counter

Documentation

Overview

Package counter implements linear counter estimator

Index

• Constants
• type Counter
  • func FromBinary(data []byte) (*Counter, error)
  • func New(cap uint) *Counter
  • func (c *Counter) Count() uint
  • func (c *Counter) Mark(key string)
  • func (c *Counter) Reset()
  • func (c *Counter) ToBinary() ([]byte, error)

Constants

const (
	// DefaultCap max capacity for the counter
	DefaultCap = 1 << 19
)

Types

type Counter

type Counter struct {
	Bits *bitset.BitSet `json:"bits"`
}

Counter implements a simple probabilistic counter estimator with 1% estimation accuracy as described in https://www.waitingforcode.com/big-data-algorithms/cardinality-estimation-linear-probabilistic-counting/read

func FromBinary

func FromBinary(data []byte) (*Counter, error)

FromBinary unmarshals counter state

func New

func New(cap uint) *Counter

New creates a counter for the maximum amount unique elements provided

func (*Counter) Count

func (c *Counter) Count() uint

Count returns an estimate of distinct elements in the set

func (*Counter) Mark

func (c *Counter) Mark(key string)

Mark marks key as present in the set

func (*Counter) Reset

func (c *Counter) Reset()

Reset the counter

func (*Counter) ToBinary

func (c *Counter) ToBinary() ([]byte, error)

ToBinary marshals counter state