feeds

package
v1.17.2 Latest Latest
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 Go to latest Published: Aug 10, 2023 License: BSD-3-Clause Imports: 13 Imported by: 10

Documentation

Overview

Package feeds implements generic interfaces and methods for time-based feeds indexing schemes are implemented in subpackages - epochs - sequence

Index

Constants

This section is empty.

Variables

View Source 
var ErrFeedTypeNotFound = errors.New("no such feed type")

Functions

func FromChunk 

func FromChunk(ch swarm.Chunk) (uint64, []byte, error)

FromChunk parses out the timestamp and the payload

func Id added in v0.5.1 

func Id(topic []byte, index Index) ([]byte, error)

Id calculates the feed id from a topic and an index

func Latest 

func Latest(ctx context.Context, l Lookup, after int64) (swarm.Chunk, error)

Latest looks up the latest update of the feed after is a unix time hint of the latest known update

func NewUpdate 

func NewUpdate(f *Feed, idx Index, timestamp int64, payload, sig []byte) (swarm.Chunk, error)

NewUpdate creates an update from an index, timestamp, payload and signature

func UpdatedAt 

func UpdatedAt(ch swarm.Chunk) (uint64, error)

UpdatedAt extracts the time of feed other than update

Types

type Factory 

type Factory interface {
	NewLookup(Type, *Feed) (Lookup, error)
}

Factory creates feed lookups for different types of feeds.

type Feed 

type Feed struct {
	Topic []byte
	Owner common.Address
}

Feed is representing an epoch based feed

func New 

func New(topic []byte, owner common.Address) *Feed

New constructs an epoch based feed from a keccak256 digest of a plaintext topic and an ether address.

func (*Feed) Update 

func (f *Feed) Update(index Index) *Update

Update called on a feed with an index and returns an Update

type Getter 

type Getter struct {
	*Feed
	// contains filtered or unexported fields
}

Getter encapsulates a chunk Getter getter and a feed and provides non-concurrent lookup methods

func NewGetter 

func NewGetter(getter storage.Getter, feed *Feed) *Getter

NewGetter constructs a feed Getter

func (*Getter) Get 

func (f *Getter) Get(ctx context.Context, i Index) (swarm.Chunk, error)

Get creates an update of the underlying feed at the given epoch and looks it up in the chunk Getter based on its address

type Index 

type Index interface {
	encoding.BinaryMarshaler
	Next(last int64, at uint64) Index
	fmt.Stringer
}

Index is the interface for feed implementations.

type Lookup 

type Lookup interface {
	At(ctx context.Context, at, after int64) (chunk swarm.Chunk, currentIndex, nextIndex Index, err error)
}

Lookup is the interface for time based feed lookup

type Putter 

type Putter struct {
	*Feed
	// contains filtered or unexported fields
}

Putter encapsulates a chunk store putter and a Feed to store feed updates

func NewPutter 

func NewPutter(putter storage.Putter, signer crypto.Signer, topic []byte) (*Putter, error)

NewPutter constructs a feed Putter

func (*Putter) Put 

func (u *Putter) Put(ctx context.Context, i Index, at int64, payload []byte) error

Put pushes an update to the feed through the chunk stores

type Type 

type Type int

Type enumerates the time-based feed types 

const (
	Sequence Type = iota
	Epoch
)

func (*Type) FromString