add get balance for rpc api

hmy/api_backend.go

@@ -7,6 +7,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/bloombits"
 	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
@@ -185,3 +186,8 @@ func (b *APIBackend) GetPoolTransactions() (types.Transactions, error) {
 	}
 	return txs, nil
 }
+
+// GetBalance ...
+func (b *APIBackend) GetBalance(address common.Address) (*hexutil.Big, error) {
+	return nil, nil
+}

hmy/backend.go

@@ -1,6 +1,9 @@
 package hmy
 
 import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/bloombits"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -34,6 +37,7 @@ type NodeAPI interface {
 	AddPendingTransaction(newTx *types.Transaction)
 	Blockchain() *core.BlockChain
 	AccountManager() *accounts.Manager
+	GetBalanceOfAddress(address common.Address) (*big.Int, error)
 }
 
 // New creates a new Harmony object (including the

internal/hmyapi/backend.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/params"
@@ -54,6 +55,8 @@ type Backend interface {
 
 	ChainConfig() *params.ChainConfig
 	CurrentBlock() *types.Block
+	// Get balance
+	GetBalance(address common.Address) (*hexutil.Big, error)
 }
 
 // GetAPIs returns all the APIs.

internal/hmyapi/blockchain.go

@@ -72,11 +72,7 @@ func (s *PublicBlockChainAPI) GetStorageAt(ctx context.Context, address common.A
 // given block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta
 // block numbers are also allowed.
 func (s *PublicBlockChainAPI) GetBalance(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (*hexutil.Big, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
-	if state == nil || err != nil {
-		return nil, err
-	}
-	return (*hexutil.Big)(state.GetBalance(address)), state.Error()
+	return s.b.GetBalance(address)
 }
 
 // BlockNumber returns the block number of the chain head.