mcs/class/System.Web/System.Web/HttpWriter.cs

   1 //
   2 // System.Web.HttpWriter
   3 //
   4 // Author:
   5 //   Patrik Torstensson (Patrik.Torstensson@labs2.com)
   6 //
   7
   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 using System;
  29 using System.IO;
  30 using System.Text;
  31 using System.Web.Util;
  32
  33 namespace System.Web
  34 {
  35         public sealed class HttpWriter : TextWriter
  36         {
  37                 internal const int MaxBufferSize = 32768;
  38
  39                 HttpResponse _Response;
  40
  41                 HttpResponseStream _ResponseStream;
  42
  43                 MemoryStream _OutputStream;
  44                 StreamWriter _OutputHelper;
  45                 Encoding _Encoding;
  46
  47                 Stream _OutputFilter;
  48                 HttpResponseStreamProxy _OutputProxy;
  49
  50                 internal HttpWriter (HttpResponse Response)
  51                 {
  52                         _Response = Response;
  53
  54                         _OutputStream = new MemoryStream (MaxBufferSize);
  55                         _OutputHelper = new StreamWriter (_OutputStream, _Response.ContentEncoding);
  56                         _ResponseStream = new HttpResponseStream (this);
  57
  58                         Update ();
  59                 }
  60
  61                 internal void Dispose ()
  62                 {
  63                         _OutputHelper.Close ();
  64                         _OutputStream.Close ();
  65                         _OutputFilter.Close ();
  66                 }
  67
  68                 internal Stream GetActiveFilter ()
  69                 {
  70                         if (null == _OutputFilter) {
  71                                 // Create a filter proxy to allow us to know if we have a valid filter
  72                                 if (null == _OutputProxy)
  73                                         _OutputProxy = new HttpResponseStreamProxy (this);
  74
  75                                 return _OutputProxy;
  76                         }
  77                         return _OutputFilter;
  78                 }
  79
  80                 internal void ActivateFilter (Stream OutputFilter)
  81                 {
  82                         if (null == _OutputProxy)
  83                                 throw new HttpException ("Invalid filter usage");
  84
  85                         _OutputFilter = OutputFilter;
  86                 }
  87
  88                 internal void FilterData (bool CloseStream)
  89                 {
  90                         // Check if we have any filter at all
  91                         if (null == _OutputFilter)
  92                                 return;
  93
  94                         FlushBuffers ();
  95
  96                         // Save our current data
  97                         byte [] arrData = _OutputStream.GetBuffer ();
  98                         int size = (int) _OutputStream.Length;
  99
 100                         // Remove our internal data
 101                         Clear ();
 102
 103                         // If we have a filter then we have a proxy
 104                         _OutputProxy.Active = true;
 105
 106                         try {
 107                                 // Call the filter (it does a callback into our HttpWriter again)
 108                                 _OutputFilter.Write (arrData, 0, size);
 109                                 _OutputFilter.Flush ();
 110
 111                                 if (CloseStream)
 112                                         _OutputFilter.Close ();
 113                         } finally {
 114                                 _OutputProxy.Active = false;
 115                         }
 116                 }
 117
 118                 internal void Clear ()
 119                 {
 120                         _OutputHelper.Close ();
 121                         _OutputStream.Close ();
 122
 123                         _OutputStream = new MemoryStream (32768);
 124                         _OutputHelper = new StreamWriter (_OutputStream, _Response.ContentEncoding);
 125                 }
 126
 127                 internal void SendContent (HttpWorkerRequest Handler)
 128                 {
 129                         FlushBuffers();
 130
 131                         int l = (int)_OutputStream.Length;
 132                         if (l > 0) {
 133                                 byte [] arrContent = _OutputStream.GetBuffer ();
 134                                 Handler.SendResponseFromMemory (arrContent, l);
 135                         }
 136                 }
 137
 138                 internal void Update ()
 139                 {
 140                         _Encoding = _Response.ContentEncoding;
 141                         _OutputHelper.Flush ();
 142                         _OutputHelper = new StreamWriter (_OutputStream, _Encoding);
 143                 }
 144
 145                 internal long BufferSize
 146                 {
 147                         get {
 148                                 FlushBuffers ();
 149                                 return _OutputStream.Length;
 150                         }
 151                 }
 152
 153                 internal void FlushBuffers ()
 154                 {
 155                         _OutputHelper.Flush ();
 156                         _OutputStream.Flush ();
 157                 }
 158
 159                 internal byte[] GetBuffer () {
 160                         return _OutputStream.GetBuffer ();
 161                 }
 162
 163                 public override Encoding Encoding
 164                 {
 165                         get { return _Encoding; }
 166                 }
 167
 168                 public Stream OutputStream
 169                 {
 170                         get { return _ResponseStream; }
 171                 }
 172
 173                 public override void Close ()
 174                 {
 175                         _Response.Flush ();
 176                         _Response.Close ();
 177                 }
 178
 179                 public override void Flush ()
 180                 {
 181                 }
 182
 183                 private void CheckIfFlush ()
 184                 {
 185                         if (!_Response.BufferOutput) {
 186                                 FlushBuffers ();
 187                         }
 188                 }
 189
 190                 public override void Write (char ch)
 191                 {
 192                         _OutputHelper.Write (ch);
 193                         CheckIfFlush ();
 194                 }
 195
 196                 public override void Write (object obj)
 197                 {
 198                         if (obj != null)
 199                         {
 200                                 _OutputHelper.Write (obj.ToString ());
 201                                 CheckIfFlush ();
 202                         }
 203                 }
 204
 205                 public override void Write (string s)
 206                 {
 207                         _OutputHelper.Write (s);
 208                         CheckIfFlush ();
 209                 }
 210
 211                 public override void Write (char [] buffer, int index, int count)
 212                 {
 213                         _OutputHelper.Write (buffer, index, count);
 214                         CheckIfFlush ();
 215                 }
 216
 217                 public void WriteBytes (byte [] buffer, int index, int count)
 218                 {
 219                         _OutputStream.Write (buffer, index, count);
 220                         CheckIfFlush ();
 221                 }
 222
 223                 public override void WriteLine ()
 224                 {
 225                         _OutputHelper.Write ("\r\n");
 226                         CheckIfFlush ();
 227                 }
 228
 229                 public void WriteString (string s, int index, int count)
 230                 {
 231                         _OutputHelper.Write (s.Substring (index, count));
 232                         CheckIfFlush ();
 233                 }
 234         }
 235 }
 236