mcs/class/System/System.Net/WebConnectionStream.cs

   1 //
   2 // System.Net.WebConnectionStream
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003 Ximian, Inc (http://www.ximian.com)
   8 // (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.IO;
  33 using System.Text;
  34 using System.Threading;
  35
  36 namespace System.Net
  37 {
  38         class WebConnectionStream : Stream
  39         {
  40                 static byte [] crlf = new byte [] { 13, 10 };
  41                 bool isRead;
  42                 WebConnection cnc;
  43                 HttpWebRequest request;
  44                 byte [] readBuffer;
  45                 int readBufferOffset;
  46                 int readBufferSize;
  47                 int stream_length; // -1 when CL not present
  48                 int contentLength;
  49                 int totalRead;
  50                 internal long totalWritten;
  51                 bool nextReadCalled;
  52                 int pendingReads;
  53                 int pendingWrites;
  54                 ManualResetEvent pending;
  55                 bool allowBuffering;
  56                 bool sendChunked;
  57                 MemoryStream writeBuffer;
  58                 bool requestWritten;
  59                 byte [] headers;
  60                 bool disposed;
  61                 bool headersSent;
  62                 object locker = new object ();
  63                 bool initRead;
  64                 bool read_eof;
  65                 bool complete_request_written;
  66                 int read_timeout;
  67                 int write_timeout;
  68                 AsyncCallback cb_wrapper; // Calls to ReadCallbackWrapper or WriteCallbacWrapper
  69                 internal bool IgnoreIOErrors;
  70
  71                 public WebConnectionStream (WebConnection cnc, WebConnectionData data)
  72                 {
  73                         if (data == null)
  74                                 throw new InvalidOperationException ("data was not initialized");
  75                         if (data.Headers == null)
  76                                 throw new InvalidOperationException ("data.Headers was not initialized");
  77                         if (data.request == null)
  78                                 throw new InvalidOperationException ("data.request was not initialized");
  79                         isRead = true;
  80                         cb_wrapper = new AsyncCallback (ReadCallbackWrapper);
  81                         pending = new ManualResetEvent (true);
  82                         this.request = data.request;
  83                         read_timeout = request.ReadWriteTimeout;
  84                         write_timeout = read_timeout;
  85                         this.cnc = cnc;
  86                         string contentType = data.Headers ["Transfer-Encoding"];
  87                         bool chunkedRead = (contentType != null && contentType.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
  88                         string clength = data.Headers ["Content-Length"];
  89                         if (!chunkedRead && clength != null && clength != "") {
  90                                 try {
  91                                         contentLength = Int32.Parse (clength);
  92                                         if (contentLength == 0 && !IsNtlmAuth ()) {
  93                                                 ReadAll ();
  94                                         }
  95                                 } catch {
  96                                         contentLength = Int32.MaxValue;
  97                                 }
  98                         } else {
  99                                 contentLength = Int32.MaxValue;
 100                         }
 101
 102                         // Negative numbers?
 103                         if (!Int32.TryParse (clength, out stream_length))
 104                                 stream_length = -1;
 105                 }
 106
 107                 public WebConnectionStream (WebConnection cnc, HttpWebRequest request)
 108                 {
 109                         read_timeout = request.ReadWriteTimeout;
 110                         write_timeout = read_timeout;
 111                         isRead = false;
 112                         cb_wrapper = new AsyncCallback (WriteCallbackWrapper);
 113                         this.cnc = cnc;
 114                         this.request = request;
 115                         allowBuffering = request.InternalAllowBuffering;
 116                         sendChunked = request.SendChunked;
 117                         if (sendChunked)
 118                                 pending = new ManualResetEvent (true);
 119                         else if (allowBuffering)
 120                                 writeBuffer = new MemoryStream ();
 121                 }
 122
 123                 bool CheckAuthHeader (string headerName)
 124                 {
 125                         var authHeader = cnc.Data.Headers [headerName];
 126                         return (authHeader != null && authHeader.IndexOf ("NTLM", StringComparison.Ordinal) != -1);
 127                 }
 128
 129                 bool IsNtlmAuth ()
 130                 {
 131                         bool isProxy = (request.Proxy != null && !request.Proxy.IsBypassed (request.Address));
 132                         if (isProxy && CheckAuthHeader ("Proxy-Authenticate"))
 133                                 return true;
 134                         return CheckAuthHeader ("WWW-Authenticate");
 135                 }
 136
 137                 internal void CheckResponseInBuffer ()
 138                 {
 139                         if (contentLength > 0 && (readBufferSize - readBufferOffset) >= contentLength) {
 140                                 if (!IsNtlmAuth ())
 141                                         ReadAll ();
 142                         }
 143                 }
