super_block

Documentation

Index

• Constants
• type ReplicaPlacement
  • func NewReplicaPlacementFromByte(b byte) (*ReplicaPlacement, error)
  • func NewReplicaPlacementFromString(t string) (*ReplicaPlacement, error)
  • func (rp *ReplicaPlacement) Byte() byte
  • func (rp *ReplicaPlacement) GetCopyCount() int
  • func (rp *ReplicaPlacement) String() string
• type SuperBlock
  • func ReadSuperBlock(datBackend backend.BackendStorageFile) (superBlock SuperBlock, err error)
  • func (s *SuperBlock) BlockSize() int
  • func (s *SuperBlock) Bytes() []byte
  • func (s *SuperBlock) Initialized() bool

Constants

const (
	SuperBlockSize = 8
)

Types

type ReplicaPlacement

type ReplicaPlacement struct {
	SameRackCount       int `json:"node,omitempty"`
	DiffRackCount       int `json:"rack,omitempty"`
	DiffDataCenterCount int `json:"dc,omitempty"`
}

func NewReplicaPlacementFromByte

func NewReplicaPlacementFromByte(b byte) (*ReplicaPlacement, error)

func NewReplicaPlacementFromString

func NewReplicaPlacementFromString(t string) (*ReplicaPlacement, error)

func (*ReplicaPlacement) Byte

func (rp *ReplicaPlacement) Byte() byte

func (*ReplicaPlacement) GetCopyCount

func (rp *ReplicaPlacement) GetCopyCount() int

func (*ReplicaPlacement) String

func (rp *ReplicaPlacement) String() string

type SuperBlock

type SuperBlock struct {
	Version            needle.Version
	ReplicaPlacement   *ReplicaPlacement
	Ttl                *needle.TTL
	CompactionRevision uint16
	Extra              *master_pb.SuperBlockExtra
	ExtraSize          uint16
}

* Super block currently has 8 bytes allocated for each volume. * Byte 0: version, 1 or 2 * Byte 1: Replica Placement strategy, 000, 001, 002, 010, etc * Byte 2 and byte 3: Time to live. See TTL for definition * Byte 4 and byte 5: The number of times the volume has been compacted. * Rest bytes: Reserved

func ReadSuperBlock

func ReadSuperBlock(datBackend backend.BackendStorageFile) (superBlock SuperBlock, err error)

ReadSuperBlock reads from data file and load it into volume's super block

func (*SuperBlock) BlockSize

func (s *SuperBlock) BlockSize() int

func (*SuperBlock) Bytes

func (s *SuperBlock) Bytes() []byte

func (*SuperBlock) Initialized

func (s *SuperBlock) Initialized() bool