[RFC] add HydrationFactory as extension point for tracking hydrations

[kbond]

This is a proposed extension point to help solve doctrine/DoctrineBundle#109. I'm thinking a HydratorInterface that AbstractHydrator implements should be added but wanted to get some feedback/input before going further.

The doctrine bundle could use this to add hydration times to the timeline:

The doctrine bundle could add something similar to https://github.com/debesha/DoctrineProfileExtraBundle#screenshots to the profiler panel.

You can see an example of how this could be used in DoctrineBundle here: https://github.com/kbond/symfony-reproducer/tree/hydration-profiler-poc (specifically kbond/symfony-reproducer@9a4e91b).

I don't think this causes any performance problems for hydration (when using the DefaultHydratorFactory).

[beberlei]

I am torn, because it will encourage people to overwrite the existing hydrators, which are a bit too complex. Besides tracking the time there are not really many other use cases to use this extension point.

[kbond]

Any other ideas how to achieve? I really think this is an important metric to make available.

Maybe a HydrationLogger - similar to CacheLogger? Maybe a HydrationEvent?

[ostrolucky]

I would be fine with this. This solves one of the inconsistencies between ODM and ORM, as ODM has this option. And I'm not a fan of not having features just because you can abuse them. I think ORM learned this lesson as well, since multiple important features have been deprecated years ago, only to get comeback recently and de-deprecated.