cmd/faucet: fix nonce-gap problem

cmd/faucet/faucet.go

@@ -613,24 +613,22 @@ func (f *faucet) loop() {
 				continue
 			}
 			// Faucet state retrieved, update locally and send to clients
-			f.lock.RLock()
 			log.Info("Updated faucet state", "number", head.Number, "hash", head.Hash(), "age", common.PrettyAge(timestamp), "balance", f.balance, "nonce", f.nonce, "price", f.price)
-
-			balance := new(big.Int).Div(f.balance, ether)
-			peers := f.stack.Server().PeerCount()
-
+			data, _ := json.Marshal(map[string]interface{}{
+				"funds":    new(big.Int).Div(f.balance, ether),
+				"funded":   f.nonce,
+				"peers":    f.stack.Server().PeerCount(),
+				"requests": f.reqs,
+			})
+			headData, _ := json.Marshal(head)
+			f.lock.RLock()
 			for _, conn := range f.conns {
-				if err := send(conn, map[string]interface{}{
-					"funds":    balance,
-					"funded":   f.nonce,
-					"peers":    peers,
-					"requests": f.reqs,
-				}, time.Second); err != nil {
+				if err := sendMarshalled(conn, data, time.Second); err != nil {
 					log.Warn("Failed to send stats to client", "err", err)
 					conn.conn.Close()
 					continue
 				}
-				if err := send(conn, head, time.Second); err != nil {
+				if err := sendMarshalled(conn, headData, time.Second); err != nil {
 					log.Warn("Failed to send header to client", "err", err)
 					conn.conn.Close()
 				}
@@ -650,9 +648,10 @@ func (f *faucet) loop() {
 
 		case <-f.update:
 			// Pending requests updated, stream to clients
+			reqData, _ := json.Marshal(map[string]interface{}{"requests": f.reqs})
 			f.lock.RLock()
 			for _, conn := range f.conns {
-				if err := send(conn, map[string]interface{}{"requests": f.reqs}, time.Second); err != nil {
+				if err := sendMarshalled(conn, reqData, time.Second); err != nil {
 					log.Warn("Failed to send requests to client", "err", err)
 					conn.conn.Close()
 				}
@@ -665,14 +664,27 @@ func (f *faucet) loop() {
 // sends transmits a data packet to the remote end of the websocket, but also
 // setting a write deadline to prevent waiting forever on the node.
 func send(conn *wsConn, value interface{}, timeout time.Duration) error {
+	data, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	sendMarshalled(conn, data, timeout)
+}
+
+// sendMarshalled transmits already marshalled json to the remote end of the websocket, but also
+// setting a write deadline to prevent waiting forever on the node.
+func sendMarshalled(conn *wsConn, data []byte, timeout time.Duration) error {
 	if timeout == 0 {
 		timeout = 60 * time.Second
 	}
 	conn.wlock.Lock()
 	defer conn.wlock.Unlock()
-
 	conn.conn.SetWriteDeadline(time.Now().Add(timeout))
-	return conn.conn.WriteJSON(value)
+	w, err := conn.conn.NextWriter(websocket.TextMessage)
+	if err != nil {
+		return err
+	}
+	return w.Write(data)
 }
 
 // sendError transmits an error to the remote end of the websocket, also setting