Add /eth/v1/beacon/deposit_snapshot endpoint

beacon-chain/rpc/eth/beacon/BUILD.bazel

@@ -76,6 +76,7 @@ go_test(
         "//api:go_default_library",
         "//api/server:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",

beacon-chain/rpc/eth/beacon/handlers.go

@@ -2070,3 +2070,52 @@ func (s *Server) GetGenesis(w http.ResponseWriter, r *http.Request) {
 	}
 	httputil.WriteJson(w, resp)
 }
+
+// GetDepositSnapshot retrieves the EIP-4881 Deposit Tree Snapshot. Either a JSON or,
+// if the Accept header was added, bytes serialized by SSZ will be returned.
+func (s *Server) GetDepositSnapshot(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.GetDepositSnapshot")
+	defer span.End()
+
+	if s.BeaconDB == nil {
+		httputil.HandleError(w, "Could not retrieve beaconDB", http.StatusInternalServerError)
+		return
+	}
+	eth1data, err := s.BeaconDB.ExecutionChainData(ctx)
+	if err != nil {
+		httputil.HandleError(w, "Could not retrieve execution chain data: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if eth1data == nil {
+		httputil.HandleError(w, "Could not retrieve execution chain data: empty Eth1Data", http.StatusInternalServerError)
+		return
+	}
+	snapshot := eth1data.DepositSnapshot
+	if snapshot == nil || len(snapshot.Finalized) == 0 {
+		httputil.HandleError(w, "No Finalized Snapshot Available", http.StatusNotFound)
+		return
+	}
+	finalized := make([][]string, 0, len(snapshot.Finalized))
+	for _, f := range snapshot.Finalized {
+		finalized = append(finalized, []string{hexutil.Encode(f)})
+	}
+	response := &GetDepositSnapshotResponse{
+		Data: &DepositSnapshot{
+			Finalized:            finalized,
+			DepositRoot:          hexutil.Encode(snapshot.DepositRoot),
+			DepositCount:         strconv.FormatUint(snapshot.DepositCount, 10),
+			ExecutionBlockHash:   hexutil.Encode(snapshot.ExecutionHash),
+			ExecutionBlockHeight: strconv.FormatUint(snapshot.ExecutionDepth, 10),
+		},
+	}
+	if httputil.RespondWithSsz(r) {
+		sszData, err := response.MarshalSSZ()
+		if err != nil {
+			httputil.HandleError(w, "Could not marshal deposit snapshot into SSZ", http.StatusInternalServerError)
+			return
+		}
+		httputil.WriteSsz(w, sszData, "deposit_snapshot.ssz")
+	} else {
+		httputil.WriteJson(w, response)
+	}
+}

beacon-chain/rpc/eth/beacon/handlers_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v4/api"
 	chainMock "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache/depositsnapshot"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	dbTest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
@@ -3617,3 +3618,64 @@ func TestGetGenesis(t *testing.T) {
 		assert.StringContains(t, "Chain genesis info is not yet known", e.Message)
 	})
 }
+
+func TestGetDepositSnapshot(t *testing.T) {
+	beaconDB := dbTest.SetupDB(t)
+	mockTrie := depositsnapshot.NewDepositTree()
+	deposits := [][32]byte{
+		bytesutil.ToBytes32([]byte{1}),
+		bytesutil.ToBytes32([]byte{2}),
+		bytesutil.ToBytes32([]byte{3}),
+	}
+	finalized := 2
+	for _, leaf := range deposits {
+		err := mockTrie.Insert(leaf[:], 0)
+		require.NoError(t, err)
+	}
+	err := mockTrie.Finalize(1, deposits[1], 1)
+	require.NoError(t, err)
+	err = mockTrie.Finalize(2, deposits[2], 2)
+	require.NoError(t, err)
+
+	snapshot, err := mockTrie.GetSnapshot()
+	require.NoError(t, err)
+	root, err := snapshot.CalculateRoot()
+	require.NoError(t, err)
+	chainData := &eth.ETH1ChainData{
+		DepositSnapshot: snapshot.ToProto(),
+	}
+	err = beaconDB.SaveExecutionChainData(context.Background(), chainData)
+	require.NoError(t, err)
+	s := Server{
+		BeaconDB: beaconDB,
+	}
+
+	request := httptest.NewRequest(http.MethodGet, "/eth/v1/beacon/deposit_snapshot", nil)
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	t.Run("JSON response", func(t *testing.T) {
+		s.GetDepositSnapshot(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		resp := &GetDepositSnapshotResponse{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		require.NotNil(t, resp.Data)
+
+		assert.Equal(t, hexutil.Encode(root[:]), resp.Data.DepositRoot)
+		assert.Equal(t, hexutil.Encode(deposits[2][:]), resp.Data.ExecutionBlockHash)
+		assert.Equal(t, strconv.Itoa(mockTrie.NumOfItems()), resp.Data.DepositCount)
+		assert.Equal(t, finalized, len(resp.Data.Finalized))
+	})
+	t.Run("SSZ response", func(t *testing.T) {
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		s.GetDepositSnapshot(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		resp := &GetDepositSnapshotResponse{}
+		require.NoError(t, resp.UnmarshalSSZ(writer.Body.Bytes()))
+		require.NotNil(t, resp.Data)
+
+		assert.Equal(t, hexutil.Encode(root[:]), resp.Data.DepositRoot)
+		assert.Equal(t, hexutil.Encode(deposits[2][:]), resp.Data.ExecutionBlockHash)
+		assert.Equal(t, strconv.Itoa(mockTrie.NumOfItems()), resp.Data.DepositCount)
+		assert.Equal(t, finalized, len(resp.Data.Finalized))
+	})
+}

