state

Documentation

Index

• Constants
• Variables
• func BlockFromBytes(blockBytes []byte) (*block, error)
• type Block
• type BlockHash
  • func BlockHashFromData(data []byte) (ret BlockHash)
  • func BlockHashFromString(blockHashString string) (BlockHash, error)
  • func (bh BlockHash) Equals(other BlockHash) bool
  • func (bh BlockHash) String() string
• type L1Commitment
  • func L1CommitmentFromBytes(data []byte) (*L1Commitment, error)
  • func OriginL1Commitment() *L1Commitment
  • func PseudoRandL1Commitment() *L1Commitment
  • func (s *L1Commitment) BlockHash() BlockHash
  • func (s *L1Commitment) Bytes() []byte
  • func (s *L1Commitment) Equals(other *L1Commitment) bool
  • func (s *L1Commitment) Read(r io.Reader) error
  • func (s *L1Commitment) String() string
  • func (s *L1Commitment) TrieRoot() trie.Hash
  • func (s *L1Commitment) Write(w io.Writer) error
• type State
• type StateCommonValues
• type StateDraft
• type Store
  • func InitChainStore(db kvstore.KVStore) Store
  • func NewStore(db kvstore.KVStore) Store

Constants

const BlockHashSize = 20

const (

	// KeyChainID is the key used to store the chain ID in the state.
	// It should not collide with any hname prefix (which are 32 bits long).
	KeyChainID = "\x00"
)

const L1CommitmentSize = trie.HashSizeBytes + BlockHashSize

Variables

var (
	ErrTrieRootNotFound      = errors.New("trie root not found")
	ErrUnknownLatestTrieRoot = errors.New("latest trie root is unknown")
)

var L1CommitmentNil = &L1Commitment{}

Functions

func BlockFromBytes

func BlockFromBytes(blockBytes []byte) (*block, error)

Types

type Block

type Block interface {
	Mutations() *buffered.Mutations
	MutationsReader() kv.KVStoreReader
	TrieRoot() trie.Hash
	PreviousL1Commitment() *L1Commitment
	StateIndex() uint32
	// L1Commitment contains the TrieRoot + block Hash
	L1Commitment() *L1Commitment
	// Hash is computed from Mutations + PreviousL1Commitment
	Hash() BlockHash
	Bytes() []byte
}

A Block contains the mutations between the previous and current states, and allows to calculate the L1 commitment. Blocks are immutable.

type BlockHash

type BlockHash [BlockHashSize]byte

func BlockHashFromData

func BlockHashFromData(data []byte) (ret BlockHash)

func BlockHashFromString

func BlockHashFromString(blockHashString string) (BlockHash, error)

func (BlockHash) Equals

func (bh BlockHash) Equals(other BlockHash) bool

func (BlockHash) String

func (bh BlockHash) String() string

type L1Commitment

type L1Commitment struct {
	// contains filtered or unexported fields
}

L1Commitment represents the data stored as metadata in the anchor output

func L1CommitmentFromBytes

func L1CommitmentFromBytes(data []byte) (*L1Commitment, error)

func OriginL1Commitment

func OriginL1Commitment() *L1Commitment

OriginL1Commitment calculates the L1Commitment for the origin block, which is the same for every chain.

func PseudoRandL1Commitment

func PseudoRandL1Commitment() *L1Commitment

PseudoRandL1Commitment is for testing only

func (*L1Commitment) BlockHash

func (s *L1Commitment) BlockHash() BlockHash

func (*L1Commitment) Bytes

func (s *L1Commitment) Bytes() []byte

func (*L1Commitment) Equals

func (s *L1Commitment) Equals(other *L1Commitment) bool

func (*L1Commitment) Read

func (s *L1Commitment) Read(r io.Reader) error

func (*L1Commitment) String

func (s *L1Commitment) String() string

func (*L1Commitment) TrieRoot

func (s *L1Commitment) TrieRoot() trie.Hash

func (*L1Commitment) Write

func (s *L1Commitment) Write(w io.Writer) error

type State

type State interface {
	kv.KVStoreReader
	TrieRoot() trie.Hash
	GetMerkleProof(key []byte) *trie.MerkleProof
	StateCommonValues
}

State is an immutable view of a specific version of the chain state.

type StateCommonValues

type StateCommonValues interface {
	ChainID() isc.ChainID
	BlockIndex() uint32
	Timestamp() time.Time
	PreviousL1Commitment() *L1Commitment
}

type StateDraft

type StateDraft interface {
	kv.KVStore
	BaseL1Commitment() *L1Commitment
	Mutations() *buffered.Mutations
	StateCommonValues
}

StateDraft allows to mutate the chain state based on a specific trie root. All mutations are stored in-memory until committed.

type Store

type Store interface {
	// HasTrieRoot returns true if the given trie root exists in the store
	HasTrieRoot(trie.Hash) bool
	// BlockByTrieRoot fetches the Block that corresponds to the given trie root
	BlockByTrieRoot(trie.Hash) (Block, error)
	// StateByTrieRoot returns the chain state corresponding to the given trie root
	StateByTrieRoot(trie.Hash) (State, error)

	// SetLatest sets the given trie root to be considered the latest one in the chain.
	// This affects all `*ByIndex` and `Latest*` functions.
	SetLatest(trieRoot trie.Hash) error
	// BlockByIndex returns the block that corresponds to the given state index (see SetLatest).
	BlockByIndex(uint32) (Block, error)
	// StateByIndex returns the chain state corresponding to the given state index (see SetLatest).
	StateByIndex(uint32) (State, error)
	// LatestBlockIndex returns the index of the latest block, if set (see SetLatest)
	LatestBlockIndex() (uint32, error)
	// LatestBlock returns the latest block of the chain, if set (see SetLatest)
	LatestBlock() (Block, error)
	// LatestState returns the latest chain state, if set (see SetLatest)
	LatestState() (State, error)

	// NewOriginStateDraft starts a new StateDraft for the origin block
	NewOriginStateDraft() StateDraft

	// NewStateDraft starts a new StateDraft.
	// The newly created StateDraft will already contain a few mutations updating the common values:
	// - timestamp
	// - block index
	// - previous L1 commitment
	NewStateDraft(timestamp time.Time, prevL1Commitment *L1Commitment) (StateDraft, error)

	// NewEmptyStateDraft starts a new StateDraft without updating any the common values.
	// It may be used to replay a block given the mutations.
	// Note that calling any of the StateCommonValues methods may return invalid data before
	// applying the mutations.
	NewEmptyStateDraft(prevL1Commitment *L1Commitment) (StateDraft, error)

	// Commit commits the given state, creating a new block and trie root in the DB.
	// SetLatest must be called manually to consider the new state as the latest one.
	Commit(StateDraft) Block

	// ExtractBlock performs a dry-run of Commit, discarding all changes that would be
	// made to the DB.
	ExtractBlock(StateDraft) Block
}

Store manages the storage of a chain's state.

The chain state is a key-value store that is updated every time a batch of requests is executed by the VM.

The purpose of the Store is to store not only the latest version of the chain state, but also past versions (up to a limit).

Each version of the key-value pairs is stored in an immutable trie (provided by the trie.go package). Therefore each *state index* corresponds to a unique *trie root*.

For each trie root, the Store also stores a Block, which contains the mutations between the previous and current states, and allows to calculate the L1 commitment.

func InitChainStore

func InitChainStore(db kvstore.KVStore) Store

InitChainStore initializes a new chain store, committing the origin block and state to the DB. The ChainID is not known at this point, so it will contain all zeroes.

func NewStore

func NewStore(db kvstore.KVStore) Store