record http requests

rechttprequests

using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading;
using System.Web;

namespace MvcApplication9.Modules {
  public class TrackHttpRequest:IHttpModule {
		public void Dispose() {
			//throw new NotImplementedException();
		}

		static ZMQ.Context ZMQContext = new ZMQ.Context();

		[ThreadStatic]
		static ZMQ.Socket _socket;
		static ZMQ.Socket Socket {
			get {
				if(_socket == null) {
					AssertReceiverSenderRunning();
					_socket = ZMQContext.Socket(ZMQ.SocketType.PUSH);
					_socket.Connect(SocketAddr);
				}
				return _socket;
			}
		}

		readonly static object _lock = new object();
		static volatile bool _receiverSenderStarted  =false;

		private static void AssertReceiverSenderRunning() {
			if(_receiverSenderStarted) {
				return;
			}
			lock(_lock) {
				if(_receiverSenderStarted) {
					return;
				}
				var receiverSender = new Thread(()=> {
					var socket = ZMQContext.Socket(ZMQ.SocketType.PULL);
					socket.Bind(SocketAddr); 	
					var senderSocket = ZMQContext.Socket(ZMQ.SocketType.REQ);
					senderSocket.Bind(RemoteSocketAddr);
					_receiverSenderStarted = true;
					while(true) {
						var received = socket.Recv();
						senderSocket.Send(received);
						senderSocket.Recv();
					}				
				});
				receiverSender.Start();

				while(!_receiverSenderStarted){}
			}
		}

		const string SocketAddr = "inproc://queuedhttprequests";
		readonly static string RemoteSocketAddr = ConfigurationManager.AppSettings["ZMQ_HttpRequestsSocketAddress"];

		public void Init(HttpApplication context) {
			context.BeginRequest+=(s,o) => {
				var request = GetHttpRequest(new HttpRequestWrapper(HttpContext.Current.Request));
				//var httpRequest = GetHttpRequest(request);
				
				Socket.Send(PrependHeader(request));
			};
		}

		private byte[] PrependHeader(byte[] httpRequest) {
			using(var ms = new MemoryStream()) {
				var writer = new StreamWriter(ms);
				
				writer.Write("{0}|{1}\r\n", DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss.fff"), Thread.CurrentThread.ManagedThreadId);
				writer.Flush();
				using(var input = new MemoryStream(httpRequest)) {
					input.CopyTo(ms);
				}
				return ms.ToArray();
			}
		}

		static byte[] GetHttpRequest(HttpRequestBase request) {
			using(var stream = new MemoryStream()) {
				var writer = new StreamWriter(stream);
				writer.Write(request.HttpMethod + " " + request.Path);
				var queryStringText = GetRawQueryString(request);

				if(!string.IsNullOrEmpty(queryStringText)) {
					writer.Write("?"+queryStringText);
				}
				writer.Write(" "+request.ServerVariables["SERVER_PROTOCOL"]+"\r\n");
				writer.Write(request.ServerVariables["ALL_RAW"]);

				writer.Write("\r\n");

				writer.Flush();

				var pos = request.InputStream.Position;
				try {
					request.InputStream.Position = 0;
					request.InputStream.CopyTo(stream);
					return stream.ToArray();
				}
				finally {
					request.InputStream.Position = pos;
				}
			}
		}

		readonly static FieldInfo _httpRequestField = typeof(HttpRequestWrapper).GetField("_httpRequest",BindingFlags.NonPublic|BindingFlags.Instance);
		readonly static PropertyInfo _httpRequestQueryStringProperty = typeof(HttpRequest).GetProperty("QueryStringText",BindingFlags.NonPublic|BindingFlags.Instance);
		private static string GetRawQueryString(HttpRequestBase request) {
			var requestObject = (HttpRequest)_httpRequestField.GetValue(request);
			var queryStringText= (string)_httpRequestQueryStringProperty.GetValue(requestObject,null);

			return queryStringText;
		}
	}
}