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