 144
 145                 internal HttpWebRequest Request {
 146                         get { return request; }
 147                 }
 148
 149                 internal WebConnection Connection {
 150                         get { return cnc; }
 151                 }
 152                 public override bool CanTimeout {
 153                         get { return true; }
 154                 }
 155
 156                 public override int ReadTimeout {
 157                         get {
 158                                 return read_timeout;
 159                         }
 160
 161                         set {
 162                                 if (value < -1)
 163                                         throw new ArgumentOutOfRangeException ("value");
 164                                 read_timeout = value;
 165                         }
 166                 }
 167
 168                 public override int WriteTimeout {
 169                         get {
 170                                 return write_timeout;
 171                         }
 172
 173                         set {
 174                                 if (value < -1)
 175                                         throw new ArgumentOutOfRangeException ("value");
 176                                 write_timeout = value;
 177                         }
 178                 }
 179
 180                 internal bool CompleteRequestWritten {
 181                         get { return complete_request_written; }
 182                 }
 183
 184                 internal bool SendChunked {
 185                         set { sendChunked = value; }
 186                 }
 187
 188                 internal byte [] ReadBuffer {
 189                         set { readBuffer = value; }
 190                 }
 191
 192                 internal int ReadBufferOffset {
 193                         set { readBufferOffset = value; }
 194                 }
 195
 196                 internal int ReadBufferSize {
 197                         set { readBufferSize = value; }
 198                 }
 199
 200                 internal byte[] WriteBuffer {
 201                         get { return writeBuffer.GetBuffer (); }
 202                 }
 203
 204                 internal int WriteBufferLength {
 205                         get { return writeBuffer != null ? (int) writeBuffer.Length : (-1); }
 206                 }
 207
 208                 internal void ForceCompletion ()
 209                 {
 210                         if (!nextReadCalled) {
 211                                 if (contentLength == Int32.MaxValue)
 212                                         contentLength = 0;
 213                                 nextReadCalled = true;
 214                                 cnc.NextRead ();
 215                         }
 216                 }
 217
 218                 internal void CheckComplete ()
 219                 {
 220                         bool nrc = nextReadCalled;
 221                         if (!nrc && readBufferSize - readBufferOffset == contentLength) {
 222                                 nextReadCalled = true;
 223                                 cnc.NextRead ();
 224                         }
 225                 }
 226
 227                 internal void ReadAll ()
 228                 {
 229                         if (!isRead || read_eof || totalRead >= contentLength || nextReadCalled) {
 230                                 if (isRead && !nextReadCalled) {
 231                                         nextReadCalled = true;
 232                                         cnc.NextRead ();
 233                                 }
 234                                 return;
 235                         }
 236
 237                         pending.WaitOne ();
 238                         lock (locker) {
 239                                 if (totalRead >= contentLength)
 240                                         return;
 241
 242                                 byte [] b = null;
 243                                 int diff = readBufferSize - readBufferOffset;
 244                                 int new_size;
 245
 246                                 if (contentLength == Int32.MaxValue) {
 247                                         MemoryStream ms = new MemoryStream ();
 248                                         byte [] buffer = null;
 249                                         if (readBuffer != null && diff > 0) {
 250                                                 ms.Write (readBuffer, readBufferOffset, diff);
 251                                                 if (readBufferSize >= 8192)
 252                                                         buffer = readBuffer;
 253                                         }
 254
 255                                         if (buffer == null)
 256                                                 buffer = new byte [8192];
 257
 258                                         int read;
 259                                         while ((read = cnc.Read (request, buffer, 0, buffer.Length)) != 0)
 260                                                 ms.Write (buffer, 0, read);
 261
 262                                         b = ms.GetBuffer ();
 263                                         new_size = (int) ms.Length;
 264                                         contentLength = new_size;
 265                                 } else {
 266                                         new_size = contentLength - totalRead;
 267                                         b = new byte [new_size];
 268                                         if (readBuffer != null && diff > 0) {
 269                                                 if (diff > new_size)
 270                                                         diff = new_size;
 271
 272                                                 Buffer.BlockCopy (readBuffer, readBufferOffset, b, 0, diff);
 273                                         }
 274
