First working RPC command eth_blockNumber

cmd/rpcdaemon/commands/daemon.go

@@ -2,11 +2,16 @@ package commands
 
 import (
 	"context"
+	"encoding/binary"
 	"fmt"
+	"net"
 	"os"
 	"os/signal"
 	"strings"
 
+	"github.com/ledgerwatch/turbo-geth/common"
+	"github.com/ledgerwatch/turbo-geth/common/dbutils"
+	"github.com/ledgerwatch/turbo-geth/ethdb/remote"
 	"github.com/ledgerwatch/turbo-geth/log"
 	"github.com/ledgerwatch/turbo-geth/rpc"
 )
@@ -26,14 +31,62 @@ type EthAPI interface {
 	BlockNumber(ctx context.Context) (uint64, error)
 }
 
-// EthAPIImpl is implementation of the EthAPI interface based on remote Db access
-type EthAPIImpl struct {
+// APIImpl is implementation of the EthAPI interface based on remote Db access
+type APIImpl struct {
 	remoteDbAdddress string
+	db               *remote.DB
+}
+
+func (api *APIImpl) ensureConnected() error {
+	if api.db == nil {
+		conn, err := net.Dial("tcp", api.remoteDbAdddress)
+		if err != nil {
+			return err
+		}
+		api.db, err = remote.NewDB(conn, conn, conn)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ConnectAPIImpl connects to the remote DB and returns APIImpl instance
+func ConnectAPIImpl(remoteDbAdddress string) (*APIImpl, error) {
+	return &APIImpl{remoteDbAdddress: remoteDbAdddress}, nil
 }
 
 // BlockNumber returns the currently highest block number available in the remote db
-func (api *EthAPIImpl) BlockNumber(ctx context.Context) (uint64, error) {
-	return 0, nil
+func (api *APIImpl) BlockNumber(ctx context.Context) (uint64, error) {
+	if err := api.ensureConnected(); err != nil {
+		return 0, err
+	}
+	var blockNumber uint64
+	if err := api.db.View(func(tx *remote.Tx) error {
+		b := tx.Bucket(dbutils.HeadHeaderKey)
+		if b == nil {
+			return fmt.Errorf("bucket %s not found", dbutils.HeadHeaderKey)
+		}
+		blockHashData := b.Get(dbutils.HeadHeaderKey)
+		if len(blockHashData) != common.HashLength {
+			return fmt.Errorf("head header hash not found or wrong size: %x", blockHashData)
+		}
+		b1 := tx.Bucket(dbutils.HeaderNumberPrefix)
+		if b1 == nil {
+			return fmt.Errorf("bucket %s not found", dbutils.HeaderNumberPrefix)
+		}
+		blockNumberData := b1.Get(blockHashData)
+		if len(blockNumberData) != 8 {
+			return fmt.Errorf("head block number not found or wrong size: %x", blockNumberData)
+		}
+		blockNumber = binary.BigEndian.Uint64(blockNumberData)
+		return nil
+	}); err != nil {
+		api.db.Close()
+		api.db = nil
+		return 0, err
+	}
+	return blockNumber, nil
 }
 
 func daemon(cfg Config) {
@@ -41,14 +94,20 @@ func daemon(cfg Config) {
 	cors := splitAndTrim(cfg.rpcCORSDomain)
 	enabledApis := splitAndTrim(cfg.rpcAPI)
 	var rpcAPI = []rpc.API{}
+	apiImpl, err := ConnectAPIImpl(cfg.remoteDbAdddress)
+	if err != nil {
+		log.Error("Could not connect to remoteDb", "error", err)
+		return
+	}
 	for _, enabledAPI := range enabledApis {
 		switch enabledAPI {
 		case "eth":
-			var ethAPI EthAPI = &EthAPIImpl{remoteDbAdddress: cfg.remoteDbAdddress}
+			var api EthAPI
+			api = apiImpl
 			rpcAPI = append(rpcAPI, rpc.API{
 				Namespace: "eth",
 				Public:    true,
-				Service:   ethAPI,
+				Service:   api,
 				Version:   "1.0",
 			})
 		default:
@@ -56,7 +115,7 @@ func daemon(cfg Config) {
 		}
 	}
 	httpEndpoint := fmt.Sprintf("%s:%d", cfg.rpcListenAddress, cfg.rpcPort)
-	listener, _, err := rpc.StartHTTPEndpoint(httpEndpoint, rpcAPI, []string{"test", "eth", "debug", "web3"}, cors, vhosts, rpc.DefaultHTTPTimeouts)
+	listener, _, err := rpc.StartHTTPEndpoint(httpEndpoint, rpcAPI, enabledApis, cors, vhosts, rpc.DefaultHTTPTimeouts)
 	if err != nil {
 		log.Error("Could not start RPC api", "error", err)
 		return