mcs/class/corlib/System.IO/FileStream.cs

   1 //
   2 // System.IO.FileStream.cs
   3 //
   4 // Authors:
   5 //      Dietmar Maurer (dietmar@ximian.com)
   6 //      Dan Lewis (dihlewis@yahoo.co.uk)
   7 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   8 //  Marek Safar (marek.safar@gmail.com)
   9 //
  10 // (C) 2001-2003 Ximian, Inc.  http://www.ximian.com
  11 // Copyright (C) 2004-2005, 2008, 2010 Novell, Inc (http://www.novell.com)
  12 // Copyright 2011 Xamarin Inc (http://www.xamarin.com).
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System.Collections;
  35 using System.Globalization;
  36 using System.Runtime.CompilerServices;
  37 using System.Runtime.InteropServices;
  38 using System.Runtime.Remoting.Messaging;
  39 using System.Security;
  40 using System.Security.Permissions;
  41 using System.Threading;
  42 using Microsoft.Win32.SafeHandles;
  43
  44 #if NET_2_1
  45 using System.IO.IsolatedStorage;
  46 #else
  47 using System.Security.AccessControl;
  48 #endif
  49
  50 #if NET_4_5
  51 using System.Threading.Tasks;
  52 #endif
  53
  54 namespace System.IO
  55 {
  56         [ComVisible (true)]
  57         public class FileStream : Stream
  58         {
  59                 // construct from handle
  60
  61                 [Obsolete ("Use FileStream(SafeFileHandle handle, FileAccess access) instead")]
  62                 public FileStream (IntPtr handle, FileAccess access)
  63                         : this (handle, access, true, DefaultBufferSize, false) {}
  64
  65                 [Obsolete ("Use FileStream(SafeFileHandle handle, FileAccess access) instead")]
  66                 public FileStream (IntPtr handle, FileAccess access, bool ownsHandle)
  67                         : this (handle, access, ownsHandle, DefaultBufferSize, false) {}
  68
  69                 [Obsolete ("Use FileStream(SafeFileHandle handle, FileAccess access, int bufferSize) instead")]
  70                 public FileStream (IntPtr handle, FileAccess access, bool ownsHandle, int bufferSize)
  71                         : this (handle, access, ownsHandle, bufferSize, false) {}
  72
  73                 [Obsolete ("Use FileStream(SafeFileHandle handle, FileAccess access, int bufferSize, bool isAsync) instead")]
  74                 public FileStream (IntPtr handle, FileAccess access, bool ownsHandle, int bufferSize, bool isAsync)
  75                         : this (handle, access, ownsHandle, bufferSize, isAsync, false) {}
  76
  77                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
  78                 internal FileStream (IntPtr handle, FileAccess access, bool ownsHandle, int bufferSize, bool isAsync, bool isZeroSize)
  79                 {
  80                         this.handle = MonoIO.InvalidHandle;
  81                         if (handle == this.handle)
  82                                 throw new ArgumentException ("handle", Locale.GetText ("Invalid."));
  83
  84                         if (access < FileAccess.Read || access > FileAccess.ReadWrite)
  85                                 throw new ArgumentOutOfRangeException ("access");
  86
  87                         MonoIOError error;
  88                         MonoFileType ftype = MonoIO.GetFileType (handle, out error);
  89
  90                         if (error != MonoIOError.ERROR_SUCCESS) {
  91                                 throw MonoIO.GetException (name, error);
  92                         }
  93
  94                         if (ftype == MonoFileType.Unknown) {
  95                                 throw new IOException ("Invalid handle.");
  96                         } else if (ftype == MonoFileType.Disk) {
  97                                 this.canseek = true;
  98                         } else {
  99                                 this.canseek = false;
 100                         }
 101
 102                         this.handle = handle;
 103                         ExposeHandle ();
 104                         this.access = access;
 105                         this.owner = ownsHandle;
 106                         this.async = isAsync;
 107 #if MOONLIGHT
 108                         // default the browser to 'all' anonymous files and let other usage (like smcs) with 'normal'
 109                         // (i.e. non-anonymous except for isolated storage) files and paths
 110                         this.anonymous = SecurityManager.SecurityEnabled;
 111 #else
 112                         this.anonymous = false;
 113 #endif
 114                         if (canseek) {
 115                                 buf_start = MonoIO.Seek (handle, 0, SeekOrigin.Current, out error);
 116                                 if (error != MonoIOError.ERROR_SUCCESS) {
 117                                         throw MonoIO.GetException (name, error);
 118                                 }
 119                         }
 120
 121                         /* Can't set append mode */
 122                         this.append_startpos=0;
 123                 }
 124
 125                 // construct from filename
 126
 127                 public FileStream (string path, FileMode mode)
 128                         : this (path, mode, (mode == FileMode.Append ? FileAccess.Write : FileAccess.ReadWrite), FileShare.Read, DefaultBufferSize, false, FileOptions.None)
 129                 {
 130                 }
 131
 132                 public FileStream (string path, FileMode mode, FileAccess access)
 133                         : this (path, mode, access, access == FileAccess.Write ? FileShare.None : FileShare.Read, DefaultBufferSize, false, false)
 134                 {
 135                 }
 136
 137                 public FileStream (string path, FileMode mode, FileAccess access, FileShare share)
 138                         : this (path, mode, access, share, DefaultBufferSize, false, FileOptions.None)
 139                 {
 140                 }
 141
 142                 public FileStream (string path, FileMode mode, FileAccess access, FileShare share, int bufferSize)
 143                         : this (path, mode, access, share, bufferSize, false, FileOptions.None)
 144                 {
 145                 }
 146
 147                 public FileStream (string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool useAsync)
 148                         : this (path, mode, access, share, bufferSize, useAsync ? FileOptions.Asynchronous : FileOptions.None)
 149                 {
 150                 }
 151
 152                 public FileStream (string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, FileOptions options)
 153                         : this (path, mode, access, share, bufferSize, false, options)
 154                 {
 155                 }
 156
 157 #if !NET_2_1
 158                 public FileStream (SafeFileHandle handle, FileAccess access)
 159                         :this(handle, access, DefaultBufferSize, false)
 160                 {
 161                 }
 162
 163                 public FileStream (SafeFileHandle handle, FileAccess access,
 164                                    int bufferSize)
 165                         :this(handle, access, bufferSize, false)
 166                 {
 167                 }
 168
 169                 [MonoLimitationAttribute("Need to use SafeFileHandle instead of underlying handle")]
 170                 public FileStream (SafeFileHandle handle, FileAccess access,
 171                                    int bufferSize, bool isAsync)
 172                         :this (handle.DangerousGetHandle (), access, false, bufferSize, isAsync)
 173                 {
