stateless

Documentation

Index

• type ExecutionWitness
• type HeaderReader
• type Witness
  • func NewWitness(context *types.Header, chain HeaderReader) (*Witness, error)
  • func (w *Witness) AddBlockHash(number uint64)
  • func (w *Witness) AddCode(code []byte)
  • func (w *Witness) AddState(nodes map[string]struct{})
  • func (w *Witness) Copy() *Witness
  • func (w *Witness) DecodeRLP(s *rlp.Stream) error
  • func (w *Witness) EncodeRLP(wr io.Writer) error
  • func (w *Witness) MakeHashDB() ethdb.Database
  • func (w *Witness) Root() common.Hash
  • func (w *Witness) ToExecutionWitness() *ExecutionWitness

Types

type ExecutionWitness

type ExecutionWitness struct {
	Headers []*types.Header   `json:"headers"`
	Codes   map[string]string `json:"codes"`
	State   map[string]string `json:"state"`
}

ExecutionWitness is a witness json encoding for transferring across clients in the future, we'll probably consider using the extWitness format instead for less overhead. currently we're using this format for compatibility with reth and also for simplicity in terms of parsing.

type HeaderReader

type HeaderReader interface {
	// GetHeader retrieves a block header from the database by hash and number,
	GetHeader(hash common.Hash, number uint64) *types.Header
}

HeaderReader is an interface to pull in headers in place of block hashes for the witness.

type Witness

type Witness struct {
	Headers []*types.Header     // Past headers in reverse order (0=parent, 1=parent's-parent, etc). First *must* be set.
	Codes   map[string]struct{} // Set of bytecodes ran or accessed
	State   map[string]struct{} // Set of MPT state trie nodes (account and storage together)
	// contains filtered or unexported fields
}

Witness encompasses the state required to apply a set of transactions and derive a post state/receipt root.

func NewWitness

func NewWitness(context *types.Header, chain HeaderReader) (*Witness, error)

NewWitness creates an empty witness ready for population.

func (*Witness) AddBlockHash

func (w *Witness) AddBlockHash(number uint64)

AddBlockHash adds a "blockhash" to the witness with the designated offset from chain head. Under the hood, this method actually pulls in enough headers from the chain to cover the block being added.

func (*Witness) AddCode

func (w *Witness) AddCode(code []byte)

AddCode adds a bytecode blob to the witness.

func (*Witness) AddState

func (w *Witness) AddState(nodes map[string]struct{})

AddState inserts a batch of MPT trie nodes into the witness.

func (*Witness) Copy

func (w *Witness) Copy() *Witness

Copy deep-copies the witness object. Witness.Block isn't deep-copied as it is never mutated by Witness

func (*Witness) DecodeRLP

func (w *Witness) DecodeRLP(s *rlp.Stream) error

DecodeRLP decodes a witness from RLP.

func (*Witness) EncodeRLP

func (w *Witness) EncodeRLP(wr io.Writer) error

EncodeRLP serializes a witness as RLP.

func (*Witness) MakeHashDB

func (w *Witness) MakeHashDB() ethdb.Database

MakeHashDB imports tries, codes and block hashes from a witness into a new hash-based memory db. We could eventually rewrite this into a pathdb, but simple is better for now.

Note, this hashdb approach is quite strictly self-validating:

• Headers are persisted keyed by hash, so blockhash will error on junk
• Codes are persisted keyed by hash, so bytecode lookup will error on junk
• Trie nodes are persisted keyed by hash, so trie expansion will error on junk

Acceleration structures built would need to explicitly validate the witness.

func (*Witness) Root

func (w *Witness) Root() common.Hash

Root returns the pre-state root from the first header.

Note, this method will panic in case of a bad witness (but RLP decoding will sanitize it and fail before that).

func (*Witness) ToExecutionWitness

func (w *Witness) ToExecutionWitness() *ExecutionWitness

ToExecutionWitness converts a witness to an execution witness format that is compatible with reth. keccak(node) => node keccak(bytecodes) => bytecodes