 275                                         int remaining = new_size - diff;
 276                                         int r = -1;
 277                                         while (remaining > 0 && r != 0) {
 278                                                 r = cnc.Read (request, b, diff, remaining);
 279                                                 remaining -= r;
 280                                                 diff += r;
 281                                         }
 282                                 }
 283
 284                                 readBuffer = b;
 285                                 readBufferOffset = 0;
 286                                 readBufferSize = new_size;
 287                                 totalRead = 0;
 288                                 nextReadCalled = true;
 289                         }
 290
 291                         cnc.NextRead ();
 292                 }
 293
 294                 void WriteCallbackWrapper (IAsyncResult r)
 295                 {
 296                         WebAsyncResult result = r as WebAsyncResult;
 297                         if (result != null && result.AsyncWriteAll)
 298                                 return;
 299
 300                         if (r.AsyncState != null) {
 301                                 result = (WebAsyncResult) r.AsyncState;
 302                                 result.InnerAsyncResult = r;
 303                                 result.DoCallback ();
 304                         } else {
 305                                 try {
 306                                         EndWrite (r);
 307                                 } catch {
 308                                 }
 309                         }
 310                 }
 311
 312                 void ReadCallbackWrapper (IAsyncResult r)
 313                 {
 314                         WebAsyncResult result;
 315                         if (r.AsyncState != null) {
 316                                 result = (WebAsyncResult) r.AsyncState;
 317                                 result.InnerAsyncResult = r;
 318                                 result.DoCallback ();
 319                         } else {
 320                                 try {
 321                                         EndRead (r);
 322                                 } catch {
 323                                 }
 324                         }
 325                 }
 326
 327                 public override int Read (byte [] buffer, int offset, int size)
 328                 {
 329                         AsyncCallback cb = cb_wrapper;
 330                         WebAsyncResult res = (WebAsyncResult) BeginRead (buffer, offset, size, cb, null);
 331                         if (!res.IsCompleted && !res.WaitUntilComplete (ReadTimeout, false)) {
 332                                 nextReadCalled = true;
 333                                 cnc.Close (true);
 334                                 throw new WebException ("The operation has timed out.", WebExceptionStatus.Timeout);
 335                         }
 336
 337                         return EndRead (res);
 338                 }
 339
 340                 public override IAsyncResult BeginRead (byte [] buffer, int offset, int size,
 341                                                         AsyncCallback cb, object state)
 342                 {
 343                         if (!isRead)
 344                                 throw new NotSupportedException ("this stream does not allow reading");
 345
 346                         if (buffer == null)
 347                                 throw new ArgumentNullException ("buffer");
 348
 349                         int length = buffer.Length;
 350                         if (offset < 0 || length < offset)
 351                                 throw new ArgumentOutOfRangeException ("offset");
 352                         if (size < 0 || (length - offset) < size)
 353                                 throw new ArgumentOutOfRangeException ("size");
 354
 355                         lock (locker) {
 356                                 pendingReads++;
 357                                 pending.Reset ();
 358                         }
 359
 360                         WebAsyncResult result = new WebAsyncResult (cb, state, buffer, offset, size);
 361                         if (totalRead >= contentLength) {
 362                                 result.SetCompleted (true, -1);
 363                                 result.DoCallback ();
 364                                 return result;
 365                         }
 366
 367                         int remaining = readBufferSize - readBufferOffset;
 368                         if (remaining > 0) {
 369                                 int copy = (remaining > size) ? size : remaining;
 370                                 Buffer.BlockCopy (readBuffer, readBufferOffset, buffer, offset, copy);
 371                                 readBufferOffset += copy;
 372                                 offset += copy;
 373                                 size -= copy;
 374                                 totalRead += copy;
 375                                 if (size == 0 || totalRead >= contentLength) {
 376                                         result.SetCompleted (true, copy);
 377                                         result.DoCallback ();
 378                                         return result;
 379                                 }
 380                                 result.NBytes = copy;
 381                         }
 382
 383                         if (cb != null)
 384                                 cb = cb_wrapper;
 385
 386                         if (contentLength != Int32.MaxValue && contentLength - totalRead < size)
 387                                 size = contentLength - totalRead;
 388
 389                         if (!read_eof) {
 390                                 result.InnerAsyncResult = cnc.BeginRead (request, buffer, offset, size, cb, result);
