HSEARCH-1268 Make it possible to plug in a custom MassIndexer implementation

[DavideD]

https://hibernate.onjira.com/browse/HSEARCH-1268

I have a couple of question. I will ask as inline comments

[DavideD]

I don't think I can leave on inline comment on this one because it's about file I didn't change, anyway:

ClassLoaderHelper#classForName is using the contextClassloader before using the one passed as a parameter. Shouldn't be the opposite?

[Sanne]

ClassLoaderHelper#classForName is using the contextClassloader before using the one passed as a parameter. Shouldn't be the opposite?

Order is not important, it only has a performance impact as it might try the correct one first, avoiding one reource access.
We expect most things to be found on the contextClassLoader as that's where the user resources are (like lists of stopwords, custom analyzers, any other extension)

[Sanne]

did you check if ORM isn't providing you the classloader as a Service?

 getClass().getClassLoader()

If we still use this code, then the fix in the previous commit isn't as useful as I thought it would be.

[DavideD]

I didn't check.

I will take a look at it

[DavideD]

ClassLoaderHelper#classForName is using the contextClassloader before using the one passed as a parameter. Shouldn't be the opposite?

Order is not important, it only has a performance impact as it might try the correct one first, avoiding one reource access.
We expect most things to be found on the contextClassLoader as that's where the user resources are (like lists of stopwords, custom analyzers, any other extension)

I'm asking because It's seems a bit awkward that I pass the classloader that I want to use and then another one is used. By the way, I've noticed this writing some unit tests.

[DavideD]

Added some documentation and javadoc

[DavideD]

Rebased. All the changes should be applied now.

[DavideD]

Changed a comment

[Sanne]

merged!