IIS的內部原理

對IIS只有表面的理解   現在模擬一下IIS的內部原理：

        public int ServerScoket { get; set; }
        private void btnStart_Click(object sender, EventArgs e)
        {
            IPAddress ipAddress = IPAddress.Parse(this.txtIP.Text);
            IPEndPoint endpoint = new IPEndPoint(ipAddress, int.Parse(this.txtPort.Text));
            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            socket.Bind(endpoint);
            socket.Listen(10);
            this.lbStatus.Text = "啟動";
            this.lbStatus.ForeColor = Color.Green;
            //開始socket的接受請求
            ThreadPool.QueueUserWorkItem(a =>
                {
                    //線程池默認都是后台線程
                    Socket serverSocket = (Socket)a;
                    while (true)
                    {
                        //獲取到跟瀏覽器交互的代理socket
                       var proxSocket= serverSocket.Accept();
                        
                       ThreadPool.QueueUserWorkItem(s => 
                       {
                           Socket pSocket = (Socket)s;
                           byte[] bytes = new byte[1024 * 1024];
                           int realLength = pSocket.Receive(bytes);
                           //把當前的報文封裝到了strRequest里面去了
                           string strRequest = Encoding.UTF8.GetString(bytes, 0, realLength);
                           //處理當前的報文，解析當前報文，看看請求是哪個文件，
                           //把請求的文件封裝成相應的報文，通過socket發送給瀏覽器
                           ProcessRequest(strRequest, pSocket);
                       }, proxSocket);
                    }
                },socket);
        }
        //處理客戶端的請求
        private void ProcessRequest(string strRequest, Socket pSocket)
        {
            //把請求行取出來
            //初始化請求信息和響應信息實例
            HttpContext context = new HttpContext(strRequest);
            HttpApplication application = new HttpApplication();

            //這時候，請求的響應已經做好了
            //正在處理HTTP請求
            application.ProcessRequest(context);

            //context response
            pSocket.Send(context.Response.GetHeader());
            pSocket.Send(context.Response.BodyData);
            pSocket.Shutdown(SocketShutdown.Both);
            pSocket.Close();
        }

HttpContext封裝上下文

  public   class HttpContext
    {
      //設置請求
      public HttpRequest Request { get; set; }
      //響應的實例
      public HttpResponse Response { get; set; }
      //構造函數
      public HttpContext(string httpRequestStr)
      {
          Request = new HttpRequest(httpRequestStr);
          Response = new HttpResponse(Request);
      }
    }

HttpRequest對象：

    /// <summary>
    /// 封裝請求報文的信息
    /// </summary>
  public  class HttpRequest
    {
        /*
         GET /login.aspx HTTP/1.1
        Accept: text/html, application/xhtml+xml, #1#*
        Accept-Language: zh-CN
        User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; QDesk 2.3.1185.202; Windows NT 6.1; Trident/5.0)
        Accept-Encoding: gzip, deflate
        Host: localhost:38888
        Connection: Keep-Alive*/

      //將報文傳進來
      public HttpRequest(string requestStr)
      {
          if(!string.IsNullOrEmpty(requestStr))
          {
            string[] lines=requestStr.Replace("\r\n","\r").Split('\r');
              //處理請求的Method
            this.Method = lines[0].Split(' ')[0];
              //設置請求的URL 地址
            this.RequestURL = lines[0].Split(' ')[1];
          }
      }
      //是Get 還是set
      public string  Method { get; set; }
      public string  RequestURL { get; set; }
    }

HttpResponse

  public class HttpResponse
    {
       //請求文件的后綴
       private string _requestFileExt;
       public HttpResponse(HttpRequest request)
       {
           _requestFileExt = Path.GetExtension(request.RequestURL);
       }
       //獲取相應提報文字節數組
       public byte[] BodyData { get; set; }
       //獲取響應頭部
       public byte[] GetHeader()
       {
           StringBuilder sb = new StringBuilder();
           sb.AppendFormat("HTTP/1.1 200 OK\r\n");
           sb.AppendFormat("Content-Type: {0} \r\n", GetContentType(_requestFileExt));
           return Encoding.UTF8.GetBytes(sb.ToString());
       }

       public string GetContentType(string _requestFileExt)
       {
           string type = "text/html";
           switch (_requestFileExt)
           {
               case ".aspx":
                   case ".html":
                case ".htm":
                    type = "text/html";
                    break;
                case ".png":
                    type = "image/png";
                    break;
                case ".gif":
                    type = "image/gif";
                    break;
                case ".jpg":
                case ".jpeg":
                    type = "image/jpeg";
                    break;
                case ".css":
                    type = "text/css";
                    break;
                case ".js":
                    type = "application/x-javascript";
                    break;
                default:
                    type = "text/plain";
                    break;
           }
           return type;
       }

       //返回響應主體
       public byte[] GetBodyData()
       {
           return BodyData;
       }
    }

HttpApplication 中處理

   public  class HttpApplication
    { public void ProcessRequest(HttpContext context)
       {
           string ext = Path.GetExtension(context.Request.RequestURL);
           switch (ext)
           {
               case ".jpg":
               case ".jpeg":
               case ".html":
               case ".htm":
               case ".css":
               case ".js":
                   ProcessStaticFile(context); break;
               case ".aspx":
                   ProcessDynamicFile(context);
                   break;
               default:
                   ProcessStaticFile(context);
                   break;
           }
       }
       //處理動態頁面
       public void ProcessDynamicFile(HttpContext context)
       {
           //假設請求Index.aspx
           string className=Path.GetFileNameWithoutExtension(context.Request.RequestURL);
           //獲取命名空間
           string nameSpace = System.Reflection.MethodBase.GetCurrentMethod().DeclaringType.Namespace;
           //_02HeimaIIS.IndexPage
           string fullName = nameSpace + "." + className;
           //用接口接受不同的實例
           IHttpHandler obj=(IHttpHandler)System.Reflection.Assembly.GetExecutingAssembly().CreateInstance(fullName,true);
           if (obj == null)
           {

           }
           else
           {
               obj.ProcessRequest(context);
           }
       }
       //處理靜態頁面
       public void ProcessStaticFile(HttpContext context)
       {
           string currentWebDir = AppDomain.CurrentDomain.BaseDirectory;
           string fileName=Path.Combine(currentWebDir,context.Request.RequestURL.TrimStart('/'));
           context.Response.BodyData = File.ReadAllBytes(fileName);
       }
    }

如果是靜態網頁直接返回

如果是動態頁面通過反射實現

以上就是面向接口編程

    public class MyPage : IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            //可以訪問數據庫，就是動態的
            string strBody = @"<html><head></head><body><h2> big shit y</h2></body></html>";
            context.Response.BodyData = Encoding.UTF8.GetBytes(strBody);
        }      
    }

 

 IIS內部處理的文字總結：

 設置一個監聽隊列，用一個應用程序池中的實例socket A，接受瀏覽器發送的數據，再從應用程序池中獲取一個實例 socket B將接受到的數據進行處理，而 socket A 不斷接受瀏覽器的請求。

socket B處理數據（用到HttpContext HttpApplication MyPage IHandler）

HttpContext

　　HttpRequest 獲取請求的方法 及請求的地址

　　HttpResponse得到響應體和 響應頭

HttpApplication

　　根據后綴名判斷是動態網頁還是靜態網頁

　　動態網頁：通過反射獲取命名空間  通過請求地址找到類名  通過反射獲取實例轉化成接口，調用其方法。

處理完成后，由代理socket發送報文頭和報文體