[Proposal] Use memoize in our helper and util function

[SukkaW]

Check List

Please check the followings before submitting a new feature request.

• I have already read Docs page
• I have already searched existing issues

Description

Most of the time, generation speed is slow not because Hexo itself is slow, but the badly written theme. E.g. #1769 turns out that the theme didn't use fragment_cache on tagscloud helper.

Theme developers might not read our developing documents carefully and such issues can still happen. What if we can always cache the tagscloud helper (and such) at our side? And what if we can cache tag plugins (used in the posts) as well?

And here is memoized function comes in.

During the development of Hexo 4.2.0, I have introduced cache in some methods of hexo-util. But with the current implementation, we can only memoize functions with simple parameters. We should use some libraries to cache functions with complex parameters as well.

Other Information

• deep-memoize-once
• nano-memoize
• moize
• fast-memoize
• micro-memoize
• nano-memoize