init

beacon-chain/blockchain/chain_info_test.go

@@ -80,9 +80,9 @@ func TestHeadRoot_Nil(t *testing.T) {
 }
 
 func TestService_ForkChoiceStore(t *testing.T) {
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New(0, 0)}}
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
 	p := c.ForkChoiceStore()
-	require.Equal(t, 0, int(p.FinalizedEpoch()))
+	require.Equal(t, types.Epoch(0), p.FinalizedCheckpoint().Epoch)
 }
 
 func TestFinalizedCheckpt_CanRetrieve(t *testing.T) {
@@ -327,7 +327,7 @@ func TestService_HeadGenesisValidatorsRoot(t *testing.T) {
 }
 func TestService_ChainHeads_ProtoArray(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New(0, 0)}}
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -357,7 +357,7 @@ func TestService_ChainHeads_ProtoArray(t *testing.T) {
 
 func TestService_ChainHeads_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New(0, 0)}}
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -452,7 +452,7 @@ func TestService_IsOptimistic_ProtoArray(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -472,7 +472,7 @@ func TestService_IsOptimistic_DoublyLinkedTree(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -495,7 +495,7 @@ func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
 
 func TestService_IsOptimisticForRoot_ProtoArray(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -510,7 +510,7 @@ func TestService_IsOptimisticForRoot_ProtoArray(t *testing.T) {
 
 func TestService_IsOptimisticForRoot_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
@@ -526,7 +526,7 @@ func TestService_IsOptimisticForRoot_DoublyLinkedTree(t *testing.T) {
 func TestService_IsOptimisticForRoot_DB_ProtoArray(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: protoarray.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
@@ -591,7 +591,7 @@ func TestService_IsOptimisticForRoot_DB_ProtoArray(t *testing.T) {
 func TestService_IsOptimisticForRoot_DB_DoublyLinkedTree(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
@@ -655,7 +655,7 @@ func TestService_IsOptimisticForRoot_DB_DoublyLinkedTree(t *testing.T) {
 func TestService_IsOptimisticForRoot_DB_non_canonical(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New(0, 0)}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10

beacon-chain/blockchain/execution_engine_test.go

@@ -11,6 +11,7 @@ import (
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
 	mockPOW "github.com/prysmaticlabs/prysm/beacon-chain/powchain/testing"
 	bstate "github.com/prysmaticlabs/prysm/beacon-chain/state"
@@ -43,7 +44,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, beaconDB.SaveBlock(ctx, altairBlk))
 	require.NoError(t, beaconDB.SaveBlock(ctx, bellatrixBlk))
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -184,7 +185,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 			st, _ := util.DeterministicGenesisState(t, 1)
 			require.NoError(t, beaconDB.SaveState(ctx, st, tt.finalizedRoot))
 			require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, tt.finalizedRoot))
-			fc := &ethpb.Checkpoint{Epoch: 1, Root: tt.finalizedRoot[:]}
+			fc := &ethpb.Checkpoint{Epoch: 0, Root: tt.finalizedRoot[:]}
 			service.store.SetFinalizedCheckptAndPayloadHash(fc, [32]byte{'a'})
 			service.store.SetJustifiedCheckptAndPayloadHash(fc, [32]byte{'b'})
 			arg := &notifyForkchoiceUpdateArg{
@@ -289,7 +290,7 @@ func Test_NotifyForkchoiceUpdateRecursive(t *testing.T) {
 	require.NoError(t, beaconDB.SaveBlock(ctx, wbg))
 
 	// Insert blocks into forkchoice
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -326,7 +327,9 @@ func Test_NotifyForkchoiceUpdateRecursive(t *testing.T) {
 	fcs.ProcessAttestation(ctx, []uint64{0}, brd, 1)
 	fcs.ProcessAttestation(ctx, []uint64{1}, brf, 1)
 	fcs.ProcessAttestation(ctx, []uint64{2}, brg, 1)
-	headRoot, err := fcs.Head(ctx, bra, []uint64{50, 100, 200})
+	jc := &forkchoicetypes.Checkpoint{Epoch: 0, Root: bra}
+	require.NoError(t, fcs.UpdateJustifiedCheckpoint(jc))
+	headRoot, err := fcs.Head(ctx, []uint64{50, 100, 200})
 	require.NoError(t, err)
 	require.Equal(t, brg, headRoot)
 
@@ -347,7 +350,7 @@ func Test_NotifyForkchoiceUpdateRecursive(t *testing.T) {
 	_, err = service.notifyForkchoiceUpdate(ctx, a)
 	require.ErrorIs(t, ErrInvalidPayload, err)
 	// Ensure Head is D
-	headRoot, err = fcs.Head(ctx, bra, service.justifiedBalances.balances)
+	headRoot, err = fcs.Head(ctx, service.justifiedBalances.balances)
 	require.NoError(t, err)
 	require.Equal(t, brd, headRoot)
 
@@ -364,7 +367,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -582,7 +585,7 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -625,7 +628,7 @@ func Test_IsOptimisticCandidateBlock(t *testing.T) {
 
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -827,7 +830,7 @@ func Test_UpdateLastValidatedCheckpoint(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	stateGen := stategen.New(beaconDB)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stateGen),
@@ -927,7 +930,7 @@ func TestService_removeInvalidBlockAndState(t *testing.T) {
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -983,7 +986,7 @@ func TestService_getPayloadHash(t *testing.T) {
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)

beacon-chain/blockchain/head.go

@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
@@ -95,16 +96,23 @@ func (s *Service) updateHead(ctx context.Context, balances []uint64) ([32]byte,
 			return [32]byte{}, err
 		}
 		if features.Get().EnableForkChoiceDoublyLinkedTree {
-			s.cfg.ForkChoiceStore = doublylinkedtree.New(j.Epoch, f.Epoch)
+			s.cfg.ForkChoiceStore = doublylinkedtree.New()
 		} else {
-			s.cfg.ForkChoiceStore = protoarray.New(j.Epoch, f.Epoch)
+			s.cfg.ForkChoiceStore = protoarray.New()
 		}
 		if err := s.insertBlockToForkChoiceStore(ctx, jb.Block(), headStartRoot, st, f, j); err != nil {
 			return [32]byte{}, err
 		}
 	}
-
-	return s.cfg.ForkChoiceStore.Head(ctx, headStartRoot, balances)
+	jc := &forkchoicetypes.Checkpoint{Epoch: j.Epoch, Root: headStartRoot}
+	fc := &forkchoicetypes.Checkpoint{Epoch: f.Epoch, Root: s.ensureRootNotZeros(bytesutil.ToBytes32(f.Root))}
+	if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(jc); err != nil {
+		return [32]byte{}, err
+	}
+	if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(fc); err != nil {
+		return [32]byte{}, err
+	}
+	return s.cfg.ForkChoiceStore.Head(ctx, balances)
 }
 
 // This saves head info to the local service cache, it also saves the

beacon-chain/blockchain/head_test.go

@@ -174,10 +174,8 @@ func TestUpdateHead_MissingJustifiedRoot(t *testing.T) {
 	service.store.SetJustifiedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: r[:]}, [32]byte{'a'})
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{}, [32]byte{'b'})
 	service.store.SetBestJustifiedCheckpt(&ethpb.Checkpoint{})
-	headRoot, err := service.updateHead(context.Background(), []uint64{})
+	_, err = service.updateHead(context.Background(), []uint64{})
 	require.NoError(t, err)
-	st, _ := util.DeterministicGenesisState(t, 1)
-	require.NoError(t, service.saveHead(context.Background(), headRoot, wsb, st))
 }
 
 func Test_notifyNewHeadEvent(t *testing.T) {
@@ -613,7 +611,7 @@ func TestUpdateHead_noSavedChanges(t *testing.T) {
 	ctx := context.Background()
 
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -630,7 +628,7 @@ func TestUpdateHead_noSavedChanges(t *testing.T) {
 	require.NoError(t, beaconDB.SaveBlock(ctx, bellatrixBlk))
 	fcp := &ethpb.Checkpoint{
 		Root:  bellatrixBlkRoot[:],
-		Epoch: 1,
+		Epoch: 0,
 	}
 	service.store.SetFinalizedCheckptAndPayloadHash(fcp, [32]byte{'a'})
 	service.store.SetJustifiedCheckptAndPayloadHash(fcp, [32]byte{'b'})

beacon-chain/blockchain/mock_test.go

@@ -13,7 +13,7 @@ import (
 
 func testServiceOptsWithDB(t *testing.T) []Option {
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	return []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),

beacon-chain/blockchain/new_slot.go

@@ -5,7 +5,9 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
@@ -68,7 +70,8 @@ func (s *Service) NewSlot(ctx context.Context, slot types.Slot) error {
 				return err
 			}
 			s.store.SetJustifiedCheckptAndPayloadHash(bj, h)
-			if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(bj); err != nil {
+			if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{
+				Epoch: bj.Epoch, Root: bytesutil.ToBytes32(bj.Root)}); err != nil {
 				return err
 			}
 		}

beacon-chain/blockchain/new_slot_test.go

@@ -20,7 +20,7 @@ import (
 
 func TestService_newSlot(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),

beacon-chain/blockchain/pow_block_test.go

@@ -109,7 +109,7 @@ func Test_validateMergeBlock(t *testing.T) {
 
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -152,7 +152,7 @@ func Test_validateMergeBlock(t *testing.T) {
 func Test_getBlkParentHashAndTD(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),

beacon-chain/blockchain/process_attestation_test.go

@@ -9,6 +9,7 @@ import (
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -28,7 +29,7 @@ func TestStore_OnAttestation_ErrorConditions_ProtoArray(t *testing.T) {
 
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
@@ -140,7 +141,7 @@ func TestStore_OnAttestation_ErrorConditions_DoublyLinkedTree(t *testing.T) {
 
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithForkChoiceStore(doublylinkedtree.New(0, 0)),
+		WithForkChoiceStore(doublylinkedtree.New()),
 		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
@@ -250,7 +251,7 @@ func TestStore_OnAttestation_Ok_ProtoArray(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -278,7 +279,7 @@ func TestStore_OnAttestation_Ok_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -487,7 +488,7 @@ func TestVerifyFinalizedConsistency_InconsistentRoot_ProtoArray(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -522,7 +523,7 @@ func TestVerifyFinalizedConsistency_InconsistentRoot_DoublyLinkedTree(t *testing
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -610,7 +611,9 @@ func TestVerifyFinalizedConsistency_IsCanonical(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 
-	_, err = service.cfg.ForkChoiceStore.Head(ctx, r32, []uint64{})
+	jc := &forkchoicetypes.Checkpoint{Epoch: 0, Root: r32}
+	require.NoError(t, service.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(jc))
+	_, err = service.cfg.ForkChoiceStore.Head(ctx, []uint64{})
 	require.NoError(t, err)
 	err = service.VerifyFinalizedConsistency(context.Background(), r33[:])
 	require.NoError(t, err)

beacon-chain/blockchain/process_block.go

@@ -222,10 +222,12 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 		}
 		s.store.SetJustifiedCheckptAndPayloadHash(postState.CurrentJustifiedCheckpoint(), h)
 		// Update Forkchoice checkpoints
-		if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(psj); err != nil {
+		if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{
+			Epoch: psj.Epoch, Root: bytesutil.ToBytes32(psj.Root)}); err != nil {
 			return err
 		}
-		if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(psf); err != nil {
+		if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{
+			Epoch: psf.Epoch, Root: bytesutil.ToBytes32(psf.Root)}); err != nil {
 			return err
 		}
 	}
@@ -441,8 +443,8 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 			}
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
-			JustifiedEpoch: jCheckpoints[i].Epoch,
-			FinalizedEpoch: fCheckpoints[i].Epoch}
+			JustifiedCheckpoint: jCheckpoints[i],
+			FinalizedCheckpoint: fCheckpoints[i]}
 		pendingNodes[len(blks)-i-1] = args
 		s.saveInitSyncBlock(blockRoots[i], b)
 		if err = s.handleBlockAfterBatchVerify(ctx, b, blockRoots[i], fCheckpoints[i], jCheckpoints[i]); err != nil {
@@ -461,7 +463,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 	}
 	// Prune forkchoice store only if the new finalized checkpoint is higher
 	// than the finalized checkpoint in forkchoice store.
-	if fCheckpoints[len(blks)-1].Epoch > s.cfg.ForkChoiceStore.FinalizedEpoch() {
+	if fCheckpoints[len(blks)-1].Epoch > s.cfg.ForkChoiceStore.FinalizedCheckpoint().Epoch {
 		if err := s.cfg.ForkChoiceStore.Prune(ctx, s.ensureRootNotZeros(bytesutil.ToBytes32(fCheckpoints[len(blks)-1].Root))); err != nil {
 			return errors.Wrap(err, "could not prune fork choice nodes")
 		}
@@ -543,7 +545,8 @@ func (s *Service) handleBlockAfterBatchVerify(ctx context.Context, signed interf
 			return err
 		}
 		s.store.SetFinalizedCheckptAndPayloadHash(fCheckpoint, h)
-		if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(fCheckpoint); err != nil {
+		if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{
+			Epoch: fCheckpoint.Epoch, Root: bytesutil.ToBytes32(fCheckpoint.Root)}); err != nil {
 			return err
 		}
 	}

