Question Non-deterministic saving of Json data

Hi there,

Has anyone else had issues with the json data for the elements of an embedded graph in the Unity scene file being in a different order when the scene is saved? It's causing a bit of a pain for us in merging changes.

I'm trawling through the serialization code to try to find a solutions. Just wondering if anyone else has come across this and if there's a workaround for it?

Thanks!
Rob.

 

OK, I think it's down to the elements being sorted in the deserialization code by dependencyOrder, which is generally a low number shared by a lot of elements (i.e. loads of elements will be 0, loads are 1 etc.).

I think a solution is to change the OnBeforeSerialize function in graph.cs to sort them into a consistent order. I've chosen to do it by dependency order and then by guid. i.e:

Code (CSharp):

1. public virtual void OnBeforeSerialize()
2. {
3.     _elements.Clear();
4.  
5.     var sortedElements = ListPool<IGraphElement>.New();
6.     foreach (var element in elements)
7.     {
8.         sortedElements.Add(element);
9.     }
10.     sortedElements.Sort(CompareElements);
11.  
12.     _elements.AddRange(sortedElements);
13. }
14.  
15. private static int CompareElements(IGraphElement a, IGraphElement b)
16. {
17.     int dependencyComparison = a.dependencyOrder.CompareTo(b.dependencyOrder);
18.     return dependencyComparison != 0 ? dependencyComparison : a.guid.CompareTo(b.guid);
19. }

I need to give this a LOT of testing. If anyone can see a problem with it, please let me know!
Rob.