Struct tauri::http::header::HeaderMap
x3A;:header::HeaderMap,
pub struct HeaderMap<T = HeaderValue> { /* fields omitted */ }Expand description
A set of HTTP headers
HeaderMap is an multimap of HeaderName to values.
Examples#
Basic usage
let mut headers = HeaderMap::new();
headers.insert(HOST, "example.com".parse().unwrap());
headers.insert(CONTENT_LENGTH, "123".parse().unwrap());
assert!(headers.contains_key(HOST));
assert!(!headers.contains_key(LOCATION));
assert_eq!(headers[HOST], "example.com");
headers.remove(HOST);
assert!(!headers.contains_key(HOST));Implementations#
impl HeaderMap<HeaderValue>[src]#
pub fn new() -> HeaderMap<HeaderValue>[src]#
Create an empty HeaderMap.
The map will be created without any capacity. This function will not allocate.
Examples#
let map = HeaderMap::new();
assert!(map.is_empty());
assert_eq!(0, map.capacity());impl<T> HeaderMap<T>[src]#
pub fn with_capacity(capacity: usize) -> HeaderMap<T>[src]#
Create an empty HeaderMap with the specified capacity.
The returned map will allocate internal storage in order to hold about capacity elements without reallocating. However, this is a “best effort” as there are usage patterns that could cause additional allocations before capacity headers are stored in the map.
More capacity than requested may be allocated.
Examples#
let map: HeaderMap<u32> = HeaderMap::with_capacity(10);
assert!(map.is_empty());
assert_eq!(12, map.capacity());pub fn len(&self) -> usize[src]#
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());pub fn keys_len(&self) -> usize[src]#
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());pub fn is_empty(&self) -> bool[src]#
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());pub fn clear(&mut self)[src]#
Clears the map, removing all key-value pairs. Keeps the allocated memory for reuse.
Examples#
let mut map = HeaderMap::new();
map.insert(HOST, "hello.world".parse().unwrap());
map.clear();
assert!(map.is_empty());
assert!(map.capacity() > 0);pub fn capacity(&self) -> usize[src]#
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());pub fn reserve(&mut self, additional: usize)[src]#
Reserves capacity for at least additional more headers to be inserted into the HeaderMap.
The header map may reserve more space to avoid frequent reallocations. Like with with_capacity, this will be a “best effort” to avoid allocations until additional more headers are inserted. Certain usage patterns could cause additional allocations before the number is reached.
Panics#
Panics if the new allocation size overflows usize.
Examples#
let mut map = HeaderMap::new();
map.reserve(10);pub fn get<K>(&self, key: K) -> Option<&T> where K: AsHeaderName,[src]#
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");pub fn get_mut<K>(&mut self, key: K) -> Option<&mutT> where K: AsHeaderName,[src]#
Returns a mutable reference to the value associated with the key.
If there are multiple values associated with the key, then the first one is returned. Use entry 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::default();
map.insert(HOST, "hello".to_string());
map.get_mut("host").unwrap().push_str("-world");
assert_eq!(map.get(HOST).unwrap(), &"hello-world");pub fn get_all<K>(&self, key: K) -> GetAll<'_, T> where K: AsHeaderName,[src]#
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());pub fn contains_key<K>(&self, key: K) -> bool where K: AsHeaderName,[src]#
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"));pub fn iter(&self) -> Iter<'_, T>ⓘNotable traits for Iter<'a, T>impl<'a, T> Iterator for Iter<'a, T>type Item = (&'a HeaderName, &'aT);[src]#
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);
}pub fn iter_mut(&mut self) -> IterMut<'_, T>ⓘNotable traits for IterMut<'a, T>impl<'a, T> Iterator for IterMut<'a, T>type Item = (&'a HeaderName, &'a mutT);[src]#
An iterator visiting all key-value pairs, with mutable value references.
The iterator 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::default();
map.insert(HOST, "hello".to_string());
map.append(HOST, "goodbye".to_string());
map.insert(CONTENT_LENGTH, "123".to_string());
for (key, value) in map.iter_mut() {
value.push_str("-boop");
}pub fn keys(&self) -> Keys<'_, T>ⓘNotable traits for Keys<'a, T>impl<'a, T> Iterator for Keys<'a, T>type Item = &'a HeaderName;[src]#
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);
}pub fn values(&self) -> Values<'_, T>ⓘNotable traits for Values<'a, T>impl<'a, T> Iterator for Values<'a, T>type Item = &'aT;[src]#
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);
}pub fn values_mut(&mut self) -> ValuesMut<'_, T>ⓘNotable traits for ValuesMut<'a, T>impl<'a, T> Iterator for ValuesMut<'a, T>type Item = &'a mutT;[src]#
An iterator visiting all values mutably.
