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, IDisposable
  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                         if (InvalidFileStream == fileStream)
  50                                 throw new ArgumentException (Locale.GetText ("Invalid file stream"), "fileStream");
  51
  52                         this.file = fileStream;
  53                         this.owner = ownsHandle;
  54
  55                         long offset = Stdlib.fseek (file, 0, SeekFlags.SEEK_CUR);
  56                         if (offset != -1)
  57                                 canSeek = true;
  58                         Stdlib.fread (IntPtr.Zero, 0, 0, file);
  59                         if (Stdlib.ferror (file) == 0)
  60                                 canRead = true;
  61                         Stdlib.fwrite (IntPtr.Zero, 0, 0, file);
  62                         if (Stdlib.ferror (file) == 0)
  63                                 canWrite = true;
  64                         Stdlib.clearerr (file);
  65                 }
  66
  67                 private void AssertNotDisposed ()
  68                 {
  69                         if (file == InvalidFileStream)
  70                                 throw new ObjectDisposedException ("Invalid File Stream");
  71                 }
  72
  73                 public IntPtr FileStream {
  74                         get {return file;}
  75                 }
  76
  77                 public override bool CanRead {
  78                         get {return canRead;}
  79                 }
  80
  81                 public override bool CanSeek {
  82                         get {return canSeek;}
  83                 }
  84
  85                 public override bool CanWrite {
  86                         get {return canWrite;}
  87                 }
  88
  89                 public override long Length {
  90                         get {
  91                                 AssertNotDisposed ();
  92                                 if (!CanSeek)
  93                                         throw new NotSupportedException ("File Stream doesn't support seeking");
  94                                 long curPos = Stdlib.ftell (file);
  95                                 if (curPos == -1)
  96                                         throw new NotSupportedException ("Unable to obtain current file position");
  97                                 int r = Stdlib.fseek (file, 0, SeekFlags.SEEK_END);
  98                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
  99
 100                                 long endPos = Stdlib.ftell (file);
 101                                 if (endPos == -1)
 102                                         UnixMarshal.ThrowExceptionForLastError ();
 103
 104                                 r = Stdlib.fseek (file, curPos, SeekFlags.SEEK_SET);
 105                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 106
 107                                 return endPos - curPos;
 108                         }
 109                 }
 110
 111                 public override long Position {
 112                         get {
 113                                 AssertNotDisposed ();
 114                                 if (!CanSeek)
 115                                         throw new NotSupportedException ("The stream does not support seeking");
 116                                 long pos = Stdlib.ftell (file);
 117                                 if (pos == -1)
 118                                         UnixMarshal.ThrowExceptionForLastError ();
 119                                 return (long) pos;
 120                         }
 121                         set {
 122                                 Seek (value, SeekOrigin.Begin);
 123                         }
 124                 }
 125
 126                 public FilePosition FilePosition {
 127                         get {
 128                                 FilePosition pos = new FilePosition ();
 129                                 int r = Stdlib.fgetpos (file, pos);
 130                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 131                                 return pos;
 132                         }
 133                         set {
 134                                 if (value == null)
 135                                         throw new ArgumentNullException ("value");
 136                                 int r = Stdlib.fsetpos (file, value);
 137                                 UnixMarshal.ThrowExceptionForLastErrorIf (r);
 138                         }
 139                 }
 140
 141                 public override void Flush ()
 142                 {
 143                         int r = Stdlib.fflush (file);
 144                         if (r != 0)
 145                                 UnixMarshal.ThrowExceptionForLastError ();
 146                 }
 147
 148                 public override unsafe int Read ([In, Out] byte[] buffer, int offset, int count)
 149                 {
 150                         AssertNotDisposed ();
 151                         AssertValidBuffer (buffer, offset, count);
 152                         if (!CanRead)
