mcs/class/System.Web/System.Web/HttpResponse.cs

   1 //
   2 // System.Web.HttpResponse.cs
   3 //
   4 //
   5 // Author:
   6 //      Miguel de Icaza (miguel@novell.com)
   7 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   8 //
   9 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Text;
  32 using System.Web.UI;
  33 using System.Collections;
  34 using System.Collections.Specialized;
  35 using System.IO;
  36 using System.Web.Caching;
  37 using System.Threading;
  38 using System.Web.Util;
  39 using System.Web.Configuration;
  40 using System.Globalization;
  41 using System.Security.Permissions;
  42 #if TARGET_J2EE
  43 using vmw.@internal.j2ee;
  44 #endif
  45
  46 namespace System.Web {
  47
  48         // CAS - no InheritanceDemand here as the class is sealed
  49         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  50         public sealed class HttpResponse {
  51                 internal HttpWorkerRequest WorkerRequest;
  52                 internal HttpResponseStream output_stream;
  53                 internal bool buffer = true;
  54
  55                 HttpContext context;
  56                 TextWriter writer;
  57                 HttpCachePolicy cache_policy;
  58                 Encoding encoding;
  59                 HttpCookieCollection cookies;
  60
  61                 int status_code = 200;
  62                 string status_description = "OK";
  63
  64                 string content_type = "text/html";
  65                 string charset;
  66                 bool charset_set;
  67                 CachedRawResponse cached_response;
  68                 string user_cache_control = "private";
  69                 string redirect_location;
  70
  71                 //
  72                 // Negative Content-Length means we auto-compute the size of content-length
  73                 // can be overwritten with AppendHeader ("Content-Length", value)
  74                 //
  75                 long content_length = -1;
  76
  77                 //
  78                 // The list of the headers that we will send back to the client, except
  79                 // the headers that we compute here.
  80                 //
  81                 ArrayList headers = new ArrayList ();
  82                 bool headers_sent;
  83                 ArrayList cached_headers;
  84
  85                 //
  86                 // Transfer encoding state
  87                 //
  88                 string transfer_encoding;
  89                 internal bool use_chunked;
  90
  91                 bool closed;
  92                 internal bool suppress_content;
  93
  94                 //
  95                 // Session State
  96                 //
  97                 string app_path_mod;
  98
  99                 //
 100                 // Passed as flags
 101                 //
 102                 internal object FlagEnd = new object ();
 103
 104 #if NET_2_0
 105                 bool is_request_being_redirected;
 106                 Encoding headerEncoding;
 107 #endif
 108
 109                 internal HttpResponse ()
 110                 {
 111                         output_stream = new HttpResponseStream (this);
 112                 }
 113
 114                 public HttpResponse (TextWriter writer) : this ()
 115                 {
 116                         this.writer = writer;
 117                 }
 118
 119                 internal HttpResponse (HttpWorkerRequest worker_request, HttpContext context) : this ()
 120                 {
 121                         WorkerRequest = worker_request;
 122                         this.context = context;
 123
 124                         if (worker_request != null)
 125                                 use_chunked = (worker_request.GetHttpVersion () == "HTTP/1.1");
 126                 }
 127
 128                 internal TextWriter SetTextWriter (TextWriter writer)
 129                 {
 130                         TextWriter prev = this.writer;
 131                         this.writer = writer;
 132                         return prev;
 133                 }
 134
 135                 public bool Buffer {
 136                         get {
 137                                 return buffer;
 138                         }
 139
 140                         set {
 141                                 buffer = value;
 142                         }
 143                 }
 144
 145                 public bool BufferOutput {
 146                         get {
 147                                 return buffer;
 148                         }
 149
 150                         set {
 151                                 buffer = value;
 152                         }
 153                 }
 154
 155                 //
 156                 // Use the default from <globalization> section if the client has not set the encoding
 157                 //
 158                 public Encoding ContentEncoding {
 159                         get {
 160                                 if (encoding == null) {
 161                                         if (context != null) {
 162                                                 string client_content_type = context.Request.ContentType;
 163                                                 string parameter = HttpRequest.GetParameter (client_content_type, "; charset=");
 164                                                 if (parameter != null) {
 165                                                         try {
 166                                                                 // Do what the #1 web server does
 167                                                                 encoding = Encoding.GetEncoding (parameter);
 168                                                         } catch {
