seqan::hibf::sketch::hyperloglog Class Reference

HyperLogLog estimates. More...

#include <hibf/sketch/hyperloglog.hpp>

Public Member Functions
void	add (uint64_t const value)
	Adds a value.
uint64_t	data_size () const
	Returns size of the internal data.
double	estimate () const
	Estimates cardinality value.
void	load (std::istream &is)
	Loads the hyperloglog from a stream.
void	merge (hyperloglog const &other)
	Merges another hyperloglog into this object.
double	merge_and_estimate (hyperloglog const &other)
	Merges another hyperloglog and returns the new estimate.
void	reset ()
	Clears added values. The size is unaffected.
void	store (std::ostream &os) const
	Write the hyperloglog to a stream.
Constructors, destructor and assignment
	hyperloglog (uint8_t const num_bits=5u)
	Default constructor.
	hyperloglog (hyperloglog const &)=default
	Defaulted.
hyperloglog &	operator= (hyperloglog const &)=default
	Defaulted.
	hyperloglog (hyperloglog &&)=default
	Defaulted.
hyperloglog &	operator= (hyperloglog &&)=default
	Defaulted.
	~hyperloglog ()=default
	Defaulted.

Friends
class	cereal::access

Detailed Description

HyperLogLog estimates.

Original work by Hideaki Ohno. Major changes have been applied for bugfixes, 64-bit support, improvements, etc.

See also

https://github.com/hideo55/cpp-HyperLogLog

Constructor & Destructor Documentation

hyperloglog()

seqan::hibf::sketch::hyperloglog::hyperloglog

(

uint8_t const

num_bits = 5u

)

Default constructor.

Parameters

[in]

num_bits

The bit width in [5,32].

Allocates 2^num_bits bytes of memory.

Exceptions

std::invalid_argument

if num_bits is not in [5,32].

Member Function Documentation

add()

void seqan::hibf::sketch::hyperloglog::add

(

uint64_t const

value

)

Adds a value.

Parameters

[in]

value

The value to add.

estimate()

double seqan::hibf::sketch::hyperloglog::estimate

(

)

const

Estimates cardinality value.

Returns

Estimated cardinality value.

merge()

void seqan::hibf::sketch::hyperloglog::merge

(

hyperloglog const &

other

)

Merges another hyperloglog into this object.

Parameters

[in]

other

The hyperloglog to be merged.

This has the same effect as adding all values that were added to other.

Warning

Merging a hyperloglog with differing bits is undefined behaviour. In debug mode, this is an assertion instead.

merge_and_estimate()

double seqan::hibf::sketch::hyperloglog::merge_and_estimate

(

hyperloglog const &

other

)

Merges another hyperloglog and returns the new estimate.

Parameters

[in]

other

The hyperloglog to be merged.

Returns

Estimated cardinality value.

Warning

Merging a hyperloglog with differing bits is undefined behaviour. In debug mode, this is an assertion instead.

data_size()

uint64_t seqan::hibf::sketch::hyperloglog::data_size ( ) const

inline

Returns size of the internal data.

Returns

Size in bytes. The returned value is equivalent to 2^bits.

store()

void seqan::hibf::sketch::hyperloglog::store

(

std::ostream &

os

)

const

Write the hyperloglog to a stream.

Parameters

[in,out]

os

The output stream to write to.

Exceptions

std::runtime_error

if storing failed.

load()

void seqan::hibf::sketch::hyperloglog::load

(

std::istream &

is

)

Loads the hyperloglog from a stream.

Parameters

[in]

is

The input stream where to read from.

Exceptions

std::runtime_error

if reading failed.

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The documentation for this class was generated from the following file:

• hyperloglog.hpp