The iteration order is arbitrary, but consistent across platforms for the same crate version.
Examples#
let mut map = HeaderMap::default();
map.insert(HOST, "hello".to_string());
map.append(HOST, "goodbye".to_string());
map.insert(CONTENT_LENGTH, "123".to_string());
for value in map.values_mut() {
value.push_str("-boop");
}pub fn drain(&mut self) -> Drain<'_, T>ⓘNotable traits for Drain<'a, T>impl<'a, T> Iterator for Drain<'a, T>type Item = (Option<HeaderName>, T);[src]#
Clears the map, returning all entries as an iterator.
The internal memory is kept for reuse.
For each yielded item that has None provided for the HeaderName, then the associated header name is the same as that of the previously yielded item. The first yielded item will have HeaderName set.
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());
let mut drain = map.drain();
assert_eq!(drain.next(), Some((Some(HOST), "hello".parse().unwrap())));
assert_eq!(drain.next(), Some((None, "goodbye".parse().unwrap())));
assert_eq!(drain.next(), Some((Some(CONTENT_LENGTH), "123".parse().unwrap())));
assert_eq!(drain.next(), None);pub fn entry<K>(&mut self, key: K) -> Entry<'_, T> where K: IntoHeaderName,[src]#
Gets the given key’s corresponding entry in the map for in-place manipulation.
Examples#
let mut map: HeaderMap<u32> = HeaderMap::default();
let headers = &[
"content-length",
"x-hello",
"Content-Length",
"x-world",
];
for &header in headers {
let counter = map.entry(header).or_insert(0);
*counter += 1;
}
assert_eq!(map["content-length"], 2);
assert_eq!(map["x-hello"], 1);pub fn try_entry<K>( &mut self, key: K ) -> Result<Entry<'_, T>, InvalidHeaderName> where K: AsHeaderName,[src]#
Gets the given key’s corresponding entry in the map for in-place manipulation.
Errors#
This method differs from entry by allowing types that may not be valid HeaderNames to passed as the key (such as String). If they do not parse as a valid HeaderName, this returns an InvalidHeaderName error.
pub fn insert<K>(&mut self, key: K, val: T) -> Option<T> where K: IntoHeaderName,[src]#
Inserts a key-value pair into the map.
If the map did not previously have this key present, then None is returned.
If the map did have this key present, the new value is associated with the key and all previous values are removed. Note that only a single one of the previous values is returned. If there are multiple values that have been previously associated with the key, then the first one is returned. See insert_mult on OccupiedEntry for an API that returns all values.
The key is not updated, though; this matters for types that can be == without being identical.
Examples#
let mut map = HeaderMap::new();
assert!(map.insert(HOST, "world".parse().unwrap()).is_none());
assert!(!map.is_empty());
let mut prev = map.insert(HOST, "earth".parse().unwrap()).unwrap();
assert_eq!("world", prev);pub fn append<K>(&mut self, key: K, value: T) -> bool where K: IntoHeaderName,[src]#
Inserts a key-value pair into the map.
If the map did not previously have this key present, then false is returned.
If the map did have this key present, the new value is pushed to the end of the list of values currently associated with the key. The key is not updated, though; this matters for types that can be == without being identical.
Examples#
let mut map = HeaderMap::new();
assert!(map.insert(HOST, "world".parse().unwrap()).is_none());
assert!(!map.is_empty());
map.append(HOST, "earth".parse().unwrap());
let values = map.get_all("host");
let mut i = values.iter();
assert_eq!("world", *i.next().unwrap());
assert_eq!("earth", *i.next().unwrap());pub fn remove<K>(&mut self, key: K) -> Option<T> where K: AsHeaderName,[src]#
Removes a key from the map, returning the value associated with the key.
Returns None if the map does not contain the key. If there are multiple values associated with the key, then the first one is returned. See remove_entry_mult on OccupiedEntry for an API that yields all values.
