mcs/class/corlib/System.Runtime.Serialization/SurrogateSelector.cs

   1 //
   2 // System.Runtime.Serialization.SurrogateSelector.cs
   3 //
   4 // Author: Duncan Mak (duncan@ximian.com)
   5 //
   6 // (C) Ximian, Inc.
   7 //
   8
   9 using System;
  10 using System.Collections;
  11
  12 namespace System.Runtime.Serialization
  13 {
  14         public class SurrogateSelector : ISurrogateSelector
  15         {
  16                 // Fields
  17                 Hashtable Surrogates = new Hashtable ();
  18                 string currentKey = null; // current key of Surrogates
  19
  20                 internal struct Bundle
  21                 {
  22                         public ISerializationSurrogate surrogate;
  23                         public ArrayList selectors;
  24
  25                         public Bundle (ISerializationSurrogate surrogate)
  26                         {
  27                                 this.surrogate = surrogate;
  28                                 selectors = new ArrayList ();
  29                         }
  30                 }
  31
  32                 // Constructor
  33                 public SurrogateSelector()
  34                         : base ()
  35                 {
  36                 }
  37
  38                 // Methods
  39                 public virtual void AddSurrogate (Type type,
  40                           StreamingContext context, ISerializationSurrogate surrogate)
  41                 {
  42                         if (type == null || surrogate == null)
  43                                 throw new ArgumentNullException ("Null reference.");
  44
  45                         currentKey = type.FullName + "#" + context.ToString ();
  46
  47                         if (Surrogates.ContainsKey (currentKey))
  48                                 throw new ArgumentException ("A surrogate for " + type.FullName + " already exists.");
  49
  50                         Bundle values = new Bundle (surrogate);
  51
  52                         Surrogates.Add (currentKey, values);
  53                 }
  54
  55                 public virtual void ChainSelector (ISurrogateSelector selector)
  56                 {
  57                         if (selector == null)
  58                                 throw new ArgumentNullException ("Selector is null.");
  59
  60                         Bundle current = (Bundle) Surrogates [currentKey];
  61                         current.selectors.Add (selector);
  62                 }
  63
  64                 public virtual ISurrogateSelector GetNextSelector ()
  65                 {
  66                         Bundle current = (Bundle) Surrogates [currentKey];
  67                         return (ISurrogateSelector) current.selectors [current.selectors.Count];
  68                 }
  69
  70                 public virtual ISerializationSurrogate GetSurrogate (Type type,
  71                              StreamingContext context, out ISurrogateSelector selector)
  72                 {
  73                         if (type == null)
  74                                 throw new ArgumentNullException ("type is null.");
  75
  76                         string key = type.FullName + "#" + context.ToString ();
  77                         Bundle current = (Bundle) Surrogates [key];
  78                         selector = (ISurrogateSelector) current.selectors [current.selectors.Count - 1];
  79
  80                         return (ISerializationSurrogate) current.surrogate;
  81                 }
  82
  83                 public virtual void RemoveSurrogate (Type type, StreamingContext context)
  84                 {
  85                         if (type == null)
  86                                 throw new ArgumentNullException ("type is null.");
  87
  88                         string key = type.FullName + "#" + context.ToString ();
  89                         Surrogates.Remove (key);
  90                 }
  91         }
  92 }