Struct Prime 

pub struct Prime { /* private fields */ }

Grow by stepping through a fixed table of primes and map with a modulo.

A modulo by a compile-time-unknown prime is still fast here because the table is small and the index selects the divisor. This policy spreads values better than PowerOfTwo when the hash is poor.

Trait Implementations

impl Clone for Prime

fn clone(&self) -> Prime

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl GrowthPolicy for Prime

fn new(min_bucket_count: usize) -> Result<(Self, usize), LengthError>

Build a policy for at least min_bucket_count buckets.

fn bucket_for_hash(&self, hash: usize) -> usize

Map hash to a bucket in [0, bucket_count).

fn next_bucket_count(&self) -> Result<usize, LengthError>

The bucket count to use on the next growth.

fn max_bucket_count(&self) -> usize

The largest bucket count the policy can represent.

fn clear(&mut self)

Reset the policy to the state of a 0-bucket table.

fn is_power_of_two() -> bool

Whether this policy keeps the bucket count a power of two.