bloom

Documentation

Index

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

Variables

var (
	// ErrTooLargeOffset indicates the offset is too large in bitset.
	ErrTooLargeOffset = errors.New("too large offset")
)

Types

type Filter

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

A Filter is a bloom filter.

func New

func New(store *redis.Redis, 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(data []byte) error

Add adds data into f.

func (*Filter) AddCtx

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

AddCtx adds data into f with context.

func (*Filter) Exists

func (f *Filter) Exists(data []byte) (bool, error)

Exists checks if data is in f.

func (*Filter) ExistsCtx

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

ExistsCtx checks if data is in f with context.