 174                         this.safeHandle = handle;
 175                 }
 176
 177                 [MonoLimitation ("This ignores the rights parameter")]
 178                 public FileStream (string path, FileMode mode,
 179                                    FileSystemRights rights, FileShare share,
 180                                    int bufferSize, FileOptions options)
 181                         : this (path, mode, (mode == FileMode.Append ? FileAccess.Write : FileAccess.ReadWrite), share, bufferSize, false, options)
 182                 {
 183                 }
 184
 185                 [MonoLimitation ("This ignores the rights and fileSecurity parameters")]
 186                 public FileStream (string path, FileMode mode,
 187                                    FileSystemRights rights, FileShare share,
 188                                    int bufferSize, FileOptions options,
 189                                    FileSecurity fileSecurity)
 190                         : this (path, mode, (mode == FileMode.Append ? FileAccess.Write : FileAccess.ReadWrite), share, bufferSize, false, options)
 191                 {
 192                 }
 193 #endif
 194
 195                 internal FileStream (string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool isAsync, bool anonymous)
 196                         : this (path, mode, access, share, bufferSize, anonymous, isAsync ? FileOptions.Asynchronous : FileOptions.None)
 197                 {
 198                 }
 199
 200                 internal FileStream (string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool anonymous, FileOptions options)
 201                 {
 202                         if (path == null) {
 203                                 throw new ArgumentNullException ("path");
 204                         }
 205
 206                         if (path.Length == 0) {
 207                                 throw new ArgumentException ("Path is empty");
 208                         }
 209
 210                         this.anonymous = anonymous;
 211                         // ignore the Inheritable flag
 212                         share &= ~FileShare.Inheritable;
 213
 214                         if (bufferSize <= 0)
 215                                 throw new ArgumentOutOfRangeException ("bufferSize", "Positive number required.");
 216
 217                         if (mode < FileMode.CreateNew || mode > FileMode.Append) {
 218 #if NET_2_1
 219                                 if (anonymous)
 220                                         throw new ArgumentException ("mode", "Enum value was out of legal range.");
 221                                 else
 222 #endif
 223                                 throw new ArgumentOutOfRangeException ("mode", "Enum value was out of legal range.");
 224                         }
 225
 226                         if (access < FileAccess.Read || access > FileAccess.ReadWrite) {
 227 #if MOONLIGHT
 228                                 if (anonymous)
 229                                         throw new IsolatedStorageException ("Enum value for FileAccess was out of legal range.");
 230                                 else
 231 #endif
 232                                 throw new ArgumentOutOfRangeException ("access", "Enum value was out of legal range.");
 233                         }
 234
 235                         if (share < FileShare.None || share > (FileShare.ReadWrite | FileShare.Delete)) {
 236 #if MOONLIGHT
 237                                 if (anonymous)
 238                                         throw new IsolatedStorageException ("Enum value for FileShare was out of legal range.");
 239                                 else
 240 #endif
 241                                 throw new ArgumentOutOfRangeException ("share", "Enum value was out of legal range.");
 242                         }
 243
 244                         if (path.IndexOfAny (Path.InvalidPathChars) != -1) {
 245                                 throw new ArgumentException ("Name has invalid chars");
 246                         }
 247
 248                         if (Directory.Exists (path)) {
 249                                 // don't leak the path information for isolated storage
 250                                 string msg = Locale.GetText ("Access to the path '{0}' is denied.");
 251                                 throw new UnauthorizedAccessException (String.Format (msg, GetSecureFileName (path, false)));
 252                         }
 253
 254                         /* Append streams can't be read (see FileMode
 255                          * docs)
 256                          */
 257                         if (mode==FileMode.Append &&
 258                                 (access&FileAccess.Read)==FileAccess.Read) {
 259                                 throw new ArgumentException("Append access can be requested only in write-only mode.");
 260                         }
 261
 262                         if ((access & FileAccess.Write) == 0 &&
 263                                 (mode != FileMode.Open && mode != FileMode.OpenOrCreate)) {
 264                                 string msg = Locale.GetText ("Combining FileMode: {0} with " +
 265                                         "FileAccess: {1} is invalid.");
 266                                 throw new ArgumentException (string.Format (msg, access, mode));
 267                         }
 268
 269                         SecurityManager.EnsureElevatedPermissions (); // this is a no-op outside moonlight
 270
 271                         string dname;
 272                         if (Path.DirectorySeparatorChar != '/' && path.IndexOf ('/') >= 0)
 273                                 dname = Path.GetDirectoryName (Path.GetFullPath (path));
 274                         else
 275                                 dname = Path.GetDirectoryName (path);
 276                         if (dname.Length > 0) {
 277                                 string fp = Path.GetFullPath (dname);
 278                                 if (!Directory.Exists (fp)) {
 279                                         // don't leak the path information for isolated storage
 280                                         string msg = Locale.GetText ("Could not find a part of the path \"{0}\".");
 281                                         string fname = (anonymous) ? dname : Path.GetFullPath (path);
 282 #if MOONLIGHT
 283                                         // don't use GetSecureFileName for the directory name
 284                                         throw new IsolatedStorageException (String.Format (msg, fname));
 285 #else
 286                                         throw new DirectoryNotFoundException (String.Format (msg, fname));
 287 #endif
 288                                 }
 289                         }
 290
 291                         if (access == FileAccess.Read && mode != FileMode.Create && mode != FileMode.OpenOrCreate &&
 292                                         mode != FileMode.CreateNew && !File.Exists (path)) {
 293                                 // don't leak the path information for isolated storage
 294                                 string msg = Locale.GetText ("Could not find file \"{0}\".");
 295                                 string fname = GetSecureFileName (path);
 296 #if MOONLIGHT
 297                                 throw new IsolatedStorageException (String.Format (msg, fname));
 298 #else
 299                                 throw new FileNotFoundException (String.Format (msg, fname), fname);
 300 #endif
 301                         }
 302
