perf(dependencies): skip doing any work when sub dependant is already cached

[xkabylgSICKAG]

Hi, we noticed very large performance gains after making this change for our app that heavily uses the dependency injection system. One of our slower endpoints went from taking ~1100ms to ~400ms.

[YuriiMotov]

It looks really reasonable to check whether the sub_dependency is already solved and cached before solving it!

Related PR, that uses almost the same approach: #4089

[YuriiMotov]

Suggested change

	if (
	sub_dependant.use_cache
	and sub_dependant.cache_key in dependency_cache
	and sub_dependant.name is not None
	):
	values[sub_dependant.name] = dependency_cache[sub_dependant.cache_key]
	continue
	if (
	sub_dependant.use_cache
	and sub_dependant.cache_key in dependency_cache
	):
	if sub_dependant.name is not None:
	values[sub_dependant.name] = dependency_cache[sub_dependant.cache_key]
	continue

To skip solving dependencies without name, that were already cached.

[xkabylgSICKAG]

That makes sense 👍

In which cases will a sub_dependant not have a name?

[xkabylgSICKAG]

@YuriiMotov

Related PR, that uses almost the same approach: #4089

That PR also has a test! :)

I think that other PR, with your suggested changes, is a better change than this PR. Do you think it makes more sense to close this in favour of the other one?

[xkabylgSICKAG]

I've rebased and updated the PR with the suggested changes from @YuriiMotov and with the change to dependency_cache empty dict checking from #4089.