Struct HyperLogLogPlusPlusBuilder 

pub struct HyperLogLogPlusPlusBuilder { /* private fields */ }

Implementations

impl HyperLogLogPlusPlusBuilder

pub fn normal_precision(self, normal_precision: i32) -> Self

Sets the normal precision to be used. Must be in the range from HyperLogLogPlusPlus::MINIMUM_PRECISION to HyperLogLogPlusPlus::MAXIMUM_PRECISION (inclusive).

The precision defines the accuracy of the HLL++ aggregator at the cost of the memory used. The upper bound on the memory required is 2^precision bytes, but less memory is used for smaller cardinalities (up to ~2^{precision - 2}). The relative error is 1.04 / sqrt(2^precision). If not specified, HyperLogLogPlusPlus::DEFAULT_NORMAL_PRECISION` is used, which gives an error of about 0.6% while requiring an upper bound of 32 nbsp;KiB of memory.

pub fn sparse_precision(self, sparse_precision: i32) -> Self

Sets the sparse precision to be used. Must be in the range from the HyperLogLogPlusPlusBuilder::normal_precision to HyperLogLogPlusPlus::MAXIMUM_SPARSE_PRECISION (inclusive), or HyperLogLogPlusPlus::SPARSE_PRECISION_DISABLED to disable the use of the sparse representation. We recommend to use HyperLogLogPlusPlusBuilder::no_sparse_mode for the latter, though.

If not specified, the normal precision + HyperLogLogPlusPlus::DEFAULT_SPARSE_PRECISION_DELTA is used.

pub fn no_sparse_mode(self) -> Self

Disable the “sparse representation” mode; i.e., the normal representation, where all registers are explicitly stored, and its method to compute the COUNT DISTINCT estimate are used from the start of the aggregation.

pub fn build_for_bytes(self) -> Result<HyperLogLogPlusPlus, SketchError>

Returns a new HLL++ aggregator for counting the number of unique byte arrays in a stream.

pub fn build_for_string(self) -> Result<HyperLogLogPlusPlus, SketchError>

Returns a new HLL++ aggregator for counting the number of unique strings in a stream.

pub fn build_for_u32(self) -> Result<HyperLogLogPlusPlus, SketchError>

Returns a new HLL++ aggregator for counting the number of unique 32-bit integers in a stream.

pub fn build_for_u64(self) -> Result<HyperLogLogPlusPlus, SketchError>

Returns a new HLL++ aggregator for counting the number of unique 64-bit integers in a stream.

Trait Implementations

impl Clone for HyperLogLogPlusPlusBuilder

fn clone(&self) -> HyperLogLogPlusPlusBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HyperLogLogPlusPlusBuilder

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

Formats the value using the given formatter.