Host: notify batch subscribers of new batches from any src (#1860)

go/host/enclave/guardian.go

@@ -186,14 +186,11 @@ func (g *Guardian) HandleBlock(block *types.Block) {
 // HandleBatch is called by the L2 repository when a new batch arrives
 // Note: this should only be called for validators, sequencers produce their own batches
 func (g *Guardian) HandleBatch(batch *common.ExtBatch) {
-	if g.hostData.IsSequencer {
-		g.logger.Error("Repo received batch but we are a sequencer, ignoring")
-		return
-	}
-	g.logger.Debug("Received L2 block", log.BatchHashKey, batch.Hash(), log.BatchSeqNoKey, batch.Header.SequencerOrderNo)
+	g.logger.Debug("Host received L2 batch", log.BatchHashKey, batch.Hash(), log.BatchSeqNoKey, batch.Header.SequencerOrderNo)
 	// record the newest batch we've seen
 	g.state.OnReceivedBatch(batch.Header.SequencerOrderNo)
-	if !g.state.IsUpToDate() {
+	// Sequencer enclaves produce batches, they cannot receive them. Also, enclave will reject new batches if it is not up-to-date
+	if g.hostData.IsSequencer || !g.state.IsUpToDate() {
 		return // ignore batches until we're up-to-date
 	}
 	err := g.submitL2Batch(batch)

go/host/enclave/state.go

@@ -97,12 +97,6 @@ func (s *StateTracker) OnReceivedBlock(l1Head gethcommon.Hash) {
 func (s *StateTracker) OnProcessedBatch(enclL2HeadSeqNo *big.Int) {
 	s.m.Lock()
 	defer s.m.Unlock()
-	if s.hostL2Head == nil || s.hostL2Head.Cmp(enclL2HeadSeqNo) < 0 {
-		// we've successfully processed this batch, so the host's head should be at least as high as the enclave's (this shouldn't happen, we want it to be visible if it happens)
-		s.logger.Trace("host head behind enclave head - updating to match", "hostHead", s.hostL2Head, "enclaveHead", enclL2HeadSeqNo)
-		s.hostL2Head = enclL2HeadSeqNo
-	}
-
 	s.enclaveL2Head = enclL2HeadSeqNo
 	s.setStatus(s.calculateStatus())
 }

go/host/l2/batchrepository.go

@@ -111,12 +111,6 @@ func (r *Repository) HandleBatches(batches []*common.ExtBatch, isLive bool) {
 			// we've already seen this batch or failed to store it for another reason - do not notify subscribers
 			return
 		}
-		if isLive {
-			// notify subscribers if the batch is new
-			for _, subscriber := range r.subscribers {
-				go subscriber.HandleBatch(batch)
-			}
-		}
 	}
 }
 
@@ -175,6 +169,7 @@ func (r *Repository) FetchBatchBySeqNo(seqNo *big.Int) (*common.ExtBatch, error)
 // If the repository already has the batch it returns an AlreadyExists error which is typically ignored.
 func (r *Repository) AddBatch(batch *common.ExtBatch) error {
 	r.logger.Debug("Saving batch", log.BatchSeqNoKey, batch.Header.SequencerOrderNo, log.BatchHashKey, batch.Hash())
+	// this returns an error if the batch already exists in the db
 	err := r.db.AddBatch(batch)
 	if err != nil {
 		return err
@@ -184,6 +179,10 @@ func (r *Repository) AddBatch(batch *common.ExtBatch) error {
 	defer r.latestSeqNoMutex.Unlock()
 	if batch.Header.SequencerOrderNo.Cmp(r.latestBatchSeqNo) > 0 {
 		r.latestBatchSeqNo = batch.Header.SequencerOrderNo
+		// notify subscribers, a new batch has been successfully added to the db
+		for _, subscriber := range r.subscribers {
+			go subscriber.HandleBatch(batch)
+		}
 	}
 	return nil
 }