mcs/class/System.Net.Http/System.Net.Http/HttpContent.cs

   1 //
   2 // HttpContent.cs
   3 //
   4 // Authors:
   5 //      Marek Safar  <marek.safar@gmail.com>
   6 //
   7 // Copyright (C) 2011 Xamarin Inc (http://www.xamarin.com)
   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
  29 using System.Net.Http.Headers;
  30 using System.IO;
  31 using System.Threading.Tasks;
  32 using System.Text;
  33
  34 namespace System.Net.Http
  35 {
  36         public abstract class HttpContent : IDisposable
  37         {
  38                 sealed class FixedMemoryStream : MemoryStream
  39                 {
  40                         readonly long maxSize;
  41
  42                         public FixedMemoryStream (long maxSize)
  43                                 : base ()
  44                         {
  45                                 this.maxSize = maxSize;
  46                         }
  47
  48                         void CheckOverflow (int count)
  49                         {
  50                                 if (Length + count > maxSize)
  51                                         throw new HttpRequestException (string.Format ("Cannot write more bytes to the buffer than the configured maximum buffer size: {0}", maxSize));
  52                         }
  53
  54                         public override void WriteByte (byte value)
  55                         {
  56                                 CheckOverflow (1);
  57                                 base.WriteByte (value);
  58                         }
  59
  60                         public override void Write (byte[] buffer, int offset, int count)
  61                         {
  62                                 CheckOverflow (count);
  63                                 base.Write (buffer, offset, count);
  64                         }
  65                 }
  66
  67                 FixedMemoryStream buffer;
  68                 Stream stream;
  69                 bool disposed;
  70                 HttpContentHeaders headers;
  71
  72                 public HttpContentHeaders Headers {
  73                         get {
  74                                 return headers ?? (headers = new HttpContentHeaders (this));
  75                         }
  76                 }
  77
  78                 public Task CopyToAsync (Stream stream)
  79                 {
  80                         return CopyToAsync (stream, null);
  81                 }
  82
  83                 public Task CopyToAsync (Stream stream, TransportContext context)
  84                 {
  85                         if (stream == null)
  86                                 throw new ArgumentNullException ("stream");
  87
  88                         if (buffer != null)
  89                                 return buffer.CopyToAsync (stream);
  90
  91                         return SerializeToStreamAsync (stream, context);
  92                 }
  93
  94                 protected async virtual Task<Stream> CreateContentReadStreamAsync ()
  95                 {
  96                         await LoadIntoBufferAsync ().ConfigureAwait (false);
  97                         return buffer;
  98                 }
  99
 100                 static FixedMemoryStream CreateFixedMemoryStream (long maxBufferSize)
 101                 {
 102                         return new FixedMemoryStream (maxBufferSize);
 103                 }
 104
 105                 public void Dispose ()
 106                 {
 107                         Dispose (true);
 108                 }
 109
 110                 protected virtual void Dispose (bool disposing)
 111                 {
 112                         if (disposing && !disposed) {
 113                                 disposed = true;
 114
 115                                 if (buffer != null)
 116                                         buffer.Dispose ();
 117                         }
 118                 }
 119
 120                 public Task LoadIntoBufferAsync ()
 121                 {
 122                         return LoadIntoBufferAsync (int.MaxValue);
 123                 }
 124
 125                 public async Task LoadIntoBufferAsync (long maxBufferSize)
 126                 {
 127                         if (disposed)
 128                                 throw new ObjectDisposedException (GetType ().ToString ());
 129
 130                         if (buffer != null)
 131                                 return;
 132
 133                         buffer = CreateFixedMemoryStream (maxBufferSize);
 134                         await SerializeToStreamAsync (buffer, null).ConfigureAwait (false);
 135                         buffer.Seek (0, SeekOrigin.Begin);
 136                 }
 137
 138                 public async Task<Stream> ReadAsStreamAsync ()
 139                 {
 140                         if (disposed)
 141                                 throw new ObjectDisposedException (GetType ().ToString ());
 142
 143                         if (buffer != null)
 144                                 return new MemoryStream (buffer.GetBuffer (), 0, (int)buffer.Length, false);
 145
 146                         if (stream == null)
 147                                 stream = await CreateContentReadStreamAsync ().ConfigureAwait (false);
 148
 149                         return stream;
 150                 }
 151
 152                 public async Task<byte[]> ReadAsByteArrayAsync ()
 153                 {
 154                         await LoadIntoBufferAsync ().ConfigureAwait (false);
 155                         return buffer.ToArray ();
 156                 }
 157
 158                 public async Task<string> ReadAsStringAsync ()
 159                 {
 160                         await LoadIntoBufferAsync ().ConfigureAwait (false);
 161                         if (buffer.Length == 0)
 162                                 return string.Empty;
 163
 164                         Encoding encoding;
 165                         if (headers != null && headers.ContentType != null && headers.ContentType.CharSet != null) {
 166                                 encoding = Encoding.GetEncoding (headers.ContentType.CharSet);
 167                         } else {
 168                                 encoding = Encoding.UTF8;
 169                         }
 170
 171                         return encoding.GetString (buffer.GetBuffer (), 0, (int) buffer.Length);
 172                 }
 173
 174                 protected internal abstract Task SerializeToStreamAsync (Stream stream, TransportContext context);
 175                 protected internal abstract bool TryComputeLength (out long length);
 176         }
 177 }