 169                                                         }
 170                                                 }
 171                                         }
 172                                         if (encoding == null)
 173                                                 encoding = WebEncoding.ResponseEncoding;
 174                                 }
 175                                 return encoding;
 176                         }
 177
 178                         set {
 179                                 if (value == null)
 180                                         throw new ArgumentException ("ContentEncoding can not be null");
 181
 182                                 encoding = value;
 183                                 HttpWriter http_writer = writer as HttpWriter;
 184                                 if (http_writer != null)
 185                                         http_writer.SetEncoding (encoding);
 186                         }
 187                 }
 188
 189                 public string ContentType {
 190                         get {
 191                                 return content_type;
 192                         }
 193
 194                         set {
 195                                 content_type = value;
 196                         }
 197                 }
 198
 199                 public string Charset {
 200                         get {
 201                                 if (charset == null)
 202                                         charset = ContentEncoding.WebName;
 203
 204                                 return charset;
 205                         }
 206
 207                         set {
 208                                 charset_set = true;
 209                                 charset = value;
 210                         }
 211                 }
 212
 213                 public HttpCookieCollection Cookies {
 214                         get {
 215                                 if (cookies == null)
 216                                         cookies = new HttpCookieCollection (true, false);
 217                                 return cookies;
 218                         }
 219                 }
 220
 221                 public int Expires {
 222                         get {
 223                                 if (cache_policy == null)
 224                                         return 0;
 225
 226                                 return cache_policy.ExpireMinutes ();
 227                         }
 228
 229                         set {
 230                                 Cache.SetExpires (DateTime.Now + new TimeSpan (0, value, 0));
 231                         }
 232                 }
 233
 234                 public DateTime ExpiresAbsolute {
 235                         get {
 236                                 return Cache.Expires;
 237                         }
 238
 239                         set {
 240                                 Cache.SetExpires (value);
 241                         }
 242                 }
 243
 244                 public Stream Filter {
 245                         get {
 246                                 if (WorkerRequest == null)
 247                                         return null;
 248
 249                                 return output_stream.Filter;
 250                         }
 251
 252                         set {
 253                                 output_stream.Filter = value;
 254                         }
 255                 }
 256 #if NET_2_0
 257                 public Encoding HeaderEncoding {
 258                         get {
 259                                 if (headerEncoding == null) {
 260                                         GlobalizationSection gs = WebConfigurationManager.SafeGetSection ("system.web/globalization", typeof (GlobalizationSection)) as GlobalizationSection;
 261
 262                                         if (gs == null)
 263                                                 headerEncoding = Encoding.UTF8;
 264                                         else {
 265                                                 headerEncoding = gs.ResponseHeaderEncoding;
 266                                                 if (headerEncoding == Encoding.Unicode)
 267                                                         throw new HttpException ("HeaderEncoding must not be Unicode");
 268                                         }
 269                                 }
 270                                 return headerEncoding;
 271                         }
 272                         set {
 273                                 if (headers_sent)
 274                                         throw new HttpException ("headers have already been sent");
 275                                 if (value == null)
 276                                         throw new ArgumentNullException ("HeaderEncoding");
 277                                 if (value == Encoding.Unicode)
 278                                         throw new HttpException ("HeaderEncoding must not be Unicode");
 279                                 headerEncoding = value;
 280                         }
 281                 }
 282 #endif
 283                 public bool IsClientConnected {
 284                         get {
 285                                 if (WorkerRequest == null)
 286                                         return true; // yep that's true
 287
 288                                 return WorkerRequest.IsClientConnected ();
 289                         }
 290                 }
 291 #if NET_2_0
 292                 public bool IsRequestBeingRedirected {
 293                         get { return is_request_being_redirected; }
 294                 }