 391                         } else {
 392                                 result.SetCompleted (true, result.NBytes);
 393                                 result.DoCallback ();
 394                         }
 395                         return result;
 396                 }
 397
 398                 public override int EndRead (IAsyncResult r)
 399                 {
 400                         WebAsyncResult result = (WebAsyncResult) r;
 401                         if (result.EndCalled) {
 402                                 int xx = result.NBytes;
 403                                 return (xx >= 0) ? xx : 0;
 404                         }
 405
 406                         result.EndCalled = true;
 407
 408                         if (!result.IsCompleted) {
 409                                 int nbytes = -1;
 410                                 try {
 411                                         nbytes = cnc.EndRead (request, result);
 412                                 } catch (Exception exc) {
 413                                         lock (locker) {
 414                                                 pendingReads--;
 415                                                 if (pendingReads == 0)
 416                                                         pending.Set ();
 417                                         }
 418
 419                                         nextReadCalled = true;
 420                                         cnc.Close (true);
 421                                         result.SetCompleted (false, exc);
 422                                         result.DoCallback ();
 423                                         throw;
 424                                 }
 425
 426                                 if (nbytes < 0) {
 427                                         nbytes = 0;
 428                                         read_eof = true;
 429                                 }
 430
 431                                 totalRead += nbytes;
 432                                 result.SetCompleted (false, nbytes + result.NBytes);
 433                                 result.DoCallback ();
 434                                 if (nbytes == 0)
 435                                         contentLength = totalRead;
 436                         }
 437
 438                         lock (locker) {
 439                                 pendingReads--;
 440                                 if (pendingReads == 0)
 441                                         pending.Set ();
 442                         }
 443
 444                         if (totalRead >= contentLength && !nextReadCalled)
 445                                 ReadAll ();
 446
 447                         int nb = result.NBytes;
 448                         return (nb >= 0) ? nb : 0;
 449                 }
 450
 451                 void WriteAsyncCB (IAsyncResult r)
 452                 {
 453                         WebAsyncResult result = (WebAsyncResult) r.AsyncState;
 454                         result.InnerAsyncResult = null;
 455
 456                         try {
 457                                 cnc.EndWrite (request, true, r);
 458                                 result.SetCompleted (false, 0);
 459                                 if (!initRead) {
 460                                         initRead = true;
 461                                         WebConnection.InitRead (cnc);
 462                                 }
 463                         } catch (Exception e) {
 464                                 KillBuffer ();
 465                                 nextReadCalled = true;
 466                                 cnc.Close (true);
 467                                 if (e is System.Net.Sockets.SocketException)
 468                                         e = new IOException ("Error writing request", e);
 469                                 result.SetCompleted (false, e);
 470                         }
 471
 472                         if (allowBuffering && !sendChunked && request.ContentLength > 0 && totalWritten == request.ContentLength)
 473                                 complete_request_written = true;
 474
 475                         result.DoCallback ();
 476                 }
 477
 478                 public override IAsyncResult BeginWrite (byte [] buffer, int offset, int size,
 479                                                         AsyncCallback cb, object state)
 480                 {
 481                         if (request.Aborted)
 482                                 throw new WebException ("The request was canceled.", null, WebExceptionStatus.RequestCanceled);
 483
 484                         if (isRead)
 485                                 throw new NotSupportedException ("this stream does not allow writing");
 486
 487                         if (buffer == null)
 488                                 throw new ArgumentNullException ("buffer");
 489
 490                         int length = buffer.Length;
 491                         if (offset < 0 || length < offset)
 492                                 throw new ArgumentOutOfRangeException ("offset");
 493                         if (size < 0 || (length - offset) < size)
 494                                 throw new ArgumentOutOfRangeException ("size");
 495
 496                         if (sendChunked) {
 497                                 lock (locker) {
 498                                         pendingWrites++;
 499                                         pending.Reset ();
 500                                 }
 501                         }
 502
 503                         WebAsyncResult result = new WebAsyncResult (cb, state);
 504                         AsyncCallback callback = new AsyncCallback (WriteAsyncCB);
 505
 506                         if (sendChunked) {
 507                                 requestWritten = true;
 508
 509                                 string cSize = String.Format ("{0:X}\r\n", size);
