2 // System.Text.CodePageEncoding.cs
5 // Kornél Pál <http://www.kornelpal.hu/>
7 // Copyright (C) 2006 Kornél Pál
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:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
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.
32 // These proxy classes implement IObjectReference.GetRealObject() that returns
33 // an instance of the appropriate Encoding, Encoder or Decoder class.
34 // As a result serialized objects of these types will transparently be
35 // deserialized to instances of the above described classes.
37 // Use SerializationInfo.SetType() in ISerializable.GetObjectData() method of
38 // serializable classes to serialize their instances using a proxy class.
40 // All of these proxy classes are non-public thus they only have to be
41 // serialization compatible with .NET Framework.
45 // .NET Framework 1.x uses this class for internal encodings and
46 // .NET Framework 2.0 serializes internal encodings using a proxy.
47 // This class supports serialization compatibility.
51 using System.Runtime.Serialization;
56 internal sealed class CodePageEncoding : ISerializable, IObjectReference
59 // .NET Framework 1.x uses this class for internal decoders and
60 // .NET Framework 2.0 can deserialize them using a proxy.
61 // This class supports serialization compatibility.
65 private sealed class Decoder : ISerializable, IObjectReference
67 private Encoding encoding;
68 private System.Text.Decoder realObject;
70 private Decoder (SerializationInfo info, StreamingContext context)
73 throw new ArgumentNullException ("info");
75 this.encoding = (Encoding) info.GetValue ("encoding", typeof (Encoding));
78 public void GetObjectData (SerializationInfo info, StreamingContext context)
80 throw new ArgumentException ("This class cannot be serialized.");
83 public object GetRealObject (StreamingContext context)
85 if (this.realObject == null)
86 this.realObject = this.encoding.GetDecoder ();
88 return this.realObject;
94 private bool isReadOnly;
95 private EncoderFallback encoderFallback;
96 private DecoderFallback decoderFallback;
98 private Encoding realObject;
100 private CodePageEncoding (SerializationInfo info, StreamingContext context)
103 throw new ArgumentNullException ("info");
105 this.codePage = (int) info.GetValue ("m_codePage", typeof (int));
109 this.isReadOnly = (bool) info.GetValue ("m_isReadOnly", typeof (bool));
110 this.encoderFallback = (EncoderFallback) info.GetValue ("encoderFallback", typeof (EncoderFallback));
111 this.decoderFallback = (DecoderFallback) info.GetValue ("decoderFallback", typeof (DecoderFallback));
112 } catch (SerializationException) {
113 // .NET Framework 1.x has no fallbacks
114 this.isReadOnly = true;
119 public void GetObjectData (SerializationInfo info, StreamingContext context)
121 throw new ArgumentException ("This class cannot be serialized.");
124 public object GetRealObject (StreamingContext context)
126 if (this.realObject == null) {
127 Encoding encoding = Encoding.GetEncoding (this.codePage);
130 if (!this.isReadOnly) {
131 encoding = (Encoding) encoding.Clone ();
132 encoding.EncoderFallback = this.encoderFallback;
133 encoding.DecoderFallback = this.decoderFallback;
137 this.realObject = encoding;
140 return this.realObject;