class/corlib/System.Runtime.Serialization/SerializationCallbacks.cs

   1 //
   2 // System.Runtime.Serialization.SerializationCallbacks.cs
   3 //
   4 // Author:
   5 //   Robert Jordan (robertj@gmx.net)
   6 //
   7 // Copyright (C) 2006 Novell, Inc (http://www.novell.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;
  30 using System.Collections;
  31 using System.Reflection;
  32
  33 namespace System.Runtime.Serialization {
  34
  35         internal sealed class SerializationCallbacks
  36         {
  37                 public delegate void CallbackHandler (StreamingContext context);
  38
  39                 readonly ArrayList onSerializingList;
  40                 readonly ArrayList onSerializedList;
  41                 readonly ArrayList onDeserializingList;
  42                 readonly ArrayList onDeserializedList;
  43
  44                 public bool HasSerializingCallbacks {
  45                         get {return onSerializingList != null;}
  46                 }
  47
  48                 public bool HasSerializedCallbacks {
  49                         get {return onSerializedList != null;}
  50                 }
  51
  52                 public bool HasDeserializingCallbacks {
  53                         get {return onDeserializingList != null;}
  54                 }
  55
  56                 public bool HasDeserializedCallbacks {
  57                         get {return onDeserializedList != null;}
  58                 }
  59
  60                 public SerializationCallbacks (Type type)
  61                 {
  62                         onSerializingList   = GetMethodsByAttribute (type, typeof (OnSerializingAttribute));
  63                         onSerializedList    = GetMethodsByAttribute (type, typeof (OnSerializedAttribute));
  64                         onDeserializingList = GetMethodsByAttribute (type, typeof (OnDeserializingAttribute));
  65                         onDeserializedList  = GetMethodsByAttribute (type, typeof (OnDeserializedAttribute));
  66                 }
  67
  68                 const BindingFlags DefaultBindingFlags = BindingFlags.Public | BindingFlags.NonPublic |
  69                         BindingFlags.Instance | BindingFlags.DeclaredOnly;
  70
  71
  72                 static ArrayList GetMethodsByAttribute (Type type, Type attr)
  73                 {
  74                         ArrayList list = new ArrayList ();
  75
  76                         Type t = type;
  77                         while (t != typeof (object)) {
  78                                 int count = 0;
  79
  80                                 foreach (MethodInfo mi in t.GetMethods (DefaultBindingFlags)) {
  81                                         if (mi.IsDefined (attr, false)) {
  82                                                 list.Add (mi);
  83                                                 count++;
  84                                         }
  85                                 }
  86
  87                                 // FIXME: MS.NET is checking for this with the verifier at assembly load time.
  88                                 if (count > 1)
  89                                         throw new TypeLoadException (
  90                                                 String.Format ("Type '{0}' has more than one method with the following attribute: '{1}'.", type.AssemblyQualifiedName, attr.FullName));
  91
  92                                 t = t.BaseType;
  93                         }
  94
  95                         // optimize memory usage
  96                         return list.Count == 0 ? null : list;
  97                 }
  98
  99                 static void Invoke (ArrayList list, object target, StreamingContext context)
 100                 {
 101                         if (list == null)
 102                                 return;
 103
 104                         CallbackHandler handler = null;
 105
 106                         // construct a delegate from the specified list
 107                         foreach (MethodInfo mi in list) {
 108                                 handler = (CallbackHandler)
 109                                         Delegate.Combine (
 110                                                 Delegate.CreateDelegate (typeof (CallbackHandler), target, mi),
 111                                                 handler);
 112                         }
 113
 114                         handler (context);
 115                 }
 116
 117                 public void RaiseOnSerializing (object target, StreamingContext contex)
 118                 {
 119                         Invoke (onSerializingList, target, contex);
 120                 }
 121
 122                 public void RaiseOnSerialized (object target, StreamingContext contex)
 123                 {
 124                         Invoke (onSerializedList, target, contex);
 125                 }
 126
 127                 public void RaiseOnDeserializing (object target, StreamingContext contex)
 128                 {
 129                         Invoke (onDeserializingList, target, contex);
 130                 }
 131
 132                 public void RaiseOnDeserialized (object target, StreamingContext contex)
 133                 {
 134                         Invoke (onDeserializedList, target, contex);
 135                 }
 136
 137                 static Hashtable cache = new Hashtable ();
 138                 static object cache_lock = new object ();
 139
 140                 public static SerializationCallbacks GetSerializationCallbacks (Type t)
 141                 {
 142                         SerializationCallbacks sc = (SerializationCallbacks) cache [t];
 143                         if (sc != null)
 144                                 return sc;
 145
 146                         // Slow path, new entry, we need to copy
 147                         lock (cache_lock){
 148                                 sc = (SerializationCallbacks)  cache [t];
 149                                 if (sc == null) {
 150                                         Hashtable copy = (Hashtable) cache.Clone ();
 151
 152                                         sc = new SerializationCallbacks (t);
 153                                         copy [t] = sc;
 154                                         cache = copy;
 155                                 }
 156                                 return sc;
 157                         }
 158                 }
 159         }
 160 }