 510                                 byte[] head = Encoding.ASCII.GetBytes (cSize);
 511                                 int chunkSize = 2 + size + head.Length;
 512                                 byte[] newBuffer = new byte [chunkSize];
 513                                 Buffer.BlockCopy (head, 0, newBuffer, 0, head.Length);
 514                                 Buffer.BlockCopy (buffer, offset, newBuffer, head.Length, size);
 515                                 Buffer.BlockCopy (crlf, 0, newBuffer, head.Length + size, crlf.Length);
 516
 517                                 if (allowBuffering) {
 518                                         if (writeBuffer == null)
 519                                                 writeBuffer = new MemoryStream ();
 520                                         writeBuffer.Write (buffer, offset, size);
 521                                         totalWritten += size;
 522                                 }
 523
 524                                 buffer = newBuffer;
 525                                 offset = 0;
 526                                 size = chunkSize;
 527                         } else {
 528                                 CheckWriteOverflow (request.ContentLength, totalWritten, size);
 529
 530                                 if (allowBuffering) {
 531                                         if (writeBuffer == null)
 532                                                 writeBuffer = new MemoryStream ();
 533                                         writeBuffer.Write (buffer, offset, size);
 534                                         totalWritten += size;
 535
 536                                         if (request.ContentLength <= 0 || totalWritten < request.ContentLength) {
 537                                                 result.SetCompleted (true, 0);
 538                                                 result.DoCallback ();
 539                                                 return result;
 540                                         }
 541
 542                                         result.AsyncWriteAll = true;
 543                                         requestWritten = true;
 544                                         buffer = writeBuffer.GetBuffer ();
 545                                         offset = 0;
 546                                         size = (int)totalWritten;
 547                                 }
 548                         }
 549
 550                         try {
 551                                 result.InnerAsyncResult = cnc.BeginWrite (request, buffer, offset, size, callback, result);
 552                                 if (result.InnerAsyncResult == null) {
 553                                         if (!result.IsCompleted)
 554                                                 result.SetCompleted (true, 0);
 555                                         result.DoCallback ();
 556                                 }
 557                         } catch (Exception) {
 558                                 if (!IgnoreIOErrors)
 559                                         throw;
 560                                 result.SetCompleted (true, 0);
 561                                 result.DoCallback ();
 562                         }
 563                         totalWritten += size;
 564                         return result;
 565                 }
 566
 567                 void CheckWriteOverflow (long contentLength, long totalWritten, long size)
 568                 {
 569                         if (contentLength == -1)
 570                                 return;
 571
 572                         long avail = contentLength - totalWritten;
 573                         if (size > avail) {
 574                                 KillBuffer ();
 575                                 nextReadCalled = true;
 576                                 cnc.Close (true);
 577                                 throw new ProtocolViolationException (
 578                                         "The number of bytes to be written is greater than " +
 579                                         "the specified ContentLength.");
 580                         }
 581                 }
 582
 583                 public override void EndWrite (IAsyncResult r)
 584                 {
 585                         if (r == null)
 586                                 throw new ArgumentNullException ("r");
 587
 588                         WebAsyncResult result = r as WebAsyncResult;
 589                         if (result == null)
 590                                 throw new ArgumentException ("Invalid IAsyncResult");
 591
 592                         if (result.EndCalled)
 593                                 return;
 594
 595                         result.EndCalled = true;
 596                         if (result.AsyncWriteAll) {
 597                                 result.WaitUntilComplete ();
 598                                 if (result.GotException)
 599                                         throw result.Exception;
 600                                 return;
 601                         }
 602
 603                         if (allowBuffering && !sendChunked)
 604                                 return;
 605
 606                         if (result.GotException)
 607                                 throw result.Exception;
 608
 609                         if (sendChunked) {
 610                                 lock (locker) {
 611                                         pendingWrites--;
 612                                         if (pendingWrites == 0)
 613                                                 pending.Set ();
 614                                 }
 615                         }
 616                 }
 617
 618                 public override void Write (byte [] buffer, int offset, int size)
 619                 {
 620                         AsyncCallback cb = cb_wrapper;
