chain

Documentation

Index

• Constants
• func BytesToRound(r []byte) uint64
• func GenesisBeacon(seed []byte) *common.Beacon
• func PreviousRequiredFromContext(ctx context.Context) bool
• func RoundToBytes(r uint64) []byte
• func SetPreviousRequiredOnContext(ctx context.Context) context.Context
• type Cursor
• type StorageType
• type Store

Constants

const (
	BoltTrimmedMetrics = iota + 1
	PostgreSQLMetrics
	MemDBMetrics
	BoltUntrimmedMetrics
)

Metrics values for reporting storage type used. Only append new values. Also, add new values to the DrandStorageBackend metric Help.

Functions

func BytesToRound

func BytesToRound(r []byte) uint64

BytesToRound unserializes a round number from bytes (8 bytes fixed length big-endian) to uint64.

func GenesisBeacon

func GenesisBeacon(seed []byte) *common.Beacon

GenesisBeacon returns the first beacon inserted in the chain

func PreviousRequiredFromContext

func PreviousRequiredFromContext(ctx context.Context) bool

func RoundToBytes

func RoundToBytes(r uint64) []byte

RoundToBytes serializes a round number to bytes (8 bytes fixed length big-endian).

func SetPreviousRequiredOnContext

func SetPreviousRequiredOnContext(ctx context.Context) context.Context

Types

type Cursor

type Cursor interface {
	First(context.Context) (*common.Beacon, error)
	Next(context.Context) (*common.Beacon, error)
	Seek(ctx context.Context, round uint64) (*common.Beacon, error)
	Last(context.Context) (*common.Beacon, error)
}

Cursor iterates over items in sorted key order. This starts from the first key/value pair and updates the k/v variables to the next key/value on each iteration.

The loop finishes at the end of the cursor when a nil key is returned.

for k, v := c.First(); k != nil; k, v = c.Next() {
    fmt.Printf("A %s is %s.\n", k, v)
}

type StorageType

type StorageType string

StorageType defines the supported storage engines

const (
	// BoltDB uses the BoltDB engine for storing data
	BoltDB StorageType = "bolt"

	// PostgreSQL uses the PostgreSQL database for storing data
	PostgreSQL StorageType = "postgres"

	// MemDB uses the in-memory database to store data
	MemDB StorageType = "memdb"
)

Storage engine types

type Store

type Store interface {
	Len(context.Context) (int, error)
	Put(context.Context, *common.Beacon) error
	Last(context.Context) (*common.Beacon, error)
	Get(ctx context.Context, round uint64) (*common.Beacon, error)
	Cursor(context.Context, func(context.Context, Cursor) error) error
	Close() error
	Del(ctx context.Context, round uint64) error
	SaveTo(ctx context.Context, w io.Writer) error
}

Store is an interface to store Beacons packets where they can also be retrieved to be delivered to end clients.