mcs/class/Mono.Posix/Mono.Unix/StdioFileStream.cs

   1 //
   2 // Mono.Unix/StdioFileStream.cs
   3 //
   4 // Authors:
   5 //   Jonathan Pryor (jonpryor@vt.edu)
   6 //
   7 // (C) 2005-2006 Jonathan Pryor
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.IO;
  31 using System.Runtime.InteropServices;
  32 using System.Text;
  33 using Mono.Unix;
  34
  35 namespace Mono.Unix {
  36
  37         public class StdioFileStream : Stream
  38         {
  39                 public static readonly IntPtr InvalidFileStream  = IntPtr.Zero;
  40                 public static readonly IntPtr StandardInput  = Native.Stdlib.stdin;
  41                 public static readonly IntPtr StandardOutput = Native.Stdlib.stdout;
  42                 public static readonly IntPtr StandardError  = Native.Stdlib.stderr;
  43
  44                 public StdioFileStream (IntPtr fileStream)
  45                         : this (fileStream, true) {}
  46
  47                 public StdioFileStream (IntPtr fileStream, bool ownsHandle)
  48                 {
  49                         InitStream (fileStream, ownsHandle);
  50                 }
  51
  52                 public StdioFileStream (IntPtr fileStream, FileAccess access)
  53                         : this (fileStream, access, true) {}
  54
  55                 public StdioFileStream (IntPtr fileStream, FileAccess access, bool ownsHandle)
  56                 {
  57                         InitStream (fileStream, ownsHandle);
  58                         InitCanReadWrite (access);
  59                 }
  60
  61                 public StdioFileStream (string path)
  62                 {
  63                         InitStream (Fopen (path, "rb"), true);
  64                 }
  65
  66                 public StdioFileStream (string path, string mode)
  67                 {
  68                         InitStream (Fopen (path, mode), true);
  69                 }
  70
  71                 public StdioFileStream (string path, FileMode mode)
  72                 {
  73                         InitStream (Fopen (path, ToFopenMode (path, mode)), true);
  74                 }
  75
  76                 public StdioFileStream (string path, FileAccess access)
  77                 {
  78                         InitStream (Fopen (path, ToFopenMode (path, access)), true);
  79                         InitCanReadWrite (access);
  80                 }
  81
  82                 public StdioFileStream (string path, FileMode mode, FileAccess access)
  83                 {
  84                         InitStream (Fopen (path, ToFopenMode (path, mode, access)), true);
  85                         InitCanReadWrite (access);
  86                 }
  87
  88                 private static IntPtr Fopen (string path, string mode)
  89                 {
  90                         if (path == null)
  91                                 throw new ArgumentNullException ("path");
  92                         if (path.Length == 0)
  93                                 throw new ArgumentException ("path");
  94                         if (mode == null)
  95                                 throw new ArgumentNullException ("mode");
  96                         IntPtr f = Native.Stdlib.fopen (path, mode);
  97                         if (f == IntPtr.Zero)
  98                                 throw new DirectoryNotFoundException ("path",
  99                                                 UnixMarshal.CreateExceptionForLastError ());
 100                         return f;
 101                 }
 102
 103                 private void InitStream (IntPtr fileStream, bool ownsHandle)
 104                 {
 105                         if (InvalidFileStream == fileStream)
 106                                 throw new ArgumentException (Locale.GetText ("Invalid file stream"), "fileStream");
 107
 108                         this.file = fileStream;
 109                         this.owner = ownsHandle;
 110
 111                         try {
 112                                 long offset = Native.Stdlib.fseek (file, 0, Native.SeekFlags.SEEK_CUR);
 113                                 if (offset != -1)
 114                                         canSeek = true;
 115                                 Native.Stdlib.fread (IntPtr.Zero, 0, 0, file);
 116                                 if (Native.Stdlib.ferror (file) == 0)
 117                                         canRead = true;
 118                                 Native.Stdlib.fwrite (IntPtr.Zero, 0, 0, file);
 119                                 if (Native.Stdlib.ferror (file) == 0)
 120                                         canWrite = true;
 121                                 Native.Stdlib.clearerr (file);
 122                         }
 123                         catch (Exception e) {
 124                                 throw new ArgumentException (Locale.GetText ("Invalid file stream"), "fileStream");
 125                         }
 126                         GC.KeepAlive (this);
 127                 }
 128
 129                 private void InitCanReadWrite (FileAccess access)
 130                 {
 131                         canRead = canRead &&
 132                                 (access == FileAccess.Read || access == FileAccess.ReadWrite);
 133                         canWrite = canWrite &&
 134                                 (access == FileAccess.Write || access == FileAccess.ReadWrite);
 135                 }
 136
 137                 private static string ToFopenMode (string file, FileMode mode)
 138                 {
 139                         string cmode = Native.NativeConvert.ToFopenMode (mode);
 140                         AssertFileMode (file, mode);
 141                         return cmode;
 142                 }
 143
 144                 private static string ToFopenMode (string file, FileAccess access)
 145                 {
 146                         return Native.NativeConvert.ToFopenMode (access);
 147                 }
 148
 149                 private static string ToFopenMode (string file, FileMode mode, FileAccess access)
 150                 {
 151                         string cmode = Native.NativeConvert.ToFopenMode (mode, access);
 152                         bool exists = AssertFileMode (file, mode);
 153                         // HACK: for open-or-create & read, mode is "rb", which doesn't create
 154                         // files.  If the file doesn't exist, we need to use "w+b" to ensure
 155                         // file creation.
 156                         if (mode == FileMode.OpenOrCreate && access == FileAccess.Read && !exists)
 157                                 cmode = "w+b";
 158                         return cmode;
 159                 }
 160
 161                 private static bool AssertFileMode (string file, FileMode mode)
 162                 {
 163                         bool exists = FileExists (file);
 164                         if (mode == FileMode.CreateNew && exists)
 165                                 throw new IOException ("File exists and FileMode.CreateNew specified");
 166                         if ((mode == FileMode.Open || mode == FileMode.Truncate) && !exists)
 167                                 throw new FileNotFoundException ("File doesn't exist and FileMode.Open specified", file);
 168                         return exists;
 169                 }
 170
 171                 private static bool FileExists (string file)
 172                 {
 173                         bool found = false;
 174                         IntPtr f = Native.Stdlib.fopen (file, "r");
 175                         found = f != IntPtr.Zero;
 176                         if (f != IntPtr.Zero)
 177                                 Native.Stdlib.fclose (f);
 178                         return found;
 179                 }
 180
 181                 private void AssertNotDisposed ()
 182                 {
 183                         if (file == InvalidFileStream)
 184                                 throw new ObjectDisposedException ("Invalid File Stream");
 185                         GC.KeepAlive (this);
 186                 }
 187
 188                 public IntPtr Handle {
 189                         get {
 190                                 AssertNotDisposed ();
 191                                 GC.KeepAlive (this);
 192                                 return file;
 193                         }
 194                 }
 195
 196                 public override bool CanRead {
 197                         get {return canRead;}
 198                 }
 199
 200                 public override bool CanSeek {
 201                         get {return canSeek;}
 202                 }
 203
 204                 public override bool CanWrite {
 205                         get {return canWrite;}
 206                 }
 207
 208                 public override long Length {
 209                         get {
 210                                 AssertNotDisposed ();
 211                                 if (!CanSeek)
 212                                         throw new NotSupportedException ("File Stream doesn't support seeking");
 213                                 long curPos = Native.Stdlib.ftell (file);
 214                                 if (curPos == -1)
 215                                         throw new NotSupportedException ("Unable to obtain current file position");
 216                                 int r = Native.Stdlib.fseek (file, 0, Native.SeekFlags.SEEK_END);
 217                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 218
 219                                 long endPos = Native.Stdlib.ftell (file);
 220                                 if (endPos == -1)
 221                                         UnixMarshal.ThrowExceptionForLastError ();
 222
 223                                 r = Native.Stdlib.fseek (file, curPos, Native.SeekFlags.SEEK_SET);
 224                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 225
 226                                 GC.KeepAlive (this);
 227                                 return endPos;
 228                         }
 229                 }
 230
 231                 public override long Position {
 232                         get {
 233                                 AssertNotDisposed ();
 234                                 if (!CanSeek)
 235                                         throw new NotSupportedException ("The stream does not support seeking");
 236                                 long pos = Native.Stdlib.ftell (file);
 237                                 if (pos == -1)
 238                                         UnixMarshal.ThrowExceptionForLastError ();
 239                                 GC.KeepAlive (this);
 240                                 return (long) pos;
 241                         }
 242                         set {
 243                                 AssertNotDisposed ();
 244                                 Seek (value, SeekOrigin.Begin);
 245                         }
 246                 }
 247
 248                 public void SaveFilePosition (Native.FilePosition pos)
 249                 {
 250                         AssertNotDisposed ();
 251                         int r = Native.Stdlib.fgetpos (file, pos);
 252                         UnixMarshal.ThrowExceptionForLastErrorIf (r);
 253                         GC.KeepAlive (this);
 254                 }
 255
 256                 public void RestoreFilePosition (Native.FilePosition pos)
 257                 {
 258                         AssertNotDisposed ();
 259                         if (pos == null)
 260                                 throw new ArgumentNullException ("value");
 261                         int r = Native.Stdlib.fsetpos (file, pos);
 262                         UnixMarshal.ThrowExceptionForLastErrorIf (r);
 263                         GC.KeepAlive (this);
 264                 }
 265
 266                 public override void Flush ()
 267                 {
 268                         AssertNotDisposed ();
 269                         int r = Native.Stdlib.fflush (file);
 270                         if (r != 0)
 271                                 UnixMarshal.ThrowExceptionForLastError ();
 272                         GC.KeepAlive (this);
 273                 }
 274
 275                 public override unsafe int Read ([In, Out] byte[] buffer, int offset, int count)
 276                 {
 277                         AssertNotDisposed ();
 278                         AssertValidBuffer (buffer, offset, count);
 279                         if (!CanRead)
 280                                 throw new NotSupportedException ("Stream does not support reading");
 281
 282                         ulong r = 0;
 283                         fixed (byte* buf = &buffer[offset]) {
 284                                 r = Native.Stdlib.fread (buf, 1, (ulong) count, file);
 285                         }
 286                         if (r != (ulong) count) {
 287                                 if (Native.Stdlib.ferror (file) != 0)
 288                                         throw new IOException ();
 289                         }
 290                         GC.KeepAlive (this);
 291                         return (int) r;
 292                 }
 293
 294                 private void AssertValidBuffer (byte[] buffer, int offset, int count)
 295                 {
 296                         if (buffer == null)
 297                                 throw new ArgumentNullException ("buffer");
 298                         if (offset < 0)
 299                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 300                         if (count < 0)
 301                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 302                         if (offset > buffer.Length)
 303                                 throw new ArgumentException ("destination offset is beyond array size");
 304                         if (offset > (buffer.Length - count))
 305                                 throw new ArgumentException ("would overrun buffer");
 306                 }
 307
 308                 public void Rewind ()
 309                 {
 310                         AssertNotDisposed ();
 311                         Native.Stdlib.rewind (file);
 312                         GC.KeepAlive (this);
 313                 }
 314
 315                 public override long Seek (long offset, SeekOrigin origin)
 316                 {
 317                         AssertNotDisposed ();
 318                         if (!CanSeek)
 319                                 throw new NotSupportedException ("The File Stream does not support seeking");
 320
 321                         Native.SeekFlags sf = Native.SeekFlags.SEEK_CUR;
 322                         switch (origin) {
 323                                 case SeekOrigin.Begin:   sf = Native.SeekFlags.SEEK_SET; break;
 324                                 case SeekOrigin.Current: sf = Native.SeekFlags.SEEK_CUR; break;
 325                                 case SeekOrigin.End:     sf = Native.SeekFlags.SEEK_END; break;
 326                                 default: throw new ArgumentException ("origin");
 327                         }
 328
 329                         int r = Native.Stdlib.fseek (file, offset, sf);
 330                         if (r != 0)
 331                                 throw new IOException ("Unable to seek",
 332                                                 UnixMarshal.CreateExceptionForLastError ());
 333
 334                         long pos = Native.Stdlib.ftell (file);
 335                         if (pos == -1)
 336                                 throw new IOException ("Unable to get current file position",
 337                                                 UnixMarshal.CreateExceptionForLastError ());
 338
 339                         GC.KeepAlive (this);
 340                         return pos;
 341                 }
 342
 343                 public override void SetLength (long value)
 344                 {
 345                         throw new NotSupportedException ("ANSI C doesn't provide a way to truncate a file");
 346                 }
 347
 348                 public override unsafe void Write (byte[] buffer, int offset, int count)
 349                 {
 350                         AssertNotDisposed ();
 351                         AssertValidBuffer (buffer, offset, count);
 352                         if (!CanWrite)
 353                                 throw new NotSupportedException ("File Stream does not support writing");
 354
 355                         ulong r = 0;
 356                         fixed (byte* buf = &buffer[offset]) {
 357                                 r = Native.Stdlib.fwrite (buf, (ulong) 1, (ulong) count, file);
 358                         }
 359                         if (r != (ulong) count)
 360                                 UnixMarshal.ThrowExceptionForLastError ();
 361                         GC.KeepAlive (this);
 362                 }
 363
 364                 ~StdioFileStream ()
 365                 {
 366                         Close ();
 367                 }
 368
 369                 public override void Close ()
 370                 {
 371                         if (file == InvalidFileStream)
 372                                 return;
 373
 374                         if (owner) {
 375                                 int r = Native.Stdlib.fclose (file);
 376                                 if (r != 0)
 377                                         UnixMarshal.ThrowExceptionForLastError ();
 378                         } else
 379                                 Flush ();
 380
 381                         file = InvalidFileStream;
 382                         canRead = false;
 383                         canSeek = false;
 384                         canWrite = false;
 385
 386                         GC.SuppressFinalize (this);
 387                         GC.KeepAlive (this);
 388                 }
 389
 390                 private bool canSeek  = false;
 391                 private bool canRead  = false;
 392                 private bool canWrite = false;
 393                 private bool owner    = true;
 394                 private IntPtr file   = InvalidFileStream;
 395         }
 396 }
 397
 398 // vim: noexpandtab