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

   1 //\r
   2 // System.IO.StreamWriter.cs\r
   3 //\r
   4 // Author:\r
   5 //   Dietmar Maurer (dietmar@ximian.com)\r
   6 //\r
   7 // (C) Ximian, Inc.  http://www.ximian.com\r
   8 //\r
   9 \r
  10 using System.Text;\r
  11 using System;\r
  12 \r
  13 namespace System.IO {\r
  14         \r
  15         [Serializable]\r
  16         public class StreamWriter : TextWriter {\r
  17 \r
  18                 private Encoding internalEncoding;\r
  19 \r
  20                 private Stream internalStream;\r
  21                 private bool closed = false;\r
  22 \r
  23                 private bool iflush;\r
  24                 \r
  25                 private const int DefaultBufferSize = 1024;\r
  26                 private const int DefaultFileBufferSize = 4096;\r
  27                 private const int MinimumBufferSize = 2;\r
  28 \r
  29                 private int pos;\r
  30                 private int BufferSize;\r
  31                 private byte[] TheBuffer;\r
  32 \r
  33                 private bool DisposedAlready = false;\r
  34 \r
  35                 public new static readonly StreamWriter Null = new StreamWriter (Stream.Null, Encoding.UTF8, 0);\r
  36 \r
  37                 public StreamWriter (Stream stream)\r
  38                         : this (stream, new UTF8Encoding (false, true), DefaultBufferSize) {}\r
  39 \r
  40                 public StreamWriter (Stream stream, Encoding encoding)\r
  41                         : this (stream, encoding, DefaultBufferSize) {}\r
  42 \r
  43                 internal void Initialize(Encoding encoding, int bufferSize) {\r
  44                         internalEncoding = encoding;\r
  45                         pos = 0;\r
  46                         BufferSize = Math.Max(bufferSize, MinimumBufferSize);\r
  47                         TheBuffer = new byte[BufferSize];\r
  48                 }\r
  49 \r
  50                 //[MonoTODO("Nothing is done with bufferSize")]\r
  51                 public StreamWriter (Stream stream, Encoding encoding, int bufferSize) {\r
  52                         if (null == stream)\r
  53                                 throw new ArgumentNullException("stream");\r
  54                         if (null == encoding)\r
  55                                 throw new ArgumentNullException("encoding");\r
  56                         if (bufferSize < 0)\r
  57                                 throw new ArgumentOutOfRangeException("bufferSize");\r
  58                         if (!stream.CanWrite)\r
  59                                 throw new ArgumentException("bufferSize");\r
  60 \r
  61                         internalStream = stream;\r
  62 \r
  63                         Initialize(encoding, bufferSize);\r
  64                 }\r
  65 \r
  66                 public StreamWriter (string path)\r
  67                         : this (path, false, Encoding.UTF8, DefaultFileBufferSize) {}\r
  68 \r
  69                 public StreamWriter (string path, bool append)\r
  70                         : this (path, append, Encoding.UTF8, DefaultFileBufferSize) {}\r
  71 \r
  72                 public StreamWriter (string path, bool append, Encoding encoding)\r
  73                         : this (path, append, encoding, DefaultFileBufferSize) {}\r
  74                 \r
  75                 public StreamWriter (string path, bool append, Encoding encoding, int bufferSize) {\r
  76                         if (null == path)\r
  77                                 throw new ArgumentNullException("path");\r
  78                         if (String.Empty == path)\r
  79                                 throw new ArgumentException("path cannot be empty string");\r
  80                         if (path.IndexOfAny (Path.InvalidPathChars) != -1)\r
  81                                 throw new ArgumentException("path contains invalid characters");\r
  82 \r
  83                         if (null == encoding)\r
  84                                 throw new ArgumentNullException("encoding");\r
  85                         if (bufferSize < 0)\r
  86                                 throw new ArgumentOutOfRangeException("bufferSize");\r
  87 \r
  88                         string DirName = Path.GetDirectoryName(path);\r
  89                         if (DirName != String.Empty && !Directory.Exists(DirName))\r
  90                                 throw new DirectoryNotFoundException();\r
  91 \r
  92                         FileMode mode;\r
  93 \r
  94                         if (append)\r
  95                                 mode = FileMode.Append;\r
  96                         else\r
  97                                 mode = FileMode.Create;\r
  98                         \r
  99                         internalStream = new FileStream (path, mode, FileAccess.Write);\r
 100 \r
 101                         if (append)\r
 102                                 internalStream.Position = internalStream.Length;\r
