fix(dot/sync): Gossip BlockAnnounceMessage only after successfully …

…imported (#2885)

Co-authored-by: Timothy Wu <timwu20@gmail.com>

dot/core/service.go

@@ -127,40 +127,63 @@ func (s *Service) StorageRoot() (common.Hash, error) {
 
 // HandleBlockImport handles a block that was imported via the network
 func (s *Service) HandleBlockImport(block *types.Block, state *rtstorage.TrieState) error {
-	return s.handleBlock(block, state)
+	err := s.handleBlock(block, state)
+	if err != nil {
+		return fmt.Errorf("handling block: %w", err)
+	}
+
+	bestBlockHash := s.blockState.BestBlockHash()
+	isBestBlock := bestBlockHash.Equal(block.Header.Hash())
+
+	blockAnnounce, err := createBlockAnnounce(block, isBestBlock)
+	if err != nil {
+		return fmt.Errorf("creating block announce: %w", err)
+	}
+
+	s.net.GossipMessage(blockAnnounce)
+	return nil
 }
 
 // HandleBlockProduced handles a block that was produced by us
 // It is handled the same as an imported block in terms of state updates; the only difference
 // is we send a BlockAnnounceMessage to our peers.
 func (s *Service) HandleBlockProduced(block *types.Block, state *rtstorage.TrieState) error {
-	if err := s.handleBlock(block, state); err != nil {
-		return err
+	err := s.handleBlock(block, state)
+	if err != nil {
+		return fmt.Errorf("handling block: %w", err)
 	}
 
+	blockAnnounce, err := createBlockAnnounce(block, true)
+	if err != nil {
+		return fmt.Errorf("creating block announce: %w", err)
+	}
+
+	s.net.GossipMessage(blockAnnounce)
+	return nil
+}
+
+func createBlockAnnounce(block *types.Block, isBestBlock bool) (
+	blockAnnounce *network.BlockAnnounceMessage, err error) {
 	digest := types.NewDigest()
 	for i := range block.Header.Digest.Types {
 		digestValue, err := block.Header.Digest.Types[i].Value()
 		if err != nil {
-			return fmt.Errorf("getting value of digest type at index %d: %w", i, err)
+			return nil, fmt.Errorf("getting value of digest type at index %d: %w", i, err)
 		}
 		err = digest.Add(digestValue)
 		if err != nil {
-			return err
+			return nil, fmt.Errorf("adding digest value for type at index %d: %w", i, err)
 		}
 	}
 
-	msg := &network.BlockAnnounceMessage{
+	return &network.BlockAnnounceMessage{
 		ParentHash:     block.Header.ParentHash,
 		Number:         block.Header.Number,
 		StateRoot:      block.Header.StateRoot,
 		ExtrinsicsRoot: block.Header.ExtrinsicsRoot,
 		Digest:         digest,
-		BestBlock:      true,
-	}
-
-	s.net.GossipMessage(msg)
-	return nil
+		BestBlock:      isBestBlock,
+	}, nil
 }
 
 func (s *Service) handleBlock(block *types.Block, state *rtstorage.TrieState) error {

dot/core/service_test.go

@@ -480,9 +480,9 @@ func Test_Service_HandleBlockProduced(t *testing.T) {
 	t.Parallel()
 	execTest := func(t *testing.T, s *Service, block *types.Block, trieState *rtstorage.TrieState, expErr error) {
 		err := s.HandleBlockProduced(block, trieState)
-		assert.ErrorIs(t, err, expErr)
+		require.ErrorIs(t, err, expErr)
 		if expErr != nil {
-			assert.EqualError(t, err, expErr.Error())
+			assert.EqualError(t, err, "handling block: "+expErr.Error())
 		}
 	}
 	t.Run("nil input", func(t *testing.T) {

dot/network/block_announce.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/ChainSafe/gossamer/dot/peerset"
 	"github.com/ChainSafe/gossamer/dot/types"
+	"github.com/ChainSafe/gossamer/lib/blocktree"
 	"github.com/ChainSafe/gossamer/lib/common"
 	"github.com/ChainSafe/gossamer/pkg/scale"
 
@@ -208,9 +209,10 @@ func (s *Service) handleBlockAnnounceMessage(from peer.ID, msg NotificationsMess
 		return false, errors.New("invalid message")
 	}
 
-	if err = s.syncer.HandleBlockAnnounce(from, bam); err != nil {
-		return false, err
+	err = s.syncer.HandleBlockAnnounce(from, bam)
+	if errors.Is(err, blocktree.ErrBlockExists) {
+		return true, nil
 	}
 
-	return true, nil
+	return false, err
 }

dot/network/block_announce_test.go

@@ -7,8 +7,10 @@ import (
 	"testing"
 
