prysm-pulse/beacon-chain/blockchain/head.go
Raul Jordan 29513c804c
Create Encoding Bytesutil (#9658)
* bytesutil

* gaz

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2021-09-23 15:23:37 +00:00

413 lines
13 KiB
Go

package blockchain
import (
"bytes"
"context"
"fmt"
"github.com/pkg/errors"
types "github.com/prysmaticlabs/eth2-types"
"github.com/prysmaticlabs/prysm/beacon-chain/core"
"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
"github.com/prysmaticlabs/prysm/beacon-chain/state"
"github.com/prysmaticlabs/prysm/config/features"
"github.com/prysmaticlabs/prysm/config/params"
"github.com/prysmaticlabs/prysm/encoding/bytesutil"
ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
"github.com/prysmaticlabs/prysm/time/slots"
"github.com/sirupsen/logrus"
"go.opencensus.io/trace"
)
// This defines the current chain service's view of head.
type head struct {
slot types.Slot // current head slot.
root [32]byte // current head root.
block block.SignedBeaconBlock // current head block.
state state.BeaconState // current head state.
}
// Determined the head from the fork choice service and saves its new data
// (head root, head block, and head state) to the local service cache.
func (s *Service) updateHead(ctx context.Context, balances []uint64) error {
ctx, span := trace.StartSpan(ctx, "blockChain.updateHead")
defer span.End()
// To get the proper head update, a node first checks its best justified
// can become justified. This is designed to prevent bounce attack and
// ensure head gets its best justified info.
if s.bestJustifiedCheckpt.Epoch > s.justifiedCheckpt.Epoch {
s.justifiedCheckpt = s.bestJustifiedCheckpt
if err := s.cacheJustifiedStateBalances(ctx, bytesutil.ToBytes32(s.justifiedCheckpt.Root)); err != nil {
return err
}
}
// Get head from the fork choice service.
f := s.finalizedCheckpt
j := s.justifiedCheckpt
// To get head before the first justified epoch, the fork choice will start with genesis root
// instead of zero hashes.
headStartRoot := bytesutil.ToBytes32(j.Root)
if headStartRoot == params.BeaconConfig().ZeroHash {
headStartRoot = s.genesisRoot
}
// In order to process head, fork choice store requires justified info.
// If the fork choice store is missing justified block info, a node should
// re-initiate fork choice store using the latest justified info.
// This recovers a fatal condition and should not happen in run time.
if !s.cfg.ForkChoiceStore.HasNode(headStartRoot) {
jb, err := s.cfg.BeaconDB.Block(ctx, headStartRoot)
if err != nil {
return err
}
s.cfg.ForkChoiceStore = protoarray.New(j.Epoch, f.Epoch, bytesutil.ToBytes32(f.Root))
if err := s.insertBlockToForkChoiceStore(ctx, jb.Block(), headStartRoot, f, j); err != nil {
return err
}
}
headRoot, err := s.cfg.ForkChoiceStore.Head(ctx, j.Epoch, headStartRoot, balances, f.Epoch)
if err != nil {
return err
}
// Save head to the local service cache.
return s.saveHead(ctx, headRoot)
}
// This saves head info to the local service cache, it also saves the
// new head root to the DB.
func (s *Service) saveHead(ctx context.Context, headRoot [32]byte) error {
ctx, span := trace.StartSpan(ctx, "blockChain.saveHead")
defer span.End()
// Do nothing if head hasn't changed.
r, err := s.HeadRoot(ctx)
if err != nil {
return err
}
if headRoot == bytesutil.ToBytes32(r) {
return nil
}
// If the head state is not available, just return nil.
// There's nothing to cache
if !s.cfg.BeaconDB.HasStateSummary(ctx, headRoot) {
return nil
}
// Get the new head block from DB.
newHeadBlock, err := s.cfg.BeaconDB.Block(ctx, headRoot)
if err != nil {
return err
}
if newHeadBlock == nil || newHeadBlock.IsNil() || newHeadBlock.Block().IsNil() {
return errors.New("cannot save nil head block")
}
// Get the new head state from cached state or DB.
newHeadState, err := s.cfg.StateGen.StateByRoot(ctx, headRoot)
if err != nil {
return errors.Wrap(err, "could not retrieve head state in DB")
}
if newHeadState == nil || newHeadState.IsNil() {
return errors.New("cannot save nil head state")
}
// A chain re-org occurred, so we fire an event notifying the rest of the services.
