Struct HashMap

pub struct HashMap<K, V, S = RandomState> { /* private fields */ }

Implementations

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

pub fn new() -> Self

Creates an empty HashMap.

The hash map is initially created with a capacity of 0, so it will not allocate until it is first inserted into.

pub fn with_capacity(capacity: usize) -> Self

Creates an empty HashMap with the specified capacity.

The hash map will be able to hold at least capacity elements without reallocating. If capacity is 0, the hash map will not allocate.

impl<K: Hash, V, S: BuildHasher> HashMap<K, V, S>

pub fn read<'a>(&'a self, key: &'a K) -> Readable<'a, K, V, S>

pub fn write(&self, key: K) -> Writeable<'_, K, V, S>

pub fn shard(&self, key: &K) -> &RwLock<Map<K, V, S>>

pub fn shard_idx(&self, key: &K) -> usize

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

pub fn shards(&self) -> &[RwLock<Map<K, V, S>>]

Get a reference to the map’s shards.

pub fn with_hasher(hasher: S) -> Self

Creates an empty HashMap which will use the given hash builder to hash keys.

The created map has the default initial capacity.

Warning: hash_builder is normally randomly generated, and is designed to allow HashMaps to be resistant to attacks that cause many collisions and very poor performance. Setting it manually using this function can expose a DoS attack vector.

The hash_builder passed should implement the BuildHasher trait for the HashMap to be useful.

pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> Self

Creates an empty HashMap with the specified capacity, using hash_builder to hash the keys.

The hash map will be able to hold at least capacity elements without reallocating. If capacity is 0, the hash map will not allocate.

Warning: hash_builder is normally randomly generated, and is designed to allow HashMaps to be resistant to attacks that cause many collisions and very poor performance. Setting it manually using this function can expose a DoS attack vector.

The hash_builder passed should implement the BuildHasher trait for the HashMap to be useful.

Trait Implementations

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

fn default() -> Self

Returns the “default value” for a type.