erasurecode

Documentation

Index

• Constants
• Variables
• type ErasureCoder
  • func New(ecType uint8, minSectors uint32, numSectors uint32, extra ...interface{}) (ErasureCoder, error)

Constants

const (
	// ECTypeInvalid is the type not supported
	ECTypeInvalid uint8 = iota

	// ECTypeStandard is the type code for standardErasureCode
	ECTypeStandard

	// ECTypeShard is the type code for shardErasureCode
	ECTypeShard
)

const EncodedShardUnit = 64

EncodedShardUnit minimum unit for encoded data structure

Variables

var ErrInsufficientData = errors.New("not sufficient data for recovery")

ErrInsufficientData is the error that not sufficient data is provided for recovery.

var ErrInvalidECType = errors.New("invalid erasure code type")

ErrInvalidECType is the error that the input type code is not supported

Types

type ErasureCoder

type ErasureCoder interface {
	// Type return the type of the code
	Type() uint8

	// NumSectors return the total number of encoded sectors
	NumSectors() uint32

	// MinSectors return the number of minimum sectors that is required to recover the original data
	MinSectors() uint32

	// Extra return the extra info included in the ErasureCoder
	Extra() []interface{}

	// Encode encode the segment to sectors
	Encode(data []byte) ([][]byte, error)

	// Recover decode the input sectors to the original data with length outLen
	Recover(sectors [][]byte, n int, w io.Writer) error
}

ErasureCoder is the interface supported for this package. Implemented types are

ECTypeStandard - standardErasureCode
ECTypeShard - shardErasureCode

Recommend to use the standard erasure code instead of the sharding one because of performance

func New

func New(ecType uint8, minSectors uint32, numSectors uint32, extra ...interface{}) (ErasureCoder, error)

New returns a new ErasureCoder. Type supported are ECTypeStandard, and ECTypeShard. The two parameters followed is parameters used for erasure code: num of data sectors and total number of sectors. Additional arguments could be attached for param specification. Note in this implementation, the following condition must be met: numSectors > minSectors > 0