A reverse proxy tool written in C # that can cache Web pages to local

A reverse proxy tool written in C # that can cache Web pages to local

PROXY.ASHX Master File

<%@ WebHandler language= "C #" class= "proxy"%> using system;using system.web;using system.net;using System.Text;      Using system.io;using system.collections.generic;using system.configuration; //////The contents of the HTTP headers and HTTP responses are stored separately in/proxy/header/and/proxy/body////Hierarchical creation of directories///public class proxy:ihttphandler{HttpResponse Response;    HttpRequest Request;    HttpApplicationState Application;      HttpServerUtility Server;    static string proxycachefolder = configurationmanager.appsettings["Proxycachefolder"];    static string proxydomain = configurationmanager.appsettings["Proxydomain"];    static string proxyreferer = configurationmanager.appsettings["Proxyreferer"];    BOOL proxycachedirectaccess = configurationmanager.appsettings["proxycachedirectaccess"] = = "true"; int proxycacheseconds = Int.          Parse (configurationmanager.appsettings["proxycacheseconds"]); public void ProcessRequest (HttpContext context) {Response = context.        Response; Request = context.        Request; Application = context.        Application; Server = context.          Server; String path = context.        Request.rawurl; BOOL Delcache = path.        IndexOf ("del") > 0; if (delcache) {path = path. Replace ("? del", String.         Empty);   Deletecachefile (path);        Return        } bool Allowcache = request.querystring["cache"] = = "true"; string seconds = request.querystring["seconds"]?? String.        Empty; if (!int.        TryParse (seconds, out proxycacheseconds)) {proxycacheseconds = 3600;        } if (Allowcache) {echodata (path);            } else {WebClient WC = new WebClient (); Wc.            Headers.set ("Referer", proxyreferer); byte[] buffer = WC.            Downloaddata (Proxydomain + path); Response.ContentType = WC.            responseheaders["Content-type"]; foreach (string key in WC. Responseheaders.allkeys) {Response.Headers.Set (key, WC.            Responseheaders[key]); } WC.            Dispose (); Response.OutputStream.Write (buffer, 0, buffer.)        Length);  }          }        ////// cleanup of failed caches /////void Cleartimeoutcache (DirectoryInfo d) {if (d.exists) {fileinfo[] files = d.getfiles (); foreach (FileInfo file in files) {TimeSpan timespan = Datetime.now-file.                LastAccessTime; if (Timespan.totalseconds > Proxycacheseconds) {file.                Delete (); }}}} string Getcachefolderpath (String hash) {string s = string.        Empty;        for (int i = 0; I <= 2; i++) {s + = Hash[i] + "/";    } return s; }      ////// read the cached header and output /////    void Echocacheheader (String cacheheaderpath) {string[] headers = file.readalllines (Cacheheaderpath); for (int i = 0; i < headers. Length; i++) {string[] Headerkeyvalue = headers[i].            Split (': ');                    if (headerkeyvalue.length = = 2) {if (headerkeyvalue[0] = = "Content-type") {                Response.ContentType = headerkeyvalue[1];            } Response.Headers.Set (Headerkeyvalue[0], headerkeyvalue[1]); }}} void Deletecachefile (string path) {string absfolder = Server.MapPath (proxycachefol        der);          String hash = gethashstring (path);          String folder = Getcachefolderpath (hash);        String Cachebodypath = Absfolder + "/body/" + folder + hash;          String Cacheheaderpath = Absfolder + "/header/" + folder + hash;        FileInfo cachebody = new FileInfo (Cachebodypath); FileInfo Cacheheader = new FileInfo (CachehEaderpath);        if (cachebody.exists) {cachebody.delete ();        } if (cacheheader.exists) {cacheheader.delete ();    } Response.Write ("Delete cache file success!\r\n" + path);  }      ////// Output cache /////File path for cache header///File path of the cache body///Whether to make a judgment file expiration///
 