headSlot := s.HeadSlot()
newHeadSlot := newHeadBlock.Block().Slot()
oldHeadRoot := s.headRoot()
oldStateRoot := s.headBlock().Block().StateRoot()
newStateRoot := newHeadBlock.Block().StateRoot()
if bytesutil.ToBytes32(newHeadBlock.Block().ParentRoot()) != bytesutil.ToBytes32(r) {
log.WithFields(logrus.Fields{
"newSlot": fmt.Sprintf("%d", newHeadSlot),
"oldSlot": fmt.Sprintf("%d", headSlot),
}).Debug("Chain reorg occurred")
absoluteSlotDifference := slots.AbsoluteValueSlotDifference(newHeadSlot, headSlot)
s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
Type: statefeed.Reorg,
Data: &ethpbv1.EventChainReorg{
Slot: newHeadSlot,
Depth: absoluteSlotDifference,
OldHeadBlock: oldHeadRoot[:],
NewHeadBlock: headRoot[:],
OldHeadState: oldStateRoot,
NewHeadState: newStateRoot,
Epoch: core.SlotToEpoch(newHeadSlot),
},
})
if err := s.saveOrphanedAtts(ctx, bytesutil.ToBytes32(r)); err != nil {
return err
}
reorgCount.Inc()
}
// Cache the new head info.
s.setHead(headRoot, newHeadBlock, newHeadState)
// Save the new head root to DB.
if err := s.cfg.BeaconDB.SaveHeadBlockRoot(ctx, headRoot); err != nil {
return errors.Wrap(err, "could not save head root in DB")
}
// Forward an event capturing a new chain head over a common event feed
// done in a goroutine to avoid blocking the critical runtime main routine.
go func() {
if err := s.notifyNewHeadEvent(newHeadSlot, newHeadState, newStateRoot, headRoot[:]); err != nil {
log.WithError(err).Error("Could not notify event feed of new chain head")
}
}()
return nil
}
// This gets called to update canonical root mapping. It does not save head block
// root in DB. With the inception of initial-sync-cache-state flag, it uses finalized
// check point as anchors to resume sync therefore head is no longer needed to be saved on per slot basis.
func (s *Service) saveHeadNoDB(ctx context.Context, b block.SignedBeaconBlock, r [32]byte, hs state.BeaconState) error {
if err := helpers.VerifyNilBeaconBlock(b); err != nil {
return err
}
cachedHeadRoot, err := s.HeadRoot(ctx)
if err != nil {
return errors.Wrap(err, "could not get head root from cache")
}
if bytes.Equal(r[:], cachedHeadRoot) {
return nil
}
s.setHeadInitialSync(r, b.Copy(), hs)
return nil
}
// This sets head view object which is used to track the head slot, root, block and state.
func (s *Service) setHead(root [32]byte, block block.SignedBeaconBlock, state state.BeaconState) {
s.headLock.Lock()
defer s.headLock.Unlock()
// This does a full copy of the block and state.
s.head = &head{
slot: block.Block().Slot(),
root: root,
block: block.Copy(),
state: state.Copy(),
}
}
// This sets head view object which is used to track the head slot, root, block and state. The method
// assumes that state being passed into the method will not be modified by any other alternate
// caller which holds the state's reference.
func (s *Service) setHeadInitialSync(root [32]byte, block block.SignedBeaconBlock, state state.BeaconState) {
s.headLock.Lock()
defer s.headLock.Unlock()
// This does a full copy of the block only.
s.head = &head{
slot: block.Block().Slot(),
root: root,
block: block.Copy(),
state: state,
}
}
// This returns the head slot.
// This is a lock free version.
func (s *Service) headSlot() types.Slot {
return s.head.slot
}
// This returns the head root.
// It does a full copy on head root for immutability.
// This is a lock free version.
func (s *Service) headRoot() [32]byte {
if s.head == nil {
return params.BeaconConfig().ZeroHash
}
return s.head.root
}
// This returns the head block.
// It does a full copy on head block for immutability.
// This is a lock free version.
func (s *Service) headBlock() block.SignedBeaconBlock {
return s.head.block.Copy()
}
// This returns the head state.
// It does a full copy on head state for immutability.
// This is a lock free version.
func (s *Service) headState(ctx context.Context) state.BeaconState {
ctx, span := trace.StartSpan(ctx, "blockChain.headState")
defer span.End()
return s.head.state.Copy()
}
// This returns the genesis validator root of the head state.
// This is a lock free version.
func (s *Service) headGenesisValidatorRoot() [32]byte {
return bytesutil.ToBytes32(s.head.state.GenesisValidatorRoot())
}
// This returns the validator referenced by the provided index in
// the head state.