 103                         else\r
 104                                 internalStream.SetLength (0);\r
 105 \r
 106                         Initialize(encoding, bufferSize);\r
 107                 }\r
 108 \r
 109                 public virtual bool AutoFlush {\r
 110                         get {\r
 111                                 return iflush;\r
 112                         }\r
 113                         set {\r
 114                                 iflush = value;\r
 115                         }\r
 116                 }\r
 117 \r
 118                 public virtual Stream BaseStream {\r
 119                         get {\r
 120                                 return internalStream;\r
 121                         }\r
 122                 }\r
 123 \r
 124                 public override Encoding Encoding {\r
 125                         get {\r
 126                                 return internalEncoding;\r
 127                         }\r
 128                 }\r
 129 \r
 130                 protected override void Dispose (bool disposing) {\r
 131                         if (!DisposedAlready && disposing && internalStream != null) {\r
 132                                 Flush();\r
 133                                 DisposedAlready = true;\r
 134                                 internalStream.Close ();\r
 135                         }\r
 136 \r
 137                         internalStream = null;\r
 138                         TheBuffer = null;\r
 139                         internalEncoding = null;\r
 140                 }\r
 141 \r
 142                 public override void Flush () {\r
 143                         if (DisposedAlready)\r
 144                                 throw new ObjectDisposedException("StreamWriter");\r
 145 \r
 146                         if (pos > 0) {\r
 147                                 internalStream.Write (TheBuffer, 0, pos);\r
 148                                 internalStream.Flush ();\r
 149                                 pos = 0;\r
 150                         }\r
 151                 }\r
 152                 \r
 153                 public override void Write (char[] buffer, int index, int count) {\r
 154                         if (DisposedAlready)\r
 155                                 throw new ObjectDisposedException("StreamWriter");\r
 156 \r
 157                         byte[] res = new byte [internalEncoding.GetByteCount (buffer)];\r
 158                         int len;\r
 159                         int BytesToBuffer;\r
 160                         int resPos = 0;\r
 161 \r
 162                         len = internalEncoding.GetBytes (buffer, index, count, res, 0);\r
 163 \r
 164                         // if they want AutoFlush, don't bother buffering\r
 165                         if (iflush) {\r
 166                                 Flush();\r
 167                                 internalStream.Write (res, 0, len);\r
 168                                 internalStream.Flush ();\r
 169                         } else {\r
 170                                 // otherwise use the buffer.\r
 171                                 // NOTE: this logic is not optimized for performance.\r
 172                                 while (resPos < len) {\r
 173                                         // fill the buffer if we've got more bytes than will fit\r
 174                                         BytesToBuffer = Math.Min(BufferSize - pos, len - resPos);\r
 175                                         Array.Copy(res, resPos, TheBuffer, pos, BytesToBuffer);\r
 176                                         resPos += BytesToBuffer;\r
 177                                         pos += BytesToBuffer;\r
 178                                         // if the buffer is full, flush it out.\r
 179                                         if (pos == BufferSize) Flush();\r
 180                                 }\r
 181                         }\r
 182                 }\r
 183 \r
 184                 public override void Write (char value)\r
 185                 {\r
 186                         Write (new char [] {value}, 0, 1);\r
 187                 }\r
 188 \r
 189                 public override void Write (char [] value)\r
 190                 {\r
 191                         Write (value, 0, value.Length);\r
 192                 }\r
 193 \r
 194                 public override void Write(string value) {\r
 195                         if (DisposedAlready)\r
 196                                 throw new ObjectDisposedException("StreamWriter");\r
 197 \r
 198                         if (value != null)\r
 199                                 Write (value.ToCharArray (), 0, value.Length);\r
 200                 }\r
 201 \r
 202                 public override void Close()\r
 203                 {\r
 204                         Dispose (true);\r
 205                 }\r
 206 \r
 207                 ~StreamWriter() {\r
 208                         Dispose(false);\r
 209                 }\r
 210         }\r
 211 }\r