SerializationEventsCache.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Runtime / Serialization / SerializationEventsCache.cs / 1 / SerializationEventsCache.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
/*============================================================
** 
** Class: SerializationEventsCache 
**
** 
** Purpose: Caches the various serialization events such as On(De)Seriliz(ed)ing
**
**
============================================================*/ 

namespace System.Runtime.Serialization { 
 
using System;
using System.Collections; 
using System.Collections.Generic;
using System.Reflection;
using System.Reflection.Cache;
using System.Globalization; 

    internal class SerializationEvents 
    { 
        private List m_OnSerializingMethods = null;
        private List m_OnSerializedMethods = null; 
        private List m_OnDeserializingMethods = null;
        private List m_OnDeserializedMethods = null;

        private List GetMethodsWithAttribute(Type attribute, Type t) 
        {
            List mi = new List(); 
            Type baseType = t; 
            // Traverse the hierarchy to find all methods with the particular attribute
            while (baseType != null && baseType != typeof(Object)) 
            {
                RuntimeType rt = (RuntimeType)baseType;
                // Get all methods which are declared on this type, instance and public or nonpublic
                MethodInfo[] mis = baseType.GetMethods(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public); 
#if _DEBUG
                bool found = false; 
#endif 
                foreach(MethodInfo m in mis)
                { 
                    // For each method find if attribute is present, the return type is void and the method is not virtual
                    if (m.IsDefined(attribute, false))
                    {
#if _DEBUG 
                        BCLDebug.Assert(m.ReturnType == typeof(void) && !m.IsVirtual, "serialization events methods cannot be virtual and need to have void return");
 
                        ParameterInfo[] paramInfo = m.GetParameters(); 
                        // Only add it if this method has one parameter of type StreamingContext
                        if (paramInfo.Length == 1 && paramInfo[0].ParameterType == typeof(StreamingContext)) 
                        {
                            if (found)
                                BCLDebug.Assert(false, "Mutliple methods with same serialization attribute");
#endif 
                            mi.Add(m);
#if _DEBUG 
                            found = true; 
                        }
                        else 
                            BCLDebug.Assert(false, "Incorrect serialization event signature");
#endif
                    }
                } 
#if _DEBUG
                found = false; 
#endif 
                baseType = baseType.BaseType;
            } 
            mi.Reverse();  // We should invoke the methods starting from base

            return (mi.Count == 0) ? null : mi;
        } 

        internal SerializationEvents(Type t) 
        { 
            // Initialize all events
            m_OnSerializingMethods = GetMethodsWithAttribute(typeof(OnSerializingAttribute), t); 
            m_OnSerializedMethods = GetMethodsWithAttribute(typeof(OnSerializedAttribute), t);
            m_OnDeserializingMethods = GetMethodsWithAttribute(typeof(OnDeserializingAttribute), t);
            m_OnDeserializedMethods = GetMethodsWithAttribute(typeof(OnDeserializedAttribute), t);
        } 

        internal bool HasOnSerializingEvents 
        { 
            get { return m_OnSerializingMethods != null || m_OnSerializedMethods != null; }
        } 

        internal void InvokeOnSerializing(Object obj, StreamingContext context)
        {
            BCLDebug.Assert(obj != null, "object should have been initialized"); 
            // Invoke all OnSerializingMethods
            if (m_OnSerializingMethods != null) 
            { 
                Object[] p = new Object[] {context};
                SerializationEventHandler handler = null; 
                foreach(MethodInfo m in m_OnSerializingMethods)
                {
                    SerializationEventHandler onSerializing =
                        (SerializationEventHandler)Delegate.InternalCreateDelegate(typeof(SerializationEventHandler), obj, m); 
                    handler = (SerializationEventHandler)Delegate.Combine(handler, onSerializing);
                } 
                handler(context); 
            }
        } 

        internal void InvokeOnDeserializing(Object obj, StreamingContext context)
        {
            BCLDebug.Assert(obj != null, "object should have been initialized"); 
            // Invoke all OnDeserializingMethods
            if (m_OnDeserializingMethods != null) 
            { 
                Object[] p = new Object[] {context};
                SerializationEventHandler handler = null; 
                foreach(MethodInfo m in m_OnDeserializingMethods)
                {
                    SerializationEventHandler onDeserializing =
                        (SerializationEventHandler)Delegate.InternalCreateDelegate(typeof(SerializationEventHandler), obj, m); 
                    handler = (SerializationEventHandler)Delegate.Combine(handler, onDeserializing);
                } 
                handler(context); 
            }
        } 

        internal void InvokeOnDeserialized(Object obj, StreamingContext context)
        {
            BCLDebug.Assert(obj != null, "object should have been initialized"); 
            // Invoke all OnDeserializingMethods
            if (m_OnDeserializedMethods != null) 
            { 
                Object[] p = new Object[] {context};
                SerializationEventHandler handler = null; 
                foreach(MethodInfo m in m_OnDeserializedMethods)
                {
                    SerializationEventHandler onDeserialized =
                        (SerializationEventHandler)Delegate.InternalCreateDelegate(typeof(SerializationEventHandler), obj, m); 
                    handler = (SerializationEventHandler)Delegate.Combine(handler, onDeserialized);
                } 
                handler(context); 
            }
        } 

        internal SerializationEventHandler AddOnSerialized(Object obj, SerializationEventHandler handler)
        {
            // Add all OnSerialized methods to a delegate 
            if (m_OnSerializedMethods != null)
            { 
                foreach(MethodInfo m in m_OnSerializedMethods) 
                {
                    SerializationEventHandler onSerialized = 
                        (SerializationEventHandler)Delegate.InternalCreateDelegate(typeof(SerializationEventHandler), obj, m);
                    handler = (SerializationEventHandler)Delegate.Combine(handler, onSerialized);
                }
            } 
            return handler;
        } 
 
        internal SerializationEventHandler AddOnDeserialized(Object obj, SerializationEventHandler handler)
        { 
            // Add all OnDeserialized methods to a delegate
            if (m_OnDeserializedMethods != null)
            {
                foreach(MethodInfo m in m_OnDeserializedMethods) 
                {
                    SerializationEventHandler onDeserialized = 
                        (SerializationEventHandler)Delegate.InternalCreateDelegate(typeof(SerializationEventHandler), obj, m); 
                    handler = (SerializationEventHandler)Delegate.Combine(handler, onDeserialized);
                } 
            }
            return handler;
        }
    } 

    internal static class SerializationEventsCache 
    { 
        private static Hashtable cache = new Hashtable();
 
        internal static SerializationEvents GetSerializationEventsForType(Type t)
        {
            SerializationEvents events;
            if ((events = (SerializationEvents)cache[t]) == null) 
            {
                events = new SerializationEvents(t); 
                cache[t] = events; // Add this to the cache. 
            }
            return events; 

        }
    }
}

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