Struct ReplicaLocator

pub struct ReplicaLocator { /* private fields */ }

ReplicaLocator provides a way to find the set of owning nodes for a given (token, replication strategy) pair. It does so by either using the precomputed token ranges, or doing the computation on the fly.

Implementations

impl ReplicaLocator

pub fn replicas_for_token<'a>( &'a self, token: Token, strategy: &'a Strategy, datacenter: Option<&'a str>, ) -> ReplicaSet<'a>

Returns a set of nodes that are considered to be replicas for a given token and strategy. If the datacenter parameter is set, the returned ReplicaSet is limited only to replicas from that datacenter. If a specified datacenter name does not correspond to a valid datacenter, an empty set will be returned.

Supported replication strategies: SimpleStrategy, ‘NetworkTopologyStrategy’, ‘LocalStrategy’. If other is specified, it is treated as the SimpleStrategy with replication factor equal to 1.

If a provided replication strategy did not appear in precompute_replica_sets_for parameter of Self::new, invocation of this function will trigger a computation of the desired replica set (the computation might be delegated in time and start upon interaction with the returned ReplicaSet).

pub fn ring(&self) -> &TokenRing<Arc<Node>>

Gives access to the token ring, based on which all token ranges/replica sets are computed.

pub fn unique_nodes_in_global_ring(&self) -> &[Arc<Node>]

Gives a list of all nodes in the token ring.

pub fn datacenter_names(&self) -> &[String]

Gives a list of all known datacenters.

pub fn unique_nodes_in_datacenter_ring<'a>( &'a self, datacenter_name: &str, ) -> Option<&'a [Arc<Node>]>

Gives a list of all nodes in a specified datacenter ring (which is created by filtering the original ring to only contain nodes living in the specified datacenter).

Trait Implementations

impl Clone for ReplicaLocator

fn clone(&self) -> ReplicaLocator

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ReplicaLocator

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

Formats the value using the given formatter.