[core] AutoencoderMixin to abstract common methods

[sayakpaul]

What does this PR do?

Asbtracts common methods like enable_slicing(), disable_slicing(), enable_tiling(), and disable_tiling() to a class AutoencoderMixin. Not all VAEs implement slicing and tiling and that has been addressed accordingly.

As a consequence, we also reduce a bit of code bloat.

[HuggingFaceDocBuilderDev]

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[dg845]

LGTM! Do you think the remaining autoencoders, which I believe are

• AsymmetricAutoencoderKL
• AutoencoderKLTemporalDecoder
• VQModel

should also inherit from AutoencoderMixin? It would make the autoencoder interface more consistent and I think it should be safe in the sense that e.g. AutoencoderMixin.enable_tiling should raise a NotImplementedError for these models and the associated tiling/slicing tests in AutoencoderTesterMixin should be properly skipped since these models don't define use_tiling/use_slicing attributes. (An exception is AsymmetricAutoencoderKL, which defines use_tiling/use_slicing but not enable_tiling/enable_slicing methods currently.)

[dg845]

LGTM :). I would suggest removing the use_slicing/use_tiling attributes on AsymmetricAutoencoderKL:

diffusers/src/diffusers/models/autoencoders/autoencoder_asym_kl.py

Lines 110 to 111 in cc65d0a

	self.use_slicing = False
	self.use_tiling = False

Since tiling/slicing isn't implemented for this model, I think it makes sense to skip e.g. AsymmetricAutoencoderKLTests.test_enable_disable_tiling (right now it passes since AsymmetricAutoencoderKL.enable_tiling is essentially a no-op).

[sayakpaul]

Since tiling/slicing isn't implemented for this model, I think it makes sense to skip e.g. AsymmetricAutoencoderKLTests.test_enable_disable_tiling (right now it passes since AsymmetricAutoencoderKL.enable_tiling is essentially a no-op).

I have removed them. But just a nit, I don't think the tests would actually, they should get skipped rather.

[sayakpaul]

Failing tests are unrelated.