Add support for caching entity properties

[emontnemery]

Proposed change

Add support for caching entity properties

The implementation in this PR is essentially the same as in #95315 but:

• Updates of Entity._attr_* are caught and cause the corresponding property's cache to be invalidated
• All properties which by default return the corresponding Entity._attr_* attribute are cached

With the simple test below, the time needed for calculating state is decreased by around 1/3 on my development machine, from ~3.3 µs / iteration to ~1.8 µs / iteration:

from homeassistant.helpers.entity import Entity

ent = Entity()
return timeit.timeit(ent._async_calculate_state)

If this PR is accepted, base classes for entity domains should be modified in the same way in follow-up PRs

Needs:

• Improve entity tests #106175

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.
• Untested files have been added to .coveragerc.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[MartinHjelmare]

The PR description needs to be corrected. It's talking about the wrong attribute.

[MartinHjelmare]

This test shows that time needed for calculating state is decreased by around 1/3:

What is the amount of time as an example? It also matters if it's already slow or very fast.

[emontnemery]

This test shows that time needed for calculating state is decreased by around 1/3:

What is the amount of time as an example? It also matters if it's already slow or very fast.

I updated the PR description with this information.

[bdraco]

Will test this later today.

At first glance it looks like it will take care of some of the heavy hitters we see with a large number of polling integrations.

[bdraco]

With previous testing the hot platforms where in order:

• sensor
• select
• number
• camera

These are the places where the cost is much higher where I expect this will really ✨

[bdraco]

Looks like tests.common MockEntity needs some new mocks

[MartinHjelmare]

decreased by around 1/3 on my development machine, from ~1.8 µs / iteration to ~3.3 µs / iteration

This sounds incorrect.

[emontnemery]

decreased by around 1/3 on my development machine, from ~1.8 µs / iteration to ~3.3 µs / iteration

This sounds incorrect.

Yeah, the numbers were swapped, fixed now.