 303                         // IsolatedStorage needs to keep the Name property to the default "[Unknown]"
 304                         if (!anonymous)
 305                                 this.name = path;
 306
 307                         // TODO: demand permissions
 308
 309                         MonoIOError error;
 310
 311                         this.handle = MonoIO.Open (path, mode, access, share, options, out error);
 312                         if (handle == MonoIO.InvalidHandle) {
 313                                 // don't leak the path information for isolated storage
 314                                 throw MonoIO.GetException (GetSecureFileName (path), error);
 315                         }
 316
 317                         this.access = access;
 318                         this.owner = true;
 319
 320                         /* Can we open non-files by name? */
 321
 322                         if (MonoIO.GetFileType (handle, out error) == MonoFileType.Disk) {
 323                                 this.canseek = true;
 324                                 this.async = (options & FileOptions.Asynchronous) != 0;
 325                         } else {
 326                                 this.canseek = false;
 327                                 this.async = false;
 328                         }
 329
 330
 331                         if (access == FileAccess.Read && canseek && (bufferSize == DefaultBufferSize)) {
 332                                 /* Avoid allocating a large buffer for small files */
 333                                 long len = Length;
 334                                 if (bufferSize > len) {
 335                                         bufferSize = (int)(len < 1000 ? 1000 : len);
 336                                 }
 337                         }
 338
 339                         InitBuffer (bufferSize, false);
 340
 341                         if (mode==FileMode.Append) {
 342                                 this.Seek (0, SeekOrigin.End);
 343                                 this.append_startpos=this.Position;
 344                         } else {
 345                                 this.append_startpos=0;
 346                         }
 347                 }
 348
 349                 // properties
 350
 351                 public override bool CanRead {
 352                         get {
 353                                 return access == FileAccess.Read ||
 354                                        access == FileAccess.ReadWrite;
 355                         }
 356                 }
 357
 358                 public override bool CanWrite {
 359                         get {
 360                                 return access == FileAccess.Write ||
 361                                         access == FileAccess.ReadWrite;
 362                         }
 363                 }
 364
 365                 public override bool CanSeek {
 366                         get {
 367                                 return(canseek);
 368                         }
 369                 }
 370
 371                 public virtual bool IsAsync {
 372                         get {
 373                                 return (async);
 374                         }
 375                 }
 376
 377                 public string Name {
 378                         get {
 379 #if MOONLIGHT
 380                                 return SecurityManager.CheckElevatedPermissions () ? name : "[Unknown]";
 381 #else
 382                                 return name;
 383 #endif
 384                         }
 385                 }
 386
 387                 public override long Length {
 388                         get {
 389                                 if (handle == MonoIO.InvalidHandle)
 390                                         throw new ObjectDisposedException ("Stream has been closed");
 391
 392                                 if (!CanSeek)
 393                                         throw new NotSupportedException ("The stream does not support seeking");
 394
 395                                 // Buffered data might change the length of the stream
 396                                 FlushBufferIfDirty ();
 397
 398                                 MonoIOError error;
 399                                 long length;
 400
 401                                 length = MonoIO.GetLength (handle, out error);
 402                                 if (error != MonoIOError.ERROR_SUCCESS) {
 403                                         // don't leak the path information for isolated storage
 404                                         throw MonoIO.GetException (GetSecureFileName (name), error);
 405                                 }
 406
 407                                 return(length);
 408                         }
 409                 }
 410
 411                 public override long Position {
 412                         get {
 413                                 if (handle == MonoIO.InvalidHandle)
 414                                         throw new ObjectDisposedException ("Stream has been closed");
 415
 416                                 if (CanSeek == false)
 417                                         throw new NotSupportedException("The stream does not support seeking");
 418
 419                                 if (safeHandle != null) {
 420                                         // If the handle was leaked outside we always ask the real handle
 421                                         MonoIOError error;
 422
 423                                         long ret = MonoIO.Seek (handle, 0,SeekOrigin.Current,out error);
 424
 425                                         if (error != MonoIOError.ERROR_SUCCESS) {
 426                                                 // don't leak the path information for isolated storage
 427                                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 428                                         }
 429
 430                                         return ret;
 431                                 }
 432
 433                                 return(buf_start + buf_offset);
 434                         }
 435                         set {
 436                                 if (handle == MonoIO.InvalidHandle)
 437                                         throw new ObjectDisposedException ("Stream has been closed");
 438
 439                                 if(CanSeek == false) {
 440                                         throw new NotSupportedException("The stream does not support seeking");
 441                                 }
 442
 443                                 if(value < 0) {
 444                                         throw new ArgumentOutOfRangeException("Attempt to set the position to a negative value");
 445                                 }
 446
 447                                 Seek (value, SeekOrigin.Begin);
 448                         }
 449                 }
 450
 451                 [Obsolete ("Use SafeFileHandle instead")]
 452                 public virtual IntPtr Handle {
 453                         [SecurityPermission (SecurityAction.LinkDemand, UnmanagedCode = true)]
 454                         [SecurityPermission (SecurityAction.InheritanceDemand, UnmanagedCode = true)]
 455                         get {
 456                                 if (safeHandle == null) {
 457                                         ExposeHandle ();
 458                                 }
 459                                 return handle;
 460                         }
 461                 }
 462
 463                 public virtual SafeFileHandle SafeFileHandle {
