/// <summary>
/// Gets the external object serializer for the specified type.
/// </summary>
/// <param name="type">Type to get an external object serializer for.</param>
/// <param name="version">Receives the version of the serializer.</param>
/// <returns>
/// The external object serializer for the specified type;
/// <c>null</c>, if the type does not have an external object serializer.
/// </returns>
public static IExternalObjectSerializer GetExternalObjectSerializer(Type type, out uint version)
{
// check whether a serializer for exactly the specified type is available
if (sExternalObjectSerializerInfoBySerializee.TryGetValue(type, out var eosi))
{
version = eosi.SerializerInfo.Version;
return(eosi.Serializer);
}
// there is no external object serializer instance handling the specified type, yet
// => find the external object serializer matching best...
lock (sSync)
{
// once again, check whether a serializer for exactly the specified type is available
// (maybe someone else has added the serializer meanwhile...)
if (sExternalObjectSerializerInfoBySerializee.TryGetValue(type, out eosi))
{
version = eosi.SerializerInfo.Version;
return(eosi.Serializer);
}
// get a list containing the serializee type and all interfaces it implements
var possibleSerializeeTypes = GetPossibleSerializeeTypes(type);
// check the types against the types registered external object serializers can handle
// (the order of both lists ensures that the most specific types are checked first)
foreach (var possibleSerializeeType in possibleSerializeeTypes)
{
foreach (var eosInfo in sRegisteredExternalObjectSerializers)
{
IExternalObjectSerializer eosInstance = null;
if (possibleSerializeeType == eosInfo.SerializeeType)
{
// the serializee exactly matches the serializee supported by the external object serializer
// => the serializer can handle the type directly
eosInstance = (IExternalObjectSerializer)FastActivator.CreateInstance(eosInfo.SerializerType);
}
else if (possibleSerializeeType.IsConstructedGenericType && eosInfo.SerializeeType.ContainsGenericParameters)
{
// the serializee is a generic type and the serializee supported by the external object serializer is a generic type as well
// => check whether their generic type definitions are the same, so the serializer can be used to handle the type
var possibleSerializeeTypeDefinition = possibleSerializeeType.GetGenericTypeDefinition();
var eosSerializeeTypeDefinition = eosInfo.SerializeeType.GetGenericTypeDefinition();
if (possibleSerializeeTypeDefinition == eosSerializeeTypeDefinition)
{
// both generic type definitions are the same
// => found serializer that can handle the type
var constructedEosType = eosInfo.SerializerType.MakeGenericType(possibleSerializeeType.GenericTypeArguments);
eosInstance = (IExternalObjectSerializer)FastActivator.CreateInstance(constructedEosType);
}
}
if (eosInstance != null)
{
// found an external object serializer that is capable of handling the specified type
// => add it to the serializer cache...
var eosDictCopy = new TypeKeyedDictionary <SerializeeInfo>(sExternalObjectSerializerInfoBySerializee)
{
{ type, new SerializeeInfo(type, eosInfo, eosInstance) }
};
Thread.MemoryBarrier();
sExternalObjectSerializerInfoBySerializee = eosDictCopy;
version = eosInfo.Version;
return(eosInstance);
}
}
}
}
version = 0;
return(null);
}