Question

尝试向所有连接广播（或在此情况下，多播）价格标记。 Ticks进入端口4950，并在3000上进行多播。获得以下错误;我无法理解无法读取clients数组的原因：

[keith@localhost Ritchie]$ node marketDataServer.js
UDP Server listening on 192.168.1.109:4950
Websocket multicasting to 192.168.1.109:3000
Event: 'connection'
/home/keith/Documents/2017/Ritchie/marketDataServer.js:44
    ws.clients.forEach(function each(client){
              ^

TypeError: Cannot read property 'forEach' of undefined
at WebSocketServer.incoming 
(/home/keith/Documents/2017/Ritchie/marketDataServer.js:44:13)
at emitTwo (events.js:106:13)
at Socket.emit (events.js:191:7)
at UDP.onMessage (dgram.js:548:8)

单人工作正常（在下面的代码中注明）
根据以下文档，我已将clientTracking设为true
此处的示例基于文档中的广播示例 https://github.com/websockets/ws#broadcast-example

/* *************************************
Exchange Listener
Receives price ticks from the exchange
*/
var exchange_addr = '192.168.1.109';
var exchange_port = 4950;
var dgram = require('dgram');
var server = dgram.createSocket('udp4');
server.on('listening', function () {
    var address = server.address();
    console.log('UDP Server listening on ' + address.address + ":" + address.port);
});
server.bind(exchange_port, exchange_addr);

/* *************************************
Tick Data Websocket Server
Sends price ticks out to all connected websockets
*/
var websocket_addr = '192.168.1.109';
var websocket_port = 3000;
var WebSocketServer = require('ws').Server, ws = new WebSocketServer({host:websocket_addr, port:websocket_port});
console.log('Websocket Listening to ' + websocket_addr + ':' + websocket_port + ' ...');
ws.clientTracking = true;

/* *************************************
Websocket unicast
Works fine
*/    
// ws.on('connection', function(ws) {
//     console.log('New connection');
//  server.on('message', function (message, remote) {
//      var price = message + ' ';
//      ws.send(price); 
//      console.log(remote.address + ':' + remote.port +' - ' + message);
//  });
// });


/* *************************************
Broadcast/Multicast
##### NOT WORKING
*/
ws.broadcast = function broadcast(data) {
    ws.clients.forEach(function each(client) {
        if (client.readyState === WebSocket.OPEN) {
            var price = message + ' ';
            ws.send(price); 
        }
    });
};

ws.on('connection', function(ws) {
    console.log('Event: \'connection\'');
    server.on('message', function incoming(message) {
        var price = message + ' ';
        ws.clients.forEach(function each(client){
            client.send(price);
        });
        console.log(remote.address + ':' + remote.port +' - ' + message);
    });
});

Answer 1

您正在使用

   ws.clients.forEach(function each(client){

但是wss包含所有客户端，ws只是一个客户端。所以应该是：

wss.on('broadcast',function(msg){
  this.clients.forEach(function each(client) {
            client.send(msg);
        });
});

然后（例如）

wss.broadcast(price);

顺便说一句，wss不是数组而是集合，因此您可以拥有数量为wss.clients.size（而不是.length）的客户端

无法读取nodejs ws broadcast / multicast的``clients``数组

1 个答案: