Clean Up Block Retrieval Methods

beacon-chain/db/kv/blocks.go

@@ -16,6 +16,9 @@ import (
 	"go.opencensus.io/trace"
 )
 
+// used to represent errors for inconsistent slot ranges.
+var errInvalidSlotRange = errors.New("invalid end slot and start slot provided")
+
 // Block retrieval by root.
 func (s *Store) Block(ctx context.Context, blockRoot [32]byte) (*ethpb.SignedBeaconBlock, error) {
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.Block")
@@ -418,20 +421,18 @@ func fetchBlockRootsBySlotRange(
 	}
 	min := bytesutil.Uint64ToBytesBigEndian(startSlot)
 	max := bytesutil.Uint64ToBytesBigEndian(endSlot)
-	var conditional func(key, max []byte) bool
-	if endSlot == 0 {
-		conditional = func(key, max []byte) bool {
-			return key != nil
-		}
-	} else {
-		conditional = func(key, max []byte) bool {
-			return key != nil && bytes.Compare(key, max) <= 0
-		}
+
+	conditional := func(key, max []byte) bool {
+		return key != nil && bytes.Compare(key, max) <= 0
 	}
-	rootsRange := (endSlot - startSlot) / step
 	if endSlot < startSlot {
-		rootsRange = 0
+		return nil, errInvalidSlotRange
+	}
+	// Return nothing with an end slot of 0.
+	if endSlot == 0 {
+		return [][]byte{}, nil
 	}
+	rootsRange := (endSlot - startSlot) / step
 	roots := make([][]byte, 0, rootsRange)
 	c := bkt.Cursor()
 	for k, v := c.Seek(min); conditional(k, max); k, v = c.Next() {

beacon-chain/db/kv/blocks_test.go

@@ -101,6 +101,55 @@ func TestStore_BlocksBatchDelete(t *testing.T) {
 	}
 }
 
+func TestStore_BlocksHandleZeroCase(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	numBlocks := 10
+	totalBlocks := make([]*ethpb.SignedBeaconBlock, numBlocks)
+	blockRoots := make([][32]byte, 0)
+	for i := 0; i < len(totalBlocks); i++ {
+		b := testutil.NewBeaconBlock()
+		b.Block.Slot = uint64(i)
+		b.Block.ParentRoot = bytesutil.PadTo([]byte("parent"), 32)
+		totalBlocks[i] = b
+		r, err := totalBlocks[i].Block.HashTreeRoot()
+		require.NoError(t, err)
+		blockRoots = append(blockRoots, r)
+	}
+	require.NoError(t, db.SaveBlocks(ctx, totalBlocks))
+	zeroFilter := filters.NewFilter().SetStartSlot(0).SetEndSlot(0)
+	retrieved, _, err := db.Blocks(ctx, zeroFilter)
+	require.NoError(t, err)
+	assert.Equal(t, 0, len(retrieved), "Unexpected number of blocks received, expected none")
+}
+
+func TestStore_BlocksHandleInvalidEndSlot(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	numBlocks := 10
+	totalBlocks := make([]*ethpb.SignedBeaconBlock, numBlocks)
+	blockRoots := make([][32]byte, 0)
+	// Save blocks from slot 1 onwards.
+	for i := 0; i < len(totalBlocks); i++ {
+		b := testutil.NewBeaconBlock()
+		b.Block.Slot = uint64(i) + 1
+		b.Block.ParentRoot = bytesutil.PadTo([]byte("parent"), 32)
+		totalBlocks[i] = b
+		r, err := totalBlocks[i].Block.HashTreeRoot()
+		require.NoError(t, err)
+		blockRoots = append(blockRoots, r)
+	}
+	require.NoError(t, db.SaveBlocks(ctx, totalBlocks))
+	badFilter := filters.NewFilter().SetStartSlot(5).SetEndSlot(1)
+	_, _, err := db.Blocks(ctx, badFilter)
+	require.ErrorContains(t, errInvalidSlotRange.Error(), err)
+
+	goodFilter := filters.NewFilter().SetStartSlot(0).SetEndSlot(1)
+	requested, _, err := db.Blocks(ctx, goodFilter)
+	require.NoError(t, err)
+	assert.Equal(t, 1, len(requested), "Unexpected number of blocks received, only expected two")
+}
+
 func TestStore_GenesisBlock(t *testing.T) {
 	db := setupDB(t)
 	ctx := context.Background()
@@ -188,7 +237,7 @@ func TestStore_Blocks_FiltersCorrectly(t *testing.T) {
 			expectedNumBlocks: 2,
 		},
 		{
-			filter:            filters.NewFilter().SetStartSlot(5),
+			filter:            filters.NewFilter().SetStartSlot(5).SetEndSlot(9),
 			expectedNumBlocks: 4,
 		},
 		{

beacon-chain/state/stategen/replay.go

@@ -53,6 +53,11 @@ func (s *State) ReplayBlocks(ctx context.Context, state *stateTrie.BeaconState,
 // LoadBlocks loads the blocks between start slot and end slot by recursively fetching from end block root.
 // The Blocks are returned in slot-descending order.
 func (s *State) LoadBlocks(ctx context.Context, startSlot, endSlot uint64, endBlockRoot [32]byte) ([]*ethpb.SignedBeaconBlock, error) {
+	// Nothing to load for invalid range.
+	// TODO(#7620): Return error for invalid range.
+	if endSlot < startSlot {
+		return nil, nil
+	}
 	filter := filters.NewFilter().SetStartSlot(startSlot).SetEndSlot(endSlot)
 	blocks, blockRoots, err := s.beaconDB.Blocks(ctx, filter)
 	if err != nil {

beacon-chain/sync/rpc_beacon_blocks_by_range_test.go

@@ -82,6 +82,71 @@ func TestRPCBeaconBlocksByRange_RPCHandlerReturnsBlocks(t *testing.T) {
 	}
 }
 
+func TestRPCBeaconBlocksByRange_ReturnCorrectNumberBack(t *testing.T) {
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+	assert.Equal(t, 1, len(p1.BHost.Network().Peers()), "Expected peers to be connected")
+	d, _ := db.SetupDB(t)
+
+	req := &pb.BeaconBlocksByRangeRequest{
+		StartSlot: 0,
+		Step:      1,
+		Count:     200,
+	}
+
+	genRoot := [32]byte{}
+	// Populate the database with blocks that would match the request.
+	for i := req.StartSlot; i < req.StartSlot+(req.Step*req.Count); i += req.Step {
+		blk := testutil.NewBeaconBlock()
+		blk.Block.Slot = i
+		if i == 0 {
+			rt, err := blk.Block.HashTreeRoot()
+			require.NoError(t, err)
+			genRoot = rt
+		}
+		require.NoError(t, d.SaveBlock(context.Background(), blk))
+	}
+	require.NoError(t, d.SaveGenesisBlockRoot(context.Background(), genRoot))
+
+	// Start service with 160 as allowed blocks capacity (and almost zero capacity recovery).
+	r := &Service{p2p: p1, db: d, chain: &chainMock.ChainService{}, rateLimiter: newRateLimiter(p1)}
+	pcl := protocol.ID("/testing")
+	topic := string(pcl)
+	r.rateLimiter.limiterMap[topic] = leakybucket.NewCollector(0.000001, int64(req.Count*10), false)
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	// Use a new request to test this out
+	newReq := &pb.BeaconBlocksByRangeRequest{StartSlot: 0, Step: 1, Count: 1}
+
+	p2.BHost.SetStreamHandler(pcl, func(stream network.Stream) {
+		defer wg.Done()
+		for i := newReq.StartSlot; i < newReq.StartSlot+newReq.Count*newReq.Step; i += newReq.Step {
+			expectSuccess(t, stream)
+			res := testutil.NewBeaconBlock()
+			assert.NoError(t, r.p2p.Encoding().DecodeWithMaxLength(stream, res))
+			if (res.Block.Slot-newReq.StartSlot)%newReq.Step != 0 {
+				t.Errorf("Received unexpected block slot %d", res.Block.Slot)
+			}
+			// Expect EOF
+			b := make([]byte, 1)
+			_, err := stream.Read(b)
+			require.ErrorContains(t, io.EOF.Error(), err)
+		}
+	})
+
+	stream1, err := p1.BHost.NewStream(context.Background(), p2.BHost.ID(), pcl)
+	require.NoError(t, err)
+
+	err = r.beaconBlocksByRangeRPCHandler(context.Background(), newReq, stream1)
+	require.NoError(t, err)
+
+	if testutil.WaitTimeout(&wg, 1*time.Second) {
+		t.Fatal("Did not receive stream within 1 sec")
+	}
+}
+
 func TestRPCBeaconBlocksByRange_RPCHandlerReturnsSortedBlocks(t *testing.T) {
 	p1 := p2ptest.NewTestP2P(t)
 	p2 := p2ptest.NewTestP2P(t)