Struct ShiftOnlyWrapped 

pub struct ShiftOnlyWrapped<const MULTIPLIER: u8 = 1>;

SeedChooser to build (1-)perfect functions called PHast+ with wrapping.

Can be used with any function type: [Function], [Function2], [Perfect].

It chooses best seed using only shifting with wrapping, which leads to quite small size and quite fast construction.

MULTIPLIER should be 1, 2, or 3. Typically, increasing MULTIPLIER reduces size but slows down construction. MULTIPLIER=1 works very well with large bits_per_seed (10+), larger values (2 and 3) works well with bits_per_seed=8.

Trait Implementations

impl<const MULTIPLIER: u8> Clone for ShiftOnlyWrapped<MULTIPLIER>

fn clone(&self) -> ShiftOnlyWrapped<MULTIPLIER>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<const MULTIPLIER: u8> SeedChooser for ShiftOnlyWrapped<MULTIPLIER>

type UsedValues = CyclicSet<{MAX_VALUES/64}>

fn bucket_evaluator(&self, bits_per_seed: u8, slice_len: u16) -> Weights

fn conf( self, output_range: usize, input_size: usize, bits_per_seed: u8, bucket_size_100: u16, preferred_slice_len: u16, ) -> Conf

fn f(self, primary_code: u64, seed: u16, conf: &Conf) -> usize

Returns function value for given primary code and seed.

fn best_seed( self, used_values: &mut Self::UsedValues, keys: &[u64], conf: &Conf, bits_per_seed: u8, ) -> u16

Returns best seed to store in seeds array or u16::MAX if NO_BUMPING is true and there is no feasible seed.

const BUMPING: bool = true

Specifies whether bumping is allowed.

const FIRST_SEED: u16 = _

The lowest seed that does not indicate bumping.

const FUNCTION2_THRESHOLD: usize = 4096

Size of last level of Function2. Important when extra_shift()>0 (i.e. for ShiftOnly).

fn k(self) -> u8

Returns maximum number of keys mapped to each output value; k of k-perfect function.

fn minimal_output_range(self, num_of_keys: usize) -> usize

Returns output range of minimal (perfect or k-perfect) function for given number of keys.

fn conf_for_minimal( self, num_of_keys: usize, bits_per_seed: u8, bucket_size_100: u16, preferred_slice_len: u16, ) -> Conf

fn conf_for_minimal_p<SS: Copy + Into<u8>>( self, num_of_keys: usize, params: &Params<SS>, ) -> Conf

fn extra_shift(self, _bits_per_seed: u8) -> u16

How much the chooser can add to value over slice length.

impl<const MULTIPLIER: u8> Copy for ShiftOnlyWrapped<MULTIPLIER>