prysm-pulse/beacon-chain/sync/initial-sync/service.go
terence tsao 3e15e2fc1e Add operation feed (#4215)
* Events
* Notifiers
* Refactor
* Gaz
* Fixed rest
* Lint
* Lint
* Visibility
* Typo
* Typo
* Apply suggestions from code review

Co-Authored-By: Nishant Das <nishdas93@gmail.com>
2019-12-07 17:57:26 +00:00

161 lines
4.3 KiB
Go

package initialsync
import (
"context"
"errors"
"fmt"
"time"
"github.com/prysmaticlabs/prysm/beacon-chain/blockchain"
"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/db"
"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
"github.com/prysmaticlabs/prysm/beacon-chain/sync/peerstatus"
"github.com/prysmaticlabs/prysm/shared"
"github.com/prysmaticlabs/prysm/shared/params"
"github.com/prysmaticlabs/prysm/shared/roughtime"
)
var _ = shared.Service(&InitialSync{})
type blockchainService interface {
blockchain.BlockReceiver
blockchain.HeadFetcher
}
const (
minStatusCount = 3 // TODO(3147): Set this to more than 3, maybe configure from flag?
handshakePollingInterval = 5 * time.Second // Polling interval for checking the number of received handshakes.
)
// Config to set up the initial sync service.
type Config struct {
P2P p2p.P2P
DB db.Database
Chain blockchainService
StateNotifier statefeed.Notifier
}
// InitialSync service.
type InitialSync struct {
ctx context.Context
chain blockchainService
p2p p2p.P2P
db db.Database
synced bool
chainStarted bool
stateNotifier statefeed.Notifier
}
// NewInitialSync configures the initial sync service responsible for bringing the node up to the
// latest head of the blockchain.
func NewInitialSync(cfg *Config) *InitialSync {
return &InitialSync{
ctx: context.Background(),
chain: cfg.Chain,
p2p: cfg.P2P,
db: cfg.DB,
stateNotifier: cfg.StateNotifier,
}
}
// Start the initial sync service.
func (s *InitialSync) Start() {
var genesis time.Time
headState, err := s.chain.HeadState(s.ctx)
if headState == nil || err != nil {
// Wait for state to be initialized.
stateChannel := make(chan *feed.Event, 1)
stateSub := s.stateNotifier.StateFeed().Subscribe(stateChannel)
defer stateSub.Unsubscribe()
genesisSet := false
for !genesisSet {
select {
case event := <-stateChannel:
if event.Type == statefeed.Initialized {
data := event.Data.(*statefeed.InitializedData)
log.WithField("starttime", data.StartTime).Debug("Received state initialized event")
genesis = data.StartTime
genesisSet = true
}
case <-s.ctx.Done():
log.Debug("Context closed, exiting goroutine")
return
case err := <-stateSub.Err():
log.WithError(err).Error("Subscription to state notifier failed")
return
}
}
stateSub.Unsubscribe()
} else {
genesis = time.Unix(int64(headState.GenesisTime), 0)
}
if genesis.After(roughtime.Now()) {
log.WithField(
"genesis time",
genesis,
).Warn("Genesis time is in the future - waiting to start sync...")
time.Sleep(roughtime.Until(genesis))
}
s.chainStarted = true
currentSlot := slotsSinceGenesis(genesis)
if helpers.SlotToEpoch(currentSlot) == 0 {
log.Info("Chain started within the last epoch - not syncing")
s.synced = true
return
}
log.Info("Starting initial chain sync...")
// Are we already in sync, or close to it?
if helpers.SlotToEpoch(s.chain.HeadSlot()) == helpers.SlotToEpoch(currentSlot) {
log.Info("Already synced to the current chain head")
s.synced = true
return
}
// Every 5 sec, report handshake count.
for {
count := peerstatus.Count()
if count >= minStatusCount {
break
}
log.WithField(
"handshakes",
fmt.Sprintf("%d/%d", count, minStatusCount),
).Info("Waiting for enough peer handshakes before syncing")
time.Sleep(handshakePollingInterval)
}
if err := s.roundRobinSync(genesis); err != nil {
panic(err)
}
log.Infof("Synced up to slot %d", s.chain.HeadSlot())
s.synced = true
}
// Stop initial sync.
func (s *InitialSync) Stop() error {
return nil
}
// Status of initial sync.
func (s *InitialSync) Status() error {
if !s.synced && s.chainStarted {
return errors.New("syncing")
}
return nil
}
// Syncing returns true if initial sync is still running.
func (s *InitialSync) Syncing() bool {
return !s.synced
}
func slotsSinceGenesis(genesisTime time.Time) uint64 {
return uint64(roughtime.Since(genesisTime).Seconds()) / params.BeaconConfig().SecondsPerSlot
}