 621                         WebAsyncResult res = (WebAsyncResult) BeginWrite (buffer, offset, size, cb, null);
 622                         if (!res.IsCompleted && !res.WaitUntilComplete (WriteTimeout, false)) {
 623                                 KillBuffer ();
 624                                 nextReadCalled = true;
 625                                 cnc.Close (true);
 626                                 throw new IOException ("Write timed out.");
 627                         }
 628
 629                         EndWrite (res);
 630                 }
 631
 632                 public override void Flush ()
 633                 {
 634                 }
 635
 636                 internal void SetHeadersAsync (bool setInternalLength, SimpleAsyncCallback callback)
 637                 {
 638                         SimpleAsyncResult.Run (r => SetHeadersAsync (r, setInternalLength), callback);
 639                 }
 640
 641                 bool SetHeadersAsync (SimpleAsyncResult result, bool setInternalLength)
 642                 {
 643                         if (headersSent)
 644                                 return false;
 645
 646                         string method = request.Method;
 647                         bool no_writestream = (method == "GET" || method == "CONNECT" || method == "HEAD" ||
 648                                               method == "TRACE");
 649                         bool webdav = (method == "PROPFIND" || method == "PROPPATCH" || method == "MKCOL" ||
 650                                       method == "COPY" || method == "MOVE" || method == "LOCK" ||
 651                                       method == "UNLOCK");
 652
 653                         if (setInternalLength && !no_writestream && writeBuffer != null)
 654                                 request.InternalContentLength = writeBuffer.Length;
 655
 656                         if (!(sendChunked || request.ContentLength > -1 || no_writestream || webdav))
 657                                 return false;
 658
 659                         headersSent = true;
 660                         headers = request.GetRequestHeaders ();
 661
 662                         var innerResult = cnc.BeginWrite (request, headers, 0, headers.Length, r => {
 663                                 try {
 664                                         cnc.EndWrite (request, true, r);
 665                                         if (!initRead) {
 666                                                 initRead = true;
 667                                                 WebConnection.InitRead (cnc);
 668                                         }
 669                                         var cl = request.ContentLength;
 670                                         if (!sendChunked && cl == 0)
 671                                                 requestWritten = true;
 672                                         result.SetCompleted (false);
 673                                 } catch (WebException e) {
 674                                         result.SetCompleted (false, e);
 675                                 } catch (Exception e) {
 676                                         result.SetCompleted (false, new WebException ("Error writing headers", e, WebExceptionStatus.SendFailure));
 677                                 }
 678                         }, null);
 679
 680                         return innerResult != null;
 681                 }
 682
 683                 internal bool RequestWritten {
 684                         get { return requestWritten; }
 685                 }
 686
 687                 internal SimpleAsyncResult WriteRequestAsync (SimpleAsyncCallback callback)
 688                 {
 689                         var result = WriteRequestAsync (callback);
 690                         try {
 691                                 if (!WriteRequestAsync (result))
 692                                         result.SetCompleted (true);
 693                         } catch (Exception ex) {
 694                                 result.SetCompleted (true, ex);
 695                         }
 696                         return result;
 697                 }
 698
 699                 internal bool WriteRequestAsync (SimpleAsyncResult result)
 700                 {
 701                         if (requestWritten)
 702                                 return false;
 703
 704                         requestWritten = true;
 705                         if (sendChunked || !allowBuffering || writeBuffer == null)
 706                                 return false;
 707
 708                         // Keep the call for a potential side-effect of GetBuffer
 709                         var bytes = writeBuffer.GetBuffer ();
 710                         var length = (int)writeBuffer.Length;
 711                         if (request.ContentLength != -1 && request.ContentLength < length) {
 712                                 nextReadCalled = true;
 713                                 cnc.Close (true);
 714                                 throw new WebException ("Specified Content-Length is less than the number of bytes to write", null,
 715                                         WebExceptionStatus.ServerProtocolViolation, null);
 716                         }
 717
 718                         SetHeadersAsync (true, inner => {
 719                                 if (inner.GotException) {
 720                                         result.SetCompleted (inner.CompletedSynchronously, inner.Exception);
 721                                         return;
 722                                 }
 723
 724                                 if (cnc.Data.StatusCode != 0 && cnc.Data.StatusCode != 100) {
 725                                         result.SetCompleted (inner.CompletedSynchronously);
 726                                         return;
 727                                 }
 728
 729                                 if (!initRead) {
 730                                         initRead = true;
