Struct concread::hashmap::HashMap

pub struct HashMap<K, V>
where
    K: Hash + Eq + Clone + Debug + Sync + Send + 'static,
    V: Clone + Sync + Send + 'static,
{ /* private fields */ }

A concurrently readable map based on a modified B+Tree structured with fast parallel hashed key lookup.

This structure can be used in locations where you would otherwise us RwLock<HashMap> or Mutex<HashMap>.

This is a concurrently readable structure, meaning it has transactional properties. Writers are serialised (one after the other), and readers can exist in parallel with stable views of the structure at a point in time.

This is achieved through the use of COW or MVCC. As a write occurs subsets of the tree are cloned into the writer thread and then commited later. This may cause memory usage to increase in exchange for a gain in concurrent behaviour.

Transactions can be rolled-back (aborted) without penalty by dropping the HashMapWriteTxn without calling commit().

Implementations

impl<K: Hash + Eq + Clone + Debug + Sync + Send + 'static, V: Clone + Sync + Send + 'static> HashMap<K, V>

pub fn new() -> Self

Construct a new concurrent hashmap

pub fn read(&self) -> HashMapReadTxn<'_, K, V>

Initiate a read transaction for the Hashmap, concurrent to any other readers or writers.

pub fn write(&self) -> HashMapWriteTxn<'_, K, V>

Initiate a write transaction for the map, exclusive to this writer, and concurrently to all existing reads.

pub fn try_write(&self) -> Option<HashMapWriteTxn<'_, K, V>>

Attempt to create a new write, returns None if another writer already exists.

Trait Implementations

impl<K: Hash + Eq + Clone + Debug + Sync + Send + 'static, V: Clone + Sync + Send + 'static> Default for HashMap<K, V>

fn default() -> Self

Returns the “default value” for a type.

impl<K: Hash + Eq + Clone + Debug + Sync + Send + 'static, V: Clone + Sync + Send + 'static> FromIterator<(K, V)> for HashMap<K, V>

fn from_iter<I: IntoIterator<Item = (K, V)>>(iter: I) -> Self

Creates a value from an iterator.

impl<K: Hash + Eq + Clone + Debug + Sync + Send + 'static, V: Clone + Sync + Send + 'static> Send for HashMap<K, V>

impl<K: Hash + Eq + Clone + Debug + Sync + Send + 'static, V: Clone + Sync + Send + 'static> Sync for HashMap<K, V>