bloom

Documentation

Index

• Variables
• type Filter
  • func New(store *redis.Client, key string, bits uint) *Filter
  • func (f *Filter) Add(ctx context.Context, data []byte) error
  • func (f *Filter) Exists(ctx context.Context, data []byte) (bool, error)

Variables

var ErrTooLargeOffset = errors.New("too large offset")

ErrTooLargeOffset indicates the offset is too large in bitset.

Types

type Filter

type Filter struct {
	// contains filtered or unexported fields
}

A Filter is a bloom filter.

func New

func New(store *redis.Client, key string, bits uint) *Filter

New create a Filter, store is the backed redis, key is the key for the bloom filter, bits is how many bits will be used, maps is how many hashes for each addition. best practices: elements - means how many actual elements when maps = 14, formula: 0.7*(bits/maps), bits = 20*elements, the error rate is 0.000067 < 1e-4 for detailed error rate table, see http://pages.cs.wisc.edu/~cao/papers/summary-cache/node8.html

func (*Filter) Add

func (f *Filter) Add(ctx context.Context, data []byte) error

Add adds data into f.

func (*Filter) Exists

func (f *Filter) Exists(ctx context.Context, data []byte) (bool, error)

Exists checks if data is in f.