// This is a lock free version.
func (s *Service) headValidatorAtIndex(index types.ValidatorIndex) (state.ReadOnlyValidator, error) {
return s.head.state.ValidatorAtIndexReadOnly(index)
}
// Returns true if head state exists.
// This is the lock free version.
func (s *Service) hasHeadState() bool {
return s.head != nil && s.head.state != nil
}
// This caches justified state balances to be used for fork choice.
func (s *Service) cacheJustifiedStateBalances(ctx context.Context, justifiedRoot [32]byte) error {
if err := s.cfg.BeaconDB.SaveBlocks(ctx, s.getInitSyncBlocks()); err != nil {
return err
}
s.clearInitSyncBlocks()
var justifiedState state.BeaconState
var err error
if justifiedRoot == s.genesisRoot {
justifiedState, err = s.cfg.BeaconDB.GenesisState(ctx)
if err != nil {
return err
}
} else {
justifiedState, err = s.cfg.StateGen.StateByRoot(ctx, justifiedRoot)
if err != nil {
return err
}
}
if justifiedState == nil || justifiedState.IsNil() {
return errors.New("justified state can't be nil")
}
epoch := core.CurrentEpoch(justifiedState)
justifiedBalances := make([]uint64, justifiedState.NumValidators())
if err := justifiedState.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
if helpers.IsActiveValidatorUsingTrie(val, epoch) {
justifiedBalances[idx] = val.EffectiveBalance()
} else {
justifiedBalances[idx] = 0
}
return nil
}); err != nil {
return err
}
s.justifiedBalancesLock.Lock()
defer s.justifiedBalancesLock.Unlock()
s.justifiedBalances = justifiedBalances
return nil
}
func (s *Service) getJustifiedBalances() []uint64 {
s.justifiedBalancesLock.RLock()
defer s.justifiedBalancesLock.RUnlock()
return s.justifiedBalances
}
// Notifies a common event feed of a new chain head event. Called right after a new
// chain head is determined, set, and saved to disk.
func (s *Service) notifyNewHeadEvent(
newHeadSlot types.Slot,
newHeadState state.BeaconState,
newHeadStateRoot,
newHeadRoot []byte,
) error {
previousDutyDependentRoot := s.genesisRoot[:]
currentDutyDependentRoot := s.genesisRoot[:]
var previousDutyEpoch types.Epoch
currentDutyEpoch := core.SlotToEpoch(newHeadSlot)
if currentDutyEpoch > 0 {
previousDutyEpoch = currentDutyEpoch.Sub(1)
}
currentDutySlot, err := core.StartSlot(currentDutyEpoch)
if err != nil {
return errors.Wrap(err, "could not get duty slot")
}
previousDutySlot, err := core.StartSlot(previousDutyEpoch)
if err != nil {
return errors.Wrap(err, "could not get duty slot")
}
if currentDutySlot > 0 {
currentDutyDependentRoot, err = helpers.BlockRootAtSlot(newHeadState, currentDutySlot-1)
if err != nil {
return errors.Wrap(err, "could not get duty dependent root")
}
}
if previousDutySlot > 0 {
previousDutyDependentRoot, err = helpers.BlockRootAtSlot(newHeadState, previousDutySlot-1)
if err != nil {
return errors.Wrap(err, "could not get duty dependent root")
}
}
s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
Type: statefeed.NewHead,
Data: &ethpbv1.EventHead{
Slot: newHeadSlot,
Block: newHeadRoot,
State: newHeadStateRoot,
EpochTransition: core.IsEpochEnd(newHeadSlot),
PreviousDutyDependentRoot: previousDutyDependentRoot,
CurrentDutyDependentRoot: currentDutyDependentRoot,
},
})
return nil
}
// This saves the attestations inside the beacon block with respect to root `orphanedRoot` back into the
// attestation pool. It also filters out the attestations that is one epoch older as a
// defense so invalid attestations don't flow into the attestation pool.
func (s *Service) saveOrphanedAtts(ctx context.Context, orphanedRoot [32]byte) error {
if !features.Get().CorrectlyInsertOrphanedAtts {
return nil
}
orphanedBlk, err := s.cfg.BeaconDB.Block(ctx, orphanedRoot)
if err != nil {
return err
}
if orphanedBlk == nil || orphanedBlk.IsNil() {
return errors.New("orphaned block can't be nil")
}
for _, a := range orphanedBlk.Block().Body().Attestations() {
// Is the attestation one epoch older.
if a.Data.Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
continue
}
if helpers.IsAggregated(a) {
if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
return err
}
} else {
if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
return err
}
}
saveOrphanedAttCount.Inc()
}
return nil
}