Slight bug in Persister.GetSetHelperFactory.GenerateCode()

mabraham · **Joined:** Mon Mar 20, 2006 10:49 pm **Posts:** 59

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Hibernate version:
NHibernate 1.0.2 (ASP.NET 2.0)

I'm using NHibernate.Generics and there seems to be a minor flaw in the reflection optimizer. The relevant code from GetSetHelperFactory.GenerateCode() is excerpted below. The problem is that if setters[i] is a GenericAccessor, setters[i].Property can be null, and the line

Code:

System.Type type = setters[ i ].Property.PropertyType;

throws a NullReferenceException, effectively disabling the reflection optimizer for the class. I fixed this by moving the offending line into the scope of the if (setter is BasicSetter ... ). This doesn't change the semantics of the code in any way, and the generated code appears to function correctly.

Code:

      private string GenerateCode()
      {
         StringBuilder sb = new StringBuilder();

         sb.Append( header );
         sb.AppendFormat( classDef, mappedClass.FullName.Replace( '.', '_' ).Replace( "+", "__" ) );

         sb.AppendFormat( startSetMethod, mappedClass.FullName.Replace( '+', '.' ) );
         for( int i = 0; i < setters.Length; i++ )
         {
            ISetter setter = setters[ i ];
            System.Type type = setters[ i ].Property.PropertyType;

            if( setter is BasicSetter && IsPublic( setter.PropertyName ) )
            {
               if( type.IsValueType )
               {
                  sb.AppendFormat(
                     "  t.{0} = values[{2}] == null ? new {1}() : ({1})values[{2}];\n",
                     setter.PropertyName,
                     type.FullName.Replace( '+', '.' ),
                     i );
               }
               else
               {
                  sb.AppendFormat( "  t.{0} = ({1})values[{2}];\n",
                                   setter.PropertyName,
                                   type.FullName.Replace( '+', '.' ),
                               i );
               }
            }
            else
            {
               sb.AppendFormat( "  setters[{0}].Set(obj, values[{0}]);\n", i );
            }
         }

smudges · **Posted:** Tue Apr 11, 2006 9:42 am

Have you tried this version of NHibernate? It has a different reflection optimizer available, i.e. Lightweight Code Generation.

http://forum.hibernate.org/viewtopic.php?t=956966

Let me know if this one works in your scenario.

Cheers!

RobRoma · **Joined:** Thu Apr 27, 2006 6:03 am **Posts:** 14

I have the same problem using the version 1.0.2. Smudges, I tried also the LCG version with another reflection optimizer, but the NullReferenceException remained.

I think that the reflection optimizer does not work at all with another access strategy than the default "property" access. Is that true? We use access=”camelcase-underscore”.

So I solved the problem by disabling the reflection optimizer in the configuration file setting hibernate.use_reflection_optimizer to false.

Is this really the intended behaviour of the reflection optimizer or is anything wrong in my application? Of course, I would like to use reflection optimizer to improve performance. Do you have any advices?

Thanks

smudges · **Posted:** Fri Sep 08, 2006 3:21 pm

I believe the issue is with your app. I almost always use access strategies that are not the default. In fact, I oftem create my own to solve different issuesI run into.

RobRoma · **Joined:** Thu Apr 27, 2006 6:03 am **Posts:** 14

I found this statement regarding reflection optimizer and other access strategies than the default one:

k-dub wrote:

The optimizer only works with the default "property" access method...

http://forum.hibernate.org/viewtopic.php?t=957501&highlight=getsethelperfactory

So I do not think that the NullReferenceException is caused with my application – it seems that this is the NHibernate behaviour.

Once again: Is my conclusion correct, that I have to disable reflection optimizer if I use other access strategies than the default one?