prysm-pulse/beacon-chain/blockchain/chain_info.go
terence tsao 16a0c9f463
Don't save nil head state (#4799)
* Don't save nil head state
* Update head
2020-02-09 05:08:21 +00:00

209 lines
6.2 KiB
Go

package blockchain
import (
"bytes"
"context"
"time"
"github.com/gogo/protobuf/proto"
ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
"github.com/prysmaticlabs/go-ssz"
"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
"github.com/prysmaticlabs/prysm/beacon-chain/state"
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
"github.com/prysmaticlabs/prysm/shared/params"
)
// ChainInfoFetcher defines a common interface for methods in blockchain service which
// directly retrieves chain info related data.
type ChainInfoFetcher interface {
HeadFetcher
FinalizationFetcher
}
// TimeFetcher retrieves the Eth2 data that's related to time.
type TimeFetcher interface {
GenesisTime() time.Time
CurrentSlot() uint64
}
// HeadFetcher defines a common interface for methods in blockchain service which
// directly retrieves head related data.
type HeadFetcher interface {
HeadSlot() uint64
HeadRoot(ctx context.Context) ([]byte, error)
HeadBlock() *ethpb.SignedBeaconBlock
HeadState(ctx context.Context) (*state.BeaconState, error)
HeadValidatorsIndices(epoch uint64) ([]uint64, error)
HeadSeed(epoch uint64) ([32]byte, error)
}
// ForkFetcher retrieves the current fork information of the Ethereum beacon chain.
type ForkFetcher interface {
CurrentFork() *pb.Fork
}
// FinalizationFetcher defines a common interface for methods in blockchain service which
// directly retrieves finalization and justification related data.
type FinalizationFetcher interface {
FinalizedCheckpt() *ethpb.Checkpoint
CurrentJustifiedCheckpt() *ethpb.Checkpoint
PreviousJustifiedCheckpt() *ethpb.Checkpoint
}
// ParticipationFetcher defines a common interface for methods in blockchain service which
// directly retrieves validator participation related data.
type ParticipationFetcher interface {
Participation(epoch uint64) *precompute.Balance
}
// FinalizedCheckpt returns the latest finalized checkpoint from head state.
func (s *Service) FinalizedCheckpt() *ethpb.Checkpoint {
if s.headState == nil || s.headState.FinalizedCheckpoint() == nil {
return &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
}
cpt := s.headState.FinalizedCheckpoint()
// If head state exists but there hasn't been a finalized check point,
// the check point's root should refer to genesis block root.
if bytes.Equal(cpt.Root, params.BeaconConfig().ZeroHash[:]) {
return &ethpb.Checkpoint{Root: s.genesisRoot[:]}
}
return cpt
}
// CurrentJustifiedCheckpt returns the current justified checkpoint from head state.
func (s *Service) CurrentJustifiedCheckpt() *ethpb.Checkpoint {
if s.headState == nil || s.headState.CurrentJustifiedCheckpoint() == nil {
return &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
}
cpt := s.headState.CurrentJustifiedCheckpoint()
// If head state exists but there hasn't been a justified check point,
// the check point root should refer to genesis block root.
if bytes.Equal(cpt.Root, params.BeaconConfig().ZeroHash[:]) {
return &ethpb.Checkpoint{Root: s.genesisRoot[:]}
}
return cpt
}
// PreviousJustifiedCheckpt returns the previous justified checkpoint from head state.
func (s *Service) PreviousJustifiedCheckpt() *ethpb.Checkpoint {
if s.headState == nil || s.headState.PreviousJustifiedCheckpoint() == nil {
return &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
}
cpt := s.headState.PreviousJustifiedCheckpoint()
// If head state exists but there hasn't been a justified check point,
// the check point root should refer to genesis block root.
if bytes.Equal(cpt.Root, params.BeaconConfig().ZeroHash[:]) {
return &ethpb.Checkpoint{Root: s.genesisRoot[:]}
}
return cpt
}
// HeadSlot returns the slot of the head of the chain.
func (s *Service) HeadSlot() uint64 {
s.headLock.RLock()
defer s.headLock.RUnlock()
return s.headSlot
}
// HeadRoot returns the root of the head of the chain.
func (s *Service) HeadRoot(ctx context.Context) ([]byte, error) {
s.headLock.RLock()
defer s.headLock.RUnlock()
root := s.canonicalRoots[s.headSlot]
if len(root) != 0 {
return root, nil
}
b, err := s.beaconDB.HeadBlock(ctx)
if err != nil {
return nil, err
}
if b == nil {
return params.BeaconConfig().ZeroHash[:], nil
}
r, err := ssz.HashTreeRoot(b.Block)
if err != nil {
return nil, err
}
return r[:], nil
}
// HeadBlock returns the head block of the chain.
func (s *Service) HeadBlock() *ethpb.SignedBeaconBlock {
s.headLock.RLock()
defer s.headLock.RUnlock()
return proto.Clone(s.headBlock).(*ethpb.SignedBeaconBlock)
}
// HeadState returns the head state of the chain.
// If the head state is nil from service struct,
// it will attempt to get from DB and error if nil again.
func (s *Service) HeadState(ctx context.Context) (*state.BeaconState, error) {
s.headLock.RLock()
defer s.headLock.RUnlock()
if s.headState == nil {
headState, err := s.beaconDB.HeadState(ctx)
if err != nil {
return nil, err
}
s.headState = headState
return headState, nil
}
return s.headState.Copy(), nil
}
// HeadValidatorsIndices returns a list of active validator indices from the head view of a given epoch.
func (s *Service) HeadValidatorsIndices(epoch uint64) ([]uint64, error) {
if s.headState == nil {
return []uint64{}, nil
}
return helpers.ActiveValidatorIndices(s.headState, epoch)
}
// HeadSeed returns the seed from the head view of a given epoch.
func (s *Service) HeadSeed(epoch uint64) ([32]byte, error) {
if s.headState == nil {
return [32]byte{}, nil
}
return helpers.Seed(s.headState, epoch, params.BeaconConfig().DomainBeaconAttester)
}
// GenesisTime returns the genesis time of beacon chain.
func (s *Service) GenesisTime() time.Time {
return s.genesisTime
}
// CurrentFork retrieves the latest fork information of the beacon chain.
func (s *Service) CurrentFork() *pb.Fork {
if s.headState == nil {
return &pb.Fork{
PreviousVersion: params.BeaconConfig().GenesisForkVersion,
CurrentVersion: params.BeaconConfig().GenesisForkVersion,
}
}
return s.headState.Fork()
}
// Participation returns the participation stats of a given epoch.
func (s *Service) Participation(epoch uint64) *precompute.Balance {
s.epochParticipationLock.RLock()
defer s.epochParticipationLock.RUnlock()
return s.epochParticipation[epoch]
}