Struct ConsistentHash 

pub struct ConsistentHash { /* private fields */ }

Virtual-node consistent-hash ring.

Each real node is mapped to virtual_nodes_per_node positions on a u64 hash ring using FNV-1a hashes of the string "<node_id>_<i>". Key routing finds the first virtual-node position ≥ hash(key) on the ring (wrapping around).

Implementations

impl ConsistentHash

pub fn new(virtual_nodes: u32) -> Self

Create an empty ring with the given number of virtual nodes per real node.

pub fn add_node(&mut self, node_id: NodeId)

Add node_id to the ring by inserting virtual_nodes_per_node hash positions derived from "<node_id>_<i>" for i in 0..virtual_nodes.

pub fn remove_node(&mut self, node_id: NodeId)

Remove all virtual nodes associated with node_id.

pub fn get_node(&self, key: &[u8]) -> Option<NodeId>

Route key to the first node whose ring position is ≥ hash(key), wrapping around to the lowest position if needed.

Returns None when the ring is empty.

pub fn get_n_nodes(&self, key: &[u8], n: usize) -> Vec<NodeId>

Return up to n distinct successor nodes for key (for replication).

Starts at the primary successor and walks the ring clockwise, collecting distinct NodeIds until n unique nodes are found or the ring is exhausted.

pub fn virtual_node_count(&self) -> usize

Return the number of virtual nodes currently in the ring.

pub fn real_node_count(&self) -> usize

Return the number of distinct real nodes in the ring.

Trait Implementations

impl Clone for ConsistentHash

fn clone(&self) -> ConsistentHash

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConsistentHash

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

Formats the value using the given formatter.