  
   whether the output is successful
  
     BOOL Echocachefile (String Cacheheaderpath, String cachebodypath, bool iftimeout) {FileInfo cachebody = new        FileInfo (Cachebodypath);          FileInfo Cacheheader = new FileInfo (Cacheheaderpath);        Cleartimeoutcache (cachebody.directory);          Cleartimeoutcache (cacheheader.directory); if (cachebody.exists && cacheheader.exists) {if (iftimeout) {times                Pan TimeSpan = datetime.now-cachebody.lastwritetime;                      if (Timespan.totalseconds < proxycacheseconds) {Echocacheheader (Cacheheaderpath);                    Response.TransmitFile (Cachebodypath);                return true;                  }} else {Echocacheheader (cacheheaderpath);                Response.TransmitFile (Cachebodypath);            return true;    }} return false;   } void Echodata (string path) {       String absfolder = Server.MapPath (Proxycachefolder);          String hash = gethashstring (path);          String folder = Getcachefolderpath (hash);        String Cachebodypath = Absfolder + "/body/" + folder + hash;          String Cacheheaderpath = Absfolder + "/header/" + folder + hash;        BOOL success;            if (proxycachedirectaccess) {success = Echocachefile (Cacheheaderpath, Cachebodypath, false);            if (!success) {Response.Write ("read directly from cache failed!");        } return;          } success = Echocachefile (Cacheheaderpath, Cachebodypath, true);        if (success) {return;        }//Update cache File String applicationkey = "Cachelist"; List
 
  List = null;            if (application[applicationkey] = = null) {Application.Lock (); Application[applicationkey] = List = new List
  
   (1000);        Application.UnLock (); } else {list = (list
   
    
) Application[applicationkey]; }//Determine if another process is updating the cache File if (List.contains (hash)) {success = Echocachefile (cache            Headerpath, Cachebodypath, false);            if (success) {return;                } else {WebClient WC = new WebClient (); Wc.                Headers.set ("Referer", proxyreferer); Main content byte[] data = WC.                  Downloaddata (Proxydomain + path); Handle header Response.ContentType = WC.                responseheaders["Content-type"]; foreach (string key in WC. Responseheaders.allkeys) {Response.Headers.Set (key, WC.                Responseheaders[key]); } WC.                Dispose ();                              Response.BinaryWrite (data);            }} else {WebClient WC = new WebClient (); Wc. Headers.set ("Referer", proXyreferer);              StringBuilder HEADERSB = new StringBuilder ();            List.add (hash); Main content byte[] data = WC.                      Downloaddata (Proxydomain + path); Handle header Response.ContentType = WC.            responseheaders["Content-type"]; foreach (string key in WC. Responseheaders.allkeys) {HEADERSB.                Append (key); HEADERSB.                Append (":"); HEADERSB. Append (WC.                Responseheaders[key]); HEADERSB.                Append ("\ r \ n"); Response.Headers.Set (key, WC.            Responseheaders[key]); } WC.              Dispose (); string headers = HEADERSB. ToString ().            Trim (); if (! Directory.Exists (Absfolder + "/header/" + folder)) {directory.createdirectory (Absfolder + "/hea            der/"+ folder);            } StreamWriter SW = File.createtext (Absfolder + "/header/" + folder + hash); Sw.            Write (headers); Sw. Close ();           Sw.                Dispose (); Handle cached content if (! Directory.Exists (Absfolder + "/body/" + folder)) {directory.createdirectory (Absfolder + "/body/            "+ folder");            } FileStream fs = File.create (Absfolder + "/body/" + folder + hash); Fs. Write (data, 0, data.            Length); Fs.            Close (); Fs.              Dispose ();                                        List.remove (hash);        Response.BinaryWrite (data);        }} string Gethashstring (String path) {string MD5 = GETMD5STR (path);    return MD5; } static string Getmd5str (String convertstring) {System.Security.Cryptography.MD5CryptoServiceProvider m        d5 = new System.Security.Cryptography.MD5CryptoServiceProvider ();        String t2 = bitconverter.tostring (Md5.computehash (UTF8Encoding.Default.GetBytes (convertstring)), 4, 8); t2 = T2.          Replace ("-", "" ");    return T2;   } public bool IsReusable {     get {return false; }    }  }
   
  
 

Web. config

 
   
  
   
        
     

   
    
  
   
     
      
       
      
       ~/.*$ 
        ~/ajax/.*$ ~/proxy.ashx?cache=true&seconds=30 
               
           
         
  
      
      
       
       
       ~/proxy.ashx?cache=false         
                      
            
           
         
  
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