added feature detection for native KeepAlive support in 0.11

src/lib/connectors/_custom_agent.js

@@ -0,0 +1,48 @@
+var ForeverAgent = require('forever-agent');
+var ForeverSSLAgent = require('forever-agent').SSL;
+
+var NativeAgent = require('http').Agent;
+var NativeSSLAgent = require('https').Agent;
+
+var inherits = require('util').inherits;
+var nativeKeepAlive = (function () {
+  var a = new NativeAgent();
+  return !!a.freeSockets;
+}());
+
+function WrapForeverAgent(opts) {
+  ForeverAgent.call(this, opts);
+  var _addRequest = this.addRequest;
+  this.addRequest = function (req, host, port) {
+    req.useChunkedEncodingByDefault = false;
+    _addRequest.call(this, req, host, port);
+  };
+}
+inherits(WrapForeverAgent, ForeverAgent);
+
+function WrapForeverSSLAgent(opts) {
+  ForeverSSLAgent.call(this, opts);
+  var _addRequest = this.addRequest;
+  this.addRequest = function (req, host, port) {
+    req.useChunkedEncodingByDefault = false;
+    _addRequest.call(this, req, host, port);
+  };
+}
+inherits(WrapForeverSSLAgent, ForeverSSLAgent);
+
+function WrapNativeAgent(opts) { NativeAgent.call(this, opts); }
+inherits(WrapNativeAgent, NativeAgent);
+
+function WrapNativeSSLAgent(opts) { NativeSSLAgent.call(this, opts); }
+inherits(WrapNativeSSLAgent, NativeSSLAgent);
+
+
+if (nativeKeepAlive) {
+  module.exports = WrapNativeAgent;
+  module.exports.SSL = WrapNativeSSLAgent;
+} else {
+  module.exports = WrapForeverAgent;
+  module.exports.SSL = WrapForeverSSLAgent;
+}
+
+module.exports.supportsNativeKeepAlive = nativeKeepAlive;