blockchain

Documentation

Overview

Package blockchain defines the life-cycle of the blockchain at the core of Ethereum, including processing of new blocks and attestations using proof of stake.

Index

• Variables
• type AttestationReceiver
• type AttestationStateFetcher
• type Service
  • func NewService(ctx context.Context, opts ...Option) (*Service, error)
  • func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error)
  • func (s *Service) OnAttestation(ctx context.Context, a *ethpb.Attestation, disparity time.Duration) error
  • func (s *Service) SaveAttestation(a *ethpb.Attestation) error
  • func (s *Service) Start()
  • func (s *Service) StartFromSavedState(saved state.BeaconState) error
  • func (s *Service) Status() error
  • func (s *Service) Stop() error
  • func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
  • func (s *Service) VerifyLmdFfgConsistency(ctx context.Context, a *ethpb.Attestation) error

Variables

var ErrMissingClockSetter = errors.New("blockchain Service initialized without a startup.ClockSetter")

Types

type AttestationReceiver

type AttestationReceiver interface {
	AttestationStateFetcher
	VerifyLmdFfgConsistency(ctx context.Context, att *ethpb.Attestation) error
	InForkchoice([32]byte) bool
}

AttestationReceiver interface defines the methods of chain service receive and processing new attestations.

type AttestationStateFetcher

type AttestationStateFetcher interface {
	AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error)
}

AttestationStateFetcher allows for retrieving a beacon state corresponding to the block root of an attestation's target checkpoint.

type Service

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

Service represents a service that handles the internal logic of managing the full PoS beacon chain.

func NewService

func NewService(ctx context.Context, opts ...Option) (*Service, error)

NewService instantiates a new block service instance that will be registered into a running beacon node.

func (*Service) AttestationTargetState

func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error)

AttestationTargetState returns the pre state of attestation.

func (*Service) OnAttestation

func (s *Service) OnAttestation(ctx context.Context, a *ethpb.Attestation, disparity time.Duration) error

OnAttestation is called whenever an attestation is received, verifies the attestation is valid and saves it to the DB. As a stateless function, this does not hold nor delay attestation based on the spec descriptions. The delay is handled by the caller in `processAttestations`.

Spec pseudocode definition:

def on_attestation(store: Store, attestation: Attestation) -> None:
 """
 Run ``on_attestation`` upon receiving a new ``attestation`` from either within a block or directly on the wire.

 An ``attestation`` that is asserted as invalid may be valid at a later time,
 consider scheduling it for later processing in such case.
 """
 validate_on_attestation(store, attestation)
 store_target_checkpoint_state(store, attestation.data.target)

 # Get state at the `target` to fully validate attestation
 target_state = store.checkpoint_states[attestation.data.target]
 indexed_attestation = get_indexed_attestation(target_state, attestation)
 assert is_valid_indexed_attestation(target_state, indexed_attestation)

 # Update latest messages for attesting indices
 update_latest_messages(store, indexed_attestation.attesting_indices, attestation)

func (*Service) SaveAttestation

func (s *Service) SaveAttestation(a *ethpb.Attestation) error

func (*Service) Start

func (s *Service) Start()

Start a blockchain service's main event loop.

func (*Service) StartFromSavedState

func (s *Service) StartFromSavedState(saved state.BeaconState) error

StartFromSavedState initializes the blockchain using a previously saved finalized checkpoint.

func (*Service) Status

func (s *Service) Status() error

Status always returns nil unless there is an error condition that causes this service to be unhealthy.

func (*Service) Stop

func (s *Service) Stop() error

Stop the blockchain service's main event loop and associated goroutines.

func (*Service) UpdateHead

func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)

UpdateHead updates the canonical head of the chain based on information from fork-choice attestations and votes. The caller of this function MUST hold a lock in forkchoice

func (*Service) VerifyLmdFfgConsistency

func (s *Service) VerifyLmdFfgConsistency(ctx context.Context, a *ethpb.Attestation) error

VerifyLmdFfgConsistency verifies that attestation's LMD and FFG votes are consistency to each other.