perf!: consolidated updates to address performance issues

[Jint-lzxy]

This fixes #866 and closes #867.

cc @fecet

[ayamir]

Sorry, I can't see the improvement of the scroll velocity when open this file.

What's more, load_big_files_faster option doesn't work for this file too. The startuptime keeps 20 seconds whether enable it or not.

[fecet]

I also haven't observed any performance improvement, and I don't use scrollview and neoscroll. The performance issue should be unrelated to them.

[Jint-lzxy]

Sorry, I can't see the improvement of the scroll velocity when open this file.

Hmmm I somehow cannot reproduce this:

The current startup time on my side is close to the that of nvim --clean 🤔

Perhaps explaining some background may be helpful? What this PR hopes to address is:

• The startup time wrt opening files of normal sizes - by deferring LSP setup to prevent them from interfering with startup of those UI components;
• Open big files when load_big_files_faster is true - Stop loading most plugins to simulate the behavior of native nvim.

If the startup time of any of the above situations is still slow, it may be because:

• (For 1) The server itself caused performance degradation, indirectly affecting UI rendering (similar to High CPU usage and exit issue of Jedi-language-server #721)
• (For 2) The parsers for treesitter are still being called... Hmm I'll look into this later. You can verify it this way:

:lua vim.treesitter.get_parser():parse()

This command should take a long time to complete.

[ayamir]

Now it ok for me after Lazy sync 👍

[Jint-lzxy]

cc @fecet

[CharlesChiuGit]

Does this PR need further modifications? Or is it ready to go?

[Jint-lzxy]

I think it's good to go. Currently waiting for @fecet's response as he reported very limited performance improvements.

[fecet]

Still don't find performance improvement unless set

nvimdots/lua/modules/configs/editor/rainbow_delims.lua

Line 12 in 1c02372

return require("rainbow-delimiters").strategy["local"]

this to global.

[Jint-lzxy]

@fecet So u're using treesitter on large files? We don't make any gurantee regarding treesitter-related components under big files, as using strategy["global"] only reduces the number of times LanguageTree:parse() gets called, but each call could still leads to significant performance degradation. To verify this execute the following command urself:

:lua vim.treesitter.get_parser():parse()

This can only be resolved by updating the related parser(s), we cannot do anything. But yes we can use simpler processing methods on relatively larger files, a.k.a, strategy["global"]. Will push a fix for this.

[fecet]

The file I tested is dwm.cpp , it's not so large I guess? I don't really understand how ts works so cannot give further comment.

[Jint-lzxy]

The file I tested is dwm.cpp , it's not so large I guess? I don't really understand how ts works so cannot give further comment.

Thanks for the sample! Will do some testings there.

[Jint-lzxy]

Still don't find performance improvement

I should have identified the problem. Now rainbow-delimiters will select an appropriate subtree when the cursor moves, but due to the issue with cpp parser, the generated AST becomes too tall, making one iteration too expensive.

[CharlesChiuGit]

LGTM

[Jint-lzxy]

@fecet ec24fef should fix ur issue 👍

[fecet]

OK, it's good for me now