data

Documentation

Index

• func Marshal(obj any) ([]byte, error)
• func Unmarshal(obj any, data []byte) error
• type BloomFilter
  • func NewBloomFilter(numExpected int, falsePositiveRate float64) *BloomFilter
  • func NewBloomFilterDirect(numBits, numIdx int) *BloomFilter
  • func (bf *BloomFilter) Add(entry []byte)
  • func (bf *BloomFilter) Combine(bf2 *BloomFilter) *BloomFilter
  • func (bf *BloomFilter) Contains(entry []byte) bool
  • func (bf *BloomFilter) SameKind(bf2 *BloomFilter) bool

Functions

func Marshal

func Marshal(obj any) ([]byte, error)

Marshal creates a byte array from a (reference to an) object.

func Unmarshal

func Unmarshal(obj any, data []byte) error

Unmarshal reads a byte array to fill an object pointed to by 'obj'.

Types

type BloomFilter

type BloomFilter struct {
	NumBits    uint32 `json:"numBits"`       // number of bits in filter
	NumIdx     uint8  `json:"numIdx"`        // number of indices
	NumIdxBits uint8  `json:"numIdxBits"`    // number of bits per index
	NumHash    uint8  `json:"numHash"`       // number of SHA256 hashes needed
	Bits       []byte `json:"bits" size:"*"` // bit storage
}

A BloomFilter is a space/time efficient set of unique entries. It can not enumerate its elements, but can check if an entry is contained in the set. The check always succeeds for a contained entry, but can create "false-positives" (entries not contained in the map give a positive result). By adjusting the number of bits in the BloomFilter and the number of indices generated for an entry, a BloomFilter can handle a given number of entries with a desired upper-bound for the false-positive rate.

func NewBloomFilter

func NewBloomFilter(numExpected int, falsePositiveRate float64) *BloomFilter

NewBloomFilter creates a new BloomFilter based on the upper-bounds for the number of entries and the "false-positive" rate.

func NewBloomFilterDirect

func NewBloomFilterDirect(numBits, numIdx int) *BloomFilter

NewBloomFilterDirect creates a new BloomFilter based on the number of bits in the filter and the number of indices to be used.

func (*BloomFilter) Add

func (bf *BloomFilter) Add(entry []byte)

Add an entry to the BloomFilter.

func (*BloomFilter) Combine

func (bf *BloomFilter) Combine(bf2 *BloomFilter) *BloomFilter

Combine merges two BloomFilters (of same kind) into a new one.

func (*BloomFilter) Contains

func (bf *BloomFilter) Contains(entry []byte) bool

Contains returns true if the BloomFilter contains the given entry, and false otherwise. If an entry was added to the set, this function will always return 'true'. It can return 'true' for entries not in the set ("false-positives").

func (*BloomFilter) SameKind

func (bf *BloomFilter) SameKind(bf2 *BloomFilter) bool

SameKind checks if two BloomFilter have the same parameters.