Remove list from AcceptedFrontier message (#1578)

message/inbound_msg_builder.go

@@ -135,18 +135,16 @@ func InboundGetAcceptedFrontier(
 func InboundAcceptedFrontier(
 	chainID ids.ID,
 	requestID uint32,
-	containerIDs []ids.ID,
+	containerID ids.ID,
 	nodeID ids.NodeID,
 ) InboundMessage {
-	containerIDBytes := make([][]byte, len(containerIDs))
-	encodeIDs(containerIDs, containerIDBytes)
 	return &inboundMessage{
 		nodeID: nodeID,
 		op:     AcceptedFrontierOp,
 		message: &p2p.AcceptedFrontier{
-			ChainId:      chainID[:],
-			RequestId:    requestID,
-			ContainerIds: containerIDBytes,
+			ChainId:     chainID[:],
+			RequestId:   requestID,
+			ContainerId: containerID[:],
 		},
 		expiration: mockable.MaxTime,
 	}

message/inbound_msg_builder_test.go

@@ -185,7 +185,7 @@ func TestInboundMsgBuilder(t *testing.T) {
 			msg := InboundAcceptedFrontier(
 				chainID,
 				requestID,
-				containerIDs,
+				containerIDs[0],
 				nodeID,
 			)
 
@@ -196,12 +196,7 @@ func TestInboundMsgBuilder(t *testing.T) {
 			innerMsg := msg.Message().(*p2p.AcceptedFrontier)
 			require.Equal(chainID[:], innerMsg.ChainId)
 			require.Equal(requestID, innerMsg.RequestId)
-			containerIDsBytes := make([][]byte, len(containerIDs))
-			for i, id := range containerIDs {
-				id := id
-				containerIDsBytes[i] = id[:]
-			}
-			require.Equal(containerIDsBytes, innerMsg.ContainerIds)
+			require.Equal(containerIDs[0][:], innerMsg.ContainerId)
 		},
 	)
 

message/messages_test.go

@@ -415,9 +415,9 @@ func TestMessage(t *testing.T) {
 			msg: &p2p.Message{
 				Message: &p2p.Message_AcceptedFrontier_{
 					AcceptedFrontier_: &p2p.AcceptedFrontier{
-						ChainId:      testID[:],
-						RequestId:    1,
-						ContainerIds: [][]byte{testID[:], testID[:]},
+						ChainId:     testID[:],
+						RequestId:   1,
+						ContainerId: testID[:],
 					},
 				},
 			},

message/outbound_msg_builder.go

@@ -82,7 +82,7 @@ type OutboundMsgBuilder interface {
 	AcceptedFrontier(
 		chainID ids.ID,
 		requestID uint32,
-		containerIDs []ids.ID,
+		containerID ids.ID,
 	) (OutboundMessage, error)
 
 	GetAccepted(
@@ -400,17 +400,15 @@ func (b *outMsgBuilder) GetAcceptedFrontier(
 func (b *outMsgBuilder) AcceptedFrontier(
 	chainID ids.ID,
 	requestID uint32,
-	containerIDs []ids.ID,
+	containerID ids.ID,
 ) (OutboundMessage, error) {
-	containerIDBytes := make([][]byte, len(containerIDs))
-	encodeIDs(containerIDs, containerIDBytes)
 	return b.builder.createOutbound(
 		&p2p.Message{
 			Message: &p2p.Message_AcceptedFrontier_{
 				AcceptedFrontier_: &p2p.AcceptedFrontier{
-					ChainId:      chainID[:],
-					RequestId:    requestID,
-					ContainerIds: containerIDBytes,
+					ChainId:     chainID[:],
+					RequestId:   requestID,
+					ContainerId: containerID[:],
 				},
 			},
 		},

proto/p2p/p2p.proto

@@ -206,7 +206,7 @@ message AcceptedFrontier {
 
   bytes chain_id = 1;
   uint32 request_id = 2;
-  repeated bytes container_ids = 3;
+  bytes container_id = 3;
 }
 
 // Message to request for the accepted blocks/vertices of the "remote" peer.

snow/engine/avalanche/getter/getter.go

@@ -74,7 +74,11 @@ func (gh *getter) GetAcceptedStateSummary(_ context.Context, nodeID ids.NodeID,
 
 func (gh *getter) GetAcceptedFrontier(ctx context.Context, validatorID ids.NodeID, requestID uint32) error {
 	acceptedFrontier := gh.storage.Edge(ctx)
-	gh.sender.SendAcceptedFrontier(ctx, validatorID, requestID, acceptedFrontier)
+	// Since all the DAGs are linearized, we only need to return the stop
+	// vertex.
+	if len(acceptedFrontier) > 0 {
+		gh.sender.SendAcceptedFrontier(ctx, validatorID, requestID, acceptedFrontier[0])
+	}
 	return nil
 }
 

snow/engine/avalanche/getter/getter_test.go

@@ -68,47 +68,25 @@ func TestAcceptedFrontier(t *testing.T) {
 
 	manager, sender, config := testSetup(t)
 