Examples#
let mut map = HeaderMap::new();
map.insert(HOST, "hello.world".parse().unwrap());
let prev = map.remove(HOST).unwrap();
assert_eq!("hello.world", prev);
assert!(map.remove(HOST).is_none());Trait Implementations#
impl<T> Clone for HeaderMap<T> where T: Clone,[src]#
pub fn clone(&self) -> HeaderMap<T>[src]#
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)1.0.0[src]#
Performs copy-assignment from source. Read more
impl<T> Debug for HeaderMap<T> where T: Debug,[src]#
pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>[src]#
Formats the value using the given formatter. Read more
impl<T> Default for HeaderMap<T>[src]#
pub fn default() -> HeaderMap<T>[src]#
Returns the “default value” for a type. Read more
impl<T> Extend<(HeaderName, T)> for HeaderMap<T>[src]#
pub fn extend<I>(&mut self, iter: I) where I: IntoIterator<Item = (HeaderName, T)>,[src]#
Extends a collection with the contents of an iterator. Read more
fn extend_one(&mut self, item: A)[src]#
🔬 This is a nightly-only experimental API. (extend_one)
Extends a collection with exactly one element.
fn extend_reserve(&mut self, additional: usize)[src]#
🔬 This is a nightly-only experimental API. (extend_one)
Reserves capacity in a collection for the given number of additional elements. Read more
impl<T> Extend<(Option<HeaderName>, T)> for HeaderMap<T>[src]#
pub fn extend<I>(&mut self, iter: I) where I: IntoIterator<Item = (Option<HeaderName>, T)>,[src]#
Extend a HeaderMap with the contents of another HeaderMap.
This function expects the yielded items to follow the same structure as IntoIter.
Panics#
This panics if the first yielded item does not have a HeaderName.
Examples#
let mut map = HeaderMap::new();
map.insert(ACCEPT, "text/plain".parse().unwrap());
map.insert(HOST, "hello.world".parse().unwrap());
let mut extra = HeaderMap::new();
extra.insert(HOST, "foo.bar".parse().unwrap());
extra.insert(COOKIE, "hello".parse().unwrap());
extra.append(COOKIE, "world".parse().unwrap());
map.extend(extra);
assert_eq!(map["host"], "foo.bar");
assert_eq!(map["accept"], "text/plain");
assert_eq!(map["cookie"], "hello");
let v = map.get_all("host");
assert_eq!(1, v.iter().count());
let v = map.get_all("cookie");
assert_eq!(2, v.iter().count());fn extend_one(&mut self, item: A)[src]#
🔬 This is a nightly-only experimental API. (extend_one)
Extends a collection with exactly one element.
fn extend_reserve(&mut self, additional: usize)[src]#
🔬 This is a nightly-only experimental API. (extend_one)
Reserves capacity in a collection for the given number of additional elements. Read more
impl<T> FromIterator<(HeaderName, T)> for HeaderMap<T>[src]#
pub fn from_iter<I>(iter: I) -> HeaderMap<T> where I: IntoIterator<Item = (HeaderName, T)>,[src]#
Creates a value from an iterator. Read more
impl<'a, K, T> Index<K> for HeaderMap<T> where K: AsHeaderName,[src]#
pub fn index(&self, index: K) -> &T[src]#
Panics#
Using the index operator will cause a panic if the header you’re querying isn’t set.
type Output = T#
The returned type after indexing.
impl<'a, T> IntoIterator for &'a HeaderMap<T>[src]#
type Item = (&'a HeaderName, &'aT)#
The type of the elements being iterated over.
type IntoIter = Iter<'a, T>#
Which kind of iterator are we turning this into?
pub fn into_iter(self) -> Iter<'a, T>ⓘNotable traits for Iter<'a, T>impl<'a, T> Iterator for Iter<'a, T>type Item = (&'a HeaderName, &'aT);[src]#
Creates an iterator from a value. Read more
impl<'a, T> IntoIterator for &'a mut HeaderMap<T>[src]#
type Item = (&'a HeaderName, &'a mutT)#
The type of the elements being iterated over.
type IntoIter = IterMut<'a, T>#
Which kind of iterator are we turning this into?
pub fn into_iter(self) -> IterMut<'a, T>ⓘNotable traits for IterMut<'a, T>impl<'a, T> Iterator for IterMut<'a, T>type Item = (&'a HeaderName, &'a mutT);[src]#
Creates an iterator from a value. Read more
impl<T> IntoIterator for HeaderMap<T>[src]#
pub fn into_iter(self) -> IntoIter<T>ⓘNotable traits for IntoIter<T>impl<T> Iterator for IntoIter<T>type Item = (Option<HeaderName>, T);[src]#
Creates a consuming iterator, that is, one that moves keys and values out of the map in arbitrary order. The map cannot be used after calling this.
For each yielded item that has None provided for the HeaderName, then the associated header name is the same as that of the previously yielded item. The first yielded item will have HeaderName set.