beacon-chain/blockchain/process_block_helpers.go

@@ -218,7 +218,8 @@ func (s *Service) updateJustified(ctx context.Context, state state.ReadOnlyBeaco
 		}
 		s.store.SetJustifiedCheckptAndPayloadHash(cpt, h)
 		// Update forkchoice's justified checkpoint
-		if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(cpt); err != nil {
+		if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{
+			Epoch: cpt.Epoch, Root: bytesutil.ToBytes32(cpt.Root)}); err != nil {
 			return err
 		}
 	}
@@ -244,7 +245,8 @@ func (s *Service) updateJustifiedInitSync(ctx context.Context, cp *ethpb.Checkpo
 		return err
 	}
 	s.store.SetJustifiedCheckptAndPayloadHash(cp, h)
-	return s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(cp)
+	return s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{
+		Epoch: cp.Epoch, Root: bytesutil.ToBytes32(cp.Root)})
 }
 
 func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) error {
@@ -360,7 +362,7 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 		return err
 	}
 	pendingNodes = append(pendingNodes, &forkchoicetypes.BlockAndCheckpoints{Block: blk,
-		JustifiedEpoch: jCheckpoint.Epoch, FinalizedEpoch: fCheckpoint.Epoch})
+		JustifiedCheckpoint: jCheckpoint, FinalizedCheckpoint: fCheckpoint})
 	// As long as parent node is not in fork choice store, and parent node is in DB.
 	root := bytesutil.ToBytes32(blk.ParentRoot())
 	for !s.cfg.ForkChoiceStore.HasNode(root) && s.cfg.BeaconDB.HasBlock(ctx, root) {
@@ -373,8 +375,8 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 		}
 		root = bytesutil.ToBytes32(b.Block().ParentRoot())
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
-			JustifiedEpoch: jCheckpoint.Epoch,
-			FinalizedEpoch: fCheckpoint.Epoch}
+			JustifiedCheckpoint: jCheckpoint,
+			FinalizedCheckpoint: fCheckpoint}
 		pendingNodes = append(pendingNodes, args)
 	}
 	if len(pendingNodes) == 1 {

beacon-chain/blockchain/process_block_test.go

@@ -47,7 +47,7 @@ func TestStore_OnBlock_ProtoArray(t *testing.T) {
 	ctx := context.Background()
 
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -150,7 +150,7 @@ func TestStore_OnBlock_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -253,7 +253,7 @@ func TestStore_OnBlock_ProposerBoostEarly(t *testing.T) {
 	ctx := context.Background()
 
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New(0, 0)
+	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
@@ -268,7 +268,7 @@ func TestStore_OnBlock_ProposerBoostEarly(t *testing.T) {
 		SecondsIntoSlot: 0,
 	}
 	require.NoError(t, service.cfg.ForkChoiceStore.BoostProposerRoot(ctx, args))
-	_, err = service.cfg.ForkChoiceStore.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{})
+	_, err = service.cfg.ForkChoiceStore.Head(ctx, []uint64{})
 	require.ErrorContains(t, "could not apply proposer boost score: invalid proposer boost root", err)
 }
 
@@ -293,7 +293,7 @@ func TestStore_OnBlockBatch_ProtoArray(t *testing.T) {
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'a'})
 	service.store.SetJustifiedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'b'})
 
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -340,7 +340,7 @@ func TestStore_OnBlockBatch_ProtoArray(t *testing.T) {
 	require.NoError(t, err)
 	jroot := bytesutil.ToBytes32(jcp.Root)
 	require.Equal(t, blkRoots[63], jroot)
-	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedEpoch())
+	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedCheckpoint().Epoch)
 }
 
 func TestStore_OnBlockBatch_PruneOK(t *testing.T) {
@@ -362,7 +362,7 @@ func TestStore_OnBlockBatch_PruneOK(t *testing.T) {
 	gRoot, err := genesis.Block.HashTreeRoot()
 	require.NoError(t, err)
 
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -427,7 +427,7 @@ func TestStore_OnBlockBatch_DoublyLinkedTree(t *testing.T) {
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'a'})
 	service.store.SetJustifiedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'b'})
 
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -474,7 +474,7 @@ func TestStore_OnBlockBatch_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)
 	jroot := bytesutil.ToBytes32(jcp.Root)
 	require.Equal(t, blkRoots[63], jroot)
-	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedEpoch())
+	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedCheckpoint().Epoch)
 }
 
 func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
@@ -496,7 +496,7 @@ func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'a'})
 	service.store.SetJustifiedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{'b'})
 
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 	service.saveInitSyncBlock(gRoot, wsb)
 	st, keys := util.DeterministicGenesisState(t, 64)
 	bState := st.Copy()
@@ -577,7 +577,7 @@ func TestShouldUpdateJustified_ReturnFalse_ProtoArray(t *testing.T) {
 	opts := testServiceOptsWithDB(t)
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 	lastJustifiedBlk := util.NewBeaconBlock()
 	lastJustifiedBlk.Block.ParentRoot = bytesutil.PadTo([]byte{'G'}, 32)
 	lastJustifiedRoot, err := lastJustifiedBlk.Block.HashTreeRoot()
@@ -610,7 +610,7 @@ func TestShouldUpdateJustified_ReturnFalse_DoublyLinkedTree(t *testing.T) {
 	opts := testServiceOptsWithDB(t)
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 	lastJustifiedBlk := util.NewBeaconBlock()
 	lastJustifiedBlk.Block.ParentRoot = bytesutil.PadTo([]byte{'G'}, 32)
 	lastJustifiedRoot, err := lastJustifiedBlk.Block.HashTreeRoot()
@@ -657,7 +657,7 @@ func TestCachedPreState_CanGetFromStateSummary_ProtoArray(t *testing.T) {
 	gRoot, err := genesis.Block.HashTreeRoot()
 	require.NoError(t, err)
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{})
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -694,7 +694,7 @@ func TestCachedPreState_CanGetFromStateSummary_DoublyLinkedTree(t *testing.T) {
 	gRoot, err := genesis.Block.HashTreeRoot()
 	require.NoError(t, err)
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{})
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -728,7 +728,7 @@ func TestCachedPreState_CanGetFromDB(t *testing.T) {
 	gRoot, err := genesis.Block.HashTreeRoot()
 	require.NoError(t, err)
 	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: gRoot[:]}, [32]byte{})
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 	wsb, err = wrapper.WrappedSignedBeaconBlock(genesis)
 	require.NoError(t, err)
 	service.saveInitSyncBlock(gRoot, wsb)
@@ -759,7 +759,7 @@ func TestUpdateJustified_CouldUpdateBest(t *testing.T) {
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -805,7 +805,7 @@ func TestFillForkChoiceMissingBlocks_CanSave_ProtoArray(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -851,7 +851,7 @@ func TestFillForkChoiceMissingBlocks_CanSave_DoublyLinkedTree(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -898,7 +898,7 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_ProtoArray(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -947,7 +947,7 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_DoublyLinkedTree(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -996,7 +996,7 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_ProtoArray(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+	service.cfg.ForkChoiceStore = protoarray.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -1063,7 +1063,7 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_DoublyLinkedTree(t *testing
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -1131,7 +1131,7 @@ func TestFillForkChoiceMissingBlocks_FinalizedSibling_DoublyLinkedTree(t *testin
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New()
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -1272,7 +1272,7 @@ func TestAncestor_HandleSkipSlot(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -1363,7 +1363,7 @@ func TestAncestor_CanUseDB(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -1425,7 +1425,7 @@ func TestVerifyBlkDescendant(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -1570,7 +1570,7 @@ func TestHandleEpochBoundary_UpdateFirstSlot(t *testing.T) {
 func TestOnBlock_CanFinalize(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)
 	opts := []Option{
@@ -1626,7 +1626,7 @@ func TestOnBlock_CanFinalize(t *testing.T) {
 func TestOnBlock_NilBlock(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)
 	opts := []Option{
@@ -1645,7 +1645,7 @@ func TestOnBlock_NilBlock(t *testing.T) {
 func TestOnBlock_InvalidSignature(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)
 	opts := []Option{
@@ -1686,7 +1686,7 @@ func TestOnBlock_CallNewPayloadAndForkchoiceUpdated(t *testing.T) {
 
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)
 	opts := []Option{
@@ -1924,7 +1924,7 @@ func Test_validateMergeTransitionBlock(t *testing.T) {
 
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -2052,7 +2052,7 @@ func Test_validateMergeTransitionBlock(t *testing.T) {
 func TestService_insertSlashingsToForkChoiceStore(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),
@@ -2103,7 +2103,7 @@ func TestService_insertSlashingsToForkChoiceStore(t *testing.T) {
 func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)
 	opts := []Option{
@@ -2175,7 +2175,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 		require.NoError(t, service.cfg.BeaconDB.DeleteBlock(ctx, r2))
 		require.NoError(t, service.cfg.BeaconDB.DeleteBlock(ctx, r3))
 		require.NoError(t, service.cfg.BeaconDB.DeleteBlock(ctx, r4))
-		service.cfg.ForkChoiceStore = protoarray.New(0, 0)
+		service.cfg.ForkChoiceStore = protoarray.New()
 	}
 }
 
@@ -2183,7 +2183,7 @@ func Test_verifyBlkFinalizedSlot_invalidBlock(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 
-	fcs := protoarray.New(0, 0)
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stategen.New(beaconDB)),

beacon-chain/blockchain/receive_block_test.go

@@ -127,7 +127,7 @@ func TestService_ReceiveBlock(t *testing.T) {
 
 			opts := []Option{
 				WithDatabase(beaconDB),
-				WithForkChoiceStore(protoarray.New(0, 0)),
+				WithForkChoiceStore(protoarray.New()),
 				WithAttestationPool(attestations.NewPool()),
 				WithExitPool(voluntaryexits.NewPool()),
 				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
@@ -168,7 +168,7 @@ func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 	require.NoError(t, beaconDB.SaveState(ctx, genesis, genesisBlockRoot))
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 		WithAttestationPool(attestations.NewPool()),
 		WithExitPool(voluntaryexits.NewPool()),
 		WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
@@ -248,7 +248,7 @@ func TestService_ReceiveBlockBatch(t *testing.T) {
 			beaconDB := testDB.SetupDB(t)
 			opts := []Option{
 				WithDatabase(beaconDB),
-				WithForkChoiceStore(protoarray.New(0, 0)),
+				WithForkChoiceStore(protoarray.New()),
 				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
 				WithStateGen(stategen.New(beaconDB)),
 			}

beacon-chain/blockchain/service.go

@@ -23,6 +23,7 @@ import (
 	f "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings"
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits"
@@ -208,11 +209,20 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	var forkChoicer f.ForkChoicer
 	fRoot := s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root))
 	if features.Get().EnableForkChoiceDoublyLinkedTree {
-		forkChoicer = doublylinkedtree.New(justified.Epoch, finalized.Epoch)
+		forkChoicer = doublylinkedtree.New()
 	} else {
-		forkChoicer = protoarray.New(justified.Epoch, finalized.Epoch)
+		forkChoicer = protoarray.New()
 	}
 	s.cfg.ForkChoiceStore = forkChoicer
+	if err := forkChoicer.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: justified.Epoch,
+		Root: bytesutil.ToBytes32(justified.Root)}); err != nil {
+		return errors.Wrap(err, "could not update forkchoice's justified checkpoint")
+	}
+	if err := forkChoicer.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: finalized.Epoch,
+		Root: bytesutil.ToBytes32(finalized.Root)}); err != nil {
+		return errors.Wrap(err, "could not update forkchoice's finalized checkpoint")
+	}
+
 	st, err := s.cfg.StateGen.StateByRoot(s.ctx, fRoot)
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized checkpoint state")

beacon-chain/blockchain/service_test.go

@@ -130,7 +130,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithAttestationPool(attestations.NewPool()),
 		WithP2PBroadcaster(&mockBroadcaster{}),
 		WithStateNotifier(&mockBeaconNode{}),
-		WithForkChoiceStore(protoarray.New(0, 0)),
+		WithForkChoiceStore(protoarray.New()),
 		WithAttestationService(attService),
 		WithStateGen(stateGen),
 	}
@@ -505,7 +505,7 @@ func TestHasBlock_ForkChoiceAndDB_ProtoArray(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	s := &Service{
-		cfg:   &config{ForkChoiceStore: protoarray.New(0, 0), BeaconDB: beaconDB},
+		cfg:   &config{ForkChoiceStore: protoarray.New(), BeaconDB: beaconDB},
 		store: &store.Store{},
 	}
 	s.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 0, Root: params.BeaconConfig().ZeroHash[:]}, [32]byte{})
@@ -526,7 +526,7 @@ func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	s := &Service{
-		cfg:   &config{ForkChoiceStore: doublylinkedtree.New(0, 0), BeaconDB: beaconDB},
+		cfg:   &config{ForkChoiceStore: doublylinkedtree.New(), BeaconDB: beaconDB},
 		store: &store.Store{},
 	}
 	s.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 0, Root: params.BeaconConfig().ZeroHash[:]}, [32]byte{})
@@ -599,7 +599,7 @@ func BenchmarkHasBlockForkChoiceStore_ProtoArray(b *testing.B) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(b)
 	s := &Service{
-		cfg:   &config{ForkChoiceStore: protoarray.New(0, 0), BeaconDB: beaconDB},
+		cfg:   &config{ForkChoiceStore: protoarray.New(), BeaconDB: beaconDB},
 		store: &store.Store{},
 	}
 	s.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 0, Root: params.BeaconConfig().ZeroHash[:]}, [32]byte{})
@@ -622,7 +622,7 @@ func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(b)
 	s := &Service{
-		cfg:   &config{ForkChoiceStore: doublylinkedtree.New(0, 0), BeaconDB: beaconDB},
+		cfg:   &config{ForkChoiceStore: doublylinkedtree.New(), BeaconDB: beaconDB},
 		store: &store.Store{},
 	}
 	s.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 0, Root: params.BeaconConfig().ZeroHash[:]}, [32]byte{})

beacon-chain/forkchoice/doubly-linked-tree/BUILD.bazel

@@ -21,6 +21,8 @@ go_library(
     ],
     deps = [
         "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/epoch/precompute:go_default_library",
+        "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/state:go_default_library",

beacon-chain/forkchoice/doubly-linked-tree/ffg_update_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/testing/assert"
@@ -16,7 +17,7 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -46,7 +47,7 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2
 	//            |
 	//            3 <- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head for with justified epoch at 0")
 
