Struct HyperLogLogBuilder

pub struct HyperLogLogBuilder<H, W = usize> { /* private fields */ }

Builds a HyperLogLog cardinality-estimator logic.

Implementations

impl HyperLogLogBuilder<BuildHasherDefault<DefaultHasher>, usize>

pub fn new(n: usize) -> Self

Creates a new builder for a HyperLogLog logic with a default word type of usize.

impl<H, W: Word> HyperLogLogBuilder<H, W>

pub fn rsd(self, rsd: f64) -> Self

Sets the desired relative standard deviation.

Note

This is a high-level alternative to Self::log_2_num_reg. Calling one after the other invalidates the work done by the first one.

Arguments

• rsd: the relative standard deviation to be attained.

pub fn log_2_num_reg(self, log_2_num_registers: usize) -> Self

Sets the base-2 logarithm of the number of register.

Note

This is a low-level alternative to Self::rsd. Calling one after the other invalidates the work done by the first one.

Arguments

• log_2_num_registers: the logarithm of the number of registers per estimator.

pub fn word_type<W2>(self) -> HyperLogLogBuilder<H, W2>

Sets the type W to use to represent backends.

See the logic documentation for the limitations on the choice of W2.

pub fn num_elements(self, n: usize) -> Self

Sets the upper bound on the number of elements.

pub fn build_hasher<H2>(self, build_hasher: H2) -> HyperLogLogBuilder<H2, W>

Sets the BuildHasher to use.

Using this method you can select a specific hashed based on one or more seeds.

pub fn build<T>(self) -> Result<HyperLogLog<T, H, W>>

Builds the logic.

The type of objects the estimators keep track of is defined here by T, but it is usually inferred by the compiler.

Errors

Errors will be caused by consistency checks (at least 16 registers per estimator, backend bits divisible exactly W::BITS)

Trait Implementations

impl<H: Clone, W: Clone> Clone for HyperLogLogBuilder<H, W>

fn clone(&self) -> HyperLogLogBuilder<H, W>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<H: Debug, W: Debug> Debug for HyperLogLogBuilder<H, W>

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

Formats the value using the given formatter.