 464                         [SecurityPermission (SecurityAction.LinkDemand, UnmanagedCode = true)]
 465                         [SecurityPermission (SecurityAction.InheritanceDemand, UnmanagedCode = true)]
 466                         get {
 467                                 if (safeHandle == null) {
 468                                         ExposeHandle ();
 469                                 }
 470                                 return safeHandle;
 471                         }
 472                 }
 473
 474                 // methods
 475
 476           void ExposeHandle ()
 477                 {
 478                         safeHandle = new SafeFileHandle (handle, false);
 479                         FlushBuffer ();
 480                         InitBuffer (0, true);
 481                 }
 482
 483                 public override int ReadByte ()
 484                 {
 485                         if (handle == MonoIO.InvalidHandle)
 486                                 throw new ObjectDisposedException ("Stream has been closed");
 487
 488                         if (!CanRead)
 489                                 throw new NotSupportedException ("Stream does not support reading");
 490
 491                         if (buf_size == 0) {
 492                                 int n = ReadData (handle, buf, 0, 1);
 493                                 if (n == 0) return -1;
 494                                 else return buf[0];
 495                         }
 496                         else if (buf_offset >= buf_length) {
 497                                 RefillBuffer ();
 498
 499                                 if (buf_length == 0)
 500                                         return -1;
 501                         }
 502
 503                         return buf [buf_offset ++];
 504                 }
 505
 506                 public override void WriteByte (byte value)
 507                 {
 508                         if (handle == MonoIO.InvalidHandle)
 509                                 throw new ObjectDisposedException ("Stream has been closed");
 510
 511                         if (!CanWrite)
 512                                 throw new NotSupportedException ("Stream does not support writing");
 513
 514                         if (buf_offset == buf_size)
 515                                 FlushBuffer ();
 516
 517                         if (buf_size == 0) { // No buffering
 518                                 buf [0] = value;
 519                                 buf_dirty = true;
 520                                 buf_length = 1;
 521                                 FlushBuffer ();
 522                                 return;
 523                         }
 524
 525                         buf [buf_offset ++] = value;
 526                         if (buf_offset > buf_length)
 527                                 buf_length = buf_offset;
 528
 529                         buf_dirty = true;
 530                 }
 531
 532                 public override int Read ([In,Out] byte[] array, int offset, int count)
 533                 {
 534                         if (handle == MonoIO.InvalidHandle)
 535                                 throw new ObjectDisposedException ("Stream has been closed");
 536                         if (array == null)
 537                                 throw new ArgumentNullException ("array");
 538                         if (!CanRead)
 539                                 throw new NotSupportedException ("Stream does not support reading");
 540                         int len = array.Length;
 541                         if (offset < 0)
 542                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 543                         if (count < 0)
 544                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 545                         if (offset > len)
 546                                 throw new ArgumentException ("destination offset is beyond array size");
 547                         // reordered to avoid possible integer overflow
 548                         if (offset > len - count)
 549                                 throw new ArgumentException ("Reading would overrun buffer");
 550
 551                         if (async) {
 552                                 IAsyncResult ares = BeginRead (array, offset, count, null, null);
 553                                 return EndRead (ares);
 554                         }
 555
 556                         return ReadInternal (array, offset, count);
 557                 }
 558
 559                 int ReadInternal (byte [] dest, int offset, int count)
 560                 {
 561                         int n = ReadSegment (dest, offset, count);
 562                         if (n == count) {
 563                                 return count;
 564                         }
 565
 566                         int copied = n;
 567                         count -= n;
 568                         if (count > buf_size) {
 569                                 /* Read as much as we can, up
 570                                  * to count bytes
 571                                  */
 572                                 FlushBuffer();
 573                                 n = ReadData (handle, dest,
 574                                               offset+n,
 575                                               count);
 576
 577                                 /* Make the next buffer read
 578                                  * start from the right place
 579                                  */
 580                                 buf_start += n;
 581                         } else {
 582                                 RefillBuffer ();
 583                                 n = ReadSegment (dest,
 584                                                  offset+copied,
 585                                                  count);
 586                         }
 587
 588                         return copied + n;
 589                 }
 590
 591                 delegate int ReadDelegate (byte [] buffer, int offset, int count);
 592
 593                 public override IAsyncResult BeginRead (byte [] array, int offset, int numBytes,
 594                                                         AsyncCallback userCallback, object stateObject)
 595                 {
 596                         if (handle == MonoIO.InvalidHandle)
 597                                 throw new ObjectDisposedException ("Stream has been closed");
 598
 599                         if (!CanRead)
 600                                 throw new NotSupportedException ("This stream does not support reading");
 601
 602                         if (array == null)
 603                                 throw new ArgumentNullException ("array");
 604
 605                         if (numBytes < 0)
 606                                 throw new ArgumentOutOfRangeException ("numBytes", "Must be >= 0");
 607
 608                         if (offset < 0)
 609                                 throw new ArgumentOutOfRangeException ("offset", "Must be >= 0");
 610
 611                         // reordered to avoid possible integer overflow
 612                         if (numBytes > array.Length - offset)
 613                                 throw new ArgumentException ("Buffer too small. numBytes/offset wrong.");
 614
 615                         if (!async)
 616                                 return base.BeginRead (array, offset, numBytes, userCallback, stateObject);
 617
 618                         ReadDelegate r = new ReadDelegate (ReadInternal);
 619                         return r.BeginInvoke (array, offset, numBytes, userCallback, stateObject);
 620                 }
 621
 622                 public override int EndRead (IAsyncResult asyncResult)
 623                 {
 624                         if (asyncResult == null)
 625                                 throw new ArgumentNullException ("asyncResult");
 626
 627                         if (!async)
 628                                 return base.EndRead (asyncResult);
 629
 630                         AsyncResult ares = asyncResult as AsyncResult;
 631                         if (ares == null)
 632                                 throw new ArgumentException ("Invalid IAsyncResult", "asyncResult");
 633
 634                         ReadDelegate r = ares.AsyncDelegate as ReadDelegate;
 635                         if (r == null)
 636                                 throw new ArgumentException ("Invalid IAsyncResult", "asyncResult");
 637
 638                         return r.EndInvoke (asyncResult);
 639                 }
 640
 641                 public override void Write (byte[] array, int offset, int count)
 642                 {
 643                         if (handle == MonoIO.InvalidHandle)
 644                                 throw new ObjectDisposedException ("Stream has been closed");
 645                         if (array == null)
 646                                 throw new ArgumentNullException ("array");
 647                         if (offset < 0)
 648                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 649                         if (count < 0)
 650                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 651                         // ordered to avoid possible integer overflow
 652                         if (offset > array.Length - count)
 653                                 throw new ArgumentException ("Reading would overrun buffer");
 654                         if (!CanWrite)
 655                                 throw new NotSupportedException ("Stream does not support writing");
 656
 657                         if (async) {
 658                                 IAsyncResult ares = BeginWrite (array, offset, count, null, null);
 659                                 EndWrite (ares);
 660                                 return;
 661                         }
 662
 663                         WriteInternal (array, offset, count);
 664                 }
 665
 666                 void WriteInternal (byte [] src, int offset, int count)
 667                 {
 668                         if (count > buf_size) {
 669                                 // shortcut for long writes
 670                                 MonoIOError error;
 671
 672                                 FlushBuffer ();
 673                                 int wcount = count;
 674
 675                                 while (wcount > 0){
 676                                         int n = MonoIO.Write (handle, src, offset, wcount, out error);
 677                                         if (error != MonoIOError.ERROR_SUCCESS)
 678                                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 679
 680                                         wcount -= n;
 681                                         offset += n;
 682                                 }
 683                                 buf_start += count;
 684                         } else {
 685
 686                                 int copied = 0;
 687                                 while (count > 0) {
 688
 689                                         int n = WriteSegment (src, offset + copied, count);
 690                                         copied += n;
 691                                         count -= n;
 692
 693                                         if (count == 0) {
 694                                                 break;
 695                                         }
 696
 697                                         FlushBuffer ();
 698                                 }
 699                         }
 700                 }
 701
 702                 delegate void WriteDelegate (byte [] buffer, int offset, int count);
 703
 704                 public override IAsyncResult BeginWrite (byte [] array, int offset, int numBytes,
 705                                                         AsyncCallback userCallback, object stateObject)
 706                 {
 707                         if (handle == MonoIO.InvalidHandle)
 708                                 throw new ObjectDisposedException ("Stream has been closed");
 709
 710                         if (!CanWrite)
 711                                 throw new NotSupportedException ("This stream does not support writing");
 712
 713                         if (array == null)
 714                                 throw new ArgumentNullException ("array");
 715
 716                         if (numBytes < 0)
 717                                 throw new ArgumentOutOfRangeException ("numBytes", "Must be >= 0");
 718
 719                         if (offset < 0)
 720                                 throw new ArgumentOutOfRangeException ("offset", "Must be >= 0");
 721
 722                         // reordered to avoid possible integer overflow
 723                         if (numBytes > array.Length - offset)
 724                                 throw new ArgumentException ("array too small. numBytes/offset wrong.");
 725
 726                         if (!async)
 727                                 return base.BeginWrite (array, offset, numBytes, userCallback, stateObject);
 728
 729                         FileStreamAsyncResult result = new FileStreamAsyncResult (userCallback, stateObject);
 730                         result.BytesRead = -1;
 731                         result.Count = numBytes;
 732                         result.OriginalCount = numBytes;
 733
 734                         if (buf_dirty) {
 735                                 MemoryStream ms = new MemoryStream ();
 736                                 FlushBuffer (ms);
 737                                 ms.Write (array, offset, numBytes);
 738                                 offset = 0;
 739                                 numBytes = (int) ms.Length;
 740                         }
 741
 742                         WriteDelegate w = new WriteDelegate (WriteInternal);
 743                         return w.BeginInvoke (array, offset, numBytes, userCallback, stateObject);
 744                 }
 745
 746                 public override void EndWrite (IAsyncResult asyncResult)
 747                 {
 748                         if (asyncResult == null)
 749                                 throw new ArgumentNullException ("asyncResult");
 750
 751                         if (!async) {
 752                                 base.EndWrite (asyncResult);
 753                                 return;
 754                         }
 755
 756                         AsyncResult ares = asyncResult as AsyncResult;
 757                         if (ares == null)
 758                                 throw new ArgumentException ("Invalid IAsyncResult", "asyncResult");
 759
 760                         WriteDelegate w = ares.AsyncDelegate as WriteDelegate;
 761                         if (w == null)
 762                                 throw new ArgumentException ("Invalid IAsyncResult", "asyncResult");
 763
 764                         w.EndInvoke (asyncResult);
 765                         return;
 766                 }
 767
 768                 public override long Seek (long offset, SeekOrigin origin)
 769                 {
 770                         long pos;
 771
 772                         if (handle == MonoIO.InvalidHandle)
 773                                 throw new ObjectDisposedException ("Stream has been closed");
 774
 775                         // make absolute
 776
 777                         if(CanSeek == false) {
 778                                 throw new NotSupportedException("The stream does not support seeking");
 779                         }
 780
 781                         switch (origin) {
 782                         case SeekOrigin.End:
 783                                 pos = Length + offset;
 784                                 break;
 785
 786                         case SeekOrigin.Current:
 787                                 pos = Position + offset;
 788                                 break;
 789
 790                         case SeekOrigin.Begin:
 791                                 pos = offset;
 792                                 break;
 793
 794                         default:
 795                                 throw new ArgumentException ("origin", "Invalid SeekOrigin");
 796                         }
 797
 798                         if (pos < 0) {
 799                                 /* LAMESPEC: shouldn't this be
 800                                  * ArgumentOutOfRangeException?
 801                                  */
 802                                 throw new IOException("Attempted to Seek before the beginning of the stream");
 803                         }
 804
 805                         if(pos < this.append_startpos) {
 806                                 /* More undocumented crap */
 807                                 throw new IOException("Can't seek back over pre-existing data in append mode");
 808                         }
 809
 810                         FlushBuffer ();
 811
 812                         MonoIOError error;
 813
 814                         buf_start = MonoIO.Seek (handle, pos,
 815                                                  SeekOrigin.Begin,
 816                                                  out error);
 817
 818                         if (error != MonoIOError.ERROR_SUCCESS) {
 819                                 // don't leak the path information for isolated storage
 820                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 821                         }
 822
 823                         return(buf_start);
 824                 }
 825
 826                 public override void SetLength (long value)
 827                 {
 828                         if (handle == MonoIO.InvalidHandle)
 829                                 throw new ObjectDisposedException ("Stream has been closed");
 830
 831                         if(CanSeek == false)
 832                                 throw new NotSupportedException("The stream does not support seeking");
 833
 834                         if(CanWrite == false)
 835                                 throw new NotSupportedException("The stream does not support writing");
 836
 837                         if(value < 0)
 838                                 throw new ArgumentOutOfRangeException("value is less than 0");
 839
 840                         Flush ();
 841
 842                         MonoIOError error;
 843
 844                         MonoIO.SetLength (handle, value, out error);
 845                         if (error != MonoIOError.ERROR_SUCCESS) {
 846                                 // don't leak the path information for isolated storage
 847                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 848                         }
 849
 850                         if (Position > value)
 851                                 Position = value;
 852                 }
 853
 854                 public override void Flush ()
 855                 {
 856                         if (handle == MonoIO.InvalidHandle)
 857                                 throw new ObjectDisposedException ("Stream has been closed");
 858
 859                         FlushBuffer ();
 860                 }
 861
 862 #if NET_4_0 || MOONLIGHT || MOBILE
 863                 public virtual void Flush (bool flushToDisk)
 864                 {
 865                         FlushBuffer ();
 866
 867                         // This does the fsync
 868                         if (flushToDisk){
 869                                 MonoIOError error;
 870                                 MonoIO.Flush (handle, out error);
 871                         }
 872                 }
 873 #endif
 874
 875                 public virtual void Lock (long position, long length)
 876                 {
 877                         if (handle == MonoIO.InvalidHandle)
 878                                 throw new ObjectDisposedException ("Stream has been closed");
 879                         if (position < 0) {
 880                                 throw new ArgumentOutOfRangeException ("position must not be negative");
 881                         }
 882                         if (length < 0) {
 883                                 throw new ArgumentOutOfRangeException ("length must not be negative");
 884                         }
 885                         if (handle == MonoIO.InvalidHandle) {
 886                                 throw new ObjectDisposedException ("Stream has been closed");
 887                         }
 888
 889                         MonoIOError error;
 890
 891                         MonoIO.Lock (handle, position, length, out error);
 892                         if (error != MonoIOError.ERROR_SUCCESS) {
 893                                 // don't leak the path information for isolated storage
 894                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 895                         }
 896                 }
 897
 898                 public virtual void Unlock (long position, long length)
 899                 {
 900                         if (handle == MonoIO.InvalidHandle)
 901                                 throw new ObjectDisposedException ("Stream has been closed");
 902                         if (position < 0) {
 903                                 throw new ArgumentOutOfRangeException ("position must not be negative");
 904                         }
 905                         if (length < 0) {
 906                                 throw new ArgumentOutOfRangeException ("length must not be negative");
 907                         }
 908
 909                         MonoIOError error;
 910
 911                         MonoIO.Unlock (handle, position, length, out error);
 912                         if (error != MonoIOError.ERROR_SUCCESS) {
 913                                 // don't leak the path information for isolated storage
 914                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 915                         }
 916                 }
 917
 918                 // protected
 919
 920                 ~FileStream ()
 921                 {
 922                         Dispose (false);
 923                 }
 924
 925                 protected override void Dispose (bool disposing)
 926                 {
 927                         Exception exc = null;
 928                         if (handle != MonoIO.InvalidHandle) {
 929                                 try {
 930                                         // If the FileStream is in "exposed" status
 931                                         // it means that we do not have a buffer(we write the data without buffering)
 932                                         // therefor we don't and can't flush the buffer becouse we don't have one.
 933                                         FlushBuffer ();
 934                                 } catch (Exception e) {
 935                                         exc = e;
 936                                 }
 937
 938                                 if (owner) {
 939                                         MonoIOError error;
 940
 941                                         MonoIO.Close (handle, out error);
 942                                         if (error != MonoIOError.ERROR_SUCCESS) {
 943                                                 // don't leak the path information for isolated storage
 944                                                 throw MonoIO.GetException (GetSecureFileName (name), error);
 945                                         }
 946
 947                                         handle = MonoIO.InvalidHandle;
 948                                 }
 949                         }
 950
 951                         canseek = false;
 952                         access = 0;
 953
 954                         if (disposing && buf != null) {
 955                                 if (buf.Length == DefaultBufferSize && buf_recycle == null) {
 956                                         lock (buf_recycle_lock) {
 957                                                 if (buf_recycle == null) {
 958                                                         buf_recycle = buf;
 959                                                 }
 960                                         }
 961                                 }
 962
 963                                 buf = null;
 964                                 GC.SuppressFinalize (this);
 965                         }
 966                         if (exc != null)
 967                                 throw exc;
 968                 }
 969
 970 #if !NET_2_1
 971                 public FileSecurity GetAccessControl ()
 972                 {
 973                         return new FileSecurity (SafeFileHandle,
 974                                                  AccessControlSections.Owner |
 975                                                  AccessControlSections.Group |
 976                                                  AccessControlSections.Access);
 977                 }
 978
 979                 public void SetAccessControl (FileSecurity fileSecurity)
 980                 {
 981                         if (null == fileSecurity)
 982                                 throw new ArgumentNullException ("fileSecurity");
 983
 984                         fileSecurity.PersistModifications (SafeFileHandle);
 985                 }
 986 #endif
 987
 988 #if NET_4_5
 989                 public override Task FlushAsync (CancellationToken cancellationToken)
 990                 {
 991                         return base.FlushAsync (cancellationToken);
 992                 }
 993
 994                 public override Task<int> ReadAsync (byte[] buffer, int offset, int count, CancellationToken cancellationToken)
 995                 {
 996                         return base.ReadAsync (buffer, offset, count, cancellationToken);
 997                 }
 998
 999                 public override Task WriteAsync (byte[] buffer, int offset, int count, CancellationToken cancellationToken)
1000                 {
1001                         return base.WriteAsync (buffer, offset, count, cancellationToken);
1002                 }
1003 #endif
1004
1005                 // private.
1006
1007                 // ReadSegment, WriteSegment, FlushBuffer,
1008                 // RefillBuffer and ReadData should only be called
1009                 // when the Monitor lock is held, but these methods
1010                 // grab it again just to be safe.