@@ -58,8 +59,8 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2 <- head
 	//            |
 	//            3
-	f.store.justifiedEpoch = 1
-	r, err = f.Head(context.Background(), indexToHash(2), balances)
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Root: indexToHash(2), Epoch: 1}
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head with justified epoch at 1")
 
@@ -71,8 +72,8 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2 <- start
 	//            |
 	//            3 <- head
-	f.store.justifiedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(3), balances)
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Root: indexToHash(3), Epoch: 2}
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head with justified epoch at 2")
 }
@@ -82,7 +83,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	f := setup(0, 0)
 	ctx := context.Background()
 
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -143,7 +144,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	//         9  10 <-- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head with justified epoch at 0")
 
@@ -173,7 +174,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	// head -> 9  10
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head with justified epoch at 0")
 
@@ -203,19 +204,21 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	//         9  10 <-- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head with justified epoch at 0")
 
-	f.store.justifiedEpoch = 1
-	r, err = f.Head(context.Background(), indexToHash(1), balances)
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 1, Root: indexToHash(1)}
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(7), r, "Incorrect head with justified epoch at 0")
 }
 
 func setup(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
 	ctx := context.Background()
-	f := New(justifiedEpoch, finalizedEpoch)
+	f := New()
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: justifiedEpoch, Root: params.BeaconConfig().ZeroHash}
+	f.store.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: finalizedEpoch, Root: params.BeaconConfig().ZeroHash}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 0, params.BeaconConfig().ZeroHash, [32]byte{}, params.BeaconConfig().ZeroHash, justifiedEpoch, finalizedEpoch)
 	if err != nil {
 		return nil

beacon-chain/forkchoice/doubly-linked-tree/forkchoice.go

@@ -3,9 +3,12 @@ package doublylinkedtree
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
@@ -13,22 +16,22 @@ import (
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
-	pbrpc "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/runtime/version"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
 
 // New initializes a new fork choice store.
-func New(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
+func New() *ForkChoice {
 	s := &Store{
-		justifiedEpoch:    justifiedEpoch,
-		finalizedEpoch:    finalizedEpoch,
-		proposerBoostRoot: [32]byte{},
-		nodeByRoot:        make(map[[fieldparams.RootLength]byte]*Node),
-		nodeByPayload:     make(map[[fieldparams.RootLength]byte]*Node),
-		slashedIndices:    make(map[types.ValidatorIndex]bool),
-		pruneThreshold:    defaultPruneThreshold,
+		justifiedCheckpoint: &forkchoicetypes.Checkpoint{},
+		finalizedCheckpoint: &forkchoicetypes.Checkpoint{},
+		proposerBoostRoot:   [32]byte{},
+		nodeByRoot:          make(map[[fieldparams.RootLength]byte]*Node),
+		nodeByPayload:       make(map[[fieldparams.RootLength]byte]*Node),
+		slashedIndices:      make(map[types.ValidatorIndex]bool),
+		pruneThreshold:      defaultPruneThreshold,
 	}
 
 	b := make([]uint64, 0)
@@ -47,7 +50,6 @@ func (f *ForkChoice) NodeCount() int {
 // It firsts computes validator's balance changes then recalculates block tree from leaves to root.
 func (f *ForkChoice) Head(
 	ctx context.Context,
-	justifiedRoot [32]byte,
 	justifiedStateBalances []uint64,
 ) ([32]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "doublyLinkedForkchoice.Head")
@@ -73,10 +75,12 @@ func (f *ForkChoice) Head(
 		return [32]byte{}, errors.Wrap(err, "could not apply weight changes")
 	}
 
-	if err := f.store.treeRootNode.updateBestDescendant(ctx, f.store.justifiedEpoch, f.store.finalizedEpoch); err != nil {
+	jc := f.JustifiedCheckpoint()
+	fc := f.FinalizedCheckpoint()
+	if err := f.store.treeRootNode.updateBestDescendant(ctx, jc.Epoch, fc.Epoch); err != nil {
 		return [32]byte{}, errors.Wrap(err, "could not update best descendant")
 	}
-	return f.store.head(ctx, justifiedRoot)
+	return f.store.head(ctx)
 }
 
 // ProcessAttestation processes attestation for vote accounting, it iterates around validator indices
@@ -108,7 +112,7 @@ func (f *ForkChoice) ProcessAttestation(ctx context.Context, validatorIndices []
 }
 
 // InsertNode processes a new block by inserting it to the fork choice store.
-func (f *ForkChoice) InsertNode(ctx context.Context, state state.ReadOnlyBeaconState, root [32]byte) error {
+func (f *ForkChoice) InsertNode(ctx context.Context, state state.BeaconState, root [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "doublyLinkedForkchoice.InsertNode")
 	defer span.End()
 
@@ -138,6 +142,32 @@ func (f *ForkChoice) InsertNode(ctx context.Context, state state.ReadOnlyBeaconS
 		return errInvalidNilCheckpoint
 	}
 	finalizedEpoch := fc.Epoch
+	go func() {
+		// compute unrealized checkpoints at N+2
+		start := time.Now()
+
+		stCopy := state.Copy()
+		copyTime := time.Since(start)
+		nextStart := stCopy.Slot() + params.BeaconConfig().SlotsPerEpoch
+		nextStart = nextStart - nextStart%params.BeaconConfig().SlotsPerEpoch
+
+		stCopy, err := transition.ProcessSlots(ctx, stCopy, nextStart)
+		_ = err
+		transitionTime := time.Since(start)
+		ujc, ufc, err := precompute.UnrealizedCheckpoints(stCopy)
+		_ = err
+		elapsed := time.Since(start)
+		log.WithFields(logrus.Fields{
+			"copyTime":                copyTime,
+			"epochTransTime":          transitionTime - copyTime,
+			"unrealizedJustTime":      elapsed - transitionTime,
+			"totalElapsed":            elapsed,
+			"CurrentJustification":    jc.Epoch,
+			"UnrealizedJustification": ujc.Epoch,
+			"UnrealizedFinalization":  ufc.Epoch,
+		}).Info("Pulled block to N+2")
+	}()
+
 	return f.store.insert(ctx, slot, root, parentRoot, payloadHash, justifiedEpoch, finalizedEpoch)
 }
 
@@ -326,20 +356,24 @@ func (f *ForkChoice) SetOptimisticToValid(ctx context.Context, root [fieldparams
 	return node.setNodeAndParentValidated(ctx)
 }
 
-// JustifiedEpoch of fork choice store.
-func (f *ForkChoice) JustifiedEpoch() types.Epoch {
-	return f.store.justifiedEpoch
+// JustifiedCheckpoint of fork choice store.
+func (f *ForkChoice) JustifiedCheckpoint() *forkchoicetypes.Checkpoint {
+	f.store.checkpointsLock.RLock()
+	defer f.store.checkpointsLock.RUnlock()
+	return f.store.justifiedCheckpoint
 }
 
-// FinalizedEpoch of fork choice store.
-func (f *ForkChoice) FinalizedEpoch() types.Epoch {
-	return f.store.finalizedEpoch
+// FinalizedCheckpoint of fork choice store.
+func (f *ForkChoice) FinalizedCheckpoint() *forkchoicetypes.Checkpoint {
+	f.store.checkpointsLock.RLock()
+	defer f.store.checkpointsLock.RUnlock()
+	return f.store.finalizedCheckpoint
 }
 
-func (f *ForkChoice) ForkChoiceNodes() []*pbrpc.ForkChoiceNode {
+func (f *ForkChoice) ForkChoiceNodes() []*ethpb.ForkChoiceNode {
 	f.store.nodesLock.RLock()
 	defer f.store.nodesLock.RUnlock()
-	ret := make([]*pbrpc.ForkChoiceNode, len(f.store.nodeByRoot))
+	ret := make([]*ethpb.ForkChoiceNode, len(f.store.nodeByRoot))
 	return f.store.treeRootNode.rpcNodes(ret)
 }
 
@@ -384,25 +418,25 @@ func (f *ForkChoice) InsertSlashedIndex(_ context.Context, index types.Validator
 	}
 }
 
-// UpdateJustifiedCheckpoint sets the justified epoch to the given one
-func (f *ForkChoice) UpdateJustifiedCheckpoint(jc *pbrpc.Checkpoint) error {
+// UpdateJustifiedCheckpoint sets the justified checkpoint to the given one
+func (f *ForkChoice) UpdateJustifiedCheckpoint(jc *forkchoicetypes.Checkpoint) error {
 	if jc == nil {
 		return errInvalidNilCheckpoint
 	}
-	f.store.nodesLock.Lock()
-	defer f.store.nodesLock.Unlock()
-	f.store.justifiedEpoch = jc.Epoch
+	f.store.checkpointsLock.Lock()
+	defer f.store.checkpointsLock.Unlock()
+	f.store.justifiedCheckpoint = jc
 	return nil
 }
 
-// UpdateFinalizedCheckpoint sets the finalized epoch to the given one
-func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *pbrpc.Checkpoint) error {
+// UpdateFinalizedCheckpoint sets the finalized checkpoint to the given one
+func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *forkchoicetypes.Checkpoint) error {
 	if fc == nil {
 		return errInvalidNilCheckpoint
 	}
-	f.store.nodesLock.Lock()
-	defer f.store.nodesLock.Unlock()
-	f.store.finalizedEpoch = fc.Epoch
+	f.store.checkpointsLock.Lock()
+	defer f.store.checkpointsLock.Unlock()
+	f.store.finalizedCheckpoint = fc
 	return nil
 }
 
@@ -473,7 +507,7 @@ func (f *ForkChoice) InsertOptimisticChain(ctx context.Context, chain []*forkcho
 		}
 		if err := f.store.insert(ctx,
 			b.Slot(), r, parentRoot, payloadHash,
-			chain[i].JustifiedEpoch, chain[i].FinalizedEpoch); err != nil {
+			chain[i].JustifiedCheckpoint.Epoch, chain[i].FinalizedCheckpoint.Epoch); err != nil {
 			return err
 		}
 	}

beacon-chain/forkchoice/doubly-linked-tree/forkchoice_test.go

@@ -211,7 +211,9 @@ func TestForkChoice_IsCanonicalReorg(t *testing.T) {
 	require.DeepEqual(t, [32]byte{'3'}, f.store.treeRootNode.bestDescendant.root)
 	f.store.nodesLock.Unlock()
 
-	h, err := f.store.head(ctx, [32]byte{'1'})
+	r1 := [32]byte{'1'}
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 1, Root: r1}
+	h, err := f.store.head(ctx)
 	require.NoError(t, err)
 	require.DeepEqual(t, [32]byte{'3'}, h)
 	require.DeepEqual(t, h, f.store.headNode.root)
@@ -296,7 +298,7 @@ func TestForkChoice_RemoveEquivocating(t *testing.T) {
 	state, blkRoot, err := prepareForkchoiceState(ctx, 1, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	head, err := f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{})
+	head, err := f.Head(ctx, []uint64{})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'a'}, head)
 
@@ -307,21 +309,21 @@ func TestForkChoice_RemoveEquivocating(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(ctx, 3, [32]byte{'c'}, [32]byte{'a'}, [32]byte{'C'}, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{})
+	head, err = f.Head(ctx, []uint64{})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, head)
 
 	// Insert two attestations for block b, one for c it becomes head
 	f.ProcessAttestation(ctx, []uint64{1, 2}, [32]byte{'b'}, 1)
 	f.ProcessAttestation(ctx, []uint64{3}, [32]byte{'c'}, 1)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'b'}, head)
 
