, if a key has 3 associated values, it will be yielded 3 times.

§Examples

let mut map = HeaderMap::new();

map.insert(HOST, "hello".parse().unwrap());
map.append(HOST, "goodbye".parse().unwrap());
map.insert(CONTENT_LENGTH, "123".parse().unwrap());

for (key, value) in map.iter() {
    println!("{:?}: {:?}", key, value);
}

Source

pub fn keys(&self) -> Keys<'_, T>

An iterator visiting all keys.

The iteration order is arbitrary, but consistent across platforms for the same crate version. Each key will be yielded only once even if it has multiple associated values.

§Examples

let mut map = HeaderMap::new();

map.insert(HOST, "hello".parse().unwrap());
map.append(HOST, "goodbye".parse().unwrap());
map.insert(CONTENT_LENGTH, "123".parse().unwrap());

for key in map.keys() {
    println!("{:?}", key);
}

Source

pub fn values(&self) -> Values<'_, T>

An iterator visiting all values.

The iteration order is arbitrary, but consistent across platforms for the same crate version.

§Examples

let mut map = HeaderMap::new();

map.insert(HOST, "hello".parse().unwrap());
map.append(HOST, "goodbye".parse().unwrap());
map.insert(CONTENT_LENGTH, "123".parse().unwrap());

for value in map.values() {
    println!("{:?}", value);
}