Move engine startup into helper function (#2329)

Author: StephenButtolph

snow/engine/snowman/bootstrap/bootstrapper.go

@@ -149,7 +149,42 @@ func (b *bootstrapper) Start(ctx context.Context, startReqID uint32) error {
 	b.startingHeight = lastAccepted.Height()
 	b.Config.SharedCfg.RequestID = startReqID
 
-	if !b.StartupTracker.ShouldStart() {
+	return b.tryStartBootstrapping(ctx)
+}
+
+func (b *bootstrapper) Connected(ctx context.Context, nodeID ids.NodeID, nodeVersion *version.Application) error {
+	if err := b.VM.Connected(ctx, nodeID, nodeVersion); err != nil {
+		return err
+	}
+
+	if err := b.StartupTracker.Connected(ctx, nodeID, nodeVersion); err != nil {
+		return err
+	}
+	// Ensure fetchFrom reflects proper validator list
+	if _, ok := b.Beacons.GetValidator(b.Ctx.SubnetID, nodeID); ok {
+		b.fetchFrom.Add(nodeID)
+	}
+
+	return b.tryStartBootstrapping(ctx)
+}
+
+func (b *bootstrapper) Disconnected(ctx context.Context, nodeID ids.NodeID) error {
+	if err := b.VM.Disconnected(ctx, nodeID); err != nil {
+		return err
+	}
+
+	if err := b.StartupTracker.Disconnected(ctx, nodeID); err != nil {
+		return err
+	}
+
+	b.markUnavailable(nodeID)
+	return nil
+}
+
+// tryStartBootstrapping will start bootstrapping the first time it is called
+// while the startupTracker is reporting that the protocol should start.
+func (b *bootstrapper) tryStartBootstrapping(ctx context.Context) error {
+	if b.started || !b.StartupTracker.ShouldStart() {
 		return nil
 	}
 
@@ -246,40 +281,6 @@ func (b *bootstrapper) GetAncestorsFailed(ctx context.Context, nodeID ids.NodeID
 	return b.fetch(ctx, blkID)
 }
 
-func (b *bootstrapper) Connected(ctx context.Context, nodeID ids.NodeID, nodeVersion *version.Application) error {
-	if err := b.VM.Connected(ctx, nodeID, nodeVersion); err != nil {
-		return err
-	}
-
-	if err := b.StartupTracker.Connected(ctx, nodeID, nodeVersion); err != nil {
-		return err
-	}
-	// Ensure fetchFrom reflects proper validator list
-	if _, ok := b.Beacons.GetValidator(b.Ctx.SubnetID, nodeID); ok {
-		b.fetchFrom.Add(nodeID)
-	}
-
-	if b.started || !b.StartupTracker.ShouldStart() {
-		return nil
-	}
-
-	b.started = true
-	return b.Startup(ctx)
-}
-
-func (b *bootstrapper) Disconnected(ctx context.Context, nodeID ids.NodeID) error {
-	if err := b.VM.Disconnected(ctx, nodeID); err != nil {
-		return err
-	}
-
-	if err := b.StartupTracker.Disconnected(ctx, nodeID); err != nil {
-		return err
-	}
-
-	b.markUnavailable(nodeID)
-	return nil
-}
-
 func (b *bootstrapper) Timeout(ctx context.Context) error {
 	if !b.awaitingTimeout {
 		return errUnexpectedTimeout

snow/engine/snowman/syncer/state_syncer.go

@@ -112,6 +112,53 @@ func (ss *stateSyncer) Context() *snow.ConsensusContext {
 	return ss.Ctx
 }
 