 	// Process b's slashing, c is now head
 	f.InsertSlashedIndex(ctx, 1)
 	require.Equal(t, uint64(200), f.store.nodeByRoot[[32]byte{'b'}].balance)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.Equal(t, uint64(200), f.store.nodeByRoot[[32]byte{'b'}].weight)
 	require.Equal(t, uint64(300), f.store.nodeByRoot[[32]byte{'c'}].weight)
 	require.NoError(t, err)
@@ -330,7 +332,7 @@ func TestForkChoice_RemoveEquivocating(t *testing.T) {
 	// Process b's slashing again, should be a noop
 	f.InsertSlashedIndex(ctx, 1)
 	require.Equal(t, uint64(200), f.store.nodeByRoot[[32]byte{'b'}].balance)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.Equal(t, uint64(200), f.store.nodeByRoot[[32]byte{'b'}].weight)
 	require.Equal(t, uint64(300), f.store.nodeByRoot[[32]byte{'c'}].weight)
 	require.NoError(t, err)
@@ -352,12 +354,14 @@ func TestStore_UpdateCheckpoints(t *testing.T) {
 	f := setup(1, 1)
 	jr := [32]byte{'j'}
 	fr := [32]byte{'f'}
-	jc := &ethpb.Checkpoint{Root: jr[:], Epoch: 3}
-	fc := &ethpb.Checkpoint{Root: fr[:], Epoch: 2}
+	jc := &forkchoicetypes.Checkpoint{Root: jr, Epoch: 3}
+	fc := &forkchoicetypes.Checkpoint{Root: fr, Epoch: 2}
 	require.NoError(t, f.UpdateJustifiedCheckpoint(jc))
 	require.NoError(t, f.UpdateFinalizedCheckpoint(fc))
-	require.Equal(t, f.store.justifiedEpoch, jc.Epoch)
-	require.Equal(t, f.store.finalizedEpoch, fc.Epoch)
+	require.Equal(t, f.store.justifiedCheckpoint.Epoch, jc.Epoch)
+	require.Equal(t, f.store.justifiedCheckpoint.Root, jc.Root)
+	require.Equal(t, f.store.finalizedCheckpoint.Epoch, fc.Epoch)
+	require.Equal(t, f.store.finalizedCheckpoint.Root, fc.Root)
 }
 
 func TestStore_CommonAncestor(t *testing.T) {
@@ -562,8 +566,10 @@ func TestStore_InsertOptimisticChain(t *testing.T) {
 	require.NoError(t, err)
 	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
-	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
-		FinalizedEpoch: 1})
+	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(),
+		JustifiedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+		FinalizedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+	})
 	for i := uint64(2); i < 11; i++ {
 		blk := util.NewBeaconBlock()
 		blk.Block.Slot = types.Slot(i)
@@ -571,8 +577,10 @@ func TestStore_InsertOptimisticChain(t *testing.T) {
 		blk.Block.ParentRoot = copiedRoot[:]
 		wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 		require.NoError(t, err)
-		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
-			FinalizedEpoch: 1})
+		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(),
+			JustifiedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+			FinalizedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+		})
 		root, err = blk.Block.HashTreeRoot()
 		require.NoError(t, err)
 	}

beacon-chain/forkchoice/doubly-linked-tree/no_vote_test.go

@@ -15,7 +15,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	if r != params.BeaconConfig().ZeroHash {
 		t.Errorf("Incorrect head with genesis")
@@ -28,7 +28,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err := prepareForkchoiceState(context.Background(), 0, indexToHash(2), params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -39,7 +39,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(1), params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -52,7 +52,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(3), indexToHash(1), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -65,7 +65,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(4), indexToHash(2), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -80,7 +80,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(5), indexToHash(4), params.BeaconConfig().ZeroHash, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -92,7 +92,8 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	//  head -> 4  3
 	//          |
 	//          5 <- starting from 5 with justified epoch 0 should error
-	_, err = f.Head(context.Background(), indexToHash(5), balances)
+	f.store.justifiedCheckpoint.Root = indexToHash(5)
+	_, err = f.Head(context.Background(), balances)
 	wanted := "head at slot 0 with weight 0 is not eligible, finalizedEpoch 1 != 1, justifiedEpoch 2 != 1"
 	require.ErrorContains(t, wanted, err)
 
@@ -104,8 +105,8 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	//          4  3
 	//          |
 	//          5 <- head
-	f.store.justifiedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	f.store.justifiedCheckpoint.Epoch = 2
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(5), r, "Incorrect head for with justified epoch at 2")
 
@@ -122,7 +123,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(6), indexToHash(5), params.BeaconConfig().ZeroHash, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(6), r, "Incorrect head for with justified epoch at 2")
 }

beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go

@@ -35,7 +35,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		headRoot, err := f.Head(ctx, zeroHash, balances)
+		headRoot, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, headRoot, "Incorrect head with genesis")
 
@@ -58,7 +58,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{0}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 1")
 
@@ -82,7 +82,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{1}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 2")
 
@@ -108,7 +108,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{2}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
 
@@ -144,7 +144,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		}
 
 		require.NoError(t, f.BoostProposerRoot(ctx, args))
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
 
@@ -186,7 +186,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// Regression: process attestations for C, check that it
 		// becomes head, we need two attestations to have C.weight = 30 > 24 = D.weight
 		f.ProcessAttestation(ctx, []uint64{4, 5}, indexToHash(3), fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, indexToHash(3), headRoot, "Incorrect head for justified epoch at slot 4")
 
@@ -195,7 +195,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -220,7 +220,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -239,7 +239,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure the head is C, the honest block.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -260,7 +260,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f.ProcessAttestation(ctx, votes, honestBlock, fEpoch)
 
 		// Ensure the head is STILL C, the honest block, as the honest block had proposer boost.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 	})
@@ -268,7 +268,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -295,7 +295,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -314,7 +314,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is still the head after the malicious proposer reveals their block.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -333,7 +333,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
 
 		// Expect the head to have switched to B.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, maliciouslyWithheldBlock, r, "Expected B to become the head")
 	})
@@ -355,7 +355,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		a := zeroHash
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -374,7 +374,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Incorrect head for justified epoch at slot 2")
 
@@ -402,7 +402,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is still the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Incorrect head for justified epoch at slot 2")
 
@@ -426,7 +426,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// D cannot win without a boost.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Expected C to remain the head")
 
@@ -442,7 +442,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.BoostProposerRoot(ctx, args))
 
 		// Ensure D becomes the head thanks to boosting.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, d, r, "Expected D to become the head")
 	})

beacon-chain/forkchoice/doubly-linked-tree/store.go

@@ -60,12 +60,12 @@ func (s *Store) PruneThreshold() uint64 {
 
 // head starts from justified root and then follows the best descendant links
 // to find the best block for head. This function assumes a lock on s.nodesLock
-func (s *Store) head(ctx context.Context, justifiedRoot [32]byte) ([32]byte, error) {
+func (s *Store) head(ctx context.Context) ([32]byte, error) {
 	_, span := trace.StartSpan(ctx, "doublyLinkedForkchoice.head")
 	defer span.End()
 
 	// JustifiedRoot has to be known
-	justifiedNode, ok := s.nodeByRoot[justifiedRoot]
+	justifiedNode, ok := s.nodeByRoot[s.justifiedCheckpoint.Root]
 	if !ok || justifiedNode == nil {
 		return [32]byte{}, errUnknownJustifiedRoot
 	}
@@ -77,9 +77,9 @@ func (s *Store) head(ctx context.Context, justifiedRoot [32]byte) ([32]byte, err
 		bestDescendant = justifiedNode
 	}
 
-	if !bestDescendant.viableForHead(s.justifiedEpoch, s.finalizedEpoch) {
+	if !bestDescendant.viableForHead(s.justifiedCheckpoint.Epoch, s.finalizedCheckpoint.Epoch) {
 		return [32]byte{}, fmt.Errorf("head at slot %d with weight %d is not eligible, finalizedEpoch %d != %d, justifiedEpoch %d != %d",
-			bestDescendant.slot, bestDescendant.weight/10e9, bestDescendant.finalizedEpoch, s.finalizedEpoch, bestDescendant.justifiedEpoch, s.justifiedEpoch)
+			bestDescendant.slot, bestDescendant.weight/10e9, bestDescendant.finalizedEpoch, s.finalizedCheckpoint.Epoch, bestDescendant.justifiedEpoch, s.justifiedCheckpoint.Epoch)
 	}
 
 	// Update metrics.
@@ -134,7 +134,8 @@ func (s *Store) insert(ctx context.Context,
 		}
 	} else {
 		parent.children = append(parent.children, n)
-		if err := s.treeRootNode.updateBestDescendant(ctx, s.justifiedEpoch, s.finalizedEpoch); err != nil {
+		if err := s.treeRootNode.updateBestDescendant(ctx,
+			s.justifiedCheckpoint.Epoch, s.finalizedCheckpoint.Epoch); err != nil {
 			return err
 		}
 	}

beacon-chain/forkchoice/doubly-linked-tree/store_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/testing/assert"
@@ -22,13 +23,13 @@ func TestStore_PruneThreshold(t *testing.T) {
 func TestStore_JustifiedEpoch(t *testing.T) {
 	j := types.Epoch(100)
 	f := setup(j, j)
-	require.Equal(t, j, f.JustifiedEpoch())
+	require.Equal(t, j, f.JustifiedCheckpoint().Epoch)
 }
 
 func TestStore_FinalizedEpoch(t *testing.T) {
 	j := types.Epoch(50)
 	f := setup(j, j)
-	require.Equal(t, j, f.FinalizedEpoch())
+	require.Equal(t, j, f.FinalizedCheckpoint().Epoch)
 }
 
 func TestStore_NodeCount(t *testing.T) {
@@ -78,7 +79,8 @@ func TestForkChoice_HasNode(t *testing.T) {
 func TestStore_Head_UnknownJustifiedRoot(t *testing.T) {
 	f := setup(0, 0)
 
-	_, err := f.store.head(context.Background(), [32]byte{'a'})
+	f.store.justifiedCheckpoint.Root = [32]byte{'a'}
+	_, err := f.store.head(context.Background())
 	assert.ErrorContains(t, errUnknownJustifiedRoot.Error(), err)
 }
 
@@ -90,7 +92,8 @@ func TestStore_Head_Itself(t *testing.T) {
 
 	// Since the justified node does not have a best descendant so the best node
 	// is itself.
-	h, err := f.store.head(context.Background(), indexToHash(1))
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: indexToHash(1)}
+	h, err := f.store.head(context.Background())
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(1), h)
 }
@@ -110,7 +113,8 @@ func TestStore_Head_BestDescendant(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 4, indexToHash(4), indexToHash(2), params.BeaconConfig().ZeroHash, 0, 0)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	h, err := f.store.head(context.Background(), indexToHash(1))
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: indexToHash(1)}
+	h, err := f.store.head(context.Background())
 	require.NoError(t, err)
 	require.Equal(t, h, indexToHash(4))
 }
@@ -133,7 +137,9 @@ func TestStore_Insert(t *testing.T) {
 	treeRootNode := &Node{slot: 0, root: indexToHash(0)}
 	nodeByRoot := map[[32]byte]*Node{indexToHash(0): treeRootNode}
 	nodeByPayload := map[[32]byte]*Node{indexToHash(0): treeRootNode}
-	s := &Store{nodeByRoot: nodeByRoot, treeRootNode: treeRootNode, nodeByPayload: nodeByPayload}
+	jc := &forkchoicetypes.Checkpoint{Epoch: 0}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 0}
+	s := &Store{nodeByRoot: nodeByRoot, treeRootNode: treeRootNode, nodeByPayload: nodeByPayload, justifiedCheckpoint: jc, finalizedCheckpoint: fc}
 	payloadHash := [32]byte{'a'}
 	require.NoError(t, s.insert(context.Background(), 100, indexToHash(100), indexToHash(0), payloadHash, 1, 1))
 	assert.Equal(t, 2, len(s.nodeByRoot), "Did not insert block")

beacon-chain/forkchoice/doubly-linked-tree/types.go

@@ -3,6 +3,7 @@ package doublylinkedtree
 import (
 	"sync"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 )
@@ -17,8 +18,8 @@ type ForkChoice struct {
 
 // Store defines the fork choice store which includes block nodes and the last view of checkpoint information.
 type Store struct {
-	justifiedEpoch             types.Epoch                            // latest justified epoch in store.
-	finalizedEpoch             types.Epoch                            // latest finalized epoch in store.
+	justifiedCheckpoint        *forkchoicetypes.Checkpoint            // latest justified epoch in store.
+	finalizedCheckpoint        *forkchoicetypes.Checkpoint            // latest finalized epoch in store.
 	pruneThreshold             uint64                                 // do not prune tree unless threshold is reached.
 	proposerBoostRoot          [fieldparams.RootLength]byte           // latest block root that was boosted after being received in a timely manner.
 	previousProposerBoostRoot  [fieldparams.RootLength]byte           // previous block root that was boosted after being received in a timely manner.
@@ -30,6 +31,7 @@ type Store struct {
 	slashedIndices             map[types.ValidatorIndex]bool          // the list of equivocating validator indices
 	nodesLock                  sync.RWMutex
 	proposerBoostLock          sync.RWMutex
+	checkpointsLock            sync.RWMutex
 }
 
 // Node defines the individual block which includes its block parent, ancestor and how much weight accounted for it.

beacon-chain/forkchoice/doubly-linked-tree/unrealized_justification.go

@@ -44,11 +44,11 @@ func (f *ForkChoice) UpdateUnrealizedCheckpoints() {
 	for _, node := range f.store.nodeByRoot {
 		node.justifiedEpoch = node.unrealizedJustifiedEpoch
 		node.finalizedEpoch = node.unrealizedFinalizedEpoch
-		if node.justifiedEpoch > f.store.justifiedEpoch {
-			f.store.justifiedEpoch = node.justifiedEpoch
+		if node.justifiedEpoch > f.store.justifiedCheckpoint.Epoch {
+			f.store.justifiedCheckpoint.Epoch = node.justifiedEpoch
 		}
-		if node.finalizedEpoch > f.store.finalizedEpoch {
-			f.store.finalizedEpoch = node.finalizedEpoch
+		if node.finalizedEpoch > f.store.finalizedCheckpoint.Epoch {
+			f.store.finalizedCheckpoint.Epoch = node.finalizedEpoch
 		}
 	}
 }

beacon-chain/forkchoice/doubly-linked-tree/unrealized_justification_test.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/require"
 )
 
