Struct Partial 

pub struct Partial<SS, SC = SeedOnly, S = RandomState>
where
    SS: SeedSize,
{ /* private fields */ }

Map-or-bump function that assigns different numbers to some keys and None to other.

Can be used with any seed chooser (which specify a particular PHast variant): [ShiftOnlyWrapped], [ShiftSeedWrapped], SeedOnly, [SeedOnlyK].

See: Piotr Beling, Peter Sanders, PHast - Perfect Hashing made fast, 2025, https://arxiv.org/abs/2504.17918

Implementations

impl<SS: SeedSize, SC: SeedChooser> Partial<SS, SC, ()>

pub fn with_hashes_bps_conf_sc_be_u<'k, BE>( hashes: &'k mut [u64], seed_size: SS, conf: Conf, seed_chooser: SC, bucket_evaluator: BE, ) -> (Self, usize)

where BE: BucketToActivateEvaluator,

pub fn with_hashes_bps_conf_bs_threads_sc_be_u<'k, BE>( hashes: &'k mut [u64], seed_size: SS, conf: Conf, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE, ) -> (Self, usize)

where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send,

pub fn with_hashes_bps_conf_sc_be<'k, BE>( hashes: &'k mut [u64], seed_size: SS, conf: Conf, seed_chooser: SC, bucket_evaluator: BE, ) -> Self

where BE: BucketToActivateEvaluator,

pub fn with_hashes_bps_conf_bs_threads_sc_be<'k, BE>( hashes: &'k mut [u64], seed_size: SS, conf: Conf, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE, ) -> Self

where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send,

pub fn with_hashes_p_sc_be_u<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, bucket_evaluator: BE, ) -> (Self, usize)

where BE: BucketToActivateEvaluator,

pub fn with_hashes_p_threads_sc_be_u<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE, ) -> (Self, usize)

where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send,

pub fn with_hashes_p_sc_be<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, bucket_evaluator: BE, ) -> Self

where BE: BucketToActivateEvaluator,

pub fn with_hashes_p_threads_sc_be<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE, ) -> Self

where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send,

pub fn with_hashes_p_sc_u<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, ) -> (Self, usize)

where BE: BucketToActivateEvaluator,

pub fn with_hashes_p_threads_sc_u<'k, BE>( hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, ) -> (Self, usize)

where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send,

pub fn with_hashes_p_sc<'k>( hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, ) -> Self

pub fn with_hashes_p_threads_sc<'k>( hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, ) -> Self

where SC: Sync,

impl<SS: SeedSize, SC: SeedChooser, S> Partial<SS, SC, S>

pub fn get_for_hash(&self, key_hash: u64) -> Option<usize>

Returns value assigned to the given key hash or None.

impl<SS: SeedSize, SC: SeedChooser, S> Partial<SS, SC, S>

pub fn minimal_output_range(&self, num_of_keys: u32) -> usize

Returns output range of minimal (perfect or k-perfect) function for given number of keys, i.e. 1 + maximum value that minimal function can return.

pub fn output_range(&self) -> usize

Returns output range of self, i.e. 1 + maximum value that self can return.

impl<SS: SeedSize, SC: SeedChooser, S: BuildHasher> Partial<SS, SC, S>

pub fn get<K>(&self, key: &K) -> Option<usize>

where K: Hash + ?Sized,

Returns value assigned to the given key or None.

The returned value is in the range from 0 (inclusive) to the number of elements in the input key collection (exclusive). key must come from the input key collection given during construction.

pub fn with_keys_p_hash_sc_be_u<'k, K, BE>( keys: impl Iterator<Item = K>, params: &Params<SS>, hasher: S, seed_chooser: SC, bucket_evaluator: BE, ) -> (Self, usize)

where K: Hash, BE: BucketToActivateEvaluator,

Returns Partial function and number of keys with unassigned values for given keys, using a single thread and given parameters.

Trait Implementations

impl<SC, SS: SeedSize, S> GetSize for Partial<SS, SC, S>

const USES_DYN_MEM: bool = true

true if and only if the variables of this type can use dynamic (heap) memory.

fn size_bytes_dyn(&self) -> usize

Returns approximate number of bytes occupied by dynamic (heap) part of self. Same as self.size_bytes() - std::mem::size_of_val(self).

fn size_bytes_content_dyn(&self) -> usize

Returns approximate number of bytes occupied by dynamic (heap) part of self content. It usually equals to size_bytes_dyn(). However, sometimes it is smaller by the amount of memory reserved but not yet used (e.g., size_bytes_content_dyn() only takes into account the length of the vector and not its capacity).

fn size_bytes(&self) -> usize

Returns approximate, total (including heap memory) number of bytes occupied by self.