Make fetching balances multi-thread

cmd/client/wallet/main.go

@@ -10,6 +10,7 @@ import (
 	"math/rand"
 	"os"
 	"path"
+	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -785,7 +786,12 @@ func FetchBalance(address common.Address) []*AccountState {
 		result = append(result, nil)
 	}
 
+	var wg sync.WaitGroup
+	wg.Add(walletProfile.Shards)
+
 	for shardID := 0; shardID < walletProfile.Shards; shardID++ {
+		go func(shardID int) {
+			defer wg.Done()
 			balance := big.NewInt(0)
 			var nonce uint64
 
@@ -818,7 +824,9 @@ func FetchBalance(address common.Address) []*AccountState {
 				}
 			}
 			result[shardID] = &AccountState{balance, nonce}
+		}(shardID)
 	}
+	wg.Wait()
 	return result
 }