Struct streaming_algorithms::HyperLogLog

pub struct HyperLogLog<V: ?Sized> { /* fields omitted */ }

An implementation of the HyperLogLog data structure with bias correction.

See HyperLogLog: the analysis of a near-optimal cardinality estimation algorithm and HyperLogLog in Practice: Algorithmic Engineering of a State of The Art Cardinality Estimation Algorithm for background on HyperLogLog with bias correction.

Methods

impl<V: ?Sized> HyperLogLog<V> where     V: Hash,

pub fn new(error_rate: f64) -> Self

Create an empty HyperLogLog data structure with the specified error tolerance.

pub fn new_from(hll: &Self) -> Self

Create an empty HyperLogLog data structure, copying the error tolerance from hll.

pub fn push(&mut self, value: &V)

"Visit" an element.

pub fn len(&self) -> f64

Retrieve an estimate of the carginality of the stream.

pub fn is_empty(&self) -> bool

Returns true if the cardinality estimate is 0

pub fn union(&mut self, src: &Self)

Merge another HyperLogLog data structure into self.

This is the same as an HLL approximating cardinality of the union of two multisets.

pub fn intersect(&mut self, src: &Self)

Intersect another HyperLogLog data structure into self.

Note: This is different to an HLL approximating cardinality of the intersection of two multisets.

pub fn clear(&mut self)

Clears the HyperLogLog data structure, as if it was new.

Trait Implementations

impl<V: ?Sized> Clone for HyperLogLog<V>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<V: ?Sized> Debug for HyperLogLog<V> where     V: Hash,

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<V: ?Sized> New for HyperLogLog<V> where     V: Hash,

type Config = f64

The type of data required to instantiate a new Self.

fn new(config: &Self::Config) -> Self

Instantiate a new Self with the given <Self as New>::Config.

impl<V: ?Sized> Intersect for HyperLogLog<V> where     V: Hash,

fn intersect<'a>(     iter: impl Iterator<Item = &'a Self> ) -> Option<Self> where     Self: Sized + 'a,

Intersect.

impl<'a, V: ?Sized> UnionAssign<&'a HyperLogLog<V>> for HyperLogLog<V> where     V: Hash,

fn union_assign(&mut self, rhs: &'a Self)

Union.

impl<'a, V: ?Sized> AddAssign<&'a V> for HyperLogLog<V> where     V: Hash,

fn add_assign(&mut self, rhs: &'a V)

Performs the += operation.