Struct hnsw::HNSW

pub struct HNSW<T, M: ArrayLength<u32> = U12, M0: ArrayLength<u32> = U24, R = Pcg64> { /* fields omitted */ }

This provides a HNSW implementation for any distance function.

The type T must implement FloatingDistance to get implementations.

Methods

impl<T, M: ArrayLength<u32>, M0: ArrayLength<u32>, R> HNSW<T, M, M0, R> where
    R: RngCore + SeedableRng, 

pub fn new() -> Self

Creates a new HNSW with a PRNG which is default seeded to produce deterministic behavior.

pub fn new_params(params: Params) -> Self

Creates a new HNSW with a default seeded PRNG and with the specified params.

impl<T, M: ArrayLength<u32>, M0: ArrayLength<u32>, R> HNSW<T, M, M0, R> where
    R: RngCore,
    T: MetricPoint, 

pub fn new_prng(prng: R) -> Self

Creates a HNSW with the passed prng.

pub fn new_params_and_prng(params: Params, prng: R) -> Self

Creates a HNSW with the passed params and prng.

pub fn insert(&mut self, q: T, searcher: &mut Searcher) -> u32

Inserts a feature into the HNSW.

pub fn nearest<'a>(
    &self,
    q: &T,
    ef: usize,
    searcher: &mut Searcher,
    dest: &'a mut [Neighbor]
) -> &'a mut [Neighbor]

Does a k-NN search where q is the query element and it attempts to put up to M nearest neighbors into dest. ef is the candidate pool size. ef can be increased to get better recall at the expense of speed. If ef is less than dest.len() then dest will only be filled with ef elements.

Returns a slice of the filled neighbors.

pub fn feature(&self, item: u32) -> &T

Extract the feature for a given item returned by HNSW::nearest.

The item must be retrieved from HNSW::search_layer.

pub fn layer_feature(&self, level: usize, item: u32) -> &T

Extract the feature from a particular level for a given item returned by HNSW::search_layer.

pub fn layer_item_id(&self, level: usize, item: u32) -> u32

Retrieve the item ID for a given layer item returned by HNSW::search_layer.

pub fn layers(&self) -> usize

pub fn len(&self) -> usize

pub fn layer_len(&self, level: usize) -> usize

pub fn is_empty(&self) -> bool

pub fn layer_is_empty(&self, level: usize) -> bool

pub fn search_layer<'a>(
    &self,
    q: &T,
    ef: usize,
    level: usize,
    searcher: &mut Searcher,
    dest: &'a mut [Neighbor]
) -> &'a mut [Neighbor]

Performs the same algorithm as HNSW::nearest, but stops on a particular layer of the network and returns the unique index on that layer rather than the item index.

If this is passed a level of 0, then this has the exact same functionality as HNSW::nearest since the unique indices at layer 0 are the item indices.

Trait Implementations

impl<T: Clone, M: Clone + ArrayLength<u32>, M0: Clone + ArrayLength<u32>, R: Clone> Clone for HNSW<T, M, M0, R>

fn clone(&self) -> HNSW<T, M, M0, R>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T, M: ArrayLength<u32>, M0: ArrayLength<u32>, R> Default for HNSW<T, M, M0, R> where
    R: SeedableRng, 

fn default() -> Self

Returns the "default value" for a type.

impl<'de, T, M: ArrayLength<u32>, M0: ArrayLength<u32>, R> Deserialize<'de> for HNSW<T, M, M0, R> where
    T: Deserialize<'de>,
    R: Deserialize<'de>, 

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<T, M: ArrayLength<u32>, M0: ArrayLength<u32>, R> Serialize for HNSW<T, M, M0, R> where
    T: Serialize,
    R: Serialize, 

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.