beacon-chain/rpc/eth/beacon/structs.go

@@ -3,6 +3,7 @@ package beacon
 import (
 	"encoding/json"
 
+	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
 )
 
@@ -188,3 +189,17 @@ type GetAttesterSlashingsResponse struct {
 type GetProposerSlashingsResponse struct {
 	Data []*shared.ProposerSlashing `json:"data"`
 }
+
+type GetDepositSnapshotResponse struct {
+	Data *DepositSnapshot `json:"data"`
+	ssz.Marshaler
+	ssz.Unmarshaler
+}
+
+type DepositSnapshot struct {
+	Finalized            [][]string `json:"finalized"`
+	DepositRoot          string     `json:"deposit_root"`
+	DepositCount         string     `json:"deposit_count"`
+	ExecutionBlockHash   string     `json:"execution_block_hash"`
+	ExecutionBlockHeight string     `json:"execution_block_height"`
+}

beacon-chain/rpc/service.go

@@ -255,6 +255,7 @@ func (s *Service) initializeBeaconServerRoutes(beaconServer *beacon.Server) {
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/blocks/{block_id}/attestations", beaconServer.GetBlockAttestations).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/blinded_blocks/{block_id}", beaconServer.GetBlindedBlock).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/blocks/{block_id}/root", beaconServer.GetBlockRoot).Methods(http.MethodGet)
+	s.cfg.Router.HandleFunc("/eth/v1/beacon/deposit_snapshot", beaconServer.GetDepositSnapshot).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/pool/attestations", beaconServer.ListAttestations).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/pool/attestations", beaconServer.SubmitAttestations).Methods(http.MethodPost)
 	s.cfg.Router.HandleFunc("/eth/v1/beacon/pool/voluntary_exits", beaconServer.ListVoluntaryExits).Methods(http.MethodGet)

beacon-chain/rpc/service_test.go

@@ -93,20 +93,20 @@ func TestServer_InitializeRoutes(t *testing.T) {
 		"/eth/v1/beacon/blocks/{block_id}/attestations":              {http.MethodGet},
 		"/eth/v1/beacon/blob_sidecars/{block_id}":                    {http.MethodGet},
 		"/eth/v1/beacon/rewards/sync_committee/{block_id}":           {http.MethodPost},
-		//"/eth/v1/beacon/deposit_snapshot": {http.MethodGet}, not implemented
-		"/eth/v1/beacon/rewards/blocks/{block_id}":           {http.MethodGet},
-		"/eth/v1/beacon/rewards/attestations/{epoch}":        {http.MethodPost},
-		"/eth/v1/beacon/blinded_blocks/{block_id}":           {http.MethodGet},
-		"/eth/v1/beacon/light_client/bootstrap/{block_root}": {http.MethodGet},
-		"/eth/v1/beacon/light_client/updates":                {http.MethodGet},
-		"/eth/v1/beacon/light_client/finality_update":        {http.MethodGet},
-		"/eth/v1/beacon/light_client/optimistic_update":      {http.MethodGet},
-		"/eth/v1/beacon/pool/attestations":                   {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/attester_slashings":             {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/proposer_slashings":             {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/sync_committees":                {http.MethodPost},
-		"/eth/v1/beacon/pool/voluntary_exits":                {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/bls_to_execution_changes":       {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/deposit_snapshot":                            {http.MethodGet},
+		"/eth/v1/beacon/rewards/blocks/{block_id}":                   {http.MethodGet},
+		"/eth/v1/beacon/rewards/attestations/{epoch}":                {http.MethodPost},
+		"/eth/v1/beacon/blinded_blocks/{block_id}":                   {http.MethodGet},
+		"/eth/v1/beacon/light_client/bootstrap/{block_root}":         {http.MethodGet},
+		"/eth/v1/beacon/light_client/updates":                        {http.MethodGet},
+		"/eth/v1/beacon/light_client/finality_update":                {http.MethodGet},
+		"/eth/v1/beacon/light_client/optimistic_update":              {http.MethodGet},
+		"/eth/v1/beacon/pool/attestations":                           {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/attester_slashings":                     {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/proposer_slashings":                     {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/sync_committees":                        {http.MethodPost},
+		"/eth/v1/beacon/pool/voluntary_exits":                        {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/bls_to_execution_changes":               {http.MethodGet, http.MethodPost},
 	}
 
 	builderRoutes := map[string][]string{