mcs/class/Mono.Http/Mono.Http/GZipWriteFilter.cs

   1 //
   2 // GZipFilter.cs
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (c) 2003 Ximian, Inc (http://www.ximian.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.IO;
  33 using ICSharpCode.SharpZipLib.GZip;
  34
  35 namespace Mono.Http
  36 {
  37         public class GZipWriteFilter : Stream
  38         {
  39                 Stream baseStream;
  40                 GZipOutputStream st;
  41
  42                 public GZipWriteFilter (Stream baseStream)
  43                 {
  44                         // baseStream is not ready yet for filtering and any attemp to write
  45                         // the gzip header will throw.
  46                         this.baseStream = baseStream;
  47                 }
  48
  49                 public override bool CanRead {
  50                         get { return false; }
  51                 }
  52
  53                 public override bool CanSeek {
  54                         get { return false; }
  55                 }
  56
  57                 public override bool CanWrite {
  58                         get {
  59                                 if (st == null)
  60                                         return false;
  61
  62                                 return st.CanWrite;
  63                         }
  64                 }
  65
  66                 public override long Length {
  67                         get { return 0; }
  68                 }
  69
  70                 public override long Position {
  71                         get { return 0; }
  72                         set { }
  73                 }
  74
  75                 public override void Flush ()
  76                 {
  77                 }
  78
  79                 public override int Read (byte [] buffer, int offset, int count)
  80                 {
  81                         return 0;
  82                 }
  83
  84                 public override long Seek (long offset, SeekOrigin origin)
  85                 {
  86                         return 0;
  87                 }
  88
  89                 public override void SetLength (long value)
  90                 {
  91                 }
  92
  93                 public override void Write (byte [] buffer, int offset, int count)
  94                 {
  95                         if (st == null)
  96                                 st = new GZipOutputStream (baseStream);
  97
  98                         st.Write (buffer, offset, count);
  99                 }
 100
 101                 public override void Close ()
 102                 {
 103                         if (st == null)
 104                                 return;
 105
 106                         st.Finish ();
 107                         st = null;
 108                         base.Close ();
 109                 }
 110         }
 111 }
 112