 153                                 throw new NotSupportedException ("Stream does not support reading");
 154
 155                         ulong r = 0;
 156                         fixed (byte* buf = &buffer[offset]) {
 157                                 r = Stdlib.fread (buf, 1, (ulong) count, file);
 158                         }
 159                         if (r != (ulong) count) {
 160                                 if (Stdlib.feof (file) != 0)
 161                                         throw new EndOfStreamException ();
 162                                 if (Stdlib.ferror (file) != 0)
 163                                         throw new IOException ();
 164                         }
 165                         return (int) r;
 166                 }
 167
 168                 private void AssertValidBuffer (byte[] buffer, int offset, int count)
 169                 {
 170                         if (buffer == null)
 171                                 throw new ArgumentNullException ("buffer");
 172                         if (offset < 0)
 173                                 throw new ArgumentOutOfRangeException ("offset", "< 0");
 174                         if (count < 0)
 175                                 throw new ArgumentOutOfRangeException ("count", "< 0");
 176                         if (offset > buffer.Length)
 177                                 throw new ArgumentException ("destination offset is beyond array size");
 178                         if (offset > (buffer.Length - count))
 179                                 throw new ArgumentException ("would overrun buffer");
 180                 }
 181
 182                 public void Rewind ()
 183                 {
 184                         Stdlib.rewind (file);
 185                 }
 186
 187                 public override long Seek (long offset, SeekOrigin origin)
 188                 {
 189                         AssertNotDisposed ();
 190                         if (!CanSeek)
 191                                 throw new NotSupportedException ("The File Stream does not support seeking");
 192
 193                         SeekFlags sf = SeekFlags.SEEK_CUR;
 194                         switch (origin) {
 195                                 case SeekOrigin.Begin:   sf = SeekFlags.SEEK_SET; break;
 196                                 case SeekOrigin.Current: sf = SeekFlags.SEEK_CUR; break;
 197                                 case SeekOrigin.End:     sf = SeekFlags.SEEK_END; break;
 198                         }
 199
 200                         int r = Stdlib.fseek (file, offset, sf);
 201                         if (r != 0)
 202                                 UnixMarshal.ThrowExceptionForLastError ();
 203
 204                         long pos = Stdlib.ftell (file);
 205                         if (pos == -1)
 206                                 UnixMarshal.ThrowExceptionForLastError ();
 207
 208                         return pos;
 209                 }
 210
 211                 public override void SetLength (long value)
 212                 {
 213                         throw new NotSupportedException ("ANSI C doesn't provide a way to truncate a file");
 214                 }
 215
 216                 public override unsafe void Write (byte[] buffer, int offset, int count)
 217                 {
 218                         AssertNotDisposed ();
 219                         AssertValidBuffer (buffer, offset, count);
 220                         if (!CanWrite)
 221                                 throw new NotSupportedException ("File Stream does not support writing");
 222
 223                         ulong r = 0;
 224                         fixed (byte* buf = &buffer[offset]) {
 225                                 r = Stdlib.fwrite (buf, (ulong) 1, (ulong) count, file);
 226                         }
 227                         if (r != (ulong) count)
 228                                 UnixMarshal.ThrowExceptionForLastError ();
 229                 }
 230
 231                 ~StdioFileStream ()
 232                 {
 233                         Close ();
 234                 }
 235
 236                 public override void Close ()
 237                 {
 238                         if (file == InvalidFileStream)
 239                                 return;
 240
 241                         Flush ();
 242                         int r = Stdlib.fclose (file);
 243                         if (r != 0)
 244                                 UnixMarshal.ThrowExceptionForLastError ();
 245                         file = InvalidFileStream;
 246                 }
 247
 248                 void IDisposable.Dispose ()
 249                 {
 250                         AssertNotDisposed ();
 251                         GC.SuppressFinalize (this);
 252                         if (owner) {
 253                                 Close ();
 254                         }
 255                 }
 256
 257                 private bool canSeek  = false;
 258                 private bool canRead  = false;
 259                 private bool canWrite = false;
 260                 private bool owner    = true;
 261                 private IntPtr file   = InvalidFileStream;
 262         }
 263 }
 264
 265 // vim: noexpandtab