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