Add UDP support

README.md

@@ -16,15 +16,18 @@ You first have to define the Graphite client:
 
 ```js
 var graphite = require('graphite');
-var client = graphite.createClient('plaintext://graphite.example.org:2003/');
+// TCP
+var client = graphite.createClient('tcp://graphite.example.org:2003/');
+// UDP
+var client = graphite.createClient('udp://graphite.example.org:2003/');
 ```
 
 You can send metrics without a timestamp. The current Unix epoch will then be used in place:
 
 ```js
 var metrics = {foo: 23};
 client.write(metrics, function(err) {
-  // if err is null, your data was sent to graphite!
+  // if err is null (UDP) or undefined (TCP), your data was sent to graphite!
 });
 ```
 
@@ -34,7 +37,7 @@ If you wish to set your own timestamp, you must use `Date.now()` (millisecond pr
 var metrics = {foo: 23};
 var timestamp = Date.now();
 client.write(metrics, timestamp, function(err) {
-  // if err is null, your data was sent to graphite!
+  // if err is null (UDP) or undefined (TCP), your data was sent to graphite!
 });
 ```
 
@@ -44,7 +47,7 @@ In Graphite [1.1.1 (21.12.17)](http://graphite.readthedocs.io/en/latest/releases
 var metrics = {foo: 23};
 var tags = {'name': 'foo.bar', 'some.fancy.tag': 'somefancyvalue'};
 client.writeTagged(metrics, tags, function(err) {
-  // if err is null, your data was sent to graphite!
+  // if err is null (UDP) or undefined (TCP), your data was sent to graphite!
 });
 ```
 

lib/CarbonClient.js

@@ -27,8 +27,9 @@ CarbonClient.prototype._lazyConnect = function() {
   var dsn  = url.parse(this._dsn);
   var port = parseInt(dsn.port, 10) || 2003;
   var host = dsn.hostname;
+  var proto = dsn.protocol.replace(':', '');
 
-  this._socket = LazySocket.createConnection(port, host);
+  this._socket = LazySocket.createConnection(port, host, proto);
 };
 
 CarbonClient.prototype.end = function() {

lib/LazySocket.js

@@ -1,19 +1,21 @@
 var net = require('net');
+const dgram = require('dgram');
 
 module.exports = LazySocket;
 function LazySocket(properties) {
   properties = properties || {};
 
   this.port = properties.port;
   this.host = properties.host;
+  this.protocol = properties.protocol;
 
   this._socket    = null;
   this._closed = false;
   this._callbacks = [];
 }
 
-LazySocket.createConnection = function(port, host) {
-  var socket = new this({port: port, host: host});
+LazySocket.createConnection = function(port, host, protocol) {
+  var socket = new this({port: port, host: host, protocol: protocol});
   return socket;
 };
 
@@ -37,11 +39,15 @@ LazySocket.prototype.write = function(/* data, encoding, cb */) {
   this._lazyConnect();
 
   try {
-    this._socket.write.apply(this._socket, args);
+    if (this.protocol === 'udp') {
+      this._socket.send(args[0], this.port, this.host, cbProxy);
+    } else {
+      this._socket.write.apply(this._socket, args);
+    }
   } catch (err) {
     if (cbProxy) cbProxy(err);
 
-    this._socket.destroy();
+    this.destroy();
     this._socket = null;
   }
 };
@@ -68,18 +74,36 @@ LazySocket.prototype._lazyConnect = function() {
     }
   }
 
-  this._socket = net
+  if (this.protocol === 'udp') {
+    this._socket = dgram.createSocket({type: 'udp4'})
+      .once('error', onerror)
+      .once('close', onend);
+  } else {
+    this._socket = net
     .createConnection(this.port, this.host)
     .once('error', onerror)
     .once('end', onend);
+  }
 };
 
 LazySocket.prototype.end = function() {
   this._closed = true;
-  if (this._socket) this._socket.end();
+  if (!this._socket) return;
+
+  if (this.protocol === 'udp') {
+    this._socket.unref();
+  } else {
+    this._socket.end();
+  }
 };
 
 LazySocket.prototype.destroy = function() {
   this._closed = true;
-  if (this._socket) this._socket.destroy();
+  if (!this._socket) return;
+
+  if (this.protocol === 'udp') {
+    this._socket.unref();
+  } else {
+    this._socket.destroy();
+  }
 };