Struct HashMap 

pub struct HashMap<K: 'static, V: 'static, S = FixedState> { /* private fields */ }

High-Performance Lock-Free Map.

Implementations

impl<K, V> HashMap<K, V, FixedState>

where K: Hash + Eq + Clone + 'static, V: Clone + 'static,

pub fn new() -> Self

Creates a new empty hash map with FoldHash (FixedState).

impl<K, V, S> HashMap<K, V, S>

where K: Hash + Eq + Clone + 'static, V: Clone + 'static, S: BuildHasher,

pub fn with_hasher(hasher: S) -> Self

Creates a new hash map with custom hasher.

pub fn get<Q>(&self, key: &Q) -> Option<V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Optimized get operation.

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Checks if the key exists.

pub fn insert(&self, key: K, value: V) -> Option<V>

Insert a key-value pair.

pub fn insert_if_absent(&self, key: K, value: V) -> Option<V>

Insert a key-value pair only if the key does not exist. Returns None if inserted, Some(existing_value) if the key already exists.

pub fn get_or_insert(&self, key: K, value: V) -> V

Returns the value corresponding to the key, or inserts the given value if the key is not present.

This is linearizable: concurrent callers for the same key are guaranteed to agree on which value was inserted (exactly one thread’s CAS succeeds at the list tail, and all others see that node on retry).

pub fn remove<Q>(&self, key: &Q) -> Option<V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

Remove a key-value pair.

pub fn clear(&self)

Clear the map.

pub fn is_empty(&self) -> bool

Returns true if the map is empty.

pub fn len(&self) -> usize

Returns the number of elements in the map. Note: This is an O(N) operation as it scans all buckets.

pub fn iter(&self) -> Iter<'_, K, V, S>

Returns an iterator over the map entries. Yields (K, V) clones.

pub fn keys(&self) -> Keys<'_, K, V, S>

Returns an iterator over the map keys. Yields K clones.

pub fn hasher(&self) -> &S

Get the underlying hasher itself.

Trait Implementations

impl<K, V> Default for HashMap<K, V, FixedState>

where K: Hash + Eq + Clone + 'static, V: Clone + 'static,

Available on crate feature std only.

fn default() -> Self

Returns the “default value” for a type.

impl<K, V, S> Drop for HashMap<K, V, S>

fn drop(&mut self)

Executes the destructor for this type.

impl<'a, K, V, S> IntoIterator for &'a HashMap<K, V, S>

where K: Hash + Eq + Clone + 'static, V: Clone + 'static, S: BuildHasher,

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = Iter<'a, K, V, S>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: Send, V: Send, S: Send> Send for HashMap<K, V, S>

impl<K: Send + Sync, V: Send + Sync, S: Send + Sync> Sync for HashMap<K, V, S>