udp-kcp

KCP Protocol for Node.js

Notice

Based on github.com/leenjewel/node-kcp, and add a function getconv, 
which may be useful when you need multiple udp connections with 
the same host and port, i.e. among peer hosts

Example:

Install by npm

npm install udp-kcp

udpserver.js

var kcp = require('udp-kcp');
var dgram = require('dgram');
var server = dgram.createSocket('udp4');
var clients = {};
var interval = 200;

var output = function(data, size, context) {
    server.send(data, 0, size, context.port, context.address);
};

server.on('error', (err) => {
    console.log(`server error:\n${err.stack}`);
    server.close();
});

server.on('message', (msg, rinfo) => {
    var k = rinfo.address+'_'+rinfo.port;
    if (undefined === clients[k]) {
        var context = {
            address : rinfo.address,
            port : rinfo.port
        };
        var kcpobj = new kcp.KCP(123, context);
        kcpobj.nodelay(0, interval, 0, 0);
        kcpobj.output(output);
        clients[k] = kcpobj;
    }
    var kcpobj = clients[k];
    console.log('conv: ', kcpobj.getconv(data));
    kcpobj.input(msg);
});

server.on('listening', () => {
    var address = server.address();
    console.log(`server listening ${address.address} : ${address.port}`);
    setInterval(() => {
        for (var k in clients) {
            var kcpobj = clients[k];
        	kcpobj.update(Date.now());
        	var recv = kcpobj.recv();
        	if (recv) {
            	console.log(`server recv ${recv} from ${kcpobj.context().address}:${kcpobj.context().port}`);
           		kcpobj.send('RE-'+recv);
       	 	}
       	}
    }, interval);
});

server.bind(41234);

udpclient.js

var kcp = require('udp-kcp');
var kcpobj = new kcp.KCP(123, {address: '127.0.0.1', port: 41234});
var dgram = require('dgram');
var client = dgram.createSocket('udp4');
var msg = 'hello world';
var idx = 1;
var interval = 200;

kcpobj.nodelay(0, interval, 0, 0);

kcpobj.output((data, size, context) => {
    client.send(data, 0, size, context.port, context.address);
});

client.on('error', (err) => {
    console.log(`client error:\n${err.stack}`);
    client.close();
});

client.on('message', (msg, rinfo) => {
    kcpobj.input(msg);
});

setInterval(() => {
    kcpobj.update(Date.now());
    var recv = kcpobj.recv();
    if (recv) {
        console.log(`client recv ${recv}`);
        kcpobj.send(msg+(idx++));
    }
}, interval);

kcpobj.send(msg+(idx++));

About Pomelo and Pomelo-kcp

If you want to use udp-kcp in pomelo server, you need pomelo-kcp