@@ -80,17 +80,17 @@ func TestStore_LongFork(t *testing.T) {
 
 	// Add an attestation to c, it is head
 	f.ProcessAttestation(ctx, []uint64{0}, [32]byte{'c'}, 1)
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, headRoot)
 
 	// D is head even though its weight is lower.
-	hr := [32]byte{'d'}
-	state, blkRoot, err = prepareForkchoiceState(ctx, 103, hr, [32]byte{'b'}, [32]byte{'D'}, 2, 1)
+	ha := [32]byte{'a'}
+	state, blkRoot, err = prepareForkchoiceState(ctx, 103, [32]byte{'d'}, [32]byte{'b'}, [32]byte{'D'}, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	require.NoError(t, f.UpdateJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: 2, Root: hr[:]}))
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	require.NoError(t, f.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: 2, Root: ha}))
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'d'}, headRoot)
 	require.Equal(t, uint64(0), f.store.nodeByRoot[[32]byte{'d'}].weight)
@@ -98,7 +98,7 @@ func TestStore_LongFork(t *testing.T) {
 
 	// Update unrealized justification, c becomes head
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, headRoot)
 }
@@ -157,30 +157,31 @@ func TestStore_NoDeadLock(t *testing.T) {
 
 	// Epoch 3
 	// Current Head is H
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(0), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(0), f.JustifiedCheckpoint().Epoch)
 
 	// Insert Block I, it becomes Head
 	hr := [32]byte{'i'}
 	state, blkRoot, err = prepareForkchoiceState(ctx, 108, hr, [32]byte{'f'}, [32]byte{'I'}, 1, 0)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	require.NoError(t, f.UpdateJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: 1, Root: hr[:]}))
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	ha := [32]byte{'a'}
+	require.NoError(t, f.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: 1, Root: ha}))
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'i'}, headRoot)
-	require.Equal(t, types.Epoch(1), f.JustifiedEpoch())
-	require.Equal(t, types.Epoch(0), f.FinalizedEpoch())
+	require.Equal(t, types.Epoch(1), f.JustifiedCheckpoint().Epoch)
+	require.Equal(t, types.Epoch(0), f.FinalizedCheckpoint().Epoch)
 
 	// Realized Justified checkpoints, H becomes head
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(2), f.JustifiedEpoch())
-	require.Equal(t, types.Epoch(1), f.FinalizedEpoch())
+	require.Equal(t, types.Epoch(2), f.JustifiedCheckpoint().Epoch)
+	require.Equal(t, types.Epoch(1), f.FinalizedCheckpoint().Epoch)
 }
 
 //    Epoch  1       |         Epoch 2
@@ -225,10 +226,10 @@ func TestStore_ForkNextEpoch(t *testing.T) {
 
 	// Insert an attestation to H, H is head
 	f.ProcessAttestation(ctx, []uint64{0}, [32]byte{'h'}, 1)
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(0), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(0), f.JustifiedCheckpoint().Epoch)
 
 	// D arrives late, D is head
 	state, blkRoot, err = prepareForkchoiceState(ctx, 103, [32]byte{'d'}, [32]byte{'c'}, [32]byte{'D'}, 0, 0)
@@ -236,10 +237,10 @@ func TestStore_ForkNextEpoch(t *testing.T) {
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 	require.NoError(t, f.store.setUnrealizedJustifiedEpoch([32]byte{'d'}, 1))
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'d'}, headRoot)
-	require.Equal(t, types.Epoch(1), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(1), f.JustifiedCheckpoint().Epoch)
 	require.Equal(t, uint64(0), f.store.nodeByRoot[[32]byte{'d'}].weight)
 	require.Equal(t, uint64(100), f.store.nodeByRoot[[32]byte{'h'}].weight)
 }

beacon-chain/forkchoice/doubly-linked-tree/vote_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
@@ -15,7 +16,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -27,7 +28,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -39,7 +40,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -48,7 +49,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//           / \
 	//          2  1 <- +vote, new head
 	f.ProcessAttestation(context.Background(), []uint64{0}, indexToHash(1), 2)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(1), r, "Incorrect head for with justified epoch at 1")
 
@@ -57,7 +58,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//                    / \
 	// vote, new head -> 2  1
 	f.ProcessAttestation(context.Background(), []uint64{1}, indexToHash(2), 2)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -71,7 +72,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -82,7 +83,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//             |
 	//             3 <- new vote
 	f.ProcessAttestation(context.Background(), []uint64{0}, indexToHash(3), 3)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -93,7 +94,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//                |
 	//                3 <- head
 	f.ProcessAttestation(context.Background(), []uint64{1}, indexToHash(1), 3)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head for with justified epoch at 1")
 
@@ -109,7 +110,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -127,7 +128,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -188,7 +189,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(6), r, "Incorrect head for with justified epoch at 1")
 
@@ -209,9 +210,9 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//           8
 	//           |
 	//           9 <- head
-	f.store.justifiedEpoch = 2
-	f.store.finalizedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Root: indexToHash(5), Epoch: 2}
+	f.store.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Root: indexToHash(5), Epoch: 2}
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -237,7 +238,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -246,28 +247,28 @@ func TestVotes_CanFindHead(t *testing.T) {
 	// The new validators voted for 10.
 	f.ProcessAttestation(context.Background(), []uint64{2, 3, 4}, indexToHash(10), 5)
 	// The new head should be 10.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head for with justified epoch at 2")
 
 	// Set the balances of the last 2 validators to 0.
 	balances = []uint64{1, 1, 1, 0, 0}
 	// The head should be back to 9.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 1")
 
 	// Set the balances back to normal.
 	balances = []uint64{1, 1, 1, 1, 1}
 	// The head should be back to 10.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head for with justified epoch at 2")
 
 	// Remove the last 2 validators.
 	balances = []uint64{1, 1, 1}
 	// The head should be back to 9.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 1")
 
@@ -276,7 +277,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, f.store.prune(context.Background(), indexToHash(5)))
 	assert.Equal(t, 11, len(f.store.nodeByRoot), "Incorrect nodes length after prune")
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -300,7 +301,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, f.store.prune(context.Background(), indexToHash(5)))
 	assert.Equal(t, 5, len(f.store.nodeByRoot), "Incorrect nodes length after prune")
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -318,7 +319,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(11), r, "Incorrect head for with justified epoch at 2")
 }

beacon-chain/forkchoice/interfaces.go

@@ -23,14 +23,14 @@ type ForkChoicer interface {
 
 // HeadRetriever retrieves head root and optimistic info of the current chain.
 type HeadRetriever interface {
-	Head(context.Context, [32]byte, []uint64) ([32]byte, error)
+	Head(context.Context, []uint64) ([32]byte, error)
 	Tips() ([][32]byte, []types.Slot)
 	IsOptimistic(root [32]byte) (bool, error)
 }
 
 // BlockProcessor processes the block that's used for accounting fork choice.
 type BlockProcessor interface {
-	InsertNode(context.Context, state.ReadOnlyBeaconState, [32]byte) error
+	InsertNode(context.Context, state.BeaconState, [32]byte) error
 	InsertOptimisticChain(context.Context, []*forkchoicetypes.BlockAndCheckpoints) error
 }
 
@@ -59,8 +59,8 @@ type Getter interface {
 	AncestorRoot(ctx context.Context, root [32]byte, slot types.Slot) ([]byte, error)
 	CommonAncestorRoot(ctx context.Context, root1 [32]byte, root2 [32]byte) ([32]byte, error)
 	IsCanonical(root [32]byte) bool
-	FinalizedEpoch() types.Epoch
-	JustifiedEpoch() types.Epoch
+	FinalizedCheckpoint() *forkchoicetypes.Checkpoint
+	JustifiedCheckpoint() *forkchoicetypes.Checkpoint
 	ForkChoiceNodes() []*ethpb.ForkChoiceNode
 	NodeCount() int
 }
@@ -69,6 +69,6 @@ type Getter interface {
 type Setter interface {
 	SetOptimisticToValid(context.Context, [fieldparams.RootLength]byte) error
 	SetOptimisticToInvalid(context.Context, [fieldparams.RootLength]byte, [fieldparams.RootLength]byte, [fieldparams.RootLength]byte) ([][32]byte, error)
-	UpdateJustifiedCheckpoint(*ethpb.Checkpoint) error
-	UpdateFinalizedCheckpoint(*ethpb.Checkpoint) error
+	UpdateJustifiedCheckpoint(*forkchoicetypes.Checkpoint) error
+	UpdateFinalizedCheckpoint(*forkchoicetypes.Checkpoint) error
 }

beacon-chain/forkchoice/protoarray/ffg_update_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	v3 "github.com/prysmaticlabs/prysm/beacon-chain/state/v3"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -61,7 +62,7 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -91,7 +92,7 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2
 	//            |
 	//            3 <- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head for with justified epoch at 0")
 
@@ -103,8 +104,9 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2 <- head
 	//            |
 	//            3
-	f.store.justifiedEpoch = 1
-	r, err = f.Head(context.Background(), indexToHash(2), balances)
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1, Root: indexToHash(2)}
+	f.store.justifiedCheckpoint = jc
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head with justified epoch at 1")
 
@@ -116,8 +118,9 @@ func TestFFGUpdates_OneBranch(t *testing.T) {
 	//            2 <- start
 	//            |
 	//            3 <- head
-	f.store.justifiedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(3), balances)
+	jc = &forkchoicetypes.Checkpoint{Epoch: 2, Root: indexToHash(3)}
+	f.store.justifiedCheckpoint = jc
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head with justified epoch at 2")
 }
@@ -127,7 +130,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	f := setup(0, 0)
 	ctx := context.Background()
 
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -188,7 +191,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	//         9  10 <-- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head with justified epoch at 0")
 
@@ -218,7 +221,7 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	// head -> 9  10
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head with justified epoch at 0")
 
@@ -248,19 +251,22 @@ func TestFFGUpdates_TwoBranches(t *testing.T) {
 	//         7   8
 	//         |   |
 	//         9  10 <-- head
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head with justified epoch at 0")
 
-	f.store.justifiedEpoch = 1
-	r, err = f.Head(context.Background(), indexToHash(1), balances)
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1, Root: indexToHash(1)}
+	f.store.justifiedCheckpoint = jc
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(7), r, "Incorrect head with justified epoch at 0")
 }
 
 func setup(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
-	f := New(justifiedEpoch, finalizedEpoch)
+	f := New()
 	f.store.nodesIndices[params.BeaconConfig().ZeroHash] = 0
+	f.store.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: justifiedEpoch, Root: params.BeaconConfig().ZeroHash}
+	f.store.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: finalizedEpoch, Root: params.BeaconConfig().ZeroHash}
 	f.store.nodes = append(f.store.nodes, &Node{
 		slot:           0,
 		root:           params.BeaconConfig().ZeroHash,
@@ -271,6 +277,5 @@ func setup(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
 		bestDescendant: NonExistentNode,
 		weight:         0,
 	})
-
 	return f
 }

beacon-chain/forkchoice/protoarray/no_vote_test.go

@@ -15,7 +15,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	if r != params.BeaconConfig().ZeroHash {
 		t.Errorf("Incorrect head with genesis")
@@ -28,7 +28,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err := prepareForkchoiceState(context.Background(), 0, indexToHash(2), params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -39,7 +39,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(1), params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -52,7 +52,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(3), indexToHash(1), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -65,7 +65,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(4), indexToHash(2), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -80,7 +80,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(5), indexToHash(4), params.BeaconConfig().ZeroHash, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -92,7 +92,8 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	//  head -> 4  3
 	//          |
 	//          5 <- starting from 5 with justified epoch 0 should error
-	_, err = f.Head(context.Background(), indexToHash(5), balances)
+	f.store.justifiedCheckpoint.Root = indexToHash(5)
+	_, err = f.Head(context.Background(), balances)
 	wanted := "head at slot 0 with weight 0 is not eligible, finalizedEpoch 1 != 1, justifiedEpoch 2 != 1"
 	require.ErrorContains(t, wanted, err)
 
@@ -104,8 +105,8 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	//          4  3
 	//          |
 	//          5 <- head
-	f.store.justifiedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	f.store.justifiedCheckpoint.Epoch = 2
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(5), r, "Incorrect head for with justified epoch at 2")
 
@@ -122,7 +123,7 @@ func TestNoVote_CanFindHead(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(context.Background(), 0, indexToHash(6), indexToHash(5), params.BeaconConfig().ZeroHash, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(6), r, "Incorrect head for with justified epoch at 2")
 }

beacon-chain/forkchoice/protoarray/proposer_boost_test.go

@@ -35,7 +35,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		headRoot, err := f.Head(ctx, zeroHash, balances)
+		headRoot, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, headRoot, "Incorrect head with genesis")
 
@@ -57,7 +57,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{0}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 1")
 
@@ -81,7 +81,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{1}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 2")
 
@@ -107,7 +107,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 		f.ProcessAttestation(ctx, []uint64{2}, newRoot, fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
 
@@ -142,7 +142,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 			SecondsIntoSlot: 0,
 		}
 		require.NoError(t, f.BoostProposerRoot(ctx, args))
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
 
