add log

main.go

@@ -56,18 +56,19 @@ func SendAndWait(client *ethclient.Client, ctx context.Context, pk *ecdsa.Privat
 	if err != nil {
 		log.Fatalf("failed to sign tx: %v", err)
 	}
+	t1 := time.Now()
 	err = client.SendTransaction(ctx, signedTx)
 	if err != nil {
 		log.Fatalln(fmt.Errorf("failed to send tx: %v", err))
 	}
-	t1 := time.Now()
+	t2 := time.Now()
 	tm := time.NewTicker(100 * time.Millisecond)
 	for {
 		select {
 		case <-tm.C:
 			receipt, _ := client.TransactionReceipt(ctx, signedTx.Hash())
 			if receipt != nil {
-				fmt.Println("tx mined in ", time.Since(t1).String())
+				fmt.Printf("tx send cost %v, mined cost %v, total cost %v\n", t2.Sub(t1), time.Since(t2), time.Since(t1))
 				return
 			}
 		}