share

Documentation

Overview

Package share contains logic related to the retrieval and random sampling of shares of block data.

Though this package contains several useful methods for getting specific shares and/or sampling them at random, a particularly useful method is GetSharesByNamespace which retrieves all shares of block data of the given Namespace from the block associated with the given DataAvailabilityHeader (DAH, but referred to as AxisRoots within this package).

This package also contains declaration of the Availability interface. Implementations of the interface (light, full) are located in the availability sub-folder. Light Availability implementation samples for 16 shares of block data (enough to verify the block's availability on the network). Full Availability implementation samples for as many shares as necessary to fully reconstruct the block data.

Index

• Constants
• Variables
• func EmptyBlockShares() []libshare.Share
• func EmptyEDS() *rsmt2d.ExtendedDataSquare
• func IsAboveMax(namespace libshare.Namespace, hash []byte) (bool, error)
• func IsBelowMin(namespace libshare.Namespace, hash []byte) (bool, error)
• func IsOutsideRange(namespace libshare.Namespace, leftHash, rightHash []byte) (bool, error)
• func NewSHA256Hasher() hash.Hash
• func RootHashForCoordinates(r *AxisRoots, axisType rsmt2d.Axis, rowIdx, colIdx uint) []byte
• func RowsWithNamespace(root *AxisRoots, namespace libshare.Namespace) (idxs []int, err error)
• type Availability
• type AxisRoots
  • func EmptyEDSRoots() *AxisRoots
  • func NewAxisRoots(eds *rsmt2d.ExtendedDataSquare) (*AxisRoots, error)
• type DataHash
  • func EmptyEDSDataHash() DataHash
  • func MustDataHashFromString(datahash string) DataHash
  • func (dh DataHash) IsEmptyEDS() bool
  • func (dh DataHash) String() string
  • func (dh DataHash) Validate() error
• type ShareWithProof
  • func (s *ShareWithProof) Validate(rootHash []byte, x, y, edsSize int) bool

Constants

const (
	// DataHashSize is the size of the DataHash.
	DataHashSize = 32
	// AxisRootSize is the size of the single root in AxisRoots.
	AxisRootSize = 90
)

Variables

var DefaultRSMT2DCodec = appconsts.DefaultCodec

DefaultRSMT2DCodec sets the default rsmt2d.Codec for shares.

var ErrNotAvailable = errors.New("share: data not available")

ErrNotAvailable is returned whenever DA sampling fails.

var MaxSquareSize = appconsts.SquareSizeUpperBound(appconsts.LatestVersion)

MaxSquareSize is currently the maximum size supported for unerasured data in rsmt2d.ExtendedDataSquare.

Functions

func EmptyBlockShares

func EmptyBlockShares() []libshare.Share

EmptyBlockShares returns the shares of the empty block.

func EmptyEDS

func EmptyEDS() *rsmt2d.ExtendedDataSquare

EmptyEDS returns the EDS of the empty block data square.

func IsAboveMax

func IsAboveMax(namespace libshare.Namespace, hash []byte) (bool, error)

IsAboveMax checks if the namespace is above the maximum namespace of the given hash.

func IsBelowMin

func IsBelowMin(namespace libshare.Namespace, hash []byte) (bool, error)

IsBelowMin checks if the target namespace is below the minimum namespace of the given hash.

func IsOutsideRange

func IsOutsideRange(namespace libshare.Namespace, leftHash, rightHash []byte) (bool, error)

IsOutsideRange checks if the namespace is outside the min-max range of the given hashes.

func NewSHA256Hasher

func NewSHA256Hasher() hash.Hash

NewSHA256Hasher returns a new instance of a SHA-256 hasher.

func RootHashForCoordinates

func RootHashForCoordinates(r *AxisRoots, axisType rsmt2d.Axis, rowIdx, colIdx uint) []byte

RootHashForCoordinates returns the root hash for the given coordinates.

func RowsWithNamespace

func RowsWithNamespace(root *AxisRoots, namespace libshare.Namespace) (idxs []int, err error)

RowsWithNamespace inspects the AxisRoots for the Namespace and provides a slices of Row indexes containing the namespace.

Types

type Availability

type Availability interface {
	// SharesAvailable subjectively validates if Shares committed to the given Root are available on
	// the Network.
	SharesAvailable(context.Context, *header.ExtendedHeader) error
}

Availability defines interface for validation of Shares' availability.

type AxisRoots

type AxisRoots = da.DataAvailabilityHeader

AxisRoots represents root commitment to multiple Shares. In practice, it is a commitment to all the Data in a square.

func EmptyEDSRoots

func EmptyEDSRoots() *AxisRoots

EmptyEDSRoots returns AxisRoots of the empty block EDS.

func NewAxisRoots

func NewAxisRoots(eds *rsmt2d.ExtendedDataSquare) (*AxisRoots, error)

NewAxisRoots generates AxisRoots(DataAvailabilityHeader) using the provided extended data square.

type DataHash

type DataHash []byte

DataHash is a representation of the AxisRoots hash.

func EmptyEDSDataHash

func EmptyEDSDataHash() DataHash

EmptyEDSDataHash returns DataHash of the empty block EDS.

func MustDataHashFromString

func MustDataHashFromString(datahash string) DataHash

MustDataHashFromString converts a hex string to a valid datahash.

func (DataHash) IsEmptyEDS

func (dh DataHash) IsEmptyEDS() bool

IsEmptyEDS check whether DataHash corresponds to the root of an empty block EDS.

func (DataHash) String

func (dh DataHash) String() string

func (DataHash) Validate

func (dh DataHash) Validate() error

type ShareWithProof

type ShareWithProof struct {
	// Share is a full data including namespace
	libshare.Share
	// Proof is a Merkle Proof of current share
	Proof *nmt.Proof
	// Axis is a type of axis against which the share proof is computed
	Axis rsmt2d.Axis
}

ShareWithProof contains data with corresponding Merkle Proof

func (*ShareWithProof) Validate

func (s *ShareWithProof) Validate(rootHash []byte, x, y, edsSize int) bool

Validate validates inclusion of the share under the given root CID.