Struct ShardedHashMap 

pub struct ShardedHashMap<K, V, S = FxBuildHasher>
where
    K: Eq + Hash + Clone + Send + Sync,
    V: Clone + Send + Sync,
    S: BuildHasher + Clone + Send + Sync,
{ /* private fields */ }

Sharded concurrent HashMap (synchronous).

Cloning the map is cheap (Arc handles + atomic length).

Implementations

impl<K, V> ShardedHashMap<K, V, FxBuildHasher>

where K: Eq + Hash + Clone + Send + Sync, V: Clone + Send + Sync,

pub fn new(shard_count: usize) -> Self

Create with default hasher (FxBuildHasher).

impl<K, V, S> ShardedHashMap<K, V, S>

where K: Eq + Hash + Clone + Send + Sync, V: Clone + Send + Sync, S: BuildHasher + Clone + Send + Sync,

pub fn with_shards_and_hasher(shard_count: usize, hasher: S) -> Self

Create with explicit hasher (non-zero shard count fallback).

pub fn shard_count(&self) -> usize

Current configured shard slots.

pub fn initialized_shards(&self) -> usize

Number of shards actually initialized (allocated).

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

Insert key/value. Returns previous value if existed.

Complexity: O(1) expected.

If the key was not present, increments length counter.

Arguments

• key: key to insert.
• value: value to associate with the key

Returns

• Option<V>: previous value if the key was already present.

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

Fetch cloned value.

Arguments

• key: key to look up.

Returns

• Option<V>: cloned value if the key exists.

pub fn contains(&self, key: &K) -> bool

Check if a key exists (returns bool without cloning the value).

Arguments

• key: key to check.

Returns

• bool: true if the key exists in the map, false otherwise.

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

Remove key, returning previous value.

Arguments

• key: key to remove.

Returns

• Option<V>: previous value if the key existed.

pub fn len(&self) -> usize

Length (cached atomic).

Returns

• usize: total number of key/value pairs in the map.

pub fn is_empty(&self) -> bool

Whether empty.

Returns

• bool: true if the map contains no entries.

pub fn clear(&self)

Clear all data (retains shard allocations).

Notes

• Resets length counter to zero.

pub fn iter(&self) -> impl Iterator<Item = (K, V)>

Snapshot iteration over (K,V) clones.

Semantics:

• Collects a list of initialized shard Arcs first (short critical section).
• Each shard is read-locked independently; values cloned.
• Not a live iterator: modifications after a shard snapshot are not reflected.
• If rayon enabled, internal flattening per-shard happens in parallel for speed.

Cost:

• O(N) cloning cost for visited entries.
• Temporary Vec allocations proportional to initialized shard count (and item copies).

Returns

• impl Iterator<Item = (K, V)>: iterator over cloned key/value pairs.

Trait Implementations

impl<K, V, S> Clone for ShardedHashMap<K, V, S>

where K: Eq + Hash + Clone + Send + Sync + Clone, V: Clone + Send + Sync + Clone, S: BuildHasher + Clone + Send + Sync + Clone,

fn clone(&self) -> ShardedHashMap<K, V, S>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'de, K, V, S> Deserialize<'de> for ShardedHashMap<K, V, S>

where K: Eq + Hash + Clone + Send + Sync + Deserialize<'de>, V: Clone + Send + Sync + Deserialize<'de>, S: BuildHasher + Clone + Send + Sync + Default,

Available on crate feature serde only.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<K, V, S> Serialize for ShardedHashMap<K, V, S>

where K: Eq + Hash + Clone + Send + Sync + Serialize, V: Clone + Send + Sync + Serialize, S: BuildHasher + Clone + Send + Sync + Default,

Available on crate feature serde only.

fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>

where Ser: Serializer,

Serialize this value into the given Serde serializer.