storage

Documentation

Index

• Variables
• type KeyValue
  • func (kv KeyValue) String() string
• type Storage
• type Transaction

Variables

var (
	ErrNotFound      = errors.New("Not Found")
	ErrLayerNotFound = errors.New("Layer Not Found")
)

var EmptyHash = types.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")

Types

type KeyValue

type KeyValue struct {
	Key   []byte
	Value []byte
}

func (KeyValue) String

func (kv KeyValue) String() string

type Storage

type Storage interface {
	// View returns a transaction for interfacing with the layer indicated by the
	// specified hash.
	View(types.Hash, func(Transaction) error) error
	// AddBlock adds a new block to the storage engine. An error will be returned
	// if the parent specified does not exist. If `weight` exceeds the weight of
	// any previously handled block, this block will be returned in future calls
	// to `LatestHash()`. `blockData` and `stateUpdates` will be tracked against
	// this block and eventually persisted. The `resumption` byte string will be
	// provided by the information source, so that backups recovering from this
	// storage engine can determine where to resume from.
	AddBlock(hash, parentHash types.Hash, number uint64, weight *big.Int, updates []KeyValue, deletes [][]byte, resumption []byte) error

	// LatestHash returns the block with the highest weight added through AddBlock
	LatestHash() types.Hash

	// NumberToHash will convert a number to a hash within the range of blocks
	// that can be queried by this Storage interface
	NumberToHash(uint64) (types.Hash, error)

	// Roll back the storage engine to the specified block number in its history
	Rollback(uint64) error

	// The resumption token of the current latest block
	LatestBlock() (types.Hash, uint64, *big.Int, []byte)
}

type Transaction

type Transaction interface {
	// Get returns the data stored at a given key.
	Get([]byte) ([]byte, error)
	// ZeroCopyGet invokes the provided closure with the data stored at the given
	// key. The data should not be modified, and should not be accessed outside
	// the closure without being copied.
	ZeroCopyGet([]byte, func([]byte) error) error
	// NumberToHash returns a block hash given a block number. This may or may
	// not be able to go back to the genesis block, but likely goes back further
	// than Storage.NumberToHash
	NumberToHash(uint64) types.Hash
	// HashToNumber returns the block number corresponding to the given hash.
	// This may or may not be able to go back to the genesis block.
	HashToNumber(types.Hash) uint64
}