Struct HyperLogLog 

pub struct HyperLogLog { /* private fields */ }

Available on crate feature nip45 only.

256-register HyperLogLog sketch as defined by NIP-45.

Implementations

impl HyperLogLog

pub const fn new() -> Self

Construct an empty sketch (all registers zero).

pub const fn as_bytes(&self) -> &[u8; 256]

Borrow the underlying register array.

pub const fn from_bytes(registers: &[u8; 256]) -> Self

Construct a sketch from a register array.

pub fn to_hex(self) -> String

Render the sketch as a 512-character lowercase hex string.

pub fn from_hex(hex_str: &str) -> Result<Self, CountError>

Parse a 512-character hex sketch.

Errors

Returns CountError::HllLength when the input is not 512 characters or CountError::HllHex for non-hex input.

pub fn observe(&mut self, offset: usize, hash: &[u8; 32]) -> bool

Apply an event ID / pubkey to the sketch using the supplied offset (see hll_offset_for_value).

Returns false when offset falls outside the spec’s 8..=23 range, leaving the sketch untouched.

pub fn merge(&mut self, other: &Self)

Merge another sketch into this one, taking the per-register max (the spec’s recommended client-side combine).

pub fn estimate(&self) -> u64

Estimate the cardinality using the standard HyperLogLog formula with the spec’s 256 registers. Saturates to u64::MAX for absurd inputs (e.g. NaNs).

Trait Implementations

impl Clone for HyperLogLog

fn clone(&self) -> HyperLogLog

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for HyperLogLog

impl Debug for HyperLogLog

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

Formats the value using the given formatter.

impl Default for HyperLogLog

fn default() -> Self

Returns the “default value” for a type.

impl Eq for HyperLogLog

impl PartialEq for HyperLogLog

fn eq(&self, other: &HyperLogLog) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for HyperLogLog