 295 #endif
 296                 public TextWriter Output {
 297                         get {
 298                                 if (writer == null)
 299                                         writer = new HttpWriter (this);
 300
 301                                 return writer;
 302                         }
 303                 }
 304
 305                 public Stream OutputStream {
 306                         get {
 307                                 return output_stream;
 308                         }
 309                 }
 310
 311                 public string RedirectLocation {
 312                         get {
 313                                 return redirect_location;
 314                         }
 315
 316                         set {
 317                                 redirect_location = value;
 318                         }
 319                 }
 320
 321                 public string Status {
 322                         get {
 323                                 return String.Format ("{0} {1}", status_code, StatusDescription);
 324                         }
 325
 326                         set {
 327                                 int p = value.IndexOf (' ');
 328                                 if (p == -1)
 329                                         throw new HttpException ("Invalid format for the Status property");
 330
 331                                 string s = value.Substring (0, p);
 332
 333 #if NET_2_0
 334                                 if (!Int32.TryParse (s, out status_code))
 335                                         throw new HttpException ("Invalid format for the Status property");
 336 #else
 337
 338                                 try {
 339                                         status_code = Int32.Parse (s);
 340                                 } catch {
 341                                         throw new HttpException ("Invalid format for the Status property");
 342                                 }
 343 #endif
 344
 345                                 status_description = value.Substring (p+1);
 346                         }
 347                 }
 348
 349                 public int StatusCode {
 350                         get {
 351                                 return status_code;
 352                         }
 353
 354                         set {
 355                                 if (headers_sent)
 356                                         throw new HttpException ("headers have already been sent");
 357
 358                                 status_code = value;
 359                                 status_description = null;
 360                         }
 361                 }
 362
 363                 public string StatusDescription {
 364                         get {
 365                                 if (status_description == null)
 366                                         status_description = HttpWorkerRequest.GetStatusDescription (status_code);
 367
 368                                 return status_description;
 369                         }
 370
 371                         set {
 372                                 if (headers_sent)
 373                                         throw new HttpException ("headers have already been sent");
 374
 375                                 status_description = value;
 376                         }
 377                 }
 378
 379                 public bool SuppressContent {
 380                         get {
 381                                 return suppress_content;
 382                         }
 383
 384                         set {
 385                                 suppress_content = value;
 386                         }
 387                 }
 388
 389 #if NET_2_0
 390                 [MonoTODO ("Not implemented")]
 391                 public void AddCacheDependency (CacheDependency[] dependencies)
 392                 {
 393                         throw new NotImplementedException ();
 394                 }
 395
 396                 [MonoTODO ("Not implemented")]
 397                 public void AddCacheItemDependencies (string[] cacheKeys)
 398                 {
 399                         throw new NotImplementedException ();
 400                 }
 401 #endif
 402                 [MonoTODO("Currently does nothing")]
 403                 public void AddCacheItemDependencies (ArrayList cacheKeys)
 404                 {
 405                         // TODO: talk to jackson about the cache
 406                 }
 407
 408                 [MonoTODO("Currently does nothing")]
 409                 public void AddCacheItemDependency (string cacheKey)
 410                 {
 411                         // TODO: talk to jackson about the cache
 412                 }
 413
 414                 [MonoTODO("Currently does nothing")]
 415                 public void AddFileDependencies (ArrayList filenames)
 416                 {
 417                         // TODO: talk to jackson about the cache
 418                 }
 419 #if NET_2_0
 420                 [MonoTODO ("Not implemented")]
 421                 public void AddFileDependencies (string[] filenames)
 422                 {
 423                         throw new NotImplementedException ();
 424                 }
 425 #endif
 426                 [MonoTODO ("Currently does nothing")]
 427                 public void AddFileDependency (string filename)
 428                 {
 429                         // TODO: talk to jackson about the cache
 430                 }
 431
 432                 public void AddHeader (string name, string value)
 433                 {
 434                         AppendHeader (name, value);
 435                 }
 436
 437                 public void AppendCookie (HttpCookie cookie)
