Struct ConcurrentHashMap 

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

Concurrent hash map with segment-based locking for scalability. This provides better scalability than a single mutex-protected HashMap.

Implementations

impl<K: Hash + Eq, V> ConcurrentHashMap<K, V>

pub fn new() -> Self

Create a new concurrent hash map with default hasher.

pub fn with_segments(num_segments: usize) -> Self

Create with a specific number of segments (must be power of 2).

impl<K: Hash + Eq, V, S: BuildHasher> ConcurrentHashMap<K, V, S>

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

Insert a key-value pair.

Returns the previous value if the key existed, or None if it was a new key.

Errors

Returns SegmentPoisoned if the segment lock was poisoned by a panicked writer.

pub fn get_or_insert_with<F>( &self, key: K, default: F, ) -> Result<V, SegmentPoisoned>

where F: FnOnce() -> V, V: Clone,

Get a value by key, or insert it if it is not present.

Executes atomically under the segment’s write lock, ensuring that the default closure runs exactly once on a cache miss and no concurrent insert can overwrite it.

Errors

Returns SegmentPoisoned if the segment lock was poisoned by a panicked writer.

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

where V: Clone,

Get a value by key.

Returns the cloned value if found, or None if not found.

Errors

Returns SegmentPoisoned if the segment lock was poisoned by a panicked writer.

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

Remove a key-value pair.

Returns the removed value if the key existed, or None if it didn’t exist.

Errors

Returns SegmentPoisoned if the segment lock was poisoned by a panicked writer.

pub fn contains_key(&self, key: &K) -> Result<bool, SegmentPoisoned>

Check if a key exists.

Returns true if the key exists, false otherwise.

Errors

Returns SegmentPoisoned if the segment lock was poisoned by a panicked writer.

Trait Implementations

impl<K, V, S> Debug for ConcurrentHashMap<K, V, S>

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

Formats the value using the given formatter.

impl<K: Hash + Eq, V> Default for ConcurrentHashMap<K, V>

fn default() -> Self

Returns the “default value” for a type.