Add TCP support

lib/statsd.js

@@ -3,6 +3,7 @@
 var dgram         = require('dgram'),
     util          = require('util'),
     dns           = require('dns'),
+    net           = require('net'),
     helpers       = require('./helpers'),
     applyStatsFns = require('./statsFunctions');
 
@@ -25,7 +26,7 @@ var dgram         = require('dgram'),
  * @constructor
  */
 var Client = function (host, port, prefix, suffix, globalize, cacheDns, mock,
-    globalTags, maxBufferSize, bufferFlushInterval, telegraf, sampleRate) {
+    globalTags, maxBufferSize, bufferFlushInterval, telegraf, sampleRate, protocol) {
   var options = host || {},
          self = this;
 
@@ -42,18 +43,37 @@ var Client = function (host, port, prefix, suffix, globalize, cacheDns, mock,
       maxBufferSize : maxBufferSize,
       bufferFlushInterval: bufferFlushInterval,
       telegraf    : telegraf,
-      sampleRate    : sampleRate
+      sampleRate  : sampleRate,
+      protocol    : protocol
     };
   }
 
+  function createSocket(args) {
+    var socket;
+
+    if (args.protocol === 'tcp') {
+      socket = net.connect(args.port, args.host);
+      socket.setKeepAlive(true);
+    } else {
+      socket = dgram.createSocket('udp4');
+    }
+
+    return socket;
+  }
+
   // hidden global_tags option for backwards compatibility
   options.globalTags = options.globalTags || options.global_tags;
 
+  this.protocol = options.protocol;
   this.host        = options.host || 'localhost';
   this.port        = options.port || 8125;
   this.prefix      = options.prefix || '';
   this.suffix      = options.suffix || '';
-  this.socket      = options.isChild ? options.socket : dgram.createSocket('udp4');
+  this.socket      = options.isChild ? options.socket : createSocket({
+    host: this.host,
+    port: this.port,
+    protocol: this.protocol
+  });
   this.mock        = options.mock;
   this.globalTags  = typeof options.globalTags === "object" ?
       helpers.formatTags(options.globalTags, options.telegraf) : [];
@@ -216,6 +236,11 @@ Client.prototype.send = function (message, tags, callback) {
       message += '|#' + mergedTags.join(',');
     }
   }
+
+  if (this.protocol === 'tcp') {
+    message += '\n';
+  }
+
   this._send(message, callback);
 };
 
@@ -298,7 +323,11 @@ Client.prototype.sendMessage = function(message, callback){
   }
   var buf = new Buffer(message);
   try {
-    this.socket.send(buf, 0, buf.length, this.port, this.host, callback);
+    if(this.protocol === 'tcp') {
+      this.socket.write(buf, 'ascii', callback);
+    } else {
+      this.socket.send(buf, 0, buf.length, this.port, this.host, callback);
+    }
   }
   catch(err) {
     var errMessage = 'Error sending hot-shots message: ' + err;
@@ -375,7 +404,8 @@ var ChildClient = function (parent, options) {
         helpers.overrideTags(parent.globalTags, options.globalTags, parent.telegraf) : parent.globalTags,
     maxBufferSize : parent.maxBufferSize,
     bufferFlushInterval: parent.bufferFlushInterval,
-    telegraf    : parent.telegraf
+    telegraf    : parent.telegraf,
+    protocol    : parent.protocol
   });
 };
 util.inherits(ChildClient, Client);