Algorithm::HyperLogLog(3pm)

Usage

  use Algorithm::HyperLogLog;
  
  my $hll = Algorithm::HyperLogLog->new(14);
  
  while(<>){
      $hll->add($_);
  }
  
  my $cardinality = $hll->estimate(); # Estimate cardinality
  $hll->dump_to_file('hll_register.dump');# Dumps internal data

Construct object from dumped file.

  use Algorithm::HyperLogLog;
  
  # Restore internal state 
  my $hll = Algorithm::HyperLogLog->new_from_file('hll_register.dump');

Overview

This module is implementation of the HyperLogLog algorithm.

HyperLogLog is an algorithm for estimating the cardinality of a set.

Methods

new($b)

Constructor.

`$b` is the parameter for determining register size. (The register size is 2^$b.)

`$b` must be a integer between 4 and 16.

new_from_file($filename)

This method constructs object and restore the internal data of object from dumped file(dumped by dump_to_file() method).

dump_to_file($filename)

This method dumps the internal data of an object to a file.

add($data)

Adds element to the cardinality estimator.

estimate()

Returns estimated cardinality value in floating point number.

merge($other)

Merges the estimate from 'other' into this object, returning the estimate of their union.

register_size()

Return number of register.(In the XS implementation, this equals size in bytes)

XS()

If using XS backend, this method return true value.

Thanks to

MurmurHash3(<https://github.com/PeterScott/murmur3>)

Austin Appleby

Peter Scott

Releases

2 releases since Debian 12 (Bookworm); the text changed 1 time.

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