Struct ModelShardManager 

pub struct ModelShardManager { /* private fields */ }

Partitions embedding tables (entity and relation) by stable hash of the ID.

Implementations

impl ModelShardManager

pub fn new(num_shards: usize, strategy: ShardingStrategy) -> Self

Create a new shard manager with num_shards shards.

Panics

Does not panic. If num_shards == 0 it is silently coerced to 1 (single-shard / no sharding) so the manager is always usable.

pub fn num_shards(&self) -> usize

Number of shards this manager partitions across.

pub fn strategy(&self) -> ShardingStrategy

Hashing strategy.

pub fn shard_for(&self, id: &str) -> usize

Compute the shard index for id.

Always returns a value in 0..self.num_shards(). Calling this method repeatedly with the same id and same num_shards always yields the same answer — it is the basis of the parameter-server routing scheme.

pub fn partition<I, S>(&mut self, ids: I) -> ShardAssignment

where I: IntoIterator<Item = S>, S: Into<String>,

Partition a list of IDs into shards in input order.

In EntityHash mode this is equivalent to shard_for on each ID. In RoundRobin mode it also populates the manager’s internal round-robin table so that subsequent shard_for calls give consistent answers.

pub fn reshard(&mut self, prior: &ShardAssignment) -> ShardAssignment

Re-shard an existing assignment after num_shards changes.

Returns a fresh ShardAssignment computed by routing every existing ID through the new manager. Used by elastic scaling tests.

Trait Implementations

impl Clone for ModelShardManager

fn clone(&self) -> ModelShardManager

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ModelShardManager

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

Formats the value using the given formatter.