@@ -180,7 +180,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// Regression: process attestations for C, check that it
 		// becomes head, we need two attestations to have C.weight = 30 > 24 = D.weight
 		f.ProcessAttestation(ctx, []uint64{4, 5}, indexToHash(3), fEpoch)
-		headRoot, err = f.Head(ctx, zeroHash, balances)
+		headRoot, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, indexToHash(3), headRoot, "Incorrect head for justified epoch at slot 4")
 	})
@@ -188,7 +188,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -213,7 +213,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -232,7 +232,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure the head is C, the honest block.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -253,7 +253,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f.ProcessAttestation(ctx, votes, honestBlock, fEpoch)
 
 		// Ensure the head is STILL C, the honest block, as the honest block had proposer boost.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 	})
@@ -261,7 +261,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f := setup(jEpoch, fEpoch)
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -288,7 +288,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -307,7 +307,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is still the head after the malicious proposer reveals their block.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, honestBlock, r, "Incorrect head for justified epoch at slot 2")
 
@@ -326,7 +326,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
 
 		// Expect the head to have switched to B.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, maliciouslyWithheldBlock, r, "Expected B to become the head")
 	})
@@ -348,7 +348,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		a := zeroHash
 
 		// The head should always start at the finalized block.
-		r, err := f.Head(ctx, zeroHash, balances)
+		r, err := f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, zeroHash, r, "Incorrect head with genesis")
 
@@ -367,7 +367,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Incorrect head for justified epoch at slot 2")
 
@@ -395,7 +395,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// Ensure C is still the head.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Incorrect head for justified epoch at slot 2")
 
@@ -419,7 +419,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		// D cannot win without a boost.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, c, r, "Expected C to remain the head")
 
@@ -435,7 +435,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.BoostProposerRoot(ctx, args))
 
 		// Ensure D becomes the head thanks to boosting.
-		r, err = f.Head(ctx, zeroHash, balances)
+		r, err = f.Head(ctx, balances)
 		require.NoError(t, err)
 		assert.Equal(t, d, r, "Expected D to become the head")
 	})

beacon-chain/forkchoice/protoarray/store.go

@@ -29,17 +29,17 @@ const defaultPruneThreshold = 256
 var lastHeadRoot [32]byte
 
 // New initializes a new fork choice store.
-func New(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
+func New() *ForkChoice {
 	s := &Store{
-		justifiedEpoch:    justifiedEpoch,
-		finalizedEpoch:    finalizedEpoch,
-		proposerBoostRoot: [32]byte{},
-		nodes:             make([]*Node, 0),
-		nodesIndices:      make(map[[32]byte]uint64),
-		payloadIndices:    make(map[[32]byte]uint64),
-		canonicalNodes:    make(map[[32]byte]bool),
-		slashedIndices:    make(map[types.ValidatorIndex]bool),
-		pruneThreshold:    defaultPruneThreshold,
+		justifiedCheckpoint: &forkchoicetypes.Checkpoint{},
+		finalizedCheckpoint: &forkchoicetypes.Checkpoint{},
+		proposerBoostRoot:   [32]byte{},
+		nodes:               make([]*Node, 0),
+		nodesIndices:        make(map[[32]byte]uint64),
+		payloadIndices:      make(map[[32]byte]uint64),
+		canonicalNodes:      make(map[[32]byte]bool),
+		slashedIndices:      make(map[types.ValidatorIndex]bool),
+		pruneThreshold:      defaultPruneThreshold,
 	}
 
 	b := make([]uint64, 0)
@@ -49,11 +49,7 @@ func New(justifiedEpoch, finalizedEpoch types.Epoch) *ForkChoice {
 
 // Head returns the head root from fork choice store.
 // It firsts computes validator's balance changes then recalculates block tree from leaves to root.
-func (f *ForkChoice) Head(
-	ctx context.Context,
-	justifiedRoot [32]byte,
-	justifiedStateBalances []uint64,
-) ([32]byte, error) {
+func (f *ForkChoice) Head(ctx context.Context, justifiedStateBalances []uint64) ([32]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "protoArrayForkChoice.Head")
 	defer span.End()
 	f.votesLock.Lock()
@@ -76,7 +72,7 @@ func (f *ForkChoice) Head(
 	}
 	f.balances = newBalances
 
-	return f.store.head(ctx, justifiedRoot)
+	return f.store.head(ctx)
 }
 
 // ProcessAttestation processes attestation for vote accounting, it iterates around validator indices
@@ -120,7 +116,7 @@ func (f *ForkChoice) ProposerBoost() [fieldparams.RootLength]byte {
 }
 
 // InsertNode processes a new block by inserting it to the fork choice store.
-func (f *ForkChoice) InsertNode(ctx context.Context, state state.ReadOnlyBeaconState, root [32]byte) error {
+func (f *ForkChoice) InsertNode(ctx context.Context, state state.BeaconState, root [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "protoArrayForkChoice.InsertNode")
 	defer span.End()
 
@@ -273,14 +269,18 @@ func (s *Store) PruneThreshold() uint64 {
 	return s.pruneThreshold
 }
 
-// JustifiedEpoch of fork choice store.
-func (f *ForkChoice) JustifiedEpoch() types.Epoch {
-	return f.store.justifiedEpoch
+// JustifiedCheckpoint of fork choice store.
+func (f *ForkChoice) JustifiedCheckpoint() *forkchoicetypes.Checkpoint {
+	f.store.checkpointsLock.RLock()
+	defer f.store.checkpointsLock.RUnlock()
+	return f.store.justifiedCheckpoint
 }
 
-// FinalizedEpoch of fork choice store.
-func (f *ForkChoice) FinalizedEpoch() types.Epoch {
-	return f.store.finalizedEpoch
+// FinalizedCheckpoint of fork choice store.
+func (f *ForkChoice) FinalizedCheckpoint() *forkchoicetypes.Checkpoint {
+	f.store.checkpointsLock.RLock()
+	defer f.store.checkpointsLock.RUnlock()
+	return f.store.finalizedCheckpoint
 }
 
 // proposerBoost of fork choice store.
@@ -291,20 +291,23 @@ func (s *Store) proposerBoost() [fieldparams.RootLength]byte {
 }
 
 // head starts from justified root and then follows the best descendant links
-// to find the best block for head.
-func (s *Store) head(ctx context.Context, justifiedRoot [32]byte) ([32]byte, error) {
+// to find the best block for head. It assumes the caller has a lock on nodes.
+func (s *Store) head(ctx context.Context) ([32]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "protoArrayForkChoice.head")
 	defer span.End()
 
 	// Justified index has to be valid in node indices map, and can not be out of bound.
-	justifiedIndex, ok := s.nodesIndices[justifiedRoot]
+	if s.justifiedCheckpoint == nil {
+		return [32]byte{}, errInvalidNilCheckpoint
+	}
+
+	justifiedIndex, ok := s.nodesIndices[s.justifiedCheckpoint.Root]
 	if !ok {
 		return [32]byte{}, errUnknownJustifiedRoot
 	}
 	if justifiedIndex >= uint64(len(s.nodes)) {
 		return [32]byte{}, errInvalidJustifiedIndex
 	}
-
 	justifiedNode := s.nodes[justifiedIndex]
 	bestDescendantIndex := justifiedNode.bestDescendant
 	// If the justified node doesn't have a best descendant,
@@ -315,12 +318,11 @@ func (s *Store) head(ctx context.Context, justifiedRoot [32]byte) ([32]byte, err
 	if bestDescendantIndex >= uint64(len(s.nodes)) {
 		return [32]byte{}, errInvalidBestDescendantIndex
 	}
-
 	bestNode := s.nodes[bestDescendantIndex]
 
 	if !s.viableForHead(bestNode) {
 		return [32]byte{}, fmt.Errorf("head at slot %d with weight %d is not eligible, finalizedEpoch %d != %d, justifiedEpoch %d != %d",
-			bestNode.slot, bestNode.weight/10e9, bestNode.finalizedEpoch, s.finalizedEpoch, bestNode.justifiedEpoch, s.justifiedEpoch)
+			bestNode.slot, bestNode.weight/10e9, bestNode.finalizedEpoch, s.finalizedCheckpoint.Epoch, bestNode.justifiedEpoch, s.justifiedCheckpoint.Epoch)
 	}
 
 	// Update metrics.
@@ -743,10 +745,12 @@ func (s *Store) leadsToViableHead(node *Node) (bool, error) {
 // Any node with diff finalized or justified epoch than the ones in fork choice store
 // should not be viable to head.
 func (s *Store) viableForHead(node *Node) bool {
+	s.checkpointsLock.RLock()
+	defer s.checkpointsLock.RUnlock()
 	// `node` is viable if its justified epoch and finalized epoch are the same as the one in `Store`.
 	// It's also viable if we are in genesis epoch.
-	justified := s.justifiedEpoch == node.justifiedEpoch || s.justifiedEpoch == 0
-	finalized := s.finalizedEpoch == node.finalizedEpoch || s.finalizedEpoch == 0
+	justified := s.justifiedCheckpoint.Epoch == node.justifiedEpoch || s.justifiedCheckpoint.Epoch == 0
+	finalized := s.finalizedCheckpoint.Epoch == node.finalizedEpoch || s.finalizedCheckpoint.Epoch == 0
 
 	return justified && finalized
 }
@@ -857,25 +861,25 @@ func (f *ForkChoice) InsertSlashedIndex(ctx context.Context, index types.Validat
 	}
 }
 
-// UpdateJustifiedCheckpoint sets the justified epoch to the given one
-func (f *ForkChoice) UpdateJustifiedCheckpoint(jc *pbrpc.Checkpoint) error {
+// UpdateJustifiedCheckpoint sets the justified checkpoint to the given one
+func (f *ForkChoice) UpdateJustifiedCheckpoint(jc *forkchoicetypes.Checkpoint) error {
 	if jc == nil {
 		return errInvalidNilCheckpoint
 	}
-	f.store.nodesLock.Lock()
-	defer f.store.nodesLock.Unlock()
-	f.store.justifiedEpoch = jc.Epoch
+	f.store.checkpointsLock.Lock()
+	defer f.store.checkpointsLock.Unlock()
+	f.store.justifiedCheckpoint = jc
 	return nil
 }
 
-// UpdateFinalizedCheckpoint sets the finalized epoch to the given one
-func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *pbrpc.Checkpoint) error {
+// UpdateFinalizedCheckpoint sets the finalized checkpoint to the given one
+func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *forkchoicetypes.Checkpoint) error {
 	if fc == nil {
 		return errInvalidNilCheckpoint
 	}
-	f.store.nodesLock.Lock()
-	defer f.store.nodesLock.Unlock()
-	f.store.finalizedEpoch = fc.Epoch
+	f.store.checkpointsLock.Lock()
+	defer f.store.checkpointsLock.Unlock()
+	f.store.finalizedCheckpoint = fc
 	return nil
 }
 
@@ -895,7 +899,7 @@ func (f *ForkChoice) InsertOptimisticChain(ctx context.Context, chain []*forkcho
 		}
 		if err := f.store.insert(ctx,
 			b.Slot(), r, parentRoot, payloadHash,
-			chain[i].JustifiedEpoch, chain[i].FinalizedEpoch); err != nil {
+			chain[i].JustifiedCheckpoint.Epoch, chain[i].FinalizedCheckpoint.Epoch); err != nil {
 			return err
 		}
 	}

beacon-chain/forkchoice/protoarray/store_test.go

@@ -28,13 +28,13 @@ func TestStore_PruneThreshold(t *testing.T) {
 func TestStore_JustifiedEpoch(t *testing.T) {
 	j := types.Epoch(100)
 	f := setup(j, j)
-	require.Equal(t, j, f.JustifiedEpoch())
+	require.Equal(t, j, f.JustifiedCheckpoint().Epoch)
 }
 
 func TestStore_FinalizedEpoch(t *testing.T) {
 	j := types.Epoch(50)
 	f := setup(j, j)
-	require.Equal(t, j, f.FinalizedEpoch())
+	require.Equal(t, j, f.FinalizedCheckpoint().Epoch)
 }
 
 func TestForkChoice_HasNode(t *testing.T) {
@@ -51,8 +51,9 @@ func TestForkChoice_HasNode(t *testing.T) {
 
 func TestStore_Head_UnknownJustifiedRoot(t *testing.T) {
 	s := &Store{nodesIndices: make(map[[32]byte]uint64)}
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: [32]byte{'a'}}
 
-	_, err := s.head(context.Background(), [32]byte{})
+	_, err := s.head(context.Background())
 	assert.ErrorContains(t, errUnknownJustifiedRoot.Error(), err)
 }
 
@@ -61,8 +62,9 @@ func TestStore_Head_UnknownJustifiedIndex(t *testing.T) {
 	indices := make(map[[32]byte]uint64)
 	indices[r] = 1
 	s := &Store{nodesIndices: indices}
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
 
-	_, err := s.head(context.Background(), r)
+	_, err := s.head(context.Background())
 	assert.ErrorContains(t, errInvalidJustifiedIndex.Error(), err)
 }
 
