Struct SerializeableHeaderMap 

struct SerializeableHeaderMap(HeaderMap);

Wrapper type for HeaderMap

Tuple Fields

0: HeaderMap

Methods from Deref<Target = HeaderMap>

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());

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());

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());

pub fn clear(&mut self)

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

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)

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 HeaderMap MAX_SIZE.

Examples

let mut map = HeaderMap::new();
map.reserve(10);

pub fn try_reserve(&mut self, additional: usize) -> Result<(), MaxSizeReached>

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.

Errors

This method differs from reserve by returning an error instead of panicking if the value is too large.

Examples

let mut map = HeaderMap::new();
map.try_reserve(10).unwrap();

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");

pub fn get_mut<K>(&mut self, key: K) -> Option<&mut T>

where K: AsHeaderName,

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,

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,

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>

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>

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>

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>

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>

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>

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,

Gets the given key’s corresponding entry in the map for in-place manipulation.

Panics

This method panics if capacity exceeds max HeaderMap capacity

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,

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.

If reserving space goes over the maximum, this will also return an error. However, to prevent breaking changes to the return type, the error will still say InvalidHeaderName, unlike other try_* methods which return a MaxSizeReached error.

pub fn insert<K>(&mut self, key: K, val: T) -> Option<T>

where K: IntoHeaderName,

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.

Panics

This method panics if capacity exceeds max HeaderMap capacity

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 try_insert<K>( &mut self, key: K, val: T, ) -> Result<Option<T>, MaxSizeReached>

where K: IntoHeaderName,

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.

Errors

This function may return an error if HeaderMap exceeds max capacity

Examples

let mut map = HeaderMap::new();
assert!(map.try_insert(HOST, "world".parse().unwrap()).unwrap().is_none());
assert!(!map.is_empty());

let mut prev = map.try_insert(HOST, "earth".parse().unwrap()).unwrap().unwrap();
assert_eq!("world", prev);

pub fn append<K>(&mut self, key: K, value: T) -> bool

where K: IntoHeaderName,

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.

Panics

This method panics if capacity exceeds max HeaderMap capacity

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 try_append<K>( &mut self, key: K, value: T, ) -> Result<bool, MaxSizeReached>

where K: IntoHeaderName,

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.

Errors

This function may return an error if HeaderMap exceeds max capacity

Examples

let mut map = HeaderMap::new();
assert!(map.try_insert(HOST, "world".parse().unwrap()).unwrap().is_none());
assert!(!map.is_empty());

map.try_append(HOST, "earth".parse().unwrap()).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,

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 Debug for SerializeableHeaderMap

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for SerializeableHeaderMap

type Target = HeaderMap

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for SerializeableHeaderMap

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'de> Deserialize<'de> for SerializeableHeaderMap

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<HeaderMap> for SerializeableHeaderMap

fn from(value: HeaderMap) -> Self

Converts to this type from the input type.

impl MallocSizeOf for SerializeableHeaderMap

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.

impl Serialize for SerializeableHeaderMap

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.