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 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  = Stdlib.stdin;
  41                 public static readonly IntPtr StandardOutput = Stdlib.stdout;
  42                 public static readonly IntPtr StandardError  = 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, "r"), 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 ("path");
  96                         IntPtr f = 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 = Stdlib.fseek (file, 0, SeekFlags.SEEK_CUR);
 113                                 if (offset != -1)
 114                                         canSeek = true;
 115                                 Stdlib.fread (IntPtr.Zero, 0, 0, file);
 116                                 if (Stdlib.ferror (file) == 0)
 117                                         canRead = true;
 118                                 Stdlib.fwrite (IntPtr.Zero, 0, 0, file);
 119                                 if (Stdlib.ferror (file) == 0)
 120                                         canWrite = true;
 121                                 Stdlib.clearerr (file);
 122                         }
 123                         catch (Exception e) {
 124                                 throw new ArgumentException (Locale.GetText ("Invalid file stream"), "fileStream");
 125                         }
 126                 }
 127
 128                 private void InitCanReadWrite (FileAccess access)
 129                 {
 130                         canRead = canRead &&
 131                                 (access == FileAccess.Read || access == FileAccess.ReadWrite);
 132                         canWrite = canWrite &&
 133                                 (access == FileAccess.Write || access == FileAccess.ReadWrite);
 134                 }
 135
 136                 private static string ToFopenMode (string file, FileMode mode)
 137                 {
 138                         string cmode = UnixConvert.ToFopenMode (mode);
 139                         AssertFileMode (file, mode);
 140                         return cmode;
 141                 }
 142
 143                 private static string ToFopenMode (string file, FileAccess access)
 144                 {
 145                         return UnixConvert.ToFopenMode (access);
 146                 }
 147
 148                 private static string ToFopenMode (string file, FileMode mode, FileAccess access)
 149                 {
 150                         string cmode = UnixConvert.ToFopenMode (mode, access);
 151                         bool exists = AssertFileMode (file, mode);
 152                         // HACK: for open-or-create & read, mode is "rb", which doesn't create
 153                         // files.  If the file doesn't exist, we need to use "w+b" to ensure
 154                         // file creation.
 155                         if (mode == FileMode.OpenOrCreate && access == FileAccess.Read && !exists)
 156                                 cmode = "w+b";
 157                         return cmode;
 158                 }
 159
 160                 private static bool AssertFileMode (string file, FileMode mode)
 161                 {
 162                         bool exists = FileExists (file);
 163                         if (mode == FileMode.CreateNew && exists)
 164                                 throw new IOException ("File exists and FileMode.CreateNew specified");
 165                         if ((mode == FileMode.Open || mode == FileMode.Truncate) && !exists)
 166                                 throw new FileNotFoundException ("File doesn't exist and FileMode.Open specified", file);
 167                         return exists;
 168                 }
 169
 170                 private static bool FileExists (string file)
 171                 {
 172                         bool found = false;
 173                         IntPtr f = Stdlib.fopen (file, "r");
 174                         found = f != IntPtr.Zero;
 175                         if (f != IntPtr.Zero)
 176                                 Stdlib.fclose (f);
 177                         return found;
 178                 }
 179
 180                 private void AssertNotDisposed ()
 181                 {
 182                         if (file == InvalidFileStream)
 183                                 throw new ObjectDisposedException ("Invalid File Stream");
 184                 }
 185
 186                 public IntPtr Handle {
 187                         get {AssertNotDisposed (); return file;}
 188                 }
 189
 190                 public override bool CanRead {
 191                         get {return canRead;}
 192                 }
 193
 194                 public override bool CanSeek {
 195                         get {return canSeek;}
 196                 }
 197
 198                 public override bool CanWrite {
 199                         get {return canWrite;}
 200                 }
 201
 202                 public override long Length {
 203                         get {
 204                                 AssertNotDisposed ();
 205                                 if (!CanSeek)
 206                                         throw new NotSupportedException ("File Stream doesn't support seeking");
 207                                 long curPos = Stdlib.ftell (file);
 208                                 if (curPos == -1)
 209                                         throw new NotSupportedException ("Unable to obtain current file position");
 210                                 int r = Stdlib.fseek (file, 0, SeekFlags.SEEK_END);
 211                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 212
 213                                 long endPos = Stdlib.ftell (file);
 214                                 if (endPos == -1)
 215                                         UnixMarshal.ThrowExceptionForLastError ();
 216
 217                                 r = Stdlib.fseek (file, curPos, SeekFlags.SEEK_SET);
 218                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 219
 220                                 return endPos;
 221                         }
 222                 }
 223
 224                 public override long Position {
 225                         get {
 226                                 AssertNotDisposed ();
 227                                 if (!CanSeek)
 228                                         throw new NotSupportedException ("The stream does not support seeking");
 229                                 long pos = Stdlib.ftell (file);
 230                                 if (pos == -1)
 231                                         UnixMarshal.ThrowExceptionForLastError ();
 232                                 return (long) pos;
 233                         }
 234                         set {
 235                                 AssertNotDisposed ();
 236                                 Seek (value, SeekOrigin.Begin);
 237                         }
 238                 }
 239
 240                 public void SaveFilePosition (FilePosition pos)
 241                 {
 242                         AssertNotDisposed ();
 243                         int r = Stdlib.fgetpos (file, pos);
 244                         UnixMarshal.ThrowExceptionForLastErrorIf (r);
 245                 }
 246
 247                 public void RestoreFilePosition (FilePosition pos)
 248                 {
 249                         AssertNotDisposed ();
 250                         if (pos == null)
 251                                 throw new ArgumentNullException ("value");
 252                         int r = Stdlib.fsetpos (file, pos);
 253                         UnixMarshal.ThrowExceptionForLastErrorIf (r);
 254                 }
 255
 256                 public override void Flush ()
 257                 {
 258                         AssertNotDisposed ();
 259                         int r = Stdlib.fflush (file);
 260                         if (r != 0)
 261                                 UnixMarshal.ThrowExceptionForLastError ();
 262                 }
 263
 264                 public override unsafe int Read ([In, Out] byte[] buffer, int offset, int count)
 265                 {
 266                         AssertNotDisposed ();
 267                         AssertValidBuffer (buffer, offset, count);
 268                         if (!CanRead)
 269                                 throw new NotSupportedException ("Stream does not support reading");
 270
 271                         ulong r = 0;
 272                         fixed (byte* buf = &buffer[offset]) {
 273                                 r = Stdlib.fread (buf, 1, (ulong) count, file);
 274                         }
 275                         if (r != (ulong) count) {
 276                                 if (Stdlib.ferror (file) != 0)
 277                                         throw new IOException ();
 278                         }
 279                         return (int) r;
 280                 }
 281
 282                 private void AssertValidBuffer (byte[] buffer, int offset, int count)
 283                 {
 284                         if (buffer == null)
 285                                 throw new ArgumentNullException ("buffer");
 286                         if (offset < 0)
 287                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 288                         if (count < 0)
 289                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 290                         if (offset > buffer.Length)
 291                                 throw new ArgumentException ("destination offset is beyond array size");
 292                         if (offset > (buffer.Length - count))
 293                                 throw new ArgumentException ("would overrun buffer");
 294                 }
 295
 296                 public void Rewind ()
 297                 {
 298                         AssertNotDisposed ();
 299                         Stdlib.rewind (file);
 300                 }
 301
 302                 public override long Seek (long offset, SeekOrigin origin)
 303                 {
 304                         AssertNotDisposed ();
 305                         if (!CanSeek)
 306                                 throw new NotSupportedException ("The File Stream does not support seeking");
 307
 308                         SeekFlags sf = SeekFlags.SEEK_CUR;
 309                         switch (origin) {
 310                                 case SeekOrigin.Begin:   sf = SeekFlags.SEEK_SET; break;
 311                                 case SeekOrigin.Current: sf = SeekFlags.SEEK_CUR; break;
 312                                 case SeekOrigin.End:     sf = SeekFlags.SEEK_END; break;
 313                                 default: throw new ArgumentException ("origin");
 314                         }
 315
 316                         int r = Stdlib.fseek (file, offset, sf);
 317                         if (r != 0)
 318                                 throw new IOException ("Unable to seek",
 319                                                 UnixMarshal.CreateExceptionForLastError ());
 320
 321                         long pos = Stdlib.ftell (file);
 322                         if (pos == -1)
 323                                 throw new IOException ("Unable to get current file position",
 324                                                 UnixMarshal.CreateExceptionForLastError ());
 325
 326                         return pos;
 327                 }
 328
 329                 public override void SetLength (long value)
 330                 {
 331                         throw new NotSupportedException ("ANSI C doesn't provide a way to truncate a file");
 332                 }
 333
 334                 public override unsafe void Write (byte[] buffer, int offset, int count)
 335                 {
 336                         AssertNotDisposed ();
 337                         AssertValidBuffer (buffer, offset, count);
 338                         if (!CanWrite)
 339                                 throw new NotSupportedException ("File Stream does not support writing");
 340
 341                         ulong r = 0;
 342                         fixed (byte* buf = &buffer[offset]) {
 343                                 r = Stdlib.fwrite (buf, (ulong) 1, (ulong) count, file);
 344                         }
 345                         if (r != (ulong) count)
 346                                 UnixMarshal.ThrowExceptionForLastError ();
 347                 }
 348
 349                 ~StdioFileStream ()
 350                 {
 351                         Close ();
 352                 }
 353
 354                 public override void Close ()
 355                 {
 356                         if (file == InvalidFileStream)
 357                                 return;
 358
 359                         if (owner) {
 360                                 int r = Stdlib.fclose (file);
 361                                 if (r != 0)
 362                                         UnixMarshal.ThrowExceptionForLastError ();
 363                         } else
 364                                 Flush ();
 365
 366                         file = InvalidFileStream;
 367                         canRead = false;
 368                         canSeek = false;
 369                         canWrite = false;
 370
 371                         GC.SuppressFinalize (this);
 372                 }
 373
 374                 private bool canSeek  = false;
 375                 private bool canRead  = false;
 376                 private bool canWrite = false;
 377                 private bool owner    = true;
 378                 private IntPtr file   = InvalidFileStream;
 379         }
 380 }
 381
 382 // vim: noexpandtab