Using c-ares-backed DNS resolution

README.md

@@ -73,6 +73,10 @@ Possible option values
  * **outputEncoding** valid for `fetchUrl`
  * **disableDecoding** valid for `fetchUrl`, set to true to disable automatic charset decoding to utf-8
  * **overrideCharset** valid for `fetchUrl`, set input encoding
+ * **asyncDnsLoookup** use high performance asyncronous DNS resolution based on c-ares instead of a thread pool calling getaddrinfo(3)
+ * **timeout** set a timeout in ms
+ * **agent** pass-through http.request agent parameter
+
 
 ## Meta object
 

lib/fetch.js

@@ -3,6 +3,7 @@ var http = require("http"),
     urllib = require("url"),
     utillib = require("util"),
     zlib = require('zlib'),
+    dns = require('dns'),
     Stream = require("stream").Stream,
     CookieJar = require("./cookiejar").CookieJar,
     Iconv = require("iconv").Iconv;
@@ -16,6 +17,9 @@ maxResponseLength : Infinity
 method: GET
 payload: str
 disableGzip: false
+asyncDnsLoookup: false
+timeout: null
+agent: undefined
 
 cookies: ['name=val']
 
@@ -239,6 +243,30 @@ FetchStream.prototype.runStream = function(url){
         url_data.urloptions.headers['content-length'] = this.options.payloadSize;
     }
 
+    url_data.urloptions.agent = this.options.agent;
+
+    if (this.options.asyncDnsLoookup) {
+        var dnsCallback = (function (err, adresses){
+            if (err) {
+                this.emit("error", err);
+                return;
+            }
+
+            url_data.urloptions.headers['host'] = url_data.urloptions.hostname+url_data.urloptions.port;
+            url_data.urloptions.hostname = adresses[0];
+            url_data.urloptions.host=url_data.urloptions.hostname + (url_data.urloptions.port? ':' + url_data.urloptions.port: '');
+
+            this._runStream(url_data, url);
+        }).bind(this);
+
+        dns.resolve4(url_data.urloptions.host, dnsCallback);
+    } else {
+        this._runStream(url_data, url);
+    }
+}
+
+FetchStream.prototype._runStream = function(url_data, url){
+
     var req = url_data.transport.request(url_data.urloptions, (function(res) {
 
         // catch new cookies before potential redirect
@@ -329,6 +357,10 @@ FetchStream.prototype.runStream = function(url){
         this.emit("error", e);
     }).bind(this));
 
+    if (this.options.timeout) {
+        req.setTimeout(this.options.timeout, req.abort.bind(req));
+    }
+
     if(this.options.payload){
         req.end(this.options.payload);
     }else if(this.options.payloadStream){