@@ -73,7 +75,9 @@ func TestStore_Head_Itself(t *testing.T) {
 	// Since the justified node does not have a best descendant so the best node
 	// is itself.
 	s := &Store{nodesIndices: indices, nodes: []*Node{{root: r, parent: NonExistentNode, bestDescendant: NonExistentNode}}, canonicalNodes: make(map[[32]byte]bool)}
-	h, err := s.head(context.Background(), r)
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	h, err := s.head(context.Background())
 	require.NoError(t, err)
 	assert.Equal(t, r, h)
 }
@@ -86,7 +90,9 @@ func TestStore_Head_BestDescendant(t *testing.T) {
 	// Since the justified node's best descendant is at index 1, and its root is `best`,
 	// the head should be `best`.
 	s := &Store{nodesIndices: indices, nodes: []*Node{{root: r, bestDescendant: 1, parent: NonExistentNode}, {root: best, parent: 0}}, canonicalNodes: make(map[[32]byte]bool)}
-	h, err := s.head(context.Background(), r)
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	h, err := s.head(context.Background())
 	require.NoError(t, err)
 	assert.Equal(t, best, h)
 }
@@ -99,7 +105,9 @@ func TestStore_Head_ContextCancelled(t *testing.T) {
 
 	s := &Store{nodesIndices: indices, nodes: []*Node{{root: r, parent: NonExistentNode, bestDescendant: 1}, {root: best, parent: 0}}, canonicalNodes: make(map[[32]byte]bool)}
 	cancel()
-	_, err := s.head(ctx, r)
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{Epoch: 0, Root: r}
+	_, err := s.head(ctx)
 	require.ErrorContains(t, "context canceled", err)
 }
 
@@ -123,6 +131,8 @@ func TestStore_Insert_KnownParent(t *testing.T) {
 	p := [32]byte{'B'}
 	s.nodesIndices[p] = 0
 	payloadHash := [32]byte{'c'}
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{}
 	require.NoError(t, s.insert(context.Background(), 100, [32]byte{'A'}, p, payloadHash, 1, 1))
 	assert.Equal(t, 2, len(s.nodes), "Did not insert block")
 	assert.Equal(t, 2, len(s.nodesIndices), "Did not insert block")
@@ -150,6 +160,8 @@ func TestStore_ApplyScoreChanges_UpdateWeightsPositiveDelta(t *testing.T) {
 
 	// Each node gets one unique vote. The weight should look like 103 <- 102 <- 101 because
 	// they get propagated back.
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{}
 	require.NoError(t, s.applyWeightChanges(context.Background(), []uint64{}, []int{1, 1, 1}))
 	assert.Equal(t, uint64(103), s.nodes[0].weight)
 	assert.Equal(t, uint64(102), s.nodes[1].weight)
@@ -165,6 +177,8 @@ func TestStore_ApplyScoreChanges_UpdateWeightsNegativeDelta(t *testing.T) {
 
 	// Each node gets one unique vote which contributes to negative delta.
 	// The weight should look like 97 <- 98 <- 99 because they get propagated back.
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{}
 	require.NoError(t, s.applyWeightChanges(context.Background(), []uint64{}, []int{-1, -1, -1}))
 	assert.Equal(t, uint64(97), s.nodes[0].weight)
 	assert.Equal(t, uint64(98), s.nodes[1].weight)
@@ -179,6 +193,8 @@ func TestStore_ApplyScoreChanges_UpdateWeightsMixedDelta(t *testing.T) {
 		{parent: 1, root: [32]byte{'A'}, weight: 100}}}
 
 	// Each node gets one mixed vote. The weight should look like 100 <- 200 <- 250.
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{}
 	require.NoError(t, s.applyWeightChanges(context.Background(), []uint64{}, []int{-100, -50, 150}))
 	assert.Equal(t, uint64(100), s.nodes[0].weight)
 	assert.Equal(t, uint64(200), s.nodes[1].weight)
@@ -187,7 +203,9 @@ func TestStore_ApplyScoreChanges_UpdateWeightsMixedDelta(t *testing.T) {
 
 func TestStore_UpdateBestChildAndDescendant_RemoveChild(t *testing.T) {
 	// Make parent's best child equal's to input child index and child is not viable.
-	s := &Store{nodes: []*Node{{bestChild: 1}, {}}, justifiedEpoch: 1, finalizedEpoch: 1}
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	s := &Store{nodes: []*Node{{bestChild: 1}, {}}, justifiedCheckpoint: jc, finalizedCheckpoint: fc}
 	require.NoError(t, s.updateBestChildAndDescendant(0, 1))
 
 	// Verify parent's best child and best descendant are `none`.
@@ -198,6 +216,8 @@ func TestStore_UpdateBestChildAndDescendant_RemoveChild(t *testing.T) {
 func TestStore_UpdateBestChildAndDescendant_UpdateDescendant(t *testing.T) {
 	// Make parent's best child equal to child index and child is viable.
 	s := &Store{nodes: []*Node{{bestChild: 1}, {bestDescendant: NonExistentNode}}}
+	s.justifiedCheckpoint = &forkchoicetypes.Checkpoint{}
+	s.finalizedCheckpoint = &forkchoicetypes.Checkpoint{}
 	require.NoError(t, s.updateBestChildAndDescendant(0, 1))
 
 	// Verify parent's best child is the same and best descendant is not set to child index.
@@ -208,9 +228,11 @@ func TestStore_UpdateBestChildAndDescendant_UpdateDescendant(t *testing.T) {
 func TestStore_UpdateBestChildAndDescendant_ChangeChildByViability(t *testing.T) {
 	// Make parent's best child not equal to child index, child leads to viable index and
 	// parent's best child doesn't lead to viable index.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: 1, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1}}}
@@ -224,9 +246,11 @@ func TestStore_UpdateBestChildAndDescendant_ChangeChildByViability(t *testing.T)
 func TestStore_UpdateBestChildAndDescendant_ChangeChildByWeight(t *testing.T) {
 	// Make parent's best child not equal to child index, child leads to viable index and
 	// parents best child leads to viable index but child has more weight than parent's best child.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: 1, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1, weight: 1}}}
@@ -239,9 +263,11 @@ func TestStore_UpdateBestChildAndDescendant_ChangeChildByWeight(t *testing.T) {
 
 func TestStore_UpdateBestChildAndDescendant_ChangeChildAtLeaf(t *testing.T) {
 	// Make parent's best child to none and input child leads to viable index.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1}}}
@@ -255,9 +281,11 @@ func TestStore_UpdateBestChildAndDescendant_ChangeChildAtLeaf(t *testing.T) {
 func TestStore_UpdateBestChildAndDescendant_NoChangeByViability(t *testing.T) {
 	// Make parent's best child not equal to child index, child leads to not viable index and
 	// parents best child leads to viable index.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: 1, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode}}}
@@ -271,9 +299,11 @@ func TestStore_UpdateBestChildAndDescendant_NoChangeByViability(t *testing.T) {
 func TestStore_UpdateBestChildAndDescendant_NoChangeByWeight(t *testing.T) {
 	// Make parent's best child not equal to child index, child leads to viable index and
 	// parents best child leads to viable index but parent's best child has more weight.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: 1, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1, weight: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1}}}
@@ -286,9 +316,11 @@ func TestStore_UpdateBestChildAndDescendant_NoChangeByWeight(t *testing.T) {
 
 func TestStore_UpdateBestChildAndDescendant_NoChangeAtLeaf(t *testing.T) {
 	// Make parent's best child to none and input child does not lead to viable index.
+	jc := &forkchoicetypes.Checkpoint{Epoch: 1}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 1}
 	s := &Store{
-		justifiedEpoch: 1,
-		finalizedEpoch: 1,
+		justifiedCheckpoint: jc,
+		finalizedCheckpoint: fc,
 		nodes: []*Node{{bestChild: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode, justifiedEpoch: 1, finalizedEpoch: 1},
 			{bestDescendant: NonExistentNode}}}
@@ -786,10 +818,12 @@ func TestStore_LeadsToViableHead(t *testing.T) {
 		{&Node{finalizedEpoch: 3, justifiedEpoch: 4}, 4, 3, true},
 	}
 	for _, tc := range tests {
+		jc := &forkchoicetypes.Checkpoint{Epoch: tc.justifiedEpoch}
+		fc := &forkchoicetypes.Checkpoint{Epoch: tc.finalizedEpoch}
 		s := &Store{
-			justifiedEpoch: tc.justifiedEpoch,
-			finalizedEpoch: tc.finalizedEpoch,
-			nodes:          []*Node{tc.n},
+			justifiedCheckpoint: jc,
+			finalizedCheckpoint: fc,
+			nodes:               []*Node{tc.n},
 		}
 		got, err := s.leadsToViableHead(tc.n)
 		require.NoError(t, err)
@@ -812,9 +846,11 @@ func TestStore_ViableForHead(t *testing.T) {
 		{&Node{finalizedEpoch: 3, justifiedEpoch: 4}, 4, 3, true},
 	}
 	for _, tc := range tests {
+		jc := &forkchoicetypes.Checkpoint{Epoch: tc.justifiedEpoch}
+		fc := &forkchoicetypes.Checkpoint{Epoch: tc.finalizedEpoch}
 		s := &Store{
-			justifiedEpoch: tc.justifiedEpoch,
-			finalizedEpoch: tc.finalizedEpoch,
+			justifiedCheckpoint: jc,
+			finalizedCheckpoint: fc,
 		}
 		assert.Equal(t, tc.want, s.viableForHead(tc.n))
 	}
@@ -984,7 +1020,7 @@ func TestStore_RemoveEquivocating(t *testing.T) {
 	state, blkRoot, err := prepareForkchoiceState(ctx, 1, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	head, err := f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{})
+	head, err := f.Head(ctx, []uint64{})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'a'}, head)
 
@@ -995,20 +1031,20 @@ func TestStore_RemoveEquivocating(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(ctx, 3, [32]byte{'c'}, [32]byte{'a'}, [32]byte{'C'}, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{})
+	head, err = f.Head(ctx, []uint64{})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, head)
 
 	// Insert two attestations for block b, it becomes head
 	f.ProcessAttestation(ctx, []uint64{1, 2}, [32]byte{'b'}, 1)
 	f.ProcessAttestation(ctx, []uint64{3}, [32]byte{'c'}, 1)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'b'}, head)
 
 	// Process b's slashing, c is now head
 	f.InsertSlashedIndex(ctx, 1)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, head)
 	require.Equal(t, uint64(200), f.store.nodes[2].weight)
@@ -1016,7 +1052,7 @@ func TestStore_RemoveEquivocating(t *testing.T) {
 
 	// Process the same slashing again, should be a noop
 	f.InsertSlashedIndex(ctx, 1)
-	head, err = f.Head(ctx, params.BeaconConfig().ZeroHash, []uint64{100, 200, 200, 300})
+	head, err = f.Head(ctx, []uint64{100, 200, 200, 300})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, head)
 	require.Equal(t, uint64(200), f.store.nodes[2].weight)
@@ -1032,12 +1068,12 @@ func TestStore_UpdateCheckpoints(t *testing.T) {
 	f := setup(1, 1)
 	jr := [32]byte{'j'}
 	fr := [32]byte{'f'}
-	jc := &ethpb.Checkpoint{Root: jr[:], Epoch: 3}
-	fc := &ethpb.Checkpoint{Root: fr[:], Epoch: 2}
+	jc := &forkchoicetypes.Checkpoint{Root: jr, Epoch: 3}
+	fc := &forkchoicetypes.Checkpoint{Root: fr, Epoch: 2}
 	require.NoError(t, f.UpdateJustifiedCheckpoint(jc))
 	require.NoError(t, f.UpdateFinalizedCheckpoint(fc))
-	require.Equal(t, f.store.justifiedEpoch, jc.Epoch)
-	require.Equal(t, f.store.finalizedEpoch, fc.Epoch)
+	require.Equal(t, f.store.justifiedCheckpoint, jc)
+	require.Equal(t, f.store.finalizedCheckpoint, fc)
 }
 
 func TestStore_InsertOptimisticChain(t *testing.T) {
@@ -1051,8 +1087,10 @@ func TestStore_InsertOptimisticChain(t *testing.T) {
 	require.NoError(t, err)
 	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
-	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
-		FinalizedEpoch: 1})
+	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(),
+		JustifiedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+		FinalizedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+	})
 	for i := uint64(2); i < 11; i++ {
 		blk := util.NewBeaconBlock()
 		blk.Block.Slot = types.Slot(i)
@@ -1060,8 +1098,10 @@ func TestStore_InsertOptimisticChain(t *testing.T) {
 		blk.Block.ParentRoot = copiedRoot[:]
 		wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 		require.NoError(t, err)
-		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
-			FinalizedEpoch: 1})
+		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(),
+			JustifiedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+			FinalizedCheckpoint: &ethpb.Checkpoint{Epoch: 1, Root: params.BeaconConfig().ZeroHash[:]},
+		})
 		root, err = blk.Block.HashTreeRoot()
 		require.NoError(t, err)
 	}

beacon-chain/forkchoice/protoarray/types.go

@@ -3,6 +3,7 @@ package protoarray
 import (
 	"sync"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 )
@@ -18,8 +19,8 @@ type ForkChoice struct {
 // Store defines the fork choice store which includes block nodes and the last view of checkpoint information.
 type Store struct {
 	pruneThreshold             uint64                                  // do not prune tree unless threshold is reached.
-	justifiedEpoch             types.Epoch                             // latest justified epoch in store.
-	finalizedEpoch             types.Epoch                             // latest finalized epoch in store.
+	justifiedCheckpoint        *forkchoicetypes.Checkpoint             // latest justified checkpoint in store.
+	finalizedCheckpoint        *forkchoicetypes.Checkpoint             // latest finalized checkpoint in store.
 	proposerBoostRoot          [fieldparams.RootLength]byte            // latest block root that was boosted after being received in a timely manner.
 	previousProposerBoostRoot  [fieldparams.RootLength]byte            // previous block root that was boosted after being received in a timely manner.
 	previousProposerBoostScore uint64                                  // previous proposer boosted root score.
@@ -30,6 +31,7 @@ type Store struct {
 	slashedIndices             map[types.ValidatorIndex]bool           // The list of equivocating validators
 	nodesLock                  sync.RWMutex
 	proposerBoostLock          sync.RWMutex
+	checkpointsLock            sync.RWMutex
 }
 
