[refactor] Manage our own internal list of Agent instances

lib/node-http-proxy.js

@@ -36,6 +36,11 @@ var util = require('util'),
 //
 exports.version = [0, 5, 7];
 
+//
+// Track our own list of agents internal to `node-http-proxy`
+//
+var _agents = {};
+
 //
 // ### function _getAgent (host, port, secure)
 // #### @host {string} Host of the agent to get
@@ -45,13 +50,23 @@ exports.version = [0, 5, 7];
 // and sets the `maxSockets` property appropriately.
 //
 function _getAgent (host, port, secure) {
-  var agent = !secure ? http.getAgent(host, port) : https.getAgent({ 
-    host: host, 
-    port: port 
-  });
-      
-  agent.maxSockets = maxSockets;
-  return agent;
+  var Agent, id = [host, port].join(':');
+  
+  if (!port) {
+    port = secure ? 443 : 80;
+  }
+  
+  if (!_agents[id]) {
+    Agent = secure ? https.Agent : http.Agent;
+
+    _agents[id] = new Agent({ 
+      host: host, 
+      port: port,
+      maxSockets: maxSockets
+    });
+  }
+
+  return _agents[id];
 }
 
 //