-	vtxID0 := ids.GenerateTestID()
-	vtxID1 := ids.GenerateTestID()
-	vtxID2 := ids.GenerateTestID()
+	vtxID := ids.GenerateTestID()
 
 	bsIntf, err := New(manager, config)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(err)
 	require.IsType(&getter{}, bsIntf)
 	bs := bsIntf.(*getter)
 
 	manager.EdgeF = func(context.Context) []ids.ID {
 		return []ids.ID{
-			vtxID0,
-			vtxID1,
+			vtxID,
 		}
 	}
 
-	var accepted []ids.ID
-	sender.SendAcceptedFrontierF = func(_ context.Context, _ ids.NodeID, _ uint32, frontier []ids.ID) {
-		accepted = frontier
-	}
-
-	if err := bs.GetAcceptedFrontier(context.Background(), ids.EmptyNodeID, 0); err != nil {
-		t.Fatal(err)
-	}
-
-	acceptedSet := set.Set[ids.ID]{}
-	acceptedSet.Add(accepted...)
-
-	manager.EdgeF = nil
-
-	if !acceptedSet.Contains(vtxID0) {
-		t.Fatalf("Vtx should be accepted")
-	}
-	if !acceptedSet.Contains(vtxID1) {
-		t.Fatalf("Vtx should be accepted")
-	}
-	if acceptedSet.Contains(vtxID2) {
-		t.Fatalf("Vtx shouldn't be accepted")
+	var accepted ids.ID
+	sender.SendAcceptedFrontierF = func(_ context.Context, _ ids.NodeID, _ uint32, containerID ids.ID) {
+		accepted = containerID
 	}
+	require.NoError(bs.GetAcceptedFrontier(context.Background(), ids.EmptyNodeID, 0))
+	require.Equal(vtxID, accepted)
 }
 
 func TestFilterAccepted(t *testing.T) {

snow/engine/common/bootstrapper.go

@@ -80,7 +80,7 @@ func NewCommonBootstrapper(config Config) Bootstrapper {
 	}
 }
 
-func (b *bootstrapper) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerIDs []ids.ID) error {
+func (b *bootstrapper) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error {
 	// ignores any late responses
 	if requestID != b.Config.SharedCfg.RequestID {
 		b.Ctx.Log.Debug("received out-of-sync AcceptedFrontier message",
@@ -98,12 +98,39 @@ func (b *bootstrapper) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID,
 		return nil
 	}
 
-	// Mark that we received a response from [nodeID]
-	b.pendingReceiveAcceptedFrontier.Remove(nodeID)
-
 	// Union the reported accepted frontier from [nodeID] with the accepted
 	// frontier we got from others
-	b.acceptedFrontierSet.Add(containerIDs...)
+	b.acceptedFrontierSet.Add(containerID)
+	return b.markAcceptedFrontierReceived(ctx, nodeID)
+}
+
+func (b *bootstrapper) GetAcceptedFrontierFailed(ctx context.Context, nodeID ids.NodeID, requestID uint32) error {
+	// ignores any late responses
+	if requestID != b.Config.SharedCfg.RequestID {
+		b.Ctx.Log.Debug("received out-of-sync GetAcceptedFrontierFailed message",
+			zap.Stringer("nodeID", nodeID),
+			zap.Uint32("expectedRequestID", b.Config.SharedCfg.RequestID),
+			zap.Uint32("requestID", requestID),
+		)
+		return nil
+	}
+
+	if !b.pendingReceiveAcceptedFrontier.Contains(nodeID) {
+		b.Ctx.Log.Debug("received unexpected GetAcceptedFrontierFailed message",
+			zap.Stringer("nodeID", nodeID),
+		)
+		return nil
+	}
+
+	// If we can't get a response from [nodeID], act as though they said their
+	// accepted frontier is empty and we add the validator to the failed list
+	b.failedAcceptedFrontier.Add(nodeID)
+	return b.markAcceptedFrontierReceived(ctx, nodeID)
+}
+
+func (b *bootstrapper) markAcceptedFrontierReceived(ctx context.Context, nodeID ids.NodeID) error {
+	// Mark that we received a response from [nodeID]
+	b.pendingReceiveAcceptedFrontier.Remove(nodeID)
 
 	b.sendGetAcceptedFrontiers(ctx)
 
@@ -150,23 +177,6 @@ func (b *bootstrapper) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID,
 	return nil
 }
 
