presence

package

v1.64.1 Latest Latest Go to latest Published: Oct 13, 2026 License: Apache-2.0 Imports: 4 Imported by: 0

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Valid go.mod file
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Repository

github.com/gobackio/goback

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Documentation ¶

Overview ¶

Package presence holds the Bloom filter an agent consults before uploading a blob: a positive answer is probably right, a negative one is certain.

Constants ¶

View Source

const FalsePositiveRate = 0.01

FalsePositiveRate is what filters are sized for.

View Source

const Version = 1

Version is the format written by Proto.

Variables ¶

This section is empty.

Functions ¶

This section is empty.

Types ¶

type Filter ¶

type Filter struct {

	// Commit and Set say which commit the filter was built from.
	Commit *proto.Ref
	Set    string
	// contains filtered or unexported fields
}

Filter is a Bloom filter over refs.

func FromProto ¶

func FromProto(p *proto.PresenceFilter) (*Filter, error)

FromProto decodes a filter written by Proto.

func New ¶

func New(n uint64) *Filter

New returns an empty filter sized for n refs at FalsePositiveRate.

func Sized ¶

func Sized(n uint64, p float64) *Filter

Sized returns an empty filter sized for n refs at false-positive rate p.

func (*Filter) Add ¶

func (f *Filter) Add(hash []byte)

Add records a ref. Refs shorter than 16 bytes are ignored.

func (*Filter) Entries ¶

func (f *Filter) Entries() uint64

Entries is the number of refs added.

func (*Filter) Proto ¶

func (f *Filter) Proto() *proto.PresenceFilter

Proto encodes the filter for storage and transport.

func (*Filter) Size ¶

func (f *Filter) Size() int

Size is the byte size of the bit array.

func (*Filter) Test ¶

func (f *Filter) Test(hash []byte) bool

Test reports whether the ref may have been added.

type Set ¶

type Set []*Filter

Set is the filters of one scope, consulted together.

func (Set) Entries ¶

func (s Set) Entries() uint64

Entries is the number of refs over all filters.

func (Set) Size ¶

func (s Set) Size() int

Size is the byte size of all bit arrays.

func (Set) Test ¶

func (s Set) Test(hash []byte) bool

Test reports whether any filter may hold the ref.

Source Files ¶

View all Source files

presence.go

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