+func (ss *stateSyncer) Start(ctx context.Context, startReqID uint32) error {
+	ss.Ctx.Log.Info("starting state sync")
+
+	ss.Ctx.State.Set(snow.EngineState{
+		Type:  p2p.EngineType_ENGINE_TYPE_SNOWMAN,
+		State: snow.StateSyncing,
+	})
+	if err := ss.VM.SetState(ctx, snow.StateSyncing); err != nil {
+		return fmt.Errorf("failed to notify VM that state syncing has started: %w", err)
+	}
+
+	ss.requestID = startReqID
+
+	return ss.tryStartSyncing(ctx)
+}
+
+func (ss *stateSyncer) Connected(ctx context.Context, nodeID ids.NodeID, nodeVersion *version.Application) error {
+	if err := ss.VM.Connected(ctx, nodeID, nodeVersion); err != nil {
+		return err
+	}
+
+	if err := ss.StartupTracker.Connected(ctx, nodeID, nodeVersion); err != nil {
+		return err
+	}
+
+	return ss.tryStartSyncing(ctx)
+}
+
+func (ss *stateSyncer) Disconnected(ctx context.Context, nodeID ids.NodeID) error {
+	if err := ss.VM.Disconnected(ctx, nodeID); err != nil {
+		return err
+	}
+
+	return ss.StartupTracker.Disconnected(ctx, nodeID)
+}
+
+// tryStartSyncing will start syncing the first time it is called while the
+// startupTracker is reporting that the protocol should start.
+func (ss *stateSyncer) tryStartSyncing(ctx context.Context) error {
+	if ss.started || !ss.StartupTracker.ShouldStart() {
+		return nil
+	}
+
+	ss.started = true
+	return ss.startup(ctx)
+}
+
 func (ss *stateSyncer) StateSummaryFrontier(ctx context.Context, nodeID ids.NodeID, requestID uint32, summaryBytes []byte) error {
 	// ignores any late responses
 	if requestID != ss.requestID {
@@ -426,27 +473,6 @@ func (ss *stateSyncer) GetAcceptedStateSummaryFailed(ctx context.Context, nodeID
 	return ss.AcceptedStateSummary(ctx, nodeID, requestID, nil)
 }
 
-func (ss *stateSyncer) Start(ctx context.Context, startReqID uint32) error {
-	ss.Ctx.Log.Info("starting state sync")
-
-	ss.Ctx.State.Set(snow.EngineState{
-		Type:  p2p.EngineType_ENGINE_TYPE_SNOWMAN,
-		State: snow.StateSyncing,
-	})
-	if err := ss.VM.SetState(ctx, snow.StateSyncing); err != nil {
-		return fmt.Errorf("failed to notify VM that state syncing has started: %w", err)
-	}
-
-	ss.requestID = startReqID
-
-	if !ss.StartupTracker.ShouldStart() {
-		return nil
-	}
-
-	ss.started = true
-	return ss.startup(ctx)
-}
-
 // startup do start the whole state sync process by
 // sampling frontier seeders, listing state syncers to request votes to
 // and reaching out frontier seeders if any. Otherwise, it moves immediately
@@ -580,31 +606,6 @@ func (ss *stateSyncer) Notify(ctx context.Context, msg common.Message) error {
 	return ss.onDoneStateSyncing(ctx, ss.requestID)
 }
 
-func (ss *stateSyncer) Connected(ctx context.Context, nodeID ids.NodeID, nodeVersion *version.Application) error {
-	if err := ss.VM.Connected(ctx, nodeID, nodeVersion); err != nil {
-		return err
-	}
-
-	if err := ss.StartupTracker.Connected(ctx, nodeID, nodeVersion); err != nil {
-		return err
-	}
-
-	if ss.started || !ss.StartupTracker.ShouldStart() {
-		return nil
-	}
-
-	ss.started = true
-	return ss.startup(ctx)
-}
-
-func (ss *stateSyncer) Disconnected(ctx context.Context, nodeID ids.NodeID) error {
-	if err := ss.VM.Disconnected(ctx, nodeID); err != nil {
-		return err
-	}
-
-	return ss.StartupTracker.Disconnected(ctx, nodeID)
-}
-
 func (*stateSyncer) Gossip(context.Context) error {
 	return nil
 }