-func (b *bootstrapper) GetAcceptedFrontierFailed(ctx context.Context, nodeID ids.NodeID, requestID uint32) error {
-	// ignores any late responses
-	if requestID != b.Config.SharedCfg.RequestID {
-		b.Ctx.Log.Debug("received out-of-sync GetAcceptedFrontierFailed message",
-			zap.Stringer("nodeID", nodeID),
-			zap.Uint32("expectedRequestID", b.Config.SharedCfg.RequestID),
-			zap.Uint32("requestID", requestID),
-		)
-		return nil
-	}
-
-	// If we can't get a response from [nodeID], act as though they said their
-	// accepted frontier is empty and we add the validator to the failed list
-	b.failedAcceptedFrontier.Add(nodeID)
-	return b.AcceptedFrontier(ctx, nodeID, requestID, nil)
-}
-
 func (b *bootstrapper) Accepted(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerIDs []ids.ID) error {
 	// ignores any late responses
 	if requestID != b.Config.SharedCfg.RequestID {

snow/engine/common/engine.go

@@ -161,13 +161,13 @@ type AcceptedFrontierHandler interface {
 	//
 	// This function can be called by any validator. It is not safe to assume
 	// this message is in response to a GetAcceptedFrontier message, is
-	// utilizing a unique requestID, or that the containerIDs from a valid
+	// utilizing a unique requestID, or that the containerID is a valid
 	// frontier.
 	AcceptedFrontier(
 		ctx context.Context,
 		validatorID ids.NodeID,
 		requestID uint32,
-		containerIDs []ids.ID,
+		containerID ids.ID,
 	) error
 
 	// Notify this engine that a get accepted frontier request it issued has

snow/engine/common/no_ops_handlers.go

@@ -93,12 +93,13 @@ func NewNoOpAcceptedFrontierHandler(log logging.Logger) AcceptedFrontierHandler
 	return &noOpAcceptedFrontierHandler{log: log}
 }
 
-func (nop *noOpAcceptedFrontierHandler) AcceptedFrontier(_ context.Context, nodeID ids.NodeID, requestID uint32, _ []ids.ID) error {
+func (nop *noOpAcceptedFrontierHandler) AcceptedFrontier(_ context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error {
 	nop.log.Debug("dropping request",
 		zap.String("reason", "unhandled by this gear"),
 		zap.Stringer("messageOp", message.AcceptedFrontierOp),
 		zap.Stringer("nodeID", nodeID),
 		zap.Uint32("requestID", requestID),
+		zap.Stringer("containerID", containerID),
 	)
 	return nil
 }

snow/engine/common/sender.go

@@ -62,7 +62,7 @@ type FrontierSender interface {
 		ctx context.Context,
 		nodeID ids.NodeID,
 		requestID uint32,
-		containerIDs []ids.ID,
+		containerID ids.ID,
 	)
 }
 

snow/engine/common/test_engine.go

@@ -105,17 +105,18 @@ type EngineTest struct {
 
 	CantGetVM bool
 
-	StartF                                     func(ctx context.Context, startReqID uint32) error
-	IsBootstrappedF                            func() bool
-	ContextF                                   func() *snow.ConsensusContext
-	HaltF                                      func(context.Context)
-	TimeoutF, GossipF, ShutdownF               func(context.Context) error
-	NotifyF                                    func(context.Context, Message) error
-	GetF, GetAncestorsF, PullQueryF            func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error
-	PutF, PushQueryF                           func(ctx context.Context, nodeID ids.NodeID, requestID uint32, container []byte) error
-	AncestorsF                                 func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containers [][]byte) error
-	AcceptedFrontierF, GetAcceptedF, AcceptedF func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID) error
-	ChitsF                                     func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) error
+	StartF                          func(ctx context.Context, startReqID uint32) error
+	IsBootstrappedF                 func() bool
+	ContextF                        func() *snow.ConsensusContext
+	HaltF                           func(context.Context)
+	TimeoutF, GossipF, ShutdownF    func(context.Context) error
+	NotifyF                         func(context.Context, Message) error
+	GetF, GetAncestorsF, PullQueryF func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error
+	PutF, PushQueryF                func(ctx context.Context, nodeID ids.NodeID, requestID uint32, container []byte) error
+	AncestorsF                      func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containers [][]byte) error
+	AcceptedFrontierF               func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error
+	GetAcceptedF, AcceptedF         func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID) error
+	ChitsF                          func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) error
 	GetStateSummaryFrontierF, GetStateSummaryFrontierFailedF, GetAcceptedStateSummaryFailedF,
 	GetAcceptedFrontierF, GetFailedF, GetAncestorsFailedF,
 	QueryFailedF, GetAcceptedFrontierFailedF, GetAcceptedFailedF func(ctx context.Context, nodeID ids.NodeID, requestID uint32) error
@@ -371,9 +372,9 @@ func (e *EngineTest) GetAcceptedFrontierFailed(ctx context.Context, nodeID ids.N
 	return errGetAcceptedFrontierFailed
 }
 
-func (e *EngineTest) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerIDs []ids.ID) error {
+func (e *EngineTest) AcceptedFrontier(ctx context.Context, nodeID ids.NodeID, requestID uint32, containerID ids.ID) error {
 	if e.AcceptedFrontierF != nil {
-		return e.AcceptedFrontierF(ctx, nodeID, requestID, containerIDs)
+		return e.AcceptedFrontierF(ctx, nodeID, requestID, containerID)
 	}
 	if !e.CantAcceptedFrontier {
 		return nil