 // Node defines the individual block which includes its block parent, ancestor and how much weight accounted for it.

beacon-chain/forkchoice/protoarray/unrealized_justification.go

@@ -55,11 +55,11 @@ func (f *ForkChoice) UpdateUnrealizedCheckpoints() {
 	for _, node := range f.store.nodes {
 		node.justifiedEpoch = node.unrealizedJustifiedEpoch
 		node.finalizedEpoch = node.unrealizedFinalizedEpoch
-		if node.justifiedEpoch > f.store.justifiedEpoch {
-			f.store.justifiedEpoch = node.justifiedEpoch
+		if node.justifiedEpoch > f.store.justifiedCheckpoint.Epoch {
+			f.store.justifiedCheckpoint.Epoch = node.justifiedEpoch
 		}
-		if node.finalizedEpoch > f.store.finalizedEpoch {
-			f.store.finalizedEpoch = node.finalizedEpoch
+		if node.finalizedEpoch > f.store.finalizedCheckpoint.Epoch {
+			f.store.finalizedCheckpoint.Epoch = node.finalizedEpoch
 		}
 	}
 }

beacon-chain/forkchoice/protoarray/unrealized_justification_test.go

@@ -5,9 +5,9 @@ import (
 
 	"context"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/require"
 )
 
@@ -81,25 +81,25 @@ func TestStore_LongFork(t *testing.T) {
 
 	// Add an attestation to c, it is head
 	f.ProcessAttestation(ctx, []uint64{0}, [32]byte{'c'}, 1)
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, headRoot)
 
 	// D is head even though its weight is lower.
-	hr := [32]byte{'d'}
-	state, blkRoot, err = prepareForkchoiceState(ctx, 103, hr, [32]byte{'b'}, [32]byte{'D'}, 2, 1)
+	ha := [32]byte{'a'}
+	state, blkRoot, err = prepareForkchoiceState(ctx, 103, [32]byte{'d'}, [32]byte{'b'}, [32]byte{'D'}, 2, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	require.NoError(t, f.UpdateJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: 2, Root: hr[:]}))
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	require.NoError(t, f.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: 2, Root: ha}))
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
-	require.Equal(t, hr, headRoot)
+	require.Equal(t, [32]byte{'d'}, headRoot)
 	require.Equal(t, uint64(0), f.store.nodes[4].weight)
 	require.Equal(t, uint64(100), f.store.nodes[3].weight)
 
 	// Update unrealized justification, c becomes head
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'c'}, headRoot)
 }
@@ -158,30 +158,31 @@ func TestStore_NoDeadLock(t *testing.T) {
 
 	// Epoch 3
 	// Current Head is H
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(0), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(0), f.JustifiedCheckpoint().Epoch)
 
 	// Insert Block I, it becomes Head
 	hr := [32]byte{'i'}
 	state, blkRoot, err = prepareForkchoiceState(ctx, 108, hr, [32]byte{'f'}, [32]byte{'I'}, 1, 0)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-	require.NoError(t, f.UpdateJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: 1, Root: hr[:]}))
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	ha := [32]byte{'a'}
+	require.NoError(t, f.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: 1, Root: ha}))
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, hr, headRoot)
-	require.Equal(t, types.Epoch(1), f.JustifiedEpoch())
-	require.Equal(t, types.Epoch(0), f.FinalizedEpoch())
+	require.Equal(t, types.Epoch(1), f.JustifiedCheckpoint().Epoch)
+	require.Equal(t, types.Epoch(0), f.FinalizedCheckpoint().Epoch)
 
 	// Realized Justified checkpoints, H becomes head
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(2), f.JustifiedEpoch())
-	require.Equal(t, types.Epoch(1), f.FinalizedEpoch())
+	require.Equal(t, types.Epoch(2), f.JustifiedCheckpoint().Epoch)
+	require.Equal(t, types.Epoch(1), f.FinalizedCheckpoint().Epoch)
 }
 
 //    Epoch  1       |         Epoch 2
@@ -226,10 +227,10 @@ func TestStore_ForkNextEpoch(t *testing.T) {
 
 	// Insert an attestation to H, H is head
 	f.ProcessAttestation(ctx, []uint64{0}, [32]byte{'h'}, 1)
-	headRoot, err := f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err := f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'h'}, headRoot)
-	require.Equal(t, types.Epoch(0), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(0), f.JustifiedCheckpoint().Epoch)
 
 	// D arrives late, D is head
 	state, blkRoot, err = prepareForkchoiceState(ctx, 103, [32]byte{'d'}, [32]byte{'c'}, [32]byte{'D'}, 0, 0)
@@ -237,10 +238,10 @@ func TestStore_ForkNextEpoch(t *testing.T) {
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 	require.NoError(t, f.store.setUnrealizedJustifiedEpoch([32]byte{'d'}, 1))
 	f.UpdateUnrealizedCheckpoints()
-	headRoot, err = f.Head(ctx, [32]byte{}, []uint64{100})
+	headRoot, err = f.Head(ctx, []uint64{100})
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{'d'}, headRoot)
-	require.Equal(t, types.Epoch(1), f.JustifiedEpoch())
+	require.Equal(t, types.Epoch(1), f.JustifiedCheckpoint().Epoch)
 	// nodes[8] = D since it's late!
 	require.Equal(t, uint64(0), f.store.nodes[8].weight)
 	require.Equal(t, uint64(100), f.store.nodes[7].weight)

beacon-chain/forkchoice/protoarray/vote_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
@@ -15,7 +16,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	ctx := context.Background()
 
 	// The head should always start at the finalized block.
-	r, err := f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err := f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().ZeroHash, r, "Incorrect head with genesis")
 
@@ -27,7 +28,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -39,7 +40,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -48,7 +49,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//           / \
 	//          2  1 <- +vote, new head
 	f.ProcessAttestation(context.Background(), []uint64{0}, indexToHash(1), 2)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(1), r, "Incorrect head for with justified epoch at 1")
 
@@ -57,7 +58,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//                    / \
 	// vote, new head -> 2  1
 	f.ProcessAttestation(context.Background(), []uint64{1}, indexToHash(2), 2)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -71,7 +72,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -82,7 +83,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//             |
 	//             3 <- new vote
 	f.ProcessAttestation(context.Background(), []uint64{0}, indexToHash(3), 3)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(2), r, "Incorrect head for with justified epoch at 1")
 
@@ -93,7 +94,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//                |
 	//                3 <- head
 	f.ProcessAttestation(context.Background(), []uint64{1}, indexToHash(1), 3)
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(3), r, "Incorrect head for with justified epoch at 1")
 
@@ -109,7 +110,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -127,7 +128,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(4), r, "Incorrect head for with justified epoch at 1")
 
@@ -188,7 +189,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), params.BeaconConfig().ZeroHash, balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(6), r, "Incorrect head for with justified epoch at 1")
 
@@ -209,9 +210,11 @@ func TestVotes_CanFindHead(t *testing.T) {
 	//           8
 	//           |
 	//           9 <- head
-	f.store.justifiedEpoch = 2
-	f.store.finalizedEpoch = 2
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	jc := &forkchoicetypes.Checkpoint{Epoch: 2, Root: indexToHash(5)}
+	fc := &forkchoicetypes.Checkpoint{Epoch: 2, Root: indexToHash(5)}
+	f.store.justifiedCheckpoint = jc
+	f.store.finalizedCheckpoint = fc
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -237,7 +240,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -246,28 +249,28 @@ func TestVotes_CanFindHead(t *testing.T) {
 	// The new validators voted for 10.
 	f.ProcessAttestation(context.Background(), []uint64{2, 3, 4}, indexToHash(10), 5)
 	// The new head should be 10.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head for with justified epoch at 2")
 
 	// Set the balances of the last 2 validators to 0.
 	balances = []uint64{1, 1, 1, 0, 0}
 	// The head should be back to 9.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 1")
 
 	// Set the balances back to normal.
 	balances = []uint64{1, 1, 1, 1, 1}
 	// The head should be back to 10.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(10), r, "Incorrect head for with justified epoch at 2")
 
 	// Remove the last 2 validators.
 	balances = []uint64{1, 1, 1}
 	// The head should be back to 9.
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 1")
 
@@ -276,7 +279,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, f.store.prune(context.Background(), indexToHash(5)))
 	assert.Equal(t, 11, len(f.store.nodes), "Incorrect nodes length after prune")
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -300,7 +303,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, f.store.prune(context.Background(), indexToHash(5)))
 	assert.Equal(t, 5, len(f.store.nodes), "Incorrect nodes length after prune")
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(9), r, "Incorrect head for with justified epoch at 2")
 
@@ -318,7 +321,7 @@ func TestVotes_CanFindHead(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
-	r, err = f.Head(context.Background(), indexToHash(5), balances)
+	r, err = f.Head(context.Background(), balances)
 	require.NoError(t, err)
 	assert.Equal(t, indexToHash(11), r, "Incorrect head for with justified epoch at 2")
 }

beacon-chain/forkchoice/types/BUILD.bazel

@@ -6,7 +6,9 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types",
     visibility = ["//visibility:public"],
     deps = [
+        "//config/fieldparams:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
     ],
 )

beacon-chain/forkchoice/types/types.go

@@ -1,8 +1,10 @@
 package types
 
 import (
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 )
 
 // ProposerBoostRootArgs to call the BoostProposerRoot function.
@@ -13,9 +15,17 @@ type ProposerBoostRootArgs struct {
 	SecondsIntoSlot uint64
 }
 
+// Checkpoint is an array version of ethpb.Checkpoint. It is used internally in
+// forkchoice, while the slice version is used in the interface to legagy code
+// in other packages
+type Checkpoint struct {
+	Epoch types.Epoch
+	Root  [fieldparams.RootLength]byte
+}
+
 // BlockAndCheckpoints to call the InsertOptimisticChain function
 type BlockAndCheckpoints struct {
-	Block          interfaces.BeaconBlock
-	JustifiedEpoch types.Epoch
-	FinalizedEpoch types.Epoch
+	Block               interfaces.BeaconBlock
+	JustifiedCheckpoint *ethpb.Checkpoint
+	FinalizedCheckpoint *ethpb.Checkpoint
 }

beacon-chain/node/node.go

@@ -348,9 +348,9 @@ func (b *BeaconNode) Close() {
 
 func (b *BeaconNode) startForkChoice() {
 	if features.Get().EnableForkChoiceDoublyLinkedTree {
-		b.forkChoiceStore = doublylinkedtree.New(0, 0)
+		b.forkChoiceStore = doublylinkedtree.New()
 	} else {
-		b.forkChoiceStore = protoarray.New(0, 0)
+		b.forkChoiceStore = protoarray.New()
 	}
 }
 

beacon-chain/rpc/prysm/v1alpha1/debug/forkchoice.go

@@ -12,8 +12,8 @@ func (ds *Server) GetForkChoice(_ context.Context, _ *empty.Empty) (*pbrpc.ForkC
 	store := ds.ForkFetcher.ForkChoicer()
 
 	return &pbrpc.ForkChoiceResponse{
-		JustifiedEpoch:  store.JustifiedEpoch(),
-		FinalizedEpoch:  store.FinalizedEpoch(),
+		JustifiedEpoch:  store.JustifiedCheckpoint().Epoch,
+		FinalizedEpoch:  store.FinalizedCheckpoint().Epoch,
 		ForkchoiceNodes: store.ForkChoiceNodes(),
 	}, nil
 }

beacon-chain/rpc/prysm/v1alpha1/debug/forkchoice_test.go

@@ -12,10 +12,10 @@ import (
 )
 
 func TestServer_GetForkChoice_ProtoArray(t *testing.T) {
-	store := protoarray.New(0, 0)
+	store := protoarray.New()
 	bs := &Server{ForkFetcher: &mock.ChainService{ForkChoiceStore: store}}
 	res, err := bs.GetForkChoice(context.Background(), &empty.Empty{})
 	require.NoError(t, err)
-	assert.Equal(t, store.JustifiedEpoch(), res.JustifiedEpoch, "Did not get wanted justified epoch")
-	assert.Equal(t, store.FinalizedEpoch(), res.FinalizedEpoch, "Did not get wanted finalized epoch")
+	assert.Equal(t, store.JustifiedCheckpoint().Epoch, res.JustifiedEpoch, "Did not get wanted justified epoch")
+	assert.Equal(t, store.FinalizedCheckpoint().Epoch, res.FinalizedEpoch, "Did not get wanted finalized epoch")
 }

testing/spectest/shared/common/forkchoice/service.go

@@ -52,7 +52,7 @@ func startChainService(t testing.TB, st state.BeaconState, block interfaces.Sign
 		blockchain.WithFinalizedStateAtStartUp(st),
 		blockchain.WithDatabase(db),
 		blockchain.WithAttestationService(attPool),
-		blockchain.WithForkChoiceStore(protoarray.New(0, 0)),
+		blockchain.WithForkChoiceStore(protoarray.New()),
 		blockchain.WithStateGen(stategen.New(db)),
 		blockchain.WithStateNotifier(&mock.MockStateNotifier{}),
 		blockchain.WithAttestationPool(attestations.NewPool()),