[stream] added downloader / consensus interface

consensus/consensus.go

@@ -130,6 +130,8 @@ type Consensus struct {
 	finality int64
 	// finalityCounter keep tracks of the finality time
 	finalityCounter int64
+
+	dHelper *downloadHelper
 }
 
 // SetCommitDelay sets the commit message delay.  If set to non-zero,

consensus/consensus_v2.go

@@ -467,13 +467,26 @@ func (consensus *Consensus) Start(
 		}
 		consensus.getLogger().Info().Msg("[ConsensusMainLoop] Ended.")
 	}()
+
+	if consensus.dHelper != nil {
+		consensus.dHelper.start()
+	}
 }
 
 // Close close the consensus. If current is in normal commit phase, wait until the commit
 // phase end.
 func (consensus *Consensus) Close() error {
-	if consensus.Mode() != Normal || consensus.phase != FBFTCommit {
+	if consensus.dHelper != nil {
+		consensus.dHelper.close()
+	}
+	consensus.waitForCommit()
 	return nil
+}
+
+// waitForCommit wait extra 2 seconds for commit phase to finish
+func (consensus *Consensus) waitForCommit() {
+	if consensus.Mode() != Normal || consensus.phase != FBFTCommit {
+		return
 	}
 	// We only need to wait consensus is in normal commit phase
 	utils.Logger().Warn().Str("phase", consensus.phase.String()).Msg("[shutdown] commit phase has to wait")
@@ -483,7 +496,6 @@ func (consensus *Consensus) Close() error {
 		utils.Logger().Warn().Msg("[shutdown] wait for consensus finished")
 		time.Sleep(time.Millisecond * 100)
 	}
-	return nil
 }
 
 // LastMileBlockIter is the iterator to iterate over the last mile blocks in consensus cache.

consensus/downloader.go

@@ -0,0 +1,131 @@
+package consensus
+
+import (
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/harmony-one/harmony/core/types"
+	"github.com/pkg/errors"
+)
+
+// downloader is the adapter interface for downloader.Downloader, which is used for
+// 1. Subscribe download finished event to help syncing to the latest block.
+// 2. Trigger the downloader to start working
+type downloader interface {
+	SubscribeDownloadFinished(ch chan struct{}) event.Subscription
+	SubscribeDownloadStarted(ch chan struct{}) event.Subscription
+	DownloadAsync()
+}
+
+// Set downloader set the downloader of the shard to consensus
+// TODO: It will be better to move this to consensus.New and register consensus as a service
+func (consensus *Consensus) SetDownloader(d downloader) {
+	consensus.dHelper = newDownloadHelper(consensus, d)
+}
+
+type downloadHelper struct {
+	d downloader
+	c *Consensus
+
+	startedCh  chan struct{}
+	finishedCh chan struct{}
+
+	startedSub  event.Subscription
+	finishedSub event.Subscription
+}
+
+func newDownloadHelper(c *Consensus, d downloader) *downloadHelper {
+	startedCh := make(chan struct{}, 1)
+	startedSub := d.SubscribeDownloadStarted(startedCh)
+
+	finishedCh := make(chan struct{}, 1)
+	finishedSub := d.SubscribeDownloadFinished(finishedCh)
+
+	return &downloadHelper{
+		c:           c,
+		d:           d,
+		startedCh:   startedCh,
+		finishedCh:  finishedCh,
+		startedSub:  startedSub,
+		finishedSub: finishedSub,
+	}
+}
+
+func (dh *downloadHelper) start() {
+	go dh.downloadStartedLoop()
+	go dh.downloadFinishedLoop()
+}
+
+func (dh *downloadHelper) close() {
+	dh.startedSub.Unsubscribe()
+	dh.finishedSub.Unsubscribe()
+}
+
+func (dh *downloadHelper) downloadStartedLoop() {
+	for {
+		select {
+		case <-dh.startedCh:
+			dh.c.BlocksNotSynchronized()
+
+		case err := <-dh.finishedSub.Err():
+			dh.c.getLogger().Info().Err(err).Msg("consensus download finished loop closed")
+			return
+		}
+	}
+}
+
+func (dh *downloadHelper) downloadFinishedLoop() {
+	for {
+		select {
+		case <-dh.finishedCh:
+			err := dh.c.addConsensusLastMile()
+			if err != nil {
+				dh.c.getLogger().Error().Err(err).Msg("add last mile failed")
+			}
+			dh.c.BlocksSynchronized()
+
+		case err := <-dh.finishedSub.Err():
+			dh.c.getLogger().Info().Err(err).Msg("consensus download finished loop closed")
+			return
+		}
+	}
+}
+
+func (consensus *Consensus) addConsensusLastMile() error {
+	curBN := consensus.Blockchain.CurrentBlock().NumberU64()
+	blockIter, err := consensus.GetLastMileBlockIter(curBN + 1)
+	if err != nil {
+		return err
+	}
+	for {
+		block := blockIter.Next()
+		if block == nil {
+			break
+		}
+		if _, err := consensus.Blockchain.InsertChain(types.Blocks{block}, true); err != nil {
+			return errors.Wrap(err, "failed to InsertChain")
+		}
+	}
+	return nil
+}
+
+func (consensus *Consensus) spinUpStateSync() {
+	if consensus.dHelper != nil {
+		consensus.dHelper.d.DownloadAsync()
+		consensus.current.SetMode(Syncing)
+		for _, v := range consensus.consensusTimeout {
+			v.Stop()
+		}
+	} else {
+		consensus.spinLegacyStateSync()
+	}
+}
+
+func (consensus *Consensus) spinLegacyStateSync() {
+	select {
+	case consensus.BlockNumLowChan <- struct{}{}:
+		consensus.current.SetMode(Syncing)
+		for _, v := range consensus.consensusTimeout {
+			v.Stop()
+		}
+	default:
+	}
+}

consensus/validator.go

@@ -402,14 +402,3 @@ func (consensus *Consensus) broadcastConsensusP2pMessages(p2pMsgs []*NetworkMess
 	}
 	return nil
 }
-
-func (consensus *Consensus) spinUpStateSync() {
-	select {
-	case consensus.BlockNumLowChan <- struct{}{}:
-		consensus.current.SetMode(Syncing)
-		for _, v := range consensus.consensusTimeout {
-			v.Stop()
-		}
-	default:
-	}
-}