 731                                         WebConnection.InitRead (cnc);
 732                                 }
 733
 734                                 if (length == 0) {
 735                                         complete_request_written = true;
 736                                         result.SetCompleted (inner.CompletedSynchronously);
 737                                         return;
 738                                 }
 739
 740                                 cnc.BeginWrite (request, bytes, 0, length, r => {
 741                                         try {
 742                                                 complete_request_written = cnc.EndWrite (request, false, r);
 743                                                 result.SetCompleted (false);
 744                                         } catch (Exception exc) {
 745                                                 result.SetCompleted (false, exc);
 746                                         }
 747                                 }, null);
 748                         });
 749
 750                         return true;
 751                 }
 752
 753                 internal void InternalClose ()
 754                 {
 755                         disposed = true;
 756                 }
 757
 758                 internal bool GetResponseOnClose {
 759                         get; set;
 760                 }
 761
 762                 public override void Close ()
 763                 {
 764                         if (GetResponseOnClose) {
 765                                 if (disposed)
 766                                         return;
 767                                 disposed = true;
 768                                 var response = (HttpWebResponse)request.GetResponse ();
 769                                 response.ReadAll ();
 770                                 response.Close ();
 771                                 return;
 772                         }
 773
 774                         if (sendChunked) {
 775                                 if (disposed)
 776                                         return;
 777                                 disposed = true;
 778                                 pending.WaitOne ();
 779                                 byte [] chunk = Encoding.ASCII.GetBytes ("0\r\n\r\n");
 780                                 string err_msg = null;
 781                                 cnc.Write (request, chunk, 0, chunk.Length, ref err_msg);
 782                                 return;
 783                         }
 784
 785                         if (isRead) {
 786                                 if (!nextReadCalled) {
 787                                         CheckComplete ();
 788                                         // If we have not read all the contents
 789                                         if (!nextReadCalled) {
 790                                                 nextReadCalled = true;
 791                                                 cnc.Close (true);
 792                                         }
 793                                 }
 794                                 return;
 795                         } else if (!allowBuffering) {
 796                                 complete_request_written = true;
 797                                 if (!initRead) {
 798                                         initRead = true;
 799                                         WebConnection.InitRead (cnc);
 800                                 }
 801                                 return;
 802                         }
 803
 804                         if (disposed || requestWritten)
 805                                 return;
 806
 807                         long length = request.ContentLength;
 808
 809                         if (!sendChunked && length != -1 && totalWritten != length) {
 810                                 IOException io = new IOException ("Cannot close the stream until all bytes are written");
 811                                 nextReadCalled = true;
 812                                 cnc.Close (true);
 813                                 throw new WebException ("Request was cancelled.", io, WebExceptionStatus.RequestCanceled);
 814                         }
 815
 816                         // Commented out the next line to fix xamarin bug #1512
 817                         //WriteRequest ();
 818                         disposed = true;
 819                 }
 820
 821                 internal void KillBuffer ()
 822                 {
 823                         writeBuffer = null;
 824                 }
 825
 826                 public override long Seek (long a, SeekOrigin b)
 827                 {
 828                         throw new NotSupportedException ();
 829                 }
 830
 831                 public override void SetLength (long a)
 832                 {
 833                         throw new NotSupportedException ();
 834                 }
 835
 836                 public override bool CanSeek {
 837                         get { return false; }
 838                 }
 839
 840                 public override bool CanRead {
 841                         get { return !disposed && isRead; }
 842                 }
 843
 844                 public override bool CanWrite {
 845                         get { return !disposed && !isRead; }
 846                 }
 847
 848                 public override long Length {
 849                         get {
 850                                 if (!isRead)
 851                                         throw new NotSupportedException ();
 852                                 return stream_length;
 853                         }
 854                 }
 855
 856                 public override long Position {
 857                         get { throw new NotSupportedException (); }
 858                         set { throw new NotSupportedException (); }
 859                 }
 860         }
 861 }
 862