Websocket message queue using streams and Delay between messages (#335)

Author: avnotaklu

lib/src/config.dart

@@ -61,8 +61,12 @@ class Settings {
 
   /// ICE Gathering Timeout (in millisecond).
   int ice_gathering_timeout = 500;
+
+  /// Sip Message Delay (in millisecond) ( default 0 ).
+  int sip_message_delay = 0;
 }
 
+
 // Configuration checks.
 class Checks {
   Map<String, Null Function(Settings src, Settings? dst)> mandatory =

lib/src/sip_ua_helper.dart

@@ -116,9 +116,10 @@ class SIPUAHelper extends EventManager {
     // Reset settings
     _settings = Settings();
     WebSocketInterface socket = WebSocketInterface(
-        uaSettings.webSocketUrl, uaSettings.webSocketSettings);
+        uaSettings.webSocketUrl, messageDelay: _settings.sip_message_delay, webSocketSettings: uaSettings.webSocketSettings);
     _settings.sockets = <WebSocketInterface>[socket];
     _settings.uri = uaSettings.uri;
+    _settings.sip_message_delay = uaSettings.sip_message_delay;
     _settings.realm = uaSettings.realm;
     _settings.password = uaSettings.password;
     _settings.ha1 = uaSettings.ha1;
@@ -698,7 +699,8 @@ class UaSettings {
 
   /// ICE Gathering Timeout, default 500ms
   int iceGatheringTimeout = 500;
-
+  /// Sip Message Delay (in millisecond) (default 0).
+  int sip_message_delay = 0;
   List<Map<String, String>> iceServers = <Map<String, String>>[
     <String, String>{'url': 'stun:stun.l.google.com:19302'},
 // turn server configuration example.

lib/src/transports/websocket_dart_impl.dart

@@ -11,17 +11,18 @@ typedef OnCloseCallback = void Function(int? code, String? reason);
 typedef OnOpenCallback = void Function();
 
 class WebSocketImpl {
-  WebSocketImpl(this._url);
+  WebSocketImpl(this._url, this.messageDelay);
 
   final String _url;
   WebSocket? _socket;
   OnOpenCallback? onOpen;
   OnMessageCallback? onMessage;
   OnCloseCallback? onClose;
-
+  final int messageDelay;
   void connect(
       {Iterable<String>? protocols,
       required WebSocketSettings webSocketSettings}) async {
+      handleQueue();
     logger.i('connect $_url, ${webSocketSettings.extraHeaders}, $protocols');
     try {
       if (webSocketSettings.allowBadCertificate) {
@@ -42,11 +43,20 @@ class WebSocketImpl {
       onClose?.call(500, e.toString());
     }
   }
+  final StreamController<dynamic> queue = StreamController<dynamic>.broadcast();
+  void handleQueue() async {
+    queue.stream.asyncMap((dynamic event) async {
+      await Future<void>.delayed(Duration(milliseconds: messageDelay));
+      return event;
+    }).listen((dynamic event) async {
+      _socket!.add(event);
+      logger.d('send: \n\n$event');
+    });
+  }
 
-  void send(dynamic data) {
+  void send(dynamic data) async {
     if (_socket != null) {
-      _socket!.add(data);
-      logger.d('send: \n\n$data');
+      queue.add(data);
     }
   }
 

lib/src/transports/websocket_interface.dart

@@ -7,7 +7,11 @@ import 'websocket_dart_impl.dart'
     if (dart.library.js) 'websocket_web_impl.dart';
 
 class WebSocketInterface implements Socket {
-  WebSocketInterface(String url, [WebSocketSettings? webSocketSettings]) {
+  final int _messageDelay;
+
+  WebSocketInterface(String url,
+      {required int messageDelay, WebSocketSettings? webSocketSettings})
+      : _messageDelay = messageDelay {
     logger.d('new() [url:$url]');
     _url = url;
     dynamic parsed_url = Grammar.parse(url, 'absoluteURI');
@@ -83,7 +87,7 @@ class WebSocketInterface implements Socket {
     }
     logger.d('connecting to WebSocket $_url');
     try {
-      _ws = WebSocketImpl(_url!);
+      _ws = WebSocketImpl(_url!, _messageDelay);
 
       _ws!.onOpen = () {
         _closed = false;