 	"github.com/ChainSafe/gossamer/dot/types"
+	"github.com/ChainSafe/gossamer/lib/blocktree"
 	"github.com/ChainSafe/gossamer/lib/common"
 	"github.com/ChainSafe/gossamer/pkg/scale"
+	gomock "github.com/golang/mock/gomock"
 
 	"github.com/libp2p/go-libp2p-core/peer"
 	"github.com/stretchr/testify/require"
@@ -126,24 +128,56 @@ func TestDecodeBlockAnnounceHandshake(t *testing.T) {
 func TestHandleBlockAnnounceMessage(t *testing.T) {
 	t.Parallel()
 
-	config := &Config{
-		BasePath:    t.TempDir(),
-		Port:        availablePort(t),
-		NoBootstrap: true,
-		NoMDNS:      true,
+	testCases := map[string]struct {
+		propagate  bool
+		mockSyncer func(*testing.T, peer.ID, *BlockAnnounceMessage) Syncer
+	}{
+		"block already exists": {
+			mockSyncer: func(t *testing.T, peer peer.ID, blockAnnounceMessage *BlockAnnounceMessage) Syncer {
+				ctrl := gomock.NewController(t)
+				syncer := NewMockSyncer(ctrl)
+				syncer.EXPECT().
+					HandleBlockAnnounce(peer, blockAnnounceMessage).
+					Return(blocktree.ErrBlockExists)
+				return syncer
+			},
+			propagate: true,
+		},
+		"block does not exists": {
+			propagate: false,
+		},
 	}
 
-	s := createTestService(t, config)
+	for tname, tt := range testCases {
+		tt := tt
 
-	peerID := peer.ID("noot")
-	msg := &BlockAnnounceMessage{
-		Number: 10,
-		Digest: types.NewDigest(),
-	}
+		t.Run(tname, func(t *testing.T) {
+			t.Parallel()
 
-	propagate, err := s.handleBlockAnnounceMessage(peerID, msg)
-	require.NoError(t, err)
-	require.True(t, propagate)
+			config := &Config{
+				BasePath:    t.TempDir(),
+				Port:        availablePort(t),
+				NoBootstrap: true,
+				NoMDNS:      true,
+			}
+
+			peerID := peer.ID("noot")
+			msg := &BlockAnnounceMessage{
+				Number: 10,
+				Digest: types.NewDigest(),
+			}
+
+			if tt.mockSyncer != nil {
+				config.Syncer = tt.mockSyncer(t, peerID, msg)
+			}
+
+			service := createTestService(t, config)
+			gotPropagate, err := service.handleBlockAnnounceMessage(peerID, msg)
+
+			require.NoError(t, err)
+			require.Equal(t, tt.propagate, gotPropagate)
+		})
+	}
 }
 
 func TestValidateBlockAnnounceHandshake(t *testing.T) {

dot/sync/chain_sync.go

@@ -21,6 +21,7 @@ import (
 	"github.com/ChainSafe/gossamer/dot/network"
 	"github.com/ChainSafe/gossamer/dot/peerset"
 	"github.com/ChainSafe/gossamer/dot/types"
+	"github.com/ChainSafe/gossamer/lib/blocktree"
 	"github.com/ChainSafe/gossamer/lib/common"
 	"github.com/ChainSafe/gossamer/lib/common/variadic"
 )
@@ -251,7 +252,7 @@ func (cs *chainSync) setBlockAnnounce(from peer.ID, header *types.Header) error
 	}
 
 	if has {
-		return nil
+		return blocktree.ErrBlockExists
 	}
 
 	if err = cs.pendingBlocks.addHeader(header); err != nil {
@@ -627,19 +628,19 @@ func (cs *chainSync) tryDispatchWorker(w *worker) {
 // if it fails due to any reason, it sets the worker `err` and returns
 // this function always places the worker into the `resultCh` for result handling upon return
 func (cs *chainSync) dispatchWorker(w *worker) {
+	if w.targetNumber == nil || w.startNumber == nil {
+		return
+	}
+
 	logger.Debugf("dispatching sync worker id %d, "+
 		"start number %d, target number %d, "+
 		"start hash %s, target hash %s, "+
 		"request data %d, direction %s",
 		w.id,
-		w.startNumber, w.targetNumber,
+		*w.startNumber, *w.targetNumber,
 		w.startHash, w.targetHash,
 		w.requestData, w.direction)
 
-	if w.targetNumber == nil || w.startNumber == nil {
-		return
-	}
-
 	start := time.Now()
 	defer func() {
 		end := time.Now()

dot/sync/chain_sync_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/ChainSafe/gossamer/dot/network"
 	"github.com/ChainSafe/gossamer/dot/peerset"
 	"github.com/ChainSafe/gossamer/dot/types"
+	"github.com/ChainSafe/gossamer/lib/blocktree"
 	"github.com/ChainSafe/gossamer/lib/common"
 	"github.com/ChainSafe/gossamer/lib/common/variadic"
 	"github.com/ChainSafe/gossamer/lib/trie"
@@ -1247,20 +1248,23 @@ func Test_chainSync_start(t *testing.T) {
 }
 
 func Test_chainSync_setBlockAnnounce(t *testing.T) {
+	t.Parallel()
+
 	type args struct {
 		from   peer.ID
 		header *types.Header
 	}
 	tests := map[string]struct {
-		chainSyncBuilder func(ctrl *gomock.Controller) chainSync
+		chainSyncBuilder func(*types.Header, *gomock.Controller) chainSync
 		args             args
 		wantErr          error
 	}{
 		"base case": {
+			wantErr: blocktree.ErrBlockExists,
 			args: args{
 				header: &types.Header{Number: 2},
 			},
-			chainSyncBuilder: func(ctrl *gomock.Controller) chainSync {
+			chainSyncBuilder: func(_ *types.Header, ctrl *gomock.Controller) chainSync {
 				mockBlockState := NewMockBlockState(ctrl)
 				mockBlockState.EXPECT().HasHeader(common.MustHexToHash(
 					"0x05bdcc454f60a08d427d05e7f19f240fdc391f570ab76fcb96ecca0b5823d3bf")).Return(true, nil)
@@ -1271,13 +1275,79 @@ func Test_chainSync_setBlockAnnounce(t *testing.T) {
 				}
 			},
 		},
+		"err_when_calling_has_header": {
+			wantErr: errors.New("checking header exists"),
+			args: args{
+				header: &types.Header{Number: 2},
+			},
+			chainSyncBuilder: func(_ *types.Header, ctrl *gomock.Controller) chainSync {
+				mockBlockState := NewMockBlockState(ctrl)
+				mockBlockState.EXPECT().
+					HasHeader(common.MustHexToHash(
+						"0x05bdcc454f60a08d427d05e7f19f240fdc391f570ab76fcb96ecca0b5823d3bf")).
+					Return(false, errors.New("checking header exists"))
+				mockDisjointBlockSet := NewMockDisjointBlockSet(ctrl)
+				return chainSync{
+					blockState:    mockBlockState,
+					pendingBlocks: mockDisjointBlockSet,
+				}
+			},
+		},
+		"adding_block_header_to_pending_blocks": {
+			args: args{
+				header: &types.Header{Number: 2},
+			},
+			chainSyncBuilder: func(expectedHeader *types.Header, ctrl *gomock.Controller) chainSync {
+				argumentHeaderHash := common.MustHexToHash(
+					"0x05bdcc454f60a08d427d05e7f19f240fdc391f570ab76fcb96ecca0b5823d3bf")
+
+				mockBlockState := NewMockBlockState(ctrl)
+				mockBlockState.EXPECT().
+					HasHeader(argumentHeaderHash).
+					Return(false, nil)
+
+				mockBlockState.EXPECT().
+					BestBlockHeader().
+					Return(&types.Header{Number: 1}, nil)
+
+				mockDisjointBlockSet := NewMockDisjointBlockSet(ctrl)
+				mockDisjointBlockSet.EXPECT().
+					addHeader(expectedHeader).
+					Return(nil)
+
+				mockDisjointBlockSet.EXPECT().
+					addHashAndNumber(argumentHeaderHash, uint(2)).
+					Return(nil)
+
+				return chainSync{
+					blockState:    mockBlockState,
+					pendingBlocks: mockDisjointBlockSet,
+					peerState:     make(map[peer.ID]*peerState),
+					// creating an buffered channel for this specific test
+					// since it will put a work on the queue and an unbufered channel
+					// will hang until we read on this channel and the goal is to
+					// put the work on the channel and don't block
+					workQueue: make(chan *peerState, 1),
+				}
+			},
+		},
 	}
 	for name, tt := range tests {
+		tt := tt
 		t.Run(name, func(t *testing.T) {
+			t.Parallel()
 			ctrl := gomock.NewController(t)
-			sync := tt.chainSyncBuilder(ctrl)
+			sync := tt.chainSyncBuilder(tt.args.header, ctrl)
 			err := sync.setBlockAnnounce(tt.args.from, tt.args.header)
-			assert.ErrorIs(t, err, tt.wantErr)
+			if tt.wantErr != nil {
+				assert.EqualError(t, err, tt.wantErr.Error())
+			} else {
+				assert.NoError(t, err)
+			}
+
+			if sync.workQueue != nil {
+				assert.Equal(t, len(sync.workQueue), 1)
+			}
 		})
 	}
 }