Struct Hll8

pub struct Hll8(/* private fields */);

HyperLogLog approximate counting mechanism

This uses a fixed set of 256 buckets (k=8, M=256), each holding a count up to 255. https://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf

This is used for NIP-45 PR #1561

Implementations

impl Hll8

pub fn new() -> Hll8

Create a new Hll8

pub fn from_hex_string(s: &str) -> Result<Hll8, Error>

Import from a (hex) string

pub fn to_hex_string(&self) -> String

Export to a (hex) string

pub fn clear(&mut self)

Clear to zero counts

pub fn add_element( &mut self, input: &[u8; 32], offset: usize, ) -> Result<(), Error>

Add an element to the count by value Returns false on error (e.g. offset is out of range)

pub fn add_element_inner(&mut self, index: u8, rho: u8)

Add an element to the count by index and rho (position of the first 1)

pub fn estimate_count(&self) -> usize

Compute the approximate count

Trait Implementations

impl AddAssign for Hll8

fn add_assign(&mut self, other: Self)

Performs the += operation.

impl Clone for Hll8

fn clone(&self) -> Hll8

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Hll8

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Hll8

fn default() -> Self

Returns the “default value” for a type.

impl Copy for Hll8