 438                 {
 439                         Cookies.Add (cookie);
 440                 }
 441
 442                 //
 443                 // AppendHeader:
 444                 //    Special case for Content-Length, Content-Type, Transfer-Encoding and Cache-Control
 445                 //
 446                 //
 447                 public void AppendHeader (string name, string value)
 448                 {
 449                         if (headers_sent)
 450                                 throw new HttpException ("headers have been already sent");
 451
 452                         if (String.Compare (name, "content-length", true, CultureInfo.InvariantCulture) == 0){
 453                                 content_length = (long) UInt64.Parse (value);
 454                                 use_chunked = false;
 455                                 return;
 456                         }
 457
 458                         if (String.Compare (name, "content-type", true, CultureInfo.InvariantCulture) == 0){
 459                                 ContentType = value;
 460                                 return;
 461                         }
 462
 463                         if (String.Compare (name, "transfer-encoding", true, CultureInfo.InvariantCulture) == 0){
 464                                 transfer_encoding = value;
 465                                 use_chunked = false;
 466                                 return;
 467                         }
 468
 469                         if (String.Compare (name, "cache-control", true, CultureInfo.InvariantCulture) == 0){
 470                                 user_cache_control = value;
 471                                 return;
 472                         }
 473
 474                         headers.Add (new UnknownResponseHeader (name, value));
 475                 }
 476
 477                 [AspNetHostingPermission (SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Medium)]
 478                 public void AppendToLog (string param)
 479                 {
 480                         Console.Write ("System.Web: ");
 481                         Console.WriteLine (param);
 482                 }
 483
 484                 public string ApplyAppPathModifier (string virtualPath)
 485                 {
 486                         if (virtualPath == null)
 487                                 return null;
 488
 489                         if (virtualPath == "")
 490                                 return context.Request.RootVirtualDir;
 491
 492                         if (UrlUtils.IsRelativeUrl (virtualPath)) {
 493                                 virtualPath = UrlUtils.Combine (context.Request.RootVirtualDir, virtualPath);
 494                         } else if (UrlUtils.IsRooted (virtualPath)) {
 495                                 virtualPath = UrlUtils.Canonic (virtualPath);
 496                         }
 497
 498                         if (app_path_mod != null && virtualPath.IndexOf (app_path_mod) < 0) {
 499                                 string rvd = context.Request.RootVirtualDir;
 500                                 string basevd = rvd.Replace (app_path_mod, "");
 501
 502                                 if (!StrUtils.StartsWith (virtualPath, basevd))
 503                                         return virtualPath;
 504
 505                                 virtualPath = UrlUtils.Combine (rvd, virtualPath.Substring (basevd.Length));
 506                         }
 507
 508                         return virtualPath;
 509                 }
 510
 511                 public void BinaryWrite (byte [] buffer)
 512                 {
 513                         output_stream.Write (buffer, 0, buffer.Length);
 514                 }
 515
 516                 internal void BinaryWrite (byte [] buffer, int start, int len)
 517                 {
 518                         output_stream.Write (buffer, start, len);
 519                 }
 520
 521                 public void Clear ()
 522                 {
 523                         ClearContent ();
 524                 }
 525
 526                 public void ClearContent ()
 527                 {
 528                         output_stream.Clear ();
 529                 }
 530
 531                 public void ClearHeaders ()
 532                 {
 533                         if (headers_sent)
 534                                 throw new HttpException ("headers have been already sent");
 535
 536                         // Reset the special case headers.
 537                         content_length = -1;
 538                         content_type = "text/html";
 539                         transfer_encoding = null;
 540                         user_cache_control = null;
 541                         headers.Clear ();
 542                 }
 543
 544                 internal bool HeadersSent {
 545                         get {
 546                                 return headers_sent;
 547                         }
 548                 }
 549
 550                 public void Close ()
 551                 {
 552                         if (closed)
 553                                 return;
 554                         if (WorkerRequest != null)
 555                                 WorkerRequest.CloseConnection ();
 556                         closed = true;
 557                 }
 558
 559                 public void End ()
 560                 {
 561                         if (context.TimeoutPossible) {
 562                                 Thread.CurrentThread.Abort (FlagEnd);
 563                         } else {
 564                                 // If this is called from an async event, signal the completion
 565                                 // but don't throw.
