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

   1 //\r
   2 // System.IO.StreamWriter.cs\r
   3 //\r
   4 // Authors:\r
   5 //   Dietmar Maurer (dietmar@ximian.com)\r
   6 //   Paolo Molaro (lupus@ximian.com)\r
   7 //   Marek Safar (marek.safar@gmail.com)\r
   8 //\r
   9 // (C) Ximian, Inc.  http://www.ximian.com\r
  10 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)\r
  11 // Copyright 2011, 2013 Xamarin Inc.\r
  12 //\r
  13 // Permission is hereby granted, free of charge, to any person obtaining\r
  14 // a copy of this software and associated documentation files (the\r
  15 // "Software"), to deal in the Software without restriction, including\r
  16 // without limitation the rights to use, copy, modify, merge, publish,\r
  17 // distribute, sublicense, and/or sell copies of the Software, and to\r
  18 // permit persons to whom the Software is furnished to do so, subject to\r
  19 // the following conditions:\r
  20 // \r
  21 // The above copyright notice and this permission notice shall be\r
  22 // included in all copies or substantial portions of the Software.\r
  23 // \r
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  31 //\r
  32 \r
  33 using System.Text;\r
  34 using System.Runtime.InteropServices;\r
  35 #if NET_4_5\r
  36 using System.Threading.Tasks;\r
  37 #endif\r
  38 \r
  39 namespace System.IO {\r
  40         \r
  41         [Serializable]\r
  42         [ComVisible (true)]\r
  43         public class StreamWriter : TextWriter {\r
  44 \r
  45                 private Encoding internalEncoding;\r
  46 \r
  47                 private Stream internalStream;\r
  48 \r
  49                 private const int DefaultBufferSize = 1024;\r
  50                 private const int DefaultFileBufferSize = 4096;\r
  51                 private const int MinimumBufferSize = 256;\r
  52 \r
  53                 private byte[] byte_buf;\r
  54                 private char[] decode_buf;\r
  55                 private int byte_pos;\r
  56                 private int decode_pos;\r
  57 \r
  58                 private bool iflush;\r
  59                 private bool preamble_done;\r
  60 \r
  61 #if NET_4_5\r
  62                 readonly bool leave_open;\r
  63                 IDecoupledTask async_task;\r
  64 #endif\r
  65 \r
  66                 public new static readonly StreamWriter Null = new StreamWriter (Stream.Null, Encoding.UTF8Unmarked, 1);\r
  67 \r
  68                 public StreamWriter (Stream stream)\r
  69                         : this (stream, Encoding.UTF8Unmarked, DefaultBufferSize) {}\r
  70 \r
  71                 public StreamWriter (Stream stream, Encoding encoding)\r
  72                         : this (stream, encoding, DefaultBufferSize) {}\r
  73 \r
  74                 internal void Initialize(Encoding encoding, int bufferSize) {\r
  75                         internalEncoding = encoding;\r
  76                         decode_pos = byte_pos = 0;\r
  77                         int BufferSize = Math.Max(bufferSize, MinimumBufferSize);\r
  78                         decode_buf = new char [BufferSize];\r
  79                         byte_buf = new byte [encoding.GetMaxByteCount (BufferSize)];\r
  80 \r
  81                         // Fixes bug http://bugzilla.ximian.com/show_bug.cgi?id=74513\r
  82                         if (internalStream.CanSeek && internalStream.Position > 0)\r
  83                                 preamble_done = true;\r
  84                 }\r
  85 \r
  86 #if NET_4_5\r
  87                 public StreamWriter (Stream stream, Encoding encoding, int bufferSize)\r
  88                         : this (stream, encoding, bufferSize, false)\r
  89                 {\r
  90                 }\r
  91                 \r
  92                 public StreamWriter (Stream stream, Encoding encoding, int bufferSize, bool leaveOpen)\r
  93 #else\r
  94                 const bool leave_open = false;\r
  95 \r
  96                 public StreamWriter (Stream stream, Encoding encoding, int bufferSize)\r
  97 #endif\r
  98                 {\r
  99                         if (null == stream)\r
 100                                 throw new ArgumentNullException("stream");\r
 101                         if (null == encoding)\r
 102                                 throw new ArgumentNullException("encoding");\r
 103                         if (bufferSize <= 0)\r
 104                                 throw new ArgumentOutOfRangeException("bufferSize");\r
 105                         if (!stream.CanWrite)\r
 106                                 throw new ArgumentException ("Can not write to stream");\r
 107 \r
 108 #if NET_4_5\r
 109                         leave_open = leaveOpen;\r
 110 #endif\r
 111                         internalStream = stream;\r
 112 \r
 113                         Initialize(encoding, bufferSize);\r
 114                 }\r
 115 \r
 116                 public StreamWriter (string path)\r
 117                         : this (path, false, Encoding.UTF8Unmarked, DefaultFileBufferSize) {}\r
 118 \r
 119                 public StreamWriter (string path, bool append)\r
 120                         : this (path, append, Encoding.UTF8Unmarked, DefaultFileBufferSize) {}\r
 121 \r
 122                 public StreamWriter (string path, bool append, Encoding encoding)\r
 123                         : this (path, append, encoding, DefaultFileBufferSize) {}\r
 124 \r
 125                 public StreamWriter (string path, bool append, Encoding encoding, int bufferSize)\r
 126                 {\r
 127                         if (null == encoding)\r
 128                                 throw new ArgumentNullException("encoding");\r
 129                         if (bufferSize <= 0)\r
 130                                 throw new ArgumentOutOfRangeException("bufferSize");\r
 131 \r
 132                         FileMode mode;\r
 133 \r
 134                         if (append)\r
 135                                 mode = FileMode.Append;\r
 136                         else\r
 137                                 mode = FileMode.Create;\r
 138                         \r
 139                         internalStream = new FileStream (path, mode, FileAccess.Write, FileShare.Read);\r
 140 \r
 141                         if (append)\r
 142                                 internalStream.Position = internalStream.Length;\r
 143                         else\r
 144                                 internalStream.SetLength (0);\r
 145 \r
 146                         Initialize(encoding, bufferSize);\r
 147                 }\r
 148 \r
 149                 public virtual bool AutoFlush {\r
 150                         get {\r
 151                                 return iflush;\r
 152                         }\r
 153                         set {\r
 154                                 iflush = value;\r
 155                                 if (iflush)\r
 156                                         Flush ();\r
 157                         }\r
 158                 }\r
 159 \r
 160                 public virtual Stream BaseStream {\r
 161                         get {\r
 162                                 return internalStream;\r
 163                         }\r
 164                 }\r
 165 \r
 166                 public override Encoding Encoding {\r
 167                         get {\r
 168                                 return internalEncoding;\r
 169                         }\r
 170                 }\r
 171 \r
 172                 protected override void Dispose (bool disposing) \r
 173                 {\r
 174                         if (byte_buf == null || !disposing)\r
 175                                 return;\r
 176 \r
 177                         try {\r
 178                                 Flush ();\r
 179                         } finally {\r
 180                                 byte_buf = null;\r
 181                                 internalEncoding = null;\r
 182                                 decode_buf = null;\r
 183 \r
 184                                 if (!leave_open) {\r
 185                                         internalStream.Close ();\r
 186                                 }\r
 187 \r
 188                                 internalStream = null;\r
 189                         }\r
 190                 }\r
 191 \r
 192                 public override void Flush ()\r
 193                 {\r
 194                         CheckState ();\r
 195                         FlushCore ();\r
 196                 }\r
 197 \r
 198                 // Keep in sync with FlushCoreAsync\r
 199                 void FlushCore ()\r
 200                 {\r
 201                         Decode ();\r
 202                         if (byte_pos > 0) {\r
 203                                 FlushBytes ();\r
 204                                 internalStream.Flush ();\r
 205                         }\r
 206                 }\r
 207 \r
 208                 // how the speedup works:\r
 209                 // the Write () methods simply copy the characters in a buffer of chars (decode_buf)\r
 210                 // Decode () is called when the buffer is full or we need to flash.\r
 211                 // Decode () will use the encoding to get the bytes and but them inside\r
 212                 // byte_buf. From byte_buf the data is finally outputted to the stream.\r
 213                 void FlushBytes () \r
 214                 {\r
 215                         // write the encoding preamble only at the start of the stream\r
 216                         if (!preamble_done && byte_pos > 0) {\r
 217                                 byte[] preamble = internalEncoding.GetPreamble ();\r
 218                                 if (preamble.Length > 0)\r
 219                                         internalStream.Write (preamble, 0, preamble.Length);\r
 220                                 preamble_done = true;\r
 221                         }\r
 222                         internalStream.Write (byte_buf, 0, byte_pos);\r
 223                         byte_pos = 0;\r
 224                 }\r
 225 \r
 226                 void Decode () \r
 227                 {\r
 228                         if (byte_pos > 0)\r
 229                                 FlushBytes ();\r
 230                         if (decode_pos > 0) {\r
 231                                 int len = internalEncoding.GetBytes (decode_buf, 0, decode_pos, byte_buf, byte_pos);\r
 232                                 byte_pos += len;\r
 233                                 decode_pos = 0;\r
 234                         }\r
 235                 }\r
 236 \r
 237                 void LowLevelWrite (char[] buffer, int index, int count)\r
 238                 {\r
 239                         while (count > 0) {\r
 240                                 int todo = decode_buf.Length - decode_pos;\r
 241                                 if (todo == 0) {\r
 242                                         Decode ();\r
 243                                         todo = decode_buf.Length;\r
 244                                 }\r
 245                                 if (todo > count)\r
 246                                         todo = count;\r
 247                                 Buffer.BlockCopy (buffer, index * 2, decode_buf, decode_pos * 2, todo * 2);\r
 248                                 count -= todo;\r
 249                                 index += todo;\r
 250                                 decode_pos += todo;\r
 251                         }\r
 252                 }\r
 253                 \r
 254                 void LowLevelWrite (string s)\r
 255                 {\r
 256                         int count = s.Length;\r
 257                         int index = 0;\r
 258                         while (count > 0) {\r
 259                                 int todo = decode_buf.Length - decode_pos;\r
 260                                 if (todo == 0) {\r
 261                                         Decode ();\r
 262                                         todo = decode_buf.Length;\r
 263                                 }\r
 264                                 if (todo > count)\r
 265                                         todo = count;\r
 266                                 \r
 267                                 for (int i = 0; i < todo; i ++)\r
 268                                         decode_buf [i + decode_pos] = s [i + index];\r
 269                                 \r
 270                                 count -= todo;\r
 271                                 index += todo;\r
 272                                 decode_pos += todo;\r
 273                         }\r
 274                 }               \r
 275 \r
 276 #if NET_4_5\r
 277                 async Task FlushCoreAsync ()\r
 278                 {\r
 279                         await DecodeAsync ().ConfigureAwait (false);\r
 280                         if (byte_pos > 0) {\r
 281                                 await FlushBytesAsync ().ConfigureAwait (false);\r
 282                                 await internalStream.FlushAsync ().ConfigureAwait (false);\r
 283                         }\r
 284                 }\r
 285 \r
 286                 async Task FlushBytesAsync ()\r
 287                 {\r
 288                         // write the encoding preamble only at the start of the stream\r
 289                         if (!preamble_done && byte_pos > 0) {\r
 290                                 byte[] preamble = internalEncoding.GetPreamble ();\r
 291                                 if (preamble.Length > 0)\r
 292                                         await internalStream.WriteAsync (preamble, 0, preamble.Length).ConfigureAwait (false);\r
 293                                 preamble_done = true;\r
 294                         }\r
 295 \r
 296                         await internalStream.WriteAsync (byte_buf, 0, byte_pos).ConfigureAwait (false);\r
 297                         byte_pos = 0;\r
 298                 }\r
 299 \r
 300                 async Task DecodeAsync () \r
 301                 {\r
 302                         if (byte_pos > 0)\r
 303                                 await FlushBytesAsync ().ConfigureAwait (false);\r
 304                         if (decode_pos > 0) {\r
 305                                 int len = internalEncoding.GetBytes (decode_buf, 0, decode_pos, byte_buf, byte_pos);\r
 306                                 byte_pos += len;\r
 307                                 decode_pos = 0;\r
 308                         }\r
 309                 }               \r
 310 \r
 311                 async Task LowLevelWriteAsync (char[] buffer, int index, int count)\r
 312                 {\r
 313                         while (count > 0) {\r
 314                                 int todo = decode_buf.Length - decode_pos;\r
 315                                 if (todo == 0) {\r
 316                                         await DecodeAsync ().ConfigureAwait (false);\r
 317                                         todo = decode_buf.Length;\r
 318                                 }\r
 319                                 if (todo > count)\r
 320                                         todo = count;\r
 321                                 Buffer.BlockCopy (buffer, index * 2, decode_buf, decode_pos * 2, todo * 2);\r
 322                                 count -= todo;\r
 323                                 index += todo;\r
 324                                 decode_pos += todo;\r
 325                         }\r
 326                 }\r
 327                 \r
 328                 async Task LowLevelWriteAsync (string s)\r
 329                 {\r
 330                         int count = s.Length;\r
 331                         int index = 0;\r
 332                         while (count > 0) {\r
 333                                 int todo = decode_buf.Length - decode_pos;\r
 334                                 if (todo == 0) {\r
 335                                         await DecodeAsync ().ConfigureAwait (false);\r
 336                                         todo = decode_buf.Length;\r
 337                                 }\r
 338                                 if (todo > count)\r
 339                                         todo = count;\r
 340                                 \r
 341                                 for (int i = 0; i < todo; i ++)\r
 342                                         decode_buf [i + decode_pos] = s [i + index];\r
 343                                 \r
 344                                 count -= todo;\r
 345                                 index += todo;\r
 346                                 decode_pos += todo;\r
 347                         }\r
 348                 }       \r
 349 #endif\r
 350 \r
 351                 public override void Write (char[] buffer, int index, int count) \r
 352                 {\r
 353                         if (buffer == null)\r
 354                                 throw new ArgumentNullException ("buffer");\r
 355                         if (index < 0)\r
 356                                 throw new ArgumentOutOfRangeException ("index", "< 0");\r
 357                         if (count < 0)\r
 358                                 throw new ArgumentOutOfRangeException ("count", "< 0");\r
 359                         // re-ordered to avoid possible integer overflow\r
 360                         if (index > buffer.Length - count)\r
 361                                 throw new ArgumentException ("index + count > buffer.Length");\r
 362 \r
 363                         CheckState ();\r
 364 \r
 365                         LowLevelWrite (buffer, index, count);\r
 366                         if (iflush)\r
 367                                 FlushCore ();\r
 368                 }\r
 369                 \r
 370                 public override void Write (char value)\r
 371                 {\r
 372                         CheckState ();\r
 373 \r
 374                         // the size of decode_buf is always > 0 and\r
 375                         // we check for overflow right away\r
 376                         if (decode_pos >= decode_buf.Length)\r
 377                                 Decode ();\r
 378                         decode_buf [decode_pos++] = value;\r
 379                         if (iflush)\r
 380                                 FlushCore ();\r
 381                 }\r
 382 \r
 383                 public override void Write (char[] buffer)\r
 384                 {\r
 385                         CheckState ();\r
 386 \r
 387                         if (buffer != null)\r
 388                                 LowLevelWrite (buffer, 0, buffer.Length);\r
 389                         if (iflush)\r
 390                                 FlushCore ();\r
 391                 }\r
 392 \r
 393                 public override void Write (string value) \r
 394                 {\r
 395                         CheckState ();\r
 396 \r
 397                         if (value == null)\r
 398                                 return;\r
 399                         \r
 400                         LowLevelWrite (value);\r
 401                         \r
 402                         if (iflush)\r
 403                                 FlushCore ();\r
 404                 }\r
 405 \r
 406                 public override void Close()\r
 407                 {\r
 408                         Dispose (true);\r
 409                 }\r
 410 \r
 411                 void CheckState ()\r
 412                 {\r
 413                         if (byte_buf == null)\r
 414                                 throw new ObjectDisposedException ("StreamWriter");\r
 415 \r
 416 #if NET_4_5\r
 417                         if (async_task != null && !async_task.IsCompleted)\r
 418                                 throw new InvalidOperationException ();\r
 419 #endif\r
 420                 }\r
 421 \r
 422 #if NET_4_5\r
 423                 public override Task FlushAsync ()\r
 424                 {\r
 425                         CheckState ();\r
 426                         DecoupledTask res;\r
 427                         async_task = res = new DecoupledTask (FlushCoreAsync ());\r
 428                         return res.Task;\r
 429                 }\r
 430 \r
 431                 public override Task WriteAsync (char value)\r
 432                 {\r
 433                         CheckState ();\r
 434 \r
 435                         DecoupledTask res;\r
 436                         async_task = res = new DecoupledTask (WriteAsyncCore (value));\r
 437                         return res.Task;\r
 438                 }\r
 439 \r
 440                 async Task WriteAsyncCore (char value)\r
 441                 {\r
 442                         // the size of decode_buf is always > 0 and\r
 443                         // we check for overflow right away\r
 444                         if (decode_pos >= decode_buf.Length)\r
 445                                 await DecodeAsync ().ConfigureAwait (false);\r
 446                         decode_buf [decode_pos++] = value;\r
 447 \r
 448                         if (iflush)\r
 449                                 await FlushCoreAsync ().ConfigureAwait (false);\r
 450                 }\r
 451 \r
 452                 public override Task WriteAsync (char[] buffer, int index, int count)\r
 453                 {\r
 454                         CheckState ();\r
 455                         if (buffer == null)\r
 456                                 return TaskConstants.Finished;\r
 457 \r
 458                         DecoupledTask res;\r
 459                         async_task = res = new DecoupledTask (WriteAsyncCore (buffer, index, count));\r
 460                         return res.Task;\r
 461                 }\r
 462 \r
 463                 async Task WriteAsyncCore (char[] buffer, int index, int count)\r
 464                 {\r
 465                         // Debug.Assert (buffer == null);\r
 466 \r
 467                         await LowLevelWriteAsync (buffer, index, count).ConfigureAwait (false);\r
 468 \r
 469                         if (iflush)\r
 470                                 await FlushCoreAsync ().ConfigureAwait (false);\r
 471                 }\r
 472 \r
 473                 public override Task WriteAsync (string value)\r
 474                 {\r
 475                         CheckState ();\r
 476 \r
 477                         if (value == null)\r
 478                                 return TaskConstants.Finished;\r
 479 \r
 480                         DecoupledTask res;                      \r
 481                         async_task = res = new DecoupledTask (WriteAsyncCore (value, false));\r
 482                         return res.Task;\r
 483                 }\r
 484 \r
 485                 async Task WriteAsyncCore (string value, bool appendNewLine)\r
 486                 {\r
 487                         // Debug.Assert (value == null);\r
 488 \r
 489                         await LowLevelWriteAsync (value).ConfigureAwait (false);\r
 490                         if (appendNewLine)\r
 491                                 await LowLevelWriteAsync (CoreNewLine, 0, CoreNewLine.Length).ConfigureAwait (false);\r
 492                         \r
 493                         if (iflush)\r
 494                                 await FlushCoreAsync ().ConfigureAwait (false);\r
 495                 }               \r
 496 \r
 497                 public override Task WriteLineAsync ()\r
 498                 {\r
 499                         CheckState ();\r
 500 \r
 501                         DecoupledTask res;\r
 502                         async_task = res = new DecoupledTask (WriteAsyncCore (CoreNewLine, 0, CoreNewLine.Length));\r
 503                         return res.Task;\r
 504                 }\r
 505 \r
 506                 public override Task WriteLineAsync (char value)\r
 507                 {\r
 508                         CheckState ();\r
 509                         DecoupledTask res;\r
 510                         async_task = res = new DecoupledTask (WriteLineAsyncCore (value));\r
 511                         return res.Task;\r
 512                 }\r
 513 \r
 514                 async Task WriteLineAsyncCore (char value)\r
 515                 {\r
 516                         await WriteAsyncCore (value).ConfigureAwait (false);\r
 517                         await LowLevelWriteAsync (CoreNewLine, 0, CoreNewLine.Length).ConfigureAwait (false);\r
 518                         \r
 519                         if (iflush)\r
 520                                 await FlushCoreAsync ().ConfigureAwait (false);\r
 521                 }               \r
 522 \r
 523                 public override Task WriteLineAsync (char[] buffer, int index, int count)\r
 524                 {\r
 525                         if (buffer == null)\r
 526                                 throw new ArgumentNullException ("buffer");\r
 527                         if (index < 0)\r
 528                                 throw new ArgumentOutOfRangeException ("index", "< 0");\r
 529                         if (count < 0)\r
 530                                 throw new ArgumentOutOfRangeException ("count", "< 0");\r
 531                         // re-ordered to avoid possible integer overflow\r
 532                         if (index > buffer.Length - count)\r
 533                                 throw new ArgumentException ("index + count > buffer.Length");\r
 534 \r
 535                         CheckState ();\r
 536                         DecoupledTask res;\r
 537                         async_task = res = new DecoupledTask (WriteLineAsyncCore (buffer, index, count));\r
 538                         return res.Task;\r
 539                 }\r
 540 \r
 541                 async Task WriteLineAsyncCore (char[] buffer, int index, int count)\r
 542                 {\r
 543                         // Debug.Assert (buffer == null);\r
 544 \r
 545                         await LowLevelWriteAsync (buffer, index, count).ConfigureAwait (false);\r
 546                         await LowLevelWriteAsync (CoreNewLine, 0, CoreNewLine.Length).ConfigureAwait (false);\r
 547                         \r
 548                         if (iflush)\r
 549                                 await FlushCoreAsync ().ConfigureAwait (false);\r
 550                 }               \r
 551 \r
 552                 public override Task WriteLineAsync (string value)\r
 553                 {\r
 554                         if (value == null)\r
 555                                 return WriteLineAsync ();\r
 556 \r
 557                         CheckState ();\r
 558                         DecoupledTask res;                      \r
 559                         async_task = res = new DecoupledTask (WriteAsyncCore (value, true));\r
 560                         return res.Task;\r
 561                 }\r
 562 #endif\r
 563         }\r
 564 }\r