mcs/class/corlib/System.IO/FileStream.cs

   1 //
   2 // System.IO/FileStream.cs
   3 //
   4 // Author:
   5 //   Dietmar Maurer (dietmar@ximian.com)
   6 //
   7 // (C) 2001 Ximian, Inc.  http://www.ximian.com
   8 //
   9 using System;
  10 using System.PAL;
  11 using System.Runtime.InteropServices;
  12
  13 // fixme: I do not know how to handle errno when calling PInvoke functions
  14 // fixme: emit the correct exceptions everywhere
  15
  16 namespace System.IO
  17 {
  18
  19         public class FileStream : Stream
  20         {
  21                 private OpSys _os = Platform.OS;
  22                 private IntPtr fd;
  23                 private FileAccess acc;
  24                 private bool owner;
  25
  26                 public FileStream (IntPtr fd, FileAccess access)
  27                         : this (fd, access, true, 0, false) {}
  28
  29                 public FileStream (IntPtr fd, FileAccess access, bool ownsHandle)
  30                         : this (fd, access, ownsHandle, 0, false) {}
  31
  32                 public FileStream (IntPtr fd, FileAccess access, bool ownsHandle, int bufferSize)
  33                         : this (fd, access, ownsHandle, bufferSize, false) {}
  34
  35                 public FileStream (IntPtr fd, FileAccess access, bool ownsHandle,
  36                                    int bufferSize, bool isAsync)
  37                 {
  38                         fd = fd;
  39                         acc = access;
  40                         owner = ownsHandle;
  41                 }
  42
  43                 public FileStream (string name, FileMode mode)
  44                         : this (name, mode, FileAccess.ReadWrite, FileShare.ReadWrite, 0, false) {}
  45
  46                 public FileStream (string name, FileMode mode, FileAccess access)
  47                         : this (name, mode, access, FileShare.ReadWrite, 0, false) {}
  48
  49                 public FileStream (string name, FileMode mode, FileAccess access, FileShare share)
  50                         : this (name, mode, access, share, 0, false) {}
  51
  52                 public FileStream (string name, FileMode mode, FileAccess access,
  53                                    FileShare share, int buferSize)
  54                         : this (name, mode, access, share, 0, false) {}
  55
  56                 // fixme: implement all share, buffer, async
  57                 public FileStream (string name, FileMode mode, FileAccess access, FileShare share,
  58                                    int buferSize, bool useAsync)
  59                 {
  60                         if ((int)(fd = _os.OpenFile (name, mode, access, share)) == -1)
  61                                 throw new IOException();
  62
  63                         acc = access;
  64                         owner = true;
  65                 }
  66
  67                 public override bool CanRead
  68                 {
  69                         get {
  70                                 switch (acc) {
  71                                 case FileAccess.Read:
  72                                 case FileAccess.ReadWrite:
  73                                         return true;
  74                                 case FileAccess.Write:
  75                                 default:
  76                                         return false;
  77                                 }
  78                         }
  79                 }
  80
  81                 public override bool CanSeek
  82                 {
  83                         get {
  84                                 // fixme: not alway true
  85                                 return true;
  86                         }
  87                 }
  88
  89                 public override bool CanWrite
  90                 {
  91                         get {
  92                                 switch (acc) {
  93                                 case FileAccess.Write:
  94                                 case FileAccess.ReadWrite:
  95                                         return true;
  96                                 default:
  97                                         return false;
  98                                 }
  99                         }
 100                 }
 101
 102                 unsafe public override long Length
 103                 {
 104                         get {
 105                                 return _os.FileLength (fd);
 106                         }
 107                 }
 108
 109                 public override long Position
 110                 {
 111                         get {
 112                                 return _os.SeekFile (fd, 0,  SeekOrigin.Current);
 113                         }
 114                         set {
 115                                 _os.SeekFile (fd, value, SeekOrigin.Begin);
 116                         }
 117                 }
 118
 119                 public override void Flush ()
 120                 {
 121                 }
 122
 123                 public override void Close ()
 124                 {
 125                         if (owner) {
 126                                 _os.CloseFile (fd);
 127                         }
 128                 }
 129
 130                 public unsafe override int Read (byte[] buffer,
 131                                           int offset,
 132                                           int count)
 133                 {
 134                         return _os.ReadFile (fd, buffer, offset, count);
 135                 }
 136
 137                 public unsafe override int ReadByte ()
 138                 {
 139                         byte[] val = new byte[1];
 140
 141                         if (Read (val, 0, 1) != 1)
 142                                 throw new IOException();
 143
 144                         return val[0];
 145                 }
 146
 147                 public override long Seek (long offset,
 148                                            SeekOrigin origin)
 149                 {
 150                         return _os.SeekFile (fd, offset, origin);
 151                 }
 152
 153                 public override void SetLength (long value)
 154                 {
 155                         int res;
 156
 157                         if ((res = _os.SetLengthFile (fd, value)) == -1)
 158                                 throw new IOException();
 159
 160
 161                 }
 162
 163                 public unsafe override void Write (byte[] buffer,
 164                                                    int offset,
 165                                                    int count)
 166                 {
 167                         int res = _os.WriteFile (fd, buffer, offset, count);
 168
 169                         if (res != count)
 170                                 throw new IOException();
 171                 }
 172
 173                 public unsafe override void WriteByte (byte value)
 174                 {
 175                         byte[] buf = new byte[1];
 176
 177                         buf[0] = value;
 178
 179                         Write (buf, 0, 1);
 180                 }
 181
 182         }
 183 }