Some bits of the methods database folder use classes implemented in the runner and the cufft modules. For example,

1. OutputRef usage for memory estimation:

   httomo/httomo/methods_database/packages/external/httomolibgpu/supporting_funcs/misc/morph.py

   Line 27 in 64069cb

   from httomo.runner.output_ref import OutputRef

2. httomo.cufft usage in memory estimation:
   

   httomo/httomo/methods_database/packages/external/httomolibgpu/supporting_funcs/recon/algorithm.py

   Line 26 in 64069cb

   from httomo.cufft import CufftType, cufft_estimate_1d

3. In this file as well, some classes are imported:

   httomo/httomo/methods_database/query.py

   Lines 8 to 11 in 64069cb

   	from httomo.runner.methods_repository_interface import GpuMemoryRequirement, MethodQuery
   	from httomo.utils import Pattern, log_exception
   	from httomo.runner.methods_repository_interface import MethodRepository

Also, the fact that logging is added to query.py, it's fairly connected to the framework. To separate the methods database from httomo, we have to move these dependencies to httomo-backends or eliminate them. Yousef suggested getting rid of OutputRef earlier.

httomo.cufft can be moved with the memory estimators; its only purpose is for memory estimation, and I believe that nowhere else in httomo is that module used apart from in a few memory estimators.

I think query.py probably should stay in httomo. It's used by the framework to query the methods database, wherever the methods database happens to be located.

So, if the methods database is being moved elsewhere (ie, into httomo-backends), this means that the querying functionality needs to:

• stay in httomo
• but be modified to work with the methods database being located in httomo-backends

For clarity, my suggestion regarding OutputRef wasn't "getting rid of it" (which sort of implies the removal of the class entirely), but to remove its usage in the memory estimator in morph.py by resolving #359.

OK, thanks - that can be done