Examples#
Basic usage.
let mut map = HeaderMap::new();
map.insert(header::CONTENT_LENGTH, "123".parse().unwrap());
map.insert(header::CONTENT_TYPE, "json".parse().unwrap());
let mut iter = map.into_iter();
assert_eq!(iter.next(), Some((Some(header::CONTENT_LENGTH), "123".parse().unwrap())));
assert_eq!(iter.next(), Some((Some(header::CONTENT_TYPE), "json".parse().unwrap())));
assert!(iter.next().is_none());Multiple values per key.
let mut map = HeaderMap::new();
map.append(header::CONTENT_LENGTH, "123".parse().unwrap());
map.append(header::CONTENT_LENGTH, "456".parse().unwrap());
map.append(header::CONTENT_TYPE, "json".parse().unwrap());
map.append(header::CONTENT_TYPE, "html".parse().unwrap());
map.append(header::CONTENT_TYPE, "xml".parse().unwrap());
let mut iter = map.into_iter();
assert_eq!(iter.next(), Some((Some(header::CONTENT_LENGTH), "123".parse().unwrap())));
assert_eq!(iter.next(), Some((None, "456".parse().unwrap())));
assert_eq!(iter.next(), Some((Some(header::CONTENT_TYPE), "json".parse().unwrap())));
assert_eq!(iter.next(), Some((None, "html".parse().unwrap())));
assert_eq!(iter.next(), Some((None, "xml".parse().unwrap())));
assert!(iter.next().is_none());type Item = (Option<HeaderName>, T)#
The type of the elements being iterated over.
type IntoIter = IntoIter<T>#
Which kind of iterator are we turning this into?
impl<T> PartialEq<HeaderMap<T>> for HeaderMap<T> where T: PartialEq<T>,[src]#
pub fn eq(&self, other: &HeaderMap<T>) -> bool[src]#
This method tests for self and other values to be equal, and is used by ==. Read more
#[must_use]fn ne(&self, other: &Rhs) -> bool1.0.0[src]#
This method tests for !=.
impl<'a, K, V, T> TryFrom<<'a HashMap<K, V, RandomState>> for HeaderMap<T> where T: TryFrom<&'aV>, K: Eq + Hash, HeaderName: TryFrom<&'aK>, <HeaderName as TryFrom<&'aK>>::Error: Into<Error>, <T as TryFrom<&'aV>>::Error: Into<Error>,[src]#
Try to convert a HashMap into a HeaderMap.
Examples#
use std::collections::HashMap;
use std::convert::TryInto;
use http::HeaderMap;
let mut map = HashMap::new();
map.insert("X-Custom-Header".to_string(), "my value".to_string());
let headers: HeaderMap = (&map).try_into().expect("valid headers");
assert_eq!(headers["X-Custom-Header"], "my value");type Error = Error#
The type returned in the event of a conversion error.
pub fn try_from( c: &'a HashMap<K, V, RandomState> ) -> Result<HeaderMap<T>, <HeaderMap<T> as TryFrom<<'a HashMap<K, V, RandomState>>>::Error>[src]#
Performs the conversion.
impl<T> Eq for HeaderMap<T> where T: Eq,#
Auto Trait Implementations#
impl<T> RefUnwindSafe for HeaderMap<T> where T: RefUnwindSafe,#
impl<T> Send for HeaderMap<T> where T: Send,#
impl<T> Sync for HeaderMap<T> where T: Sync,#
impl<T> Unpin for HeaderMap<T> where T: Unpin,#
impl<T> UnwindSafe for HeaderMap<T> where T: UnwindSafe,#
Blanket Implementations#
impl<T> Any for T where T: 'static + ?Sized,[src]#
pub fn type_id(&self) -> TypeId[src]#
Gets the TypeId of self. Read more
impl<T> Borrow<T> for T where T: ?Sized,[src]#
pub fn borrow(&self) -> &T[src]#
Immutably borrows from an owned value. Read more
impl<T> BorrowMut<T> for T where T: ?Sized,[src]#
pub fn borrow_mut(&mut self) -> &mutT[src]#
Mutably borrows from an owned value. Read more
impl<T> From<T> for T[src]#
pub fn from(t: T) -> T[src]#
Performs the conversion.
impl<T, U> Into<U> for T where U: From<T>,[src]#
pub fn into(self) -> U[src]#
Performs the conversion.
impl<T> ToOwned for T where T: Clone,[src]#
type Owned = T#
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T[src]#
Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mutT)[src]#
🔬 This is a nightly-only experimental API. (toowned_clone_into)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
impl<T, U> TryFrom<U> for T where U: Into<T>,[src]#
type Error = Infallible#
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]#
Performs the conversion.
impl<T, U> TryInto<U> for T where U: TryFrom<T>,[src]#
type Error = <U as TryFrom<T>>::Error#
The type returned in the event of a conversion error.
pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]#
Performs the conversion.