 566                                 context.ApplicationInstance.CompleteRequest ();
 567                         }
 568                 }
 569
 570                 // Generate:
 571                 //   Content-Length
 572                 //   Content-Type
 573                 //   Transfer-Encoding (chunked)
 574                 //   Cache-Control
 575                 void AddHeadersNoCache (ArrayList write_headers, bool final_flush)
 576                 {
 577                         //
 578                         // Transfer-Encoding
 579                         //
 580                         if (use_chunked)
 581                                 write_headers.Add (new UnknownResponseHeader ("Transfer-Encoding", "chunked"));
 582                         else if (transfer_encoding != null)
 583                                 write_headers.Add (new UnknownResponseHeader ("Transfer-Encoding", transfer_encoding));
 584
 585                         UnknownResponseHeader date_header = new UnknownResponseHeader ("Date",
 586                                         DateTime.UtcNow.ToString ("r", CultureInfo.InvariantCulture));
 587                         write_headers.Add (date_header);
 588
 589                         if (IsCached)
 590                                 cached_response.DateHeader = date_header;
 591
 592                         if (redirect_location != null)
 593                                 write_headers.Add (new UnknownResponseHeader ("Location", redirect_location));
 594
 595                         //
 596                         // If Content-Length is set.
 597                         //
 598                         if (content_length >= 0){
 599                                 write_headers.Add (new KnownResponseHeader (HttpWorkerRequest.HeaderContentLength,
 600                                                                       content_length.ToString (CultureInfo.InvariantCulture)));
 601                         } else if (Buffer){
 602                                 if (final_flush){
 603                                         //
 604                                         // If we are buffering and this is the last flush, not a middle-flush,
 605                                         // we know the content-length.
 606                                         //
 607                                         content_length = output_stream.total;
 608                                         write_headers.Add (new KnownResponseHeader (HttpWorkerRequest.HeaderContentLength,
 609                                                                               content_length.ToString (CultureInfo.InvariantCulture)));
 610                                 } else {
 611                                         //
 612                                         // We are buffering, and this is a flush in the middle.
 613                                         // If we are not chunked, we need to set "Connection: close".
 614                                         //
 615                                         if (use_chunked){
 616 #if DEBUG
 617                                                 Console.WriteLine ("Setting to close2");
 618 #endif
 619                                                 write_headers.Add (new KnownResponseHeader (HttpWorkerRequest.HeaderConnection, "close"));
 620                                         }
 621                                 }
 622                         } else {
 623                                 //
 624                                 // If the content-length is not set, and we are not buffering, we must
 625                                 // close at the end.
 626                                 //
 627                                 if (use_chunked){
 628 #if DEBUG
 629                                         Console.WriteLine ("Setting to close");
 630 #endif
 631                                         write_headers.Add (new KnownResponseHeader (HttpWorkerRequest.HeaderConnection, "close"));
 632                                 }
 633                         }
 634
 635                         //
 636                         // Cache Control, the cache policy takes precedence over the cache_control property.
 637                         //
 638                         if (cache_policy != null)
 639                                 cache_policy.SetHeaders (this, headers);
 640                         else
 641                                 write_headers.Add (new UnknownResponseHeader ("Cache-Control", CacheControl));
 642
 643                         //
 644                         // Content-Type
 645                         //
 646                         if (content_type != null){
 647                                 string header = content_type;
 648
 649                                 if (charset_set || header == "text/plain" || header == "text/html") {
 650                                         if (header.IndexOf ("charset=") == -1) {
 651                                                 if (charset == null || charset == "")
 652                                                         charset = ContentEncoding.HeaderName;
 653                                                 header += "; charset=" + charset;
 654                                         }
 655                                 }
 656
 657                                 write_headers.Add (new UnknownResponseHeader ("Content-Type", header));
 658                         }
 659
 660                         if (cookies != null && cookies.Count != 0){
 661                                 int n = cookies.Count;
 662                                 for (int i = 0; i < n; i++)
 663                                         write_headers.Add (cookies.Get (i).GetCookieHeader ());
 664 #if TARGET_J2EE
 665                                 // For J2EE Portal support emulate cookies by storing them in the session.
 666                                 context.Request.SetSessionCookiesForPortal (cookies);
 667 #endif
 668                         }
 669                 }
 670
 671                 internal void WriteHeaders (bool final_flush)
 672                 {
 673                         if (headers_sent)
 674                                 return;
 675
 676                         if (WorkerRequest != null)
 677                                 WorkerRequest.SendStatus (status_code, StatusDescription);
 678
 679                         if (cached_response != null)
 680                                 cached_response.SetHeaders (headers);
 681
 682                         // If this page is cached use the cached headers
 683                         // instead of the standard headers
 684                         ArrayList write_headers = headers;
 685                         if (cached_headers != null)
 686                                 write_headers = cached_headers;
 687                         else
 688                                 AddHeadersNoCache (write_headers, final_flush);
 689
 690                         //
 691                         // Flush
 692                         //
 693                         if (context != null) {
 694                                 HttpApplication app_instance = context.ApplicationInstance;
 695                                 if (app_instance != null)
 696                                         app_instance.TriggerPreSendRequestHeaders ();
 697                         }
 698                         if (WorkerRequest != null) {
 699                                 foreach (BaseResponseHeader header in write_headers){
 700                                         header.SendContent (WorkerRequest);
 701                                 }
 702                         }
 703                         headers_sent = true;
 704                 }
 705
 706                 internal void DoFilter (bool close)
 707                 {
 708                         if (output_stream.HaveFilter && context != null && context.Error == null)
 709                                 output_stream.ApplyFilter (close);
 710                 }
 711
 712                 internal void Flush (bool final_flush)
 713                 {
 714                         DoFilter (final_flush);
 715                         if (!headers_sent){
 716                                 if (final_flush || status_code != 200)
 717                                         use_chunked = false;
 718                         }
 719
 720                         bool head = ((context != null) && (context.Request.HttpMethod == "HEAD"));
 721                         if (suppress_content || head) {
 722                                 if (!headers_sent)
 723                                         WriteHeaders (true);
 724                                 output_stream.Clear ();
 725                                 if (WorkerRequest != null)
 726                                         output_stream.Flush (WorkerRequest, true); // ignore final_flush here.
 727                                 return;
 728                         }
 729
 730                         if (!headers_sent)
 731                                 WriteHeaders (final_flush);
 732
 733                         if (context != null) {
 734                                 HttpApplication app_instance = context.ApplicationInstance;
 735                                 if (app_instance != null)
 736                                         app_instance.TriggerPreSendRequestContent ();
 737                         }
 738
 739                         if (IsCached) {
 740                                 MemoryStream ms = output_stream.GetData ();
 741                                 cached_response.ContentLength = (int) ms.Length;
 742                                 cached_response.SetData (ms.GetBuffer ());
 743                         }
 744
 745                         if (WorkerRequest != null)
 746                                 output_stream.Flush (WorkerRequest, final_flush);
 747                 }
 748
 749                 public void Flush ()
 750                 {
 751                         Flush (false);
 752                 }
 753
 754                 public void Pics (string value)
 755                 {
 756                         AppendHeader ("PICS-Label", value);
 757                 }
 758
 759                 public void Redirect (string url)
 760                 {
 761                         Redirect (url, true);
 762                 }
 763
 764                 public void Redirect (string url, bool endResponse)
 765                 {
 766                         if (headers_sent)
 767                                 throw new HttpException ("header have been already sent");
 768
 769 #if TARGET_J2EE
 770                         // In J2EE portal we need to handle Redirect at the processAction phase
 771                         // using the portlet ActionResponse that will send for us the redirect header.
 772                         IPortletActionResponse resp = context.ServletResponse as IPortletActionResponse;
 773                         if (resp != null) {
 774                                 resp.sendRedirect (ApplyAppPathModifier (url));
 775                                 if (endResponse)
 776                                         End ();
 777                                 return;
 778                         }
 779 #endif
 780
 781 #if NET_2_0
 782                         is_request_being_redirected = true;
 783 #endif
 784                         ClearHeaders ();
 785                         ClearContent ();
 786
 787                         StatusCode = 302;
 788                         url = ApplyAppPathModifier (url);
 789                         headers.Add (new UnknownResponseHeader ("Location", url));
 790
 791                         // Text for browsers that can't handle location header
 792                         Write ("<html><head><title>Object moved</title></head><body>\r\n");
 793                         Write ("<h2>Object moved to <a href='" + url + "'>here</a></h2>\r\n");
 794                         Write ("</body><html>\r\n");
 795
 796                         if (endResponse)
 797                                 End ();
 798 #if NET_2_0
 799                         is_request_being_redirected = false;
 800 #endif
 801                 }
 802
 803                 public static void RemoveOutputCacheItem (string path)
 804                 {
 805                         if (path == null)
 806                                 throw new ArgumentNullException ("path");
 807
 808                         if (path.Length == 0)
 809                                 return;
 810
 811                         if (path [0] != '/')
 812                                 throw new ArgumentException ("'" + path + "' is not an absolute virtual path.");
 813
 814                         HttpRuntime.Cache.Remove (path);
 815                 }
 816
 817                 public void SetCookie (HttpCookie cookie)
 818                 {
 819                         AppendCookie (cookie);
 820                 }
 821
 822                 public void Write (char ch)
 823                 {
 824                         Output.Write (ch);
 825                 }
 826
 827                 public void Write (object obj)
 828                 {
 829                         if (obj == null)
 830                                 return;
 831
 832                         Output.Write (obj.ToString ());
 833                 }
 834
 835                 public void Write (string s)
 836                 {
 837                         Output.Write (s);
 838                 }
 839
 840                 public void Write (char [] buffer, int index, int count)
 841                 {
 842                         Output.Write (buffer, index, count);
 843                 }
 844
 845                 internal void WriteFile (FileStream fs, long offset, long size)
 846                 {
 847                         byte [] buffer = new byte [32*1024];
 848
 849                         if (offset != 0)
 850                                 fs.Position = offset;
 851
 852                         long remain = size;
 853                         int n;
 854                         while (remain > 0 && (n = fs.Read (buffer, 0, (int) Math.Min (remain, 32*1024))) != 0){
 855                                 remain -= n;
 856                                 output_stream.Write (buffer, 0, n);
 857                         }
 858                 }
 859
 860                 public void WriteFile (string filename)
 861                 {
 862                         WriteFile (filename, false);
 863                 }
 864
 865                 public void WriteFile (string filename, bool readIntoMemory)
 866                 {
 867                         if (filename == null)
 868                                 throw new ArgumentNullException ("filename");
 869
 870                         if (readIntoMemory){
 871                                 using (FileStream fs = File.OpenRead (filename))
 872                                         WriteFile (fs, 0, fs.Length);
 873                         } else {
 874                                 FileInfo fi = new FileInfo (filename);
 875                                 output_stream.WriteFile (filename, 0, fi.Length);
 876                         }
 877                         if (buffer)
 878                                 return;
 879
 880                         output_stream.ApplyFilter (false);
 881                         Flush ();
 882                 }
 883
 884 #if TARGET_JVM
 885                 public void WriteFile (IntPtr fileHandle, long offset, long size) {
 886                         throw new NotSupportedException("IntPtr not supported");
 887                 }
 888 #else
 889                 public void WriteFile (IntPtr fileHandle, long offset, long size)
 890                 {
 891                         if (offset < 0)
 892                                 throw new ArgumentNullException ("offset can not be negative");
 893                         if (size < 0)
 894                                 throw new ArgumentNullException ("size can not be negative");
 895
 896                         if (size == 0)
 897                                 return;
 898
 899                         // Note: this .ctor will throw a SecurityException if the caller
 900                         // doesn't have the UnmanagedCode permission
 901                         using (FileStream fs = new FileStream (fileHandle, FileAccess.Read))
 902                                 WriteFile (fs, offset, size);
 903
 904                         if (buffer)
 905                                 return;
 906                         output_stream.ApplyFilter (false);
 907                         Flush ();
 908                 }
 909 #endif
 910
 911                 public void WriteFile (string filename, long offset, long size)
 912                 {
 913                         if (filename == null)
 914                                 throw new ArgumentNullException ("filename");
 915                         if (offset < 0)
 916                                 throw new ArgumentNullException ("offset can not be negative");
 917                         if (size < 0)
 918                                 throw new ArgumentNullException ("size can not be negative");
 919
 920                         if (size == 0)
 921                                 return;
 922
 923                         FileStream fs = File.OpenRead (filename);
 924                         WriteFile (fs, offset, size);
 925
 926                         if (buffer)
 927                                 return;
 928
 929                         output_stream.ApplyFilter (false);
 930                         Flush ();
 931                 }
 932 #if NET_2_0
 933                 [MonoTODO ("Not implemented")]
 934                 public void WriteSubstitution (HttpResponseSubstitutionCallback callback)
 935                 {
 936                         throw new NotImplementedException ();
 937                 }
 938 #endif
 939                 //
 940                 // Like WriteFile, but never buffers, so we manually Flush here
 941                 //
 942                 public void TransmitFile (string filename)
 943                 {
 944                         if (filename == null)
 945                                 throw new ArgumentNullException ("filename");
 946
 947                         TransmitFile (filename, false);
 948                 }
 949
 950                 internal void TransmitFile (string filename, bool final_flush)
 951                 {
 952                         FileInfo fi = new FileInfo (filename);
 953                         using (Stream s = fi.OpenRead ()); // Just check if we can read.
 954                         output_stream.WriteFile (filename, 0, fi.Length);
 955                         output_stream.ApplyFilter (final_flush);
 956                         Flush (final_flush);
 957                 }
 958
 959
 960 #region Session state support
 961                 internal void SetAppPathModifier (string app_modifier)
 962                 {
 963                         app_path_mod = app_modifier;
 964                 }
 965 #endregion
 966
 967 #region Cache Support
 968                 internal void SetCachedHeaders (ArrayList headers)
 969                 {
 970                         cached_headers = headers;
 971                 }
 972
 973                 internal bool IsCached {
 974                         get {
 975                                 return cached_response != null;
 976                         }
 977                 }
 978
 979                 public HttpCachePolicy Cache {
 980                         get {
 981                                 if (cache_policy == null) {
 982                                         cache_policy = new HttpCachePolicy ();
 983                                         cache_policy.CacheabilityUpdated += new CacheabilityUpdatedCallback (OnCacheabilityUpdated);
 984                                 }
 985
 986                                 return cache_policy;
 987                         }
 988                 }
 989
 990                 private void OnCacheabilityUpdated (object sender, CacheabilityUpdatedEventArgs e)
 991                 {
 992                         if (e.Cacheability >= HttpCacheability.Server && !IsCached)
 993                                 cached_response = new CachedRawResponse (cache_policy);
 994                         else if (e.Cacheability <= HttpCacheability.Private)
 995                                 cached_response = null;
 996                 }
 997
 998                 internal CachedRawResponse GetCachedResponse ()
 999                 {
1000                         cached_response.StatusCode = StatusCode;
1001                         cached_response.StatusDescription = StatusDescription;
1002                         return cached_response;
1003                 }
1004
1005                 //
1006                 // This is one of the old ASP compatibility methods, the real cache
1007                 // control is in the Cache property, and this is a second class citizen
1008                 //
1009                 public string CacheControl {
1010                         set {
1011                                 if (value == null || value == "") {
1012                                         Cache.SetCacheability (HttpCacheability.NoCache);
1013                                         user_cache_control = null;
1014                                 } else if (String.Compare (value, "public", true, CultureInfo.InvariantCulture) == 0) {
1015                                         Cache.SetCacheability (HttpCacheability.Public);
1016                                         user_cache_control = "public";
1017                                 } else if (String.Compare (value, "private", true, CultureInfo.InvariantCulture) == 0) {
1018                                         Cache.SetCacheability (HttpCacheability.Private);
1019                                         user_cache_control = "private";
1020                                 } else if (String.Compare (value, "no-cache", true, CultureInfo.InvariantCulture) == 0) {
1021                                         Cache.SetCacheability (HttpCacheability.NoCache);
1022                                         user_cache_control = "no-cache";
1023                                 } else
1024                                         throw new ArgumentException ("CacheControl property only allows `public', " +
1025                                                                      "`private' or no-cache, for different uses, use " +
1026                                                                      "Response.AppendHeader");
1027                         }
1028
1029                         get { return (user_cache_control != null) ? user_cache_control : "private"; }
1030                 }
1031 #endregion
1032
1033                 internal int GetOutputByteCount ()
1034                 {
1035                         return output_stream.GetTotalLength ();
1036                 }
1037
1038                 internal void ReleaseResources ()
1039                 {
1040                         output_stream.ReleaseResources (true);
1041                         output_stream = null;
1042                 }
1043         }
1044 }
1045