mcs/class/Mono.Posix/Mono.Posix/PosixStream.cs

   1 //
   2 // Mono.Posix/PosixStream.cs
   3 //
   4 // Authors:
   5 //   Jonathan Pryor (jonpryor@vt.edu)
   6 //
   7 // (C) 2004 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.Posix;
  34
  35 namespace Mono.Posix {
  36
  37         public sealed class PosixStream : Stream, IDisposable
  38         {
  39                 public const int InvalidFileDescriptor = -1;
  40                 public const int StandardInputFileDescriptor = 0;
  41                 public const int StandardOutputFileDescriptor = 1;
  42                 public const int StandardErrorFileDescriptor = 2;
  43
  44                 public PosixStream (int fileDescriptor)
  45                         : this (fileDescriptor, true) {}
  46
  47                 public PosixStream (int fileDescriptor, bool ownsHandle)
  48                 {
  49                         if (InvalidFileDescriptor == fileDescriptor)
  50                                 throw new ArgumentException (Locale.GetText ("Invalid file descriptor"), "fileDescriptor");
  51
  52                         this.fileDescriptor = fileDescriptor;
  53                         this.owner = ownsHandle;
  54
  55                         long offset = Syscall.lseek (fileDescriptor, 0, SeekFlags.SEEK_CUR);
  56                         if (offset != -1)
  57                                 canSeek = true;
  58                         unsafe {
  59                                 long read = Syscall.read (fileDescriptor, null, 0);
  60                                 if (read != -1)
  61                                         canRead = true;
  62                                 long write = Syscall.write (fileDescriptor, null, 0);
  63                                 if (write != -1)
  64                                         canWrite = true;
  65                         }
  66                 }
  67
  68                 private void AssertNotDisposed ()
  69                 {
  70                         if (fileDescriptor == InvalidFileDescriptor)
  71                                 throw new ObjectDisposedException ("Invalid File Descriptor");
  72                 }
  73
  74                 public int FileDescriptor {
  75                         get {return fileDescriptor;}
  76                 }
  77
  78                 public override bool CanRead {
  79                         get {return canRead;}
  80                 }
  81
  82                 public override bool CanSeek {
  83                         get {return canSeek;}
  84                 }
  85
  86                 public override bool CanWrite {
  87                         get {return canWrite;}
  88                 }
  89
  90                 public override long Length {
  91                         get {
  92                                 AssertNotDisposed ();
  93                                 if (!CanSeek)
  94                                         throw new NotSupportedException ("File descriptor doesn't support seeking");
  95                                 Stat stat;
  96                                 int r = Syscall.fstat (fileDescriptor, out stat);
  97                                 PosixMarshal.ThrowExceptionForLastErrorIf (r);
  98                                 return (long) stat.st_size;
  99                         }
 100                 }
 101
 102                 public override long Position {
 103                         get {
 104                                 AssertNotDisposed ();
 105                                 if (!CanSeek)
 106                                         throw new NotSupportedException ("The stream does not support seeking");
 107                                 long pos = Syscall.lseek (fileDescriptor, 0, SeekFlags.SEEK_CUR);
 108                                 if (pos == -1)
 109                                         PosixMarshal.ThrowExceptionForLastError ();
 110                                 return (long) pos;
 111                         }
 112                         set {
 113                                 Seek (value, SeekOrigin.Begin);
 114                         }
 115                 }
 116
 117                 public FilePermissions Permissions {
 118                         get {
 119                                 Stat stat;
 120                                 int r = Syscall.fstat (fileDescriptor, out stat);
 121                                 PosixMarshal.ThrowExceptionForLastErrorIf (r);
 122                                 return stat.st_mode;
 123                         }
 124                         set {
 125                                 int r = Syscall.fchmod (fileDescriptor, value);
 126                                 PosixMarshal.ThrowExceptionForLastErrorIf (r);
 127                         }
 128                 }
 129
 130                 public void AdviseNormalAccess (long offset, long len)
 131                 {
 132                         PosixFile.AdviseNormalAccess (fileDescriptor, offset, len);
 133                 }
 134
 135                 public void AdviseNormalAccess ()
 136                 {
 137                         PosixFile.AdviseNormalAccess (fileDescriptor);
 138                 }
 139
 140                 public void AdviseSequentialAccess (long offset, long len)
 141                 {
 142                         PosixFile.AdviseSequentialAccess (fileDescriptor, offset, len);
 143                 }
 144
 145                 public void AdviseSequentialAccess ()
 146                 {
 147                         PosixFile.AdviseSequentialAccess (fileDescriptor);
 148                 }
 149
 150                 public void AdviseRandomAccess (long offset, long len)
 151                 {
 152                         PosixFile.AdviseRandomAccess (fileDescriptor, offset, len);
 153                 }
 154
 155                 public void AdviseRandomAccess ()
 156                 {
 157                         PosixFile.AdviseRandomAccess (fileDescriptor);
 158                 }
 159
 160                 public void AdviseNeedAccess (long offset, long len)
 161                 {
 162                         PosixFile.AdviseNeedAccess (fileDescriptor, offset, len);
 163                 }
 164
 165                 public void AdviseNeedAccess ()
 166                 {
 167                         PosixFile.AdviseNeedAccess (fileDescriptor);
 168                 }
 169
 170                 public void AdviseNoAccess (long offset, long len)
 171                 {
 172                         PosixFile.AdviseNoAccess (fileDescriptor, offset, len);
 173                 }
 174
 175                 public void AdviseNoAccess ()
 176                 {
 177                         PosixFile.AdviseNoAccess (fileDescriptor);
 178                 }
 179
 180                 public void AdviseOnceAccess (long offset, long len)
 181                 {
 182                         PosixFile.AdviseOnceAccess (fileDescriptor, offset, len);
 183                 }
 184
 185                 public void AdviseOnceAccess ()
 186                 {
 187                         PosixFile.AdviseOnceAccess (fileDescriptor);
 188                 }
 189
 190                 public override void Flush ()
 191                 {
 192                         int r = Syscall.fsync (fileDescriptor);
 193                         PosixMarshal.ThrowExceptionForLastErrorIf (r);
 194                 }
 195
 196                 public override unsafe int Read ([In, Out] byte[] buffer, int offset, int count)
 197                 {
 198                         AssertNotDisposed ();
 199                         AssertValidBuffer (buffer, offset, count);
 200                         if (!CanRead)
 201                                 throw new NotSupportedException ("Stream does not support reading");
 202
 203                         long r = 0;
 204                         fixed (byte* buf = &buffer[offset]) {
 205                                 do {
 206                                         r = Syscall.read (fileDescriptor, buf, (ulong) count);
 207                                 } while (PosixMarshal.ShouldRetrySyscall ((int) r));
 208                         }
 209                         if (r == -1)
 210                                 PosixMarshal.ThrowExceptionForLastError ();
 211                         return (int) r;
 212                 }
 213
 214                 private void AssertValidBuffer (byte[] buffer, int offset, int count)
 215                 {
 216                         if (buffer == null)
 217                                 throw new ArgumentNullException ("buffer");
 218                         if (offset < 0)
 219                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 220                         if (count < 0)
 221                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 222                         if (offset > buffer.Length)
 223                                 throw new ArgumentException ("destination offset is beyond array size");
 224                         if (offset > (buffer.Length - count))
 225                                 throw new ArgumentException ("would overrun buffer");
 226                 }
 227
 228                 public unsafe int ReadAtOffset ([In, Out] byte[] buffer,
 229                         int offset, int count, long fileOffset)
 230                 {
 231                         AssertNotDisposed ();
 232                         AssertValidBuffer (buffer, offset, count);
 233                         if (!CanRead)
 234                                 throw new NotSupportedException ("Stream does not support reading");
 235
 236                         long r = 0;
 237                         fixed (byte* buf = &buffer[offset]) {
 238                                 do {
 239                                         r = Syscall.pread (fileDescriptor, buf, (ulong) count, fileOffset);
 240                                 } while (PosixMarshal.ShouldRetrySyscall ((int) r));
 241                         }
 242                         if (r == -1)
 243                                 PosixMarshal.ThrowExceptionForLastError ();
 244                         return (int) r;
 245                 }
 246
 247                 public override long Seek (long offset, SeekOrigin origin)
 248                 {
 249                         AssertNotDisposed ();
 250                         if (!CanSeek)
 251                                 throw new NotSupportedException ("The File Descriptor does not support seeking");
 252                         if (offset > int.MaxValue)
 253                                 throw new ArgumentOutOfRangeException ("offset", "too large");
 254
 255                         SeekFlags sf = SeekFlags.SEEK_CUR;
 256                         switch (origin) {
 257                                 case SeekOrigin.Begin:   sf = SeekFlags.SEEK_SET; break;
 258                                 case SeekOrigin.Current: sf = SeekFlags.SEEK_CUR; break;
 259                                 case SeekOrigin.End:     sf = SeekFlags.SEEK_END; break;
 260                         }
 261
 262                         long pos = Syscall.lseek (fileDescriptor, offset, sf);
 263                         if (pos == -1)
 264                                 PosixMarshal.ThrowExceptionForLastError ();
 265                         return (long) pos;
 266                 }
 267
 268                 public override void SetLength (long value)
 269                 {
 270                         AssertNotDisposed ();
 271                         if (value < 0)
 272                                 throw new ArgumentOutOfRangeException ("value", "< 0");
 273                         if (!CanSeek && !CanWrite)
 274                                 throw new NotSupportedException ("You can't truncating the current file descriptor");
 275
 276                         int r;
 277                         do {
 278                                 r = Syscall.ftruncate (fileDescriptor, value);
 279                         } while (PosixMarshal.ShouldRetrySyscall (r));
 280                         PosixMarshal.ThrowExceptionForLastErrorIf (r);
 281                 }
 282
 283                 public override unsafe void Write (byte[] buffer, int offset, int count)
 284                 {
 285                         AssertNotDisposed ();
 286                         AssertValidBuffer (buffer, offset, count);
 287                         if (!CanWrite)
 288                                 throw new NotSupportedException ("File Descriptor does not support writing");
 289
 290                         long r = 0;
 291                         fixed (byte* buf = &buffer[offset]) {
 292                                 do {
 293                                         r = Syscall.write (fileDescriptor, buf, (ulong) count);
 294                                 } while (PosixMarshal.ShouldRetrySyscall ((int) r));
 295                         }
 296                         if (r == -1)
 297                                 PosixMarshal.ThrowExceptionForLastError ();
 298                 }
 299
 300                 public unsafe void WriteAtOffset (byte[] buffer,
 301                         int offset, int count, long fileOffset)
 302                 {
 303                         AssertNotDisposed ();
 304                         AssertValidBuffer (buffer, offset, count);
 305                         if (!CanWrite)
 306                                 throw new NotSupportedException ("File Descriptor does not support writing");
 307
 308                         long r = 0;
 309                         fixed (byte* buf = &buffer[offset]) {
 310                                 do {
 311                                         r = Syscall.pwrite (fileDescriptor, buf, (ulong) count, fileOffset);
 312                                 } while (PosixMarshal.ShouldRetrySyscall ((int) r));
 313                         }
 314                         if (r == -1)
 315                                 PosixMarshal.ThrowExceptionForLastError ();
 316                 }
 317
 318                 public void SendTo (PosixStream output)
 319                 {
 320                         SendTo (output, (ulong) output.Length);
 321                 }
 322
 323                 public void SendTo (PosixStream output, ulong count)
 324                 {
 325                         SendTo (output.FileDescriptor, count);
 326                 }
 327
 328                 public void SendTo (int out_fd, ulong count)
 329                 {
 330                         if (!CanWrite)
 331                                 throw new NotSupportedException ("Unable to write to the current file descriptor");
 332                         long offset = Position;
 333                         long r = Syscall.sendfile (out_fd, fileDescriptor, ref offset, count);
 334                         if (r == -1)
 335                                 PosixMarshal.ThrowExceptionForLastError ();
 336                 }
 337
 338                 public void SetOwner (uint user, uint group)
 339                 {
 340                         AssertNotDisposed ();
 341
 342                         int r = Syscall.fchown (fileDescriptor, user, group);
 343                         PosixMarshal.ThrowExceptionForLastErrorIf (r);
 344                 }
 345
 346                 public void SetOwner (string user, string group)
 347                 {
 348                         AssertNotDisposed ();
 349
 350                         uint uid = PosixUser.GetUserId (user);
 351                         uint gid = PosixGroup.GetGroupId (group);
 352                         SetOwner (uid, gid);
 353                 }
 354
 355                 public void SetOwner (string user)
 356                 {
 357                         AssertNotDisposed ();
 358
 359                         Passwd pw = Syscall.getpwnam (user);
 360                         if (pw == null)
 361                                 throw new ArgumentException (Locale.GetText ("invalid username"), "user");
 362                         uint uid = pw.pw_uid;
 363                         uint gid = pw.pw_gid;
 364                         SetOwner (uid, gid);
 365                 }
 366
 367                 public long GetConfigurationValue (PathConf name)
 368                 {
 369                         AssertNotDisposed ();
 370                         Syscall.SetLastError ((Error) 0);
 371                         long r = Syscall.fpathconf (fileDescriptor, name);
 372                         if (r == -1 && Syscall.GetLastError() != (Error) 0)
 373                                 PosixMarshal.ThrowExceptionForLastError ();
 374                         return r;
 375                 }
 376
 377                 ~PosixStream ()
 378                 {
 379                         Close ();
 380                 }
 381
 382                 public override void Close ()
 383                 {
 384                         if (fileDescriptor == InvalidFileDescriptor)
 385                                 return;
 386
 387                         Flush ();
 388                         int r;
 389                         do {
 390                                 r = Syscall.close (fileDescriptor);
 391                         } while (PosixMarshal.ShouldRetrySyscall (r));
 392                         PosixMarshal.ThrowExceptionForLastErrorIf (r);
 393                         fileDescriptor = InvalidFileDescriptor;
 394                 }
 395
 396                 void IDisposable.Dispose ()
 397                 {
 398                         AssertNotDisposed ();
 399                         if (owner) {
 400                                 Close ();
 401                         }
 402                         GC.SuppressFinalize (this);
 403                 }
 404
 405                 private bool canSeek = false;
 406                 private bool canRead = false;
 407                 private bool canWrite = false;
 408                 private bool owner = true;
 409                 private int fileDescriptor = InvalidFileDescriptor;
 410         }
 411 }
 412
 413 // vim: noexpandtab