1011
1012                 private int ReadSegment (byte [] dest, int dest_offset, int count)
1013                 {
1014                         count = Math.Min (count, buf_length - buf_offset);
1015
1016                         if (count > 0) {
1017                                 // Use the fastest method, all range checks has been done
1018                                 Buffer.BlockCopyInternal (buf, buf_offset, dest, dest_offset, count);
1019                                 buf_offset += count;
1020                         }
1021
1022                         return count;
1023                 }
1024
1025                 private int WriteSegment (byte [] src, int src_offset,
1026                                           int count)
1027                 {
1028                         if (count > buf_size - buf_offset) {
1029                                 count = buf_size - buf_offset;
1030                         }
1031
1032                         if (count > 0) {
1033                                 Buffer.BlockCopy (src, src_offset,
1034                                                   buf, buf_offset,
1035                                                   count);
1036                                 buf_offset += count;
1037                                 if (buf_offset > buf_length) {
1038                                         buf_length = buf_offset;
1039                                 }
1040
1041                                 buf_dirty = true;
1042                         }
1043
1044                         return(count);
1045                 }
1046
1047                 void FlushBuffer (Stream st)
1048                 {
1049                         if (buf_dirty) {
1050                                 MonoIOError error;
1051
1052                                 if (CanSeek == true && safeHandle == null) {
1053                                         MonoIO.Seek (handle, buf_start,
1054                                                      SeekOrigin.Begin,
1055                                                      out error);
1056                                         if (error != MonoIOError.ERROR_SUCCESS) {
1057                                                 // don't leak the path information for isolated storage
1058                                                 throw MonoIO.GetException (GetSecureFileName (name), error);
1059                                         }
1060                                 }
1061                                 if (st == null) {
1062                                         int wcount = buf_length;
1063                                         int offset = 0;
1064                                         while (wcount > 0){
1065                                                 int n = MonoIO.Write (handle, buf, 0, buf_length, out error);
1066                                                 if (error != MonoIOError.ERROR_SUCCESS) {
1067                                                         // don't leak the path information for isolated storage
1068                                                         throw MonoIO.GetException (GetSecureFileName (name), error);
1069                                                 }
1070                                                 wcount -= n;
1071                                                 offset += n;
1072                                         }
1073                                 } else {
1074                                         st.Write (buf, 0, buf_length);
1075                                 }
1076                         }
1077
1078                         buf_start += buf_offset;
1079                         buf_offset = buf_length = 0;
1080                         buf_dirty = false;
1081                 }
1082
1083                 private void FlushBuffer ()
1084                 {
1085                         FlushBuffer (null);
1086                 }
1087
1088                 private void FlushBufferIfDirty ()
1089                 {
1090                         if (buf_dirty)
1091                                 FlushBuffer (null);
1092                 }
1093
1094                 private void RefillBuffer ()
1095                 {
1096                         FlushBuffer (null);
1097
1098                         buf_length = ReadData (handle, buf, 0,
1099                                                buf_size);
1100                 }
1101
1102                 private int ReadData (IntPtr handle, byte[] buf, int offset,
1103                                       int count)
1104                 {
1105                         MonoIOError error;
1106                         int amount = 0;
1107
1108                         /* when async == true, if we get here we don't suport AIO or it's disabled
1109                          * and we're using the threadpool */
1110                         amount = MonoIO.Read (handle, buf, offset, count, out error);
1111                         if (error == MonoIOError.ERROR_BROKEN_PIPE) {
1112                                 amount = 0; // might not be needed, but well...
1113                         } else if (error != MonoIOError.ERROR_SUCCESS) {
1114                                 // don't leak the path information for isolated storage
1115                                 throw MonoIO.GetException (GetSecureFileName (name), error);
1116                         }
1117
1118                         /* Check for read error */
1119                         if(amount == -1) {
1120                                 throw new IOException ();
1121                         }
1122
1123                         return(amount);
1124                 }
1125
1126                 void InitBuffer (int size, bool isZeroSize)
1127                 {
1128                         if (isZeroSize) {
1129                                 size = 0;
1130                                 buf = new byte[1];
1131                         } else {
1132                                 if (size <= 0)
1133                                         throw new ArgumentOutOfRangeException ("bufferSize", "Positive number required.");
1134
1135                                 size = Math.Max (size, 8);
1136
1137                                 //
1138                                 // Instead of allocating a new default buffer use the
1139                                 // last one if there is any available
1140                                 //
1141                                 if (size <= DefaultBufferSize && buf_recycle != null) {
1142                                         lock (buf_recycle_lock) {
1143                                                 if (buf_recycle != null) {
1144                                                         buf = buf_recycle;
1145                                                         buf_recycle = null;
1146                                                 }
1147                                         }
1148                                 }
1149
1150                                 if (buf == null)
1151                                         buf = new byte [size];
1152                                 else
1153                                         Array.Clear (buf, 0, size);
1154                         }
1155
1156                         buf_size = size;
1157 //                      buf_start = 0;
1158 //                      buf_offset = buf_length = 0;
1159 //                      buf_dirty = false;
1160                 }
1161
1162                 private string GetSecureFileName (string filename)
1163                 {
1164                         return (anonymous) ? Path.GetFileName (filename) : Path.GetFullPath (filename);
1165                 }
1166
1167                 private string GetSecureFileName (string filename, bool full)
1168                 {
1169                         return (anonymous) ? Path.GetFileName (filename) :
1170                                 (full) ? Path.GetFullPath (filename) : filename;
1171                 }
1172
1173                 // fields
1174
1175                 internal const int DefaultBufferSize = 4096;
1176
1177                 // Input buffer ready for recycling
1178                 static byte[] buf_recycle;
1179                 static readonly object buf_recycle_lock = new object ();
1180
1181                 private byte [] buf;                    // the buffer
1182                 private string name = "[Unknown]";      // name of file.
1183
1184                 SafeFileHandle safeHandle;              // set only when using one of the
1185                                                         // constructors taking SafeFileHandle
1186
1187                 private long append_startpos;
1188                 IntPtr handle;                          // handle to underlying file
1189
1190                 private FileAccess access;
1191                 private bool owner;
1192                 private bool async;
1193                 private bool canseek;
1194                 private bool anonymous;
1195                 private bool buf_dirty;                 // true if buffer has been written to
1196
1197                 private int buf_size;                   // capacity in bytes
1198                 private int buf_length;                 // number of valid bytes in buffer
1199                 private int buf_offset;                 // position of next byte
1200                 